Blood Pressure, Proteases and Inhibitors

Blood pressure is controlled through a complex network of interacting peptide systems, principally involving the angiotensin, natriuretic peptide, endothelin and apelin families. The most complex and thoroughly investigated is the renin-angiotensin system (RAS) in which selective and potent inhibitors of the key biosynthetic proteolytic enzymes, renin and angiotensin-converting enzyme (ACE), have proved to be valuable drugs for the effective treatment of hypertension and heart failure, as well as other cardiovascular and renal disorders. Some of the other proteases in these pathways, e.g.neprilysin and ACE2, are also being explored as potential drug targets. © 2023 Elsevier Inc. All rights reserved.

Antibacterial Activity and in Silico Investigation of 2-[(3-Substitutedphenyl) Azomethine] Phenol as anti-SARS-CoV-2 Mpro and anti-Plasmodium falciparum Agents

Imine derivatives are widely used in medicine for the treatment of several diseases causing human infections;we examined Schiff's bases derivatives: 2-[(3-methylphenyl) azomethine] phenol (L1), 2-[(3-chlorophenyl) azomethine] phenol (L2) and 2-[(3-nitrophenyl) azomethine] phenol (L3) against three human pathogenic bacterial strains according to the disk diffusion test. In addition, to revealing the importances of the in silico study of these derivatives, in particular the molecular docking which is based on the protein structures: the main protease 3CL of SARS-CoV-2 and the aminopeptidase of the M1 family. Also, a molecular dynamics simulation was performed to examine the structural stability of the best docked conformation. The evaluation of the global reactivity parameters of the molecular system of Schiff base derivatives was applied by the DFT method with the hybrid functional (B3LYP)/6-31G (d) basis set. The results of the antibacterial activity showed a strong activity in the presence of the L3 ligand against Escherichia coli (ATCC 25922) with a diameter inhibition zone equal to 11 ± 0.61 mm. Molecular docking shows that the L3 ligand formed with protein targets more stable complexes by predicting interesting interactions: hydrogen, hydrophobic and electrostatic bonds with the residues of these targets 3CLpro and PfA-M1. Further, molecular dynamics simulations confirm a strong energy contribution with these interactions. Therefore, suggesting that our ligands could contribute to the development of anti-coronavirus-2 and anti-malarial drug properties. [ FROM AUTHOR] Copyright of Polycyclic Aromatic Compounds is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

COVID-19 ACE2 related to hepatocellular carcinoma in single cell analyses and immuno-cancer microenvironment infiltrated with macrophage

Background: Hepatocellular carcinoma (HCC) is the second leading cause of malignancy-related mortality and the fifth most common worldwide. Immuno-cancer microenvironment (ICME) was highlighted recently because scientists want to unlock the detailed mechanism in carcinogenesis pathway and find the novel interactions in ICME. Besides, single cell analysis could mitigate the interrupted signals between cells and tissues. On the other hand, COVID-19 angiotensin I converting enzyme (ACE) previously was reported associated with cancer. However, the robust association between COVID-19 and HCC ICME is still unaddressed. Aim(s): We plan to investigate the COVID-19 ACE relevant genes to HCC ICME regarding survival. Method(s): We used Reactome for COVID-19 ACE gene pathway mapping and explored the positive relevant gene expression. DISCO website was applied for single cell analyses using the above-collected genes from Reactome. Finally, we implanted the biomedical informatics into TIMER 2.0 for ICME survival analyses. Result(s): In Fig. 1, the gene-gene interaction mapping was shown. We collected 13 genes (CPB2, ACE2, AGT, MME, ANPEP, CPA3, ENPEP, GZMH, CTSZ, CTSD, CES1, ATP6AP2, and AOPEP) for further single cell relevant analyses, in Table 1, with detailed expression level (TPM). Among the above 13 genes, AGT, GZMH, CTSZ, CTSD, CES1, and ATP6AP2 were strongly expressed in liver tissue. We then applied the initial 13 genes to TIMER 2.0 for HCC ICME 2-year survival analyses. CPA3 and GZMH low expressions with high macrophage infiltration in HCC ICME showed significantly worse 2-year cumulative survival [hazard ratio (HR):CPA3 2.21, p-value 0.018;GZMH 2.07, p-value 0.0341]. ACE2, CPB2, AGT, MME, ANPEP, ENPEP, CTSZ, CTSD, CES1, and ATP6AP2 high expressions with high macrophage infiltration in HCC ICME revealed significantly worse 2-year cumulative survival. Conclusion(s): We demonstrate that ACE2 was strongly associated with HCC clinical survival with macrophage infiltration. However, the bidirectional translational roles about ACE2 relevant genes in HCC should be documented.

Porcine deltacoronavirus resists antibody neutralization through cell-to-cell transmission.

