Pbmc Immunophenotyping and Plasma Inflammatory Profile of Children with Long Covid

Background: Long COVID can be developed by individuals after an infection with SARS-CoV-2 as described by the WHO. Although this condition is more commonly described in adults, it can occur in children and adolescents with a wide range of estimated prevalence of 1-25%. Little is known about the role of the immune system in long COVID. However, one of the main hypotheses about the underlying mechanism in long COVID is that there is an immune and inflammatory dysregulation that persists after the acute infection. The objective of this study is to compare immune cells populations, and inflammatory biomarkers in paediatric populations with and without long COVID. Method(s): We analyzed 55 blood samples from the pediaCOVID cohort (Hospital Germans Trias i Pujol), which includes more than 130 children diagnosed with long COVID and 23 controls. We measured different immune cell populations using spectral cytometry with a panel of 37 cellular markers, and 42 inflammatory markers using Luminex or ELISA. EdgeR was used for statistical analysis of the spectral data;p-values of inflammatory markers were calculated using the likelihood ratio test and they were corrected for multiple comparisons. Result(s): The study cohort had a median age of 14.3 (IQR, 12.5-15.2) and 69.1% female. Patients had at least 3 symptoms associated with long COVID (median [IQR];10 [7-16]). The most common symptom was asthenia/fatigue (98.2%). Compared to the control cohort, children with long COVID had increased numbers of CD4+CD8+ T cells, IgA+CD21+CD27+ memory B cells, and IgA+CD21-CD27- memory B cells, while CD4+ TEMRA cells (CD45RA+, CCR7-), intermediate monocytes (CD14+, CD16+) and classical monocytes (CD14+, CD16-) were decreased (all p< 0.05;q=n.s.). None of the 42 inflammatory biomarkers showed significant differences between children with and without long COVID. Conclusion(s): The results of this study suggest that specific populations of peripheral blood immune cells might be involved in the mechanisms underlying prolonged COVID in children and adolescents. The increase in both IgA+CD21-CD27- and IgA+