ABSTRACTPorcine deltacoronavirus (PDCoV) is an emerging enteric coronavirus that has been reported to infect a variety of animals and even humans. Cell-cell fusion has been identified as an alternative pathway for the cell-to-cell transmission of certain viruses, but the ability of PDCoV to exploit this transmission model, and the relevant mechanisms, have not been fully elucidated. Herein, we provide evidence that cell-to-cell transmission is the main mechanism supporting PDCoV spread in cell culture and that this efficient spread model is mediated by spike glycoprotein-driven cell-cell fusion. We found that PDCoV efficiently spread to non-susceptible cells via cell-to-cell transmission, and demonstrated that functional receptor porcine aminopeptidase N and cathepsins in endosomes are involved in the cell-to-cell transmission of PDCoV. Most importantly, compared with non-cell-to-cell infection, the cell-to-cell transmission of PDCoV was resistant to neutralizing antibodies and immune sera that potently neutralized free viruses. Taken together, our study revealed key characteristics of the cell-to-cell transmission of PDCoV and provided new insights into the mechanism of PDCoV infection.

Molecular Docking Studies of Coronavirinae Spike Proteins with Different Vertebrate Receptors (ACE2, APN, DPP4)

Coronaviruses (CoVs) display prevalence and great cross-transmissibility due to diverse receptor recognition and high mutability of their spike proteins. In this study, spike protein interactions that influence coronavirus evolution and complex virology were determined. To establish coronavirus classification, phylogenetic analysis of spike proteins based on maximum likelihood was performed using MEGA X. To identify the most suitable interactions between spike proteins and vertebrate cell receptors, molecular docking between full spike proteins and angiotensin-converting enzyme 2 (ACE2), aminopeptidase N (APN), and dipeptidyl peptidase 4 (DPP4) receptors from vertebrates was performed using Hex, a 6D spherical polar Fourier (SPF) transform-based software. Results supported the current coronavirus taxonomy, and molecular docking showed that highly different classes recognized similar receptors. Specifically, spike protein of Munia CoV with cat ACE2 (E = -478.3 kcal/mol) and for SARS-CoV-2 variants, spike protein of alpha with chicken ACE2 (E = -349.6 kcal/mol) formed the most suitable interactions. SARS-CoV-2 variants showed additional affinity toward chicken and cat receptors. Therefore, preferred cell receptor and animal hosts were predicted for all coronaviruses using a sequence-based approach which may serve as future guide for further studies. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Delayed immunological reaction of Human Microvascular Lung Endothelium in response to Human Coronavirus 229E infection

Introduction: In the natural conditions first and major target for respiratory viruses (RVs) are epithelial cells. Nonetheless, recently we have demonstrated that RVs are able to infect not only epithelium, but also Human Microvascular Lung Endothelial Cells (HMVEC-L) which increased network is observed during severe asthma due to increased angiogenesis. Furthermore, on the surface of HMVEC-L we observed intense expression of aminopeptidase N (AP-N)- an entry receptor for Human Coronavirus 229E (HCoV-229E). Due to the facts, that possibility of being infected by HCoV-229E should be considered and there is no research based on this model the aim of this study was to assess the vulnerability of HMVEC-L to HCoV-229E infection. Method(s): HMVEC-L was incubated with HCoV-229E (MOI 0,1;1,0;3,0) for 3 hours, 3x PBS washed and cultured for 120 hours. In relevant time points (5;24;48;72;96 and 120h) viral copy number and mRNA expression of inflammatory, anti-viral and receptor factors were evaluated in Real-Time PCR. Confocal microscopy (CM) and flow cytometry (FACS) were used to measure AP-N surface expression. Result(s): FACS and CM confirmed intense surface expression of AP-N on HMVEC-L. HCoV-229E efficiently infected HMVEC-L (604 945,5 +/-194 930,2 viral copies/mul) in 48h cultures (MOI 0,1) and induced relatively late (between 72- 96h) mRNA expression of RANTES (1181,12);IL-6 (89,6);IFN-beta (53,7);OAS-1 (64,3);PKR (11,4) and TLR-3 (42,4). Increased mRNA expression was also accompanied by protein release to the supernatants. Conclusion(s): HCoV-229E may efficiently infect HMVEC-L and induce delayed inflammatory and anti-viral response.

Chicken or Porcine Aminopeptidase N Mediates Cellular Entry of Pseudoviruses Carrying Spike Glycoprotein from the Avian Deltacoronaviruses HKU11, HKU13, and HKU17.

Members of deltacoronavirus (DCoV) have mostly been identified in diverse avian species as natural reservoirs, though the porcine DCoV (PDCoV) is a major swine enteropathogenic virus with global spread. The important role of aminopeptidase N (APN) orthologues from various mammalian and avian species in PDCoV cellular entry and interspecies transmission has been revealed recently. In this study, comparative analysis indicated that three avian DCoVs, bulbul DCoV HKU11, munia DCoV HKU13, and sparrow DCoV HKU17 (Chinese strain), and PDCoV in the subgenera Buldecovirus are grouped together at whole-genome levels; however, the spike (S) glycoprotein and its S1 subunit of HKU17 are more closely related to night heron DCoV HKU19 in Herdecovirus. Nevertheless, the S1 protein of HKU11, HKU13, or HKU17 bound to or interacted with chicken APN (chAPN) or porcine APN (pAPN) by flow cytometry analysis of cell surface expression of APN and by coimmunoprecipitation in APN-overexpressing cells. Expression of chAPN or pAPN allowed entry of pseudotyped lentiviruses with the S proteins from HKU11, HKU13 and HKU17 into nonsusceptible cells and natural avian and porcine cells, which could be inhibited by the antibody against APN or anti-PDCoV-S1. APN knockdown by siRNA or knockout by CRISPR/Cas9 in chicken or swine cell lines significantly or almost completely blocked infection of these pseudoviruses. Hence, we demonstrate that HKU11, HKU13, and HKU17 with divergent S genes likely engage chAPN or pAPN to enter the cells, suggesting a potential interspecies transmission from wild birds to poultry and from birds to mammals by certain avian DCoVs. IMPORTANCE The receptor usage of avian deltacoronaviruses (DCoVs) has not been investigated thus far, though porcine deltacoronavirus (PDCoV) has been shown to utilize aminopeptidase N (APN) as a cell receptor. We report here that chicken or porcine APN also mediates cellular entry by three avian DCoV (HKU11, HKU13, and HKU17) spike pseudoviruses, and the S1 subunit of three avian DCoVs binds to APN in vitro and in the surface of avian and porcine cells. The results fill the gaps in knowledge about the avian DCoV receptor and elucidate important insights for the monitoring and prevention of potential interspecies transmission of certain avian DCoVs. In view of the diversity of DCoVs, whether this coronavirus genus will cause novel virus to emerge in other mammals from birds, are worthy of further surveillance and investigation.

Remissao Espontanea De Leucemia Mieloide Aguda Apos Infeccao Grave Por Covid-19 E Choque Septico: Relato De Caso

Introducao: A remissao espontanea de leucemia mieloide aguda e um evento muito raro, e suas descricoes na literatura medica geralmente envolvem um evento infeccioso grave. Mais recentemente, a COVID-19 tambem foi descrita como um dos fatores associados a tal fenomeno, e a hipotese mais aceita para o mesmo e de que ha uma hiperativacao imune que tambem apresenta efeito antitumoral. Relato de caso: Paciente feminina, de 54 anos, foi admitida no Hospital Brigadeiro com historia de alteracao de nivel de consciencia e lesao em pododactilo direito que motivou a procura do pronto socorro. No hemograma da admissao, apresentava hemoglobina 8,2 g/dL VCM 87, plaquetometria 11.000/mm3, leucocitos 99560 com 88% de celulas de medio a grande tamanho, alta relacao nucleo citoplasma nucleolos evidentes e presenca frequente de bastonete de Auer. A imunofenotipagem de sangue periferico,22,4% destas celulas revelaram marcacao CD13, CD15++, CD33++/+++, CD34 par, CD38+++, CD64+, CD71+, CD117, CD123+, HLA-DR, MPO par, alem de 18,6% de monocitos maduros, com diagnostico de leucemia mieloide aguda. Foi colhido teste rapido para COVID-19 antes da internacao, com resultado positivo. Nos 3 dias que se seguiram, a paciente evoluiu com desconforto respiratorio, taquipneia, e a tomografia de torax revelou ainda broncopneumonia sobreposta a COVID-19, o que resultou em intubacao orotraqueal por insuficiencia respiratoria. Durante a intubacao, a paciente evoluiu com parada cardiorrespiratoria em atividade eletrica sem pulso, com retorno a circulacao espontanea apos 10 minutos. Dada a gravidade do quadro, foi optado por nao iniciar inducao quimioterapica. Ao longo da internacao em UTI, a paciente fez uso de piperacilina tazobactam com vancomicina nos primeiro 7 dias de internacao, teve Pseudomonas aeruginosa multissensivel isolada de aspirado traqueal, e recebeu meropenem e teicoplanina por novo evento de choque septico, por 7 dias. Sua internacao em UTI durou 41 dias, contudo, ao longo dos primeiros 30 dias de internacao houve clareamento de blastos em sangue periferico, e parametros como hemoglobina e plaquetometria tambem evoluiram com melhora. Ao final do 42degree dia, quando recebeu alta da UTI para a enfermaria, foi feita avaliacao medular, quel nao revelou blastos com as caracteristicas imunofenotipicas previamente descritas. A paciente se encontra atualmente internada e com remissao citomorfologica e sem doenca residual minima pela imunofenotipagem. Nao foi administrada qualquer terapia antineoplasica, somente hidroxiureia para fins de citorreducao, nos primeiros 7 dias do quadro. Discussao: O caso evidencia uma rara e ainda nao compreendida remissao de leucemia mieloide aguda apos infeccao por COVID-19 e complicacoes infecciosas bacterianas graves. Casos semelhantes ja foram descritos em sepse grave e COVID-19 isoladamente, mas a evolucao natural do quadro envolve a recaida da doenca apos alguns meses do quadro agudo. A terapia antineoplasica, por sua vez, e indispensavel para a remissao sustentada. A explicacao mais aceita para o fenomeno e de que um mecanismo imunologico ativado e producao excessiva de citocinas pro-inflamatorias, sobretudo na COVID-19, destruiria as celulas neoplasicas, que poderiam inclusive ser infectadas pelo virus. Conclusao: Apesar de o mecanismo exato da remissao ser desconhecido, o caso apresentado reforca o papel da imunidade do individuo no tratamento antineoplasico e justifica a imersao em mais estudos envolvendo imunoterapia para a leucemia mieloide aguda. Copyright © 2022

Immune regulation of AP-N, DDP4 and ACE2 receptors and the susceptibility to infections with coronavirus 229E, MERS-CoV and SARS-CoV2

The Coronaviridae family includes the seven known human coronavi-ruses (HCoV) that cause mild to moderate respiratory infections (HCo-V-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1) as well as severe illness and death (MERS-CoV, SARS-CoV, SARS-CoV-2). Severe infections in-duce inflammatory responses that are often intensified by host ada-ptive immune pathways. Proinflammatory responses are triggered by CoV entry mediated by host cell surface receptors. Interestingly, four of the seven strains use cell surface metallopeptidases as receptors. The entry receptors for specific coronaviruses are: aminopeptidase N (AP-N), dipeptidyl peptidase 4 (DPP4) and angiotensin-converting enzyme 2 (ACE2) for HCoV-229E, MERS-CoV, SARS-CoV and SARS-CoV2, respectively. In addition, these receptors perform many physiological functions, including the regulation of the circulatory and immune sys-tems. Coronavirus receptors are also highly expressed in human tissues and organs (intestines, kidneys, heart, lungs). Additionally, some cy-tokines, chemokines, and other proteins and immune cells influence the modulation of the expression of coronavirus receptors. This review presents the biological role of receptor proteins in the regulation of human physiological systems, the impact of the immune response on susceptibility to coronavirus infections, and the potential effects of glucocorticosteroids (GCS) and specific allergen immunotherapy (AIT) used in the treatment of asthma and allergy on the suscpetibility to coronaviral infections.

In silico Analysis of ACE2 Receptor to Find Potential Herbal Drugs in COVID-19 Associated Neurological Dysfunctions

COVID-19 mainly causes the collapse of the pulmonary system thereby causing a dearth of oxygen in the human body. Patients infected with this viral disease have been reported to experience various signs and symptoms associated with brain dysfunction, from the feeling of vagueness to loss of smell and taste to severe strokes. These neurological problems have been reported by younger COVID-19 infected patients mainly in their thirties and forties. Various researchers from around the globe have discerned numerous other brain dysfunctions, such as headache, dizziness, numbness, major depressive disorder, anosmia, encephalitis, febrile seizures, and Guillain-Barre syndrome. The involvement of the CNS by this viral infection has been predicted to be for a longer period of time, even if the patient recovers from COVID-19. The neuronal cell damage caused by COVID-19 is a potent factor responsible for cognitive, behavioral, and psychological problems among its sufferers. The hypoxic conditions can also trigger the formation of beta-amyloid plaques and tau-tangles and thus the virus can even induce Alzheimer's in patients in the near future. The virus affects the brain directly, thereby causing encephalitis. This pandemic has also been shown to have a negative psychological toll on people. This research aims to highlight the brain dysfunction associated with the ACE2 receptor that is known to be a crucial player in the COVID-19 pandemic using genetic networking approaches. Furthermore, we have identified herbal drug candidates that bind to the ACE2 receptor in order to identify potential treatments for the neurological manifestations of COVID-19.

Effect of human aminopeptidase N (hAPN) on porcine deltacoronavirus infecting HEK293 cells

HEK293 cells were used as the cell model to investigate the role of human aminopeptidase N (hAPN) in the invasion of porcine deltacoronavirus (PDCoV) into human cells. The proliferation of PDCoV on HEK293 cells was firstly identified by RT-qPCR/RT-PCR. And then, hAPN knockout cell line was constructed by CRISPR/Cas9 technology and cell viability of HEK293 hAPN knockout and wild-type cells was verified by CCK-8 assay. Effect of hAPN knockout and overexpression on PDCoV replication was detected by RT-qPCR and Western blot. Meanwhile, interaction of PDCoV S protein and hAPN protein was analyzed by homology modeling and molecular docking. Results showed that PDCoV virus copies rapidly increased at 12-36 h and reached peak level at 36 h, it could propagate at least for passage 2 on HEK293 cells. There was no significant difference in cell viability between hAPN knockout cells and wild-type cells. Knockout of hAPN inhibit PDCoV replication and overexpression of hAPN enhance PDCoV replication. Homology modeling and molecular docking analysis showed S1 protein could bind hAPN domain II. Residues TYR92, THR51, THR48, PHE16 and MET14of S1 protein receptor binding motif 1 (RBM1) can form hydrogen bonds with residues PHE490, GLN531, ARG528 and SER529 of hAPN. This study indicates that hAPN plays a critical role in HEK293 cells during PDCoV infection, which provides new theoretical evidence for further studies on the mechanism of PDCoV entry into host cells and cross-species transmission.

Structure, receptor recognition, and antigenicity of the human coronavirus CCoV-HuPn-2018 spike glycoprotein.

The isolation of CCoV-HuPn-2018 from a child respiratory swab indicates that more coronaviruses are spilling over to humans than previously appreciated. We determined the structures of the CCoV-HuPn-2018 spike glycoprotein trimer in two distinct conformational states and showed that its domain 0 recognizes sialosides. We identified that the CCoV-HuPn-2018 spike binds canine, feline, and porcine aminopeptidase N (APN) orthologs, which serve as entry receptors, and determined the structure of the receptor-binding B domain in complex with canine APN. The introduction of an oligosaccharide at position N739 of human APN renders cells susceptible to CCoV-HuPn-2018 spike-mediated entry, suggesting that single-nucleotide polymorphisms might account for viral detection in some individuals. Human polyclonal plasma antibodies elicited by HCoV-229E infection and a porcine coronavirus monoclonal antibody inhibit CCoV-HuPn-2018 spike-mediated entry, underscoring the cross-neutralizing activity among ɑ-coronaviruses. These data pave the way for vaccine and therapeutic development targeting this zoonotic pathogen representing the eighth human-infecting coronavirus.

Morphology and Immunophenotype Correlation Study of Peripheral Blood from COVID19 Patients

Background: Since the first case of COVID19 infection in 2019, this RNA virus has led an unprecedented pandemic that infected more than 232 million people. Although the disease is studied extensively, much remains poorly understood. Here, we performed the first correlation study on the peripheral blood morphology and immunophenotype of the white blood cells (WBCs) from COVID19 patients. Design: A total of 52 samples from COVID19 patients and 15 blood samples as control group were analyzed. COVID19 patients were divided into two groups based on clinical severity, severe (respiratory failure) or non-severe (hospitalized but stable). The controls were the patients with negative COVID19 results by PCR and antibody tests. The WBC morphology was examined either by blood smear review or via CellaVision DM analyzer captured images. Navios flow cytometer and Beckman Kaluza C software were used for immunophenotype analysis. Two-tailed T-test was performed on the COVID19 groups and the control group Results: Almost all COVID19 patients showed marked neutrophilia and lymphopenia on the CBC tests. Morphologically, the neutrophils showed irregularities like hypogranulation, toxic granules and pseudo Pelger-Huet anomaly (Fig 1A). In severe COIVD19 group, there was an increase in neutrophils with immatures phenotypes, showing CD33 positivity while CD10, CD13 and CD16 negative (Fig 1B). Conversely, the CD10(+) mature neutrophils aberrantly expressed CD56 (Fig 1B). The percentage of CD56(+) neutrophils was significantly higher in both COVID19 groups, suggesting a stronger cellular adhesion and interaction. The monocytes from the COVID19 patients had increased cytoplasm with cytoplasmic protrusion and vacuolization (Fig 2A). Phenotypically they were positive for CD13, CD33, CD38 and HLA-DR. The lymphocytes were also atypical, including increased cytoplasm with large granules and vacuoles. Phenotypically, they are activated, expressing CD38, HLA-DR, and mainly α/β subtype. Giant platelets with cytoplasmic vacuoles and projections were easily seen. Platelet aggregations were observed (Fig 2B). These platelets were CD45(-) and expressed CD61 at lower-than-normal intensity, while expressing increased CD42b intensity when compared to the control group on a log scale. Conclusions: Despite being a small study, we were able to correlate the morphologic and phenotypic alterations of the WBCs in COVID19 patients. As such, this helped to explain some of the clinical hematologic manifestation of the disease. (Figure Presented).

SARS CoV-2;a closer look at the agent of the pandemic of modern times

Due to the COVID-19 pandemic, as of September 2021, a total of 222,309,456 people were infected in the world and a total of 4,592,685 patients were lost. The pandemic, which has a fatality rate of around 2%, has made and continues to make us live thhrough all experiences of epidemics that we have only read about in Annals of Medicine and Microbiology and that deeply affected the World at their times. The virus causing the pandemic has a positive polarity RNA genome of 30,000 bases and produces a total of 29 proteins. Of these proteins, 4 are structural, 16 are nonstructural, and 9 are accessory proteins. SARS-CoV-2 is an enveloped RNA virus with a diameter of 150-200 nm, has an S (spike-spike-tassel) glycoprotein on its surface, which, like other coronaviruses, creates the crown appearance unique to these viruses. After the S protein is synthesized as a polyprotein, it is cleaved into S1 and S2 subunits. The S1 subunit binds to the target cell, and the S2 subunit performs fusion with the cell membrane to be infected. Since these functions are critical features of a successful viral infection, the S protein is the main target of all interventions to prevent virus infection. In this context, the main target of neutralizing antibodies and drugs to stop virus infection before it starts is the S protein. The S protein has a trimer structure similar to hemagglutinin in influenza virus and contains the fusion peptide that becomes exposed during transition from the prefusion configuration to the fusion configuration and facilitates the fusion function with the cellular/endosomal membranes. Apart from the S protein, SARS-CoV-2 has structural proteins known as E (envelope), M (membrane), and N (nucleocapsid) proteins;The N protein binds to the RNA genome and together with the S, E and M proteins and the RNA genome form the virion. While SARS-CoV-2 S protein attaches to cells using Cellular Angiotensin Converting Enzyme 2 (HCoV- NL63, SARS-CoV and SARS-CoV-2), other coronaviruses use different receptors (Aminopeptidase N-HCoV-229E;dipeptidyl peptidase 4- MERS-CoV). Unlike viruses in this group, the SARS CoV-2 S1 protein with receptor binding domain (RBD) has a cleavage site made up of polybasic amino acids at the S1-S2 border and used by the cellular furin protease, which is believed to provide advantages to the virus in proteolytic cleavage, cell tropism, virulence and pathogenicity. ACE-2 is important in the renin-angiotensin-aldosterone system and although it is rarely found in the circulation, it is widely expressed in organs and is an enzyme involved in the regulation of blood pressure and fluid balance. Following intracellular entry and fusion of membranes, the SARS-CoV-2 genome is released into the cytoplasm and gene expression proceeds as a temporally and spatially well-regulated process. Non-structural proteins, which are produced from direct translation of ORF1a and ORF1b regions of positive sense genomic RNA, form the replication and transcription complex. These complexes establish the infrastructure for the next steps. The common features of coronaviruses such as cytoplasmic replication, viral gene expression through sub-genomic nested set messages, exocytosis of mature virions within vesicles occur in SARS-CoV-2 as well. One of the most important problems in the COVID-19 pandemic has been the emergence of variant viruses. These viruses adversely affecting the transmission rate, virulence, clinical course, and the effectiveness of the diagnostic or therapeutic methods carry mutations that lead to amino acid changes, especially in the RBD region. The World Health Organization and other authorities refer to these viruses as variants of concern or variants of interest. As of September 2021, WHO lists Alpha (UK, September 2020), Beta (South Africa, May 2020), Gamma (Brazil, November 2020), and Delta (India, October 2020) viruses as variants of concern. Also, Eta (December 2020), Iota (USA, November 2020), Kappa (India, October 2020), Lambda (Peru December, 2020) and Mu (Colombia, January 2021) mutant viruses are on he list variants of interest. In conclusion, less than 2 years of time has passed since the emergence of the COVID-19 agent SARS CoV-2 virus. However, this virus has been the most extensively studied viral agent in the history of medicine and the most detailed information has been gathered about the infection. Despite all these, it is difficult to indicate that the fight against this pathogen has been successful nor are we any closer to declare that the enormous danger the virus poses to humanity is reduced.

Novel Calr Mutation in Acute Lymphoblastic Leukemia

Introduction: Acute lymphoblastic leukemia in adults represent amajor therapeutic challenge even in modern era. Constantly evolvinggenomics has led to a better risk stratification and prognostication.Aims &Objectives: Here we present a novel mutation in calreticulingene in a patient with Precursor B lineage Acute lymphoblasticleukemia.Materials &Methods: A 19 year old boy presented with fever,jaundice and pancytopenia. Initial investigation revealed a hemoglobin of 5.8 g/dl with a total leukocyte count of 700 cells/mm3 andplatelet count of 11,000/mm3. Differential count showed 95% lymphocytes and 5% neutrophils and no blasts with mildanisopoikilocytosis on PBF. Bone marrow biopsy demonstartedreduction granulocytic and erythroid lineage with adequatemegakaryocytes and occasional collections of immature appearingcells, whose charcter was not able to be definitely ascertained. PETCT showed FDG avid lymph nodes on both sides of diaphragm, withPET guided biopsy was suggestive of non specific lymphocyticinflammatory infiltrate. A diagnosis of hemophagocytic lymphohistiocytosis (HLH) was made according to HLH 2004 criteria (Fever,cytopenias, hypertriglyceridemia, splenomegaly and elevated serumferritin levels). However workup for primary HLH and primaryimmune deficiencies were negative.Clinical exome sequencing forprim was postive for mvk transcript (c.808G >A). He was treatedwith IVIG and short course steroids. Repeat bone marrow was normocellular with mild erythroid prominence and adequaterepresentation of granulocytic and megakaryocytic lineage elements.He was under regular follow up thereafter.Result: He developed mild Covid illness a month after discharge. Amonth after recovery from illness, he presented with easy fatiguabilityand pancytopenia (Hb: 7.1 g/dl, TLC: 900 cells/mm3 and Plateletcount: 1.46 lakhs) with presence of occasional blast in PBF. Repeatbone marrow was markedly hypercellular with 76% blast.Megakaryocytes were relatively preserved. On flow cytometry, blastswere positive for CD 10, CD 19, CD 20, cyto CD 79a, CytoCD22, CD34, CD 45, HLA DR and TDT and negative for MPO CD 2 CD 3 CD13 aand CD 33 consistent with Precursor B Lineage acute lymphoblastic leukemia. Multiplex RT-PCR for recurrent geneticabnormalities (ALL) were negative. A never reported CALR (TYPE1) mutation was found in this patient. CALR plays an important rolein cell proliferation, apoptosis and immune responses. Patient wastreated with modified BFM regimen and Rituximab, attained CR postinduction and currently in consolidation phase of therapy.Conclusions: CALR mutation has never been reported before in acase of acute lymphoblastic leukemia. Long term follow up of patient is required to conclude whether the novel mutation has prognostic andtherapeutic implications.

Suboptimal Humoral and Cellular Immune Response to SARS-CoV-2 RNA Vaccination in Myeloma Patients Is Associated with Anti-CD38 and BCMA-Targeted Treatment

Background: Multiple myeloma (MM) patients are immunocompromised due to defects in humoral/cellular immunity and immunosuppressive therapy. Reports indicate that the antibody (Ab) response in MM after 1 dose of SARS-CoV-2 RNA vaccine is attenuated. The impact of treatment on cellular immunity after vaccination remains unknown. Methods: We analyzed SARS-CoV-2 spike-binding (anti-S) IgG level in 320 MM patients receiving SARS-CoV-2 RNA vaccination. Blood and saliva were taken at multiple time points and compared with serology data of 69 age-matched vaccinated healthcare workers. We profiled SARS-CoV-2-specific T cell responses in a subset of 45 MM patients and 12 age-matched healthy controls by flow cytometry and ELIspot. All subjects were enrolled in studies approved by the Institutional Review Board at the Icahn School of Medicine at Mount Sinai. Results: The 320 patients (median age 68 year) received two-dose RNA vaccines (69.1% BNT162b2, 27.2% mRNA-1273). Median time to diagnosis was 60 months with a median of 2 prior treatment lines (range 0-16). We included 23 patients with smoldering MM. Patients received various treatments at vaccination with 148 (43.8%) on anti-CD38-containing treatment, 36 (11.3%) on BCMA-targeted therapy and 59 (18.4%) not on active treatment (incl. SMM patients). At the last available evaluation prior to vaccination, 131 (40.9%) exhibited a complete response. At data cutoff, a total of 260 patients (81.3%) had anti-S IgG measured >10 days after the second vaccine (median 51 days). Of these, 84.2% mounted measurable anti-S IgG levels (median 149 AU/mL). In the control group, Ab levels were significantly higher (median 300 AU/mL). Ab levels in the vaccinated MM patients with prior COVID-19 were 10-fold higher than those of patients without prior COVID-19 (p<0.001). Repeat Ab measurements up to 60 days after second vaccination confirm delayed and suboptimal IgG kinetics, particularly in patients receiving anti-MM treatment compared to controls (Figure 1). MM patients on active treatment had lower anti-S IgG levels (p=0.004) compared to patients not on therapy (median 70 vs 183 AU/mL). Notably, 41 patients (15.8%) failed to develop detectable anti-S IgG: 24/41 (58.5%) were on anti-CD38, 13/41 (31.7%) on anti-BCMA bispecific Ab therapy and 4/41 (9.8%) >3 months after CAR T. Univariate analysis showed an association of disease-related factors with absence of anti-S IgG: more previous lines of treatment (>3 lines, p=0.035;>5 lines, p=0.009), receiving active MM treatment (p=0.005), grade 3 lymphopenia (p=0.018), receiving anti-CD38 therapy (p=0.042) and receiving BCMA-targeted therapy (p<0.001). Multivariate analysis (corrected for age, vaccine type, lines of treatment, time since diagnosis, response status and lymphopenia) confirmed that anti-CD38 (p=0.005) and BCMA-targeted treatment (p<0.001) are associated with not developing detectable anti-S IgG. Clinical relevance is emphasized by 10 cases of COVID-19 after 1 (n=7) or 2 vaccine doses (n=3, all without anti-S IgG) with 1 patient passing due to respiratory failure. We studied SARS-CoV-2-specific T cell responses >2 weeks after the second vaccine in 18 MM patients with undetectable anti-S IgG (seronegative), 27 with detectable anti-S IgG (seropositive) and 12 healthy seropositive controls. We found that seropositive MM patients had CD4+CD154+ T cells producing IFNg, TNFa and IL-2 at similar levels as controls, whereas in the seronegative MM cohort CD4 T cell responses were significantly reduced (p<0.005). SARS-CoV-2-specific CD8 T cell responses were overall weaker and not different across cohorts. This data suggests that absence of detectable IgG is associated with suboptimal response of humoral and cellular immunity. Conclusion: MM patients mount a suboptimal IgG response after SARS-CoV-2 vaccination, with 15.8% of patients without detectable anti-S IgG. Ongoing analyses will highlight durability of serological protection against COVID-19. Additional data on T cell responses and immunophenotyping in the context of vaccination will be upda ed at the meeting. Implications are continuation of non-pharmacological interventions, e.g. masking/social distancing, for vulnerable patients. The findings underscore a need for serological monitoring of MM patients after vaccination and for trials assessing use of prophylactic strategies or studies exploring additional immunization strategies. [Formula presented] Disclosures: Wang: Sanofi Genzyme: Consultancy. Chari: Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees;Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding;Millenium/Takeda: Consultancy, Research Funding;Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees;Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees;Pharmacyclics: Research Funding;GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees;Secura Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees;Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees;Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees;Novartis: Consultancy, Research Funding;Janssen Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Shattuck Labs: Consultancy, Membership on an entity's Board of Directors or advisory committees;BMS/Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Takeda: Consultancy, Research Funding;AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees. Cordon-Cardo: Kantaro: Patents & Royalties. Krammer: Kantaro: Patents & Royalties;Merck: Consultancy;Pfizer: Consultancy;Avimex: Consultancy;Seqirus: Consultancy. Jagannath: Legend Biotech: Consultancy;Karyopharm Therapeutics: Consultancy;Janssen Pharmaceuticals: Consultancy;Bristol Myers Squibb: Consultancy;Sanofi: Consultancy;Takeda: Consultancy. Simon: Kantaro: Patents & Royalties. Parekh: Foundation Medicine Inc: Consultancy;Amgen: Research Funding;PFIZER: Research Funding;CELGENE: Research Funding;Karyopharm Inv: Research Funding.

Is tumour-expressed aminopeptidase N (APN/CD13) structurally and functionally unique?

Aminopeptidase N (APN/CD13) is a multifunctional glycoprotein that acts as a peptidase, receptor, and signalling molecule in a tissue-dependent manner. The activities of APN have been implicated in the progression of many cancers, pointing toward significant therapeutic potential for cancer treatment. However, despite the tumour-specific functions of this protein that have been uncovered, the ubiquitous nature of its expression in normal tissues as generally reported remains a limitation to the potential utility of APN as a target for cancer therapeutics and drug discovery. With this in mind, we have extensively explored the literature, and present a comprehensive review that for the first-time provides evidence to support the suggestion that tumour-expressed APN may in fact be unique in structure, function, substrate specificity and activity, contrary to its nature in normal tissues. The review also focuses on the biology of APN, and its "moonlighting" functional roles in both normal physiology and cancer development. Several APN-targeting approaches that have been explored over recent decades as therapeutic strategies in cancer treatment, including APN-targeting agents reported both in preclinical and clinical studies, are also extensively discussed. This review concludes by posing critical questions about APN that remain unanswered and unexplored, hence providing opportunities for further research.

Generation of SARS-CoV-2 S1 Spike Glycoprotein Putative Antigenic Epitopes in Vitro by Intracellular Aminopeptidases.

Presentation of antigenic peptides by MHCI is central to cellular immune responses against viral pathogens. While adaptive immune responses versus SARS-CoV-2 can be of critical importance to both recovery and vaccine efficacy, how protein antigens from this pathogen are processed to generate antigenic peptides is largely unknown. Here, we analyzed the proteolytic processing of overlapping precursor peptides spanning the entire sequence of the S1 spike glycoprotein of SARS-CoV-2, by three key enzymes that generate antigenic peptides, aminopeptidases ERAP1, ERAP2, and IRAP. All enzymes generated shorter peptides with sequences suitable for binding onto HLA alleles, but with distinct specificity fingerprints. ERAP1 was the most efficient in generating peptides 8-11 residues long, the optimal length for HLA binding, while IRAP was the least efficient. The combination of ERAP1 with ERAP2 greatly limited the variability of peptide sequences produced. Less than 7% of computationally predicted epitopes were found to be produced experimentally, suggesting that aminopeptidase processing may constitute a significant filter to epitope presentation. These experimentally generated putative epitopes could be prioritized for SARS-CoV-2 immunogenicity studies and vaccine design. We furthermore propose that this in vitro trimming approach could constitute a general filtering method to enhance the prediction robustness for viral antigenic epitopes.

Relevance between COVID-19 and host genetics of immune response.

The outbreak of coronavirus disease 2019 (COVID-19) was caused by the newly emerged corona virus (2019-nCoV alias SARS-CoV-2) that resembles the severe acute respiratory syndrome virus (SARS-CoV). SARS-CoV-2, which was first identified in Wuhan (China) has spread globally, resulting in a high mortality worldwide reaching ~4 million deaths to date. As of first week of July 2021, ~181 million cases of COVID-19 have been reported. SARS-CoV-2 infection is mediated by the binding of virus spike protein to Angiotensin Converting Enzyme 2 (ACE2). ACE2 is expressed on many human tissues; however, the major entry point is probably pneumocytes, which are responsible for synthesis of alveolar surfactant in lungs. Viral infection of pneumocytes impairs immune responses and leads to, apart from severe hypoxia resulting from gas exchange, diseases with serious complications. During viral infection, gene products (e.g. ACE2) that mediate viral entry, antigen presentation, and cellular immunity are of crucial importance. Human leukocyte antigens (HLA) I and II present antigens to the CD8+ and CD4+ T lymphocytes, which are crucial for immune defence against pathogens including viruses. HLA gene variants affect the recognition and presentation of viral antigenic peptides to T-cells, and cytokine secretion. Additionally, endoplasmic reticulum aminopeptidases (ERAP) trim antigenic precursor peptides to fit into the binding groove of MHC class I molecules. Polymorphisms in ERAP genes leading to aberrations in ERAP's can alter antigen presentation by HLA class I molecules resulting in aberrant T-cell responses, which may affect susceptibility to infection and/or activation of immune response. Polymorphisms from these genes are associated, in global genetic association studies, with various phenotype traits/disorders many of which are related to the pathogenesis and progression of COVID-19; polymorphisms from various genes are annotated in genotype-tissue expression data as regulating the expression of ACE2, HLA's and ERAP's. We review such polymorphisms and illustrate variations in their allele frequencies in global populations. These reported findings highlight the roles of genetic modulators (e.g. genotype changes in ACE2, HLA's and ERAP's leading to aberrations in the expressed gene products or genotype changes at other genes regulating the expression levels of these genes) in the pathogenesis of viral infection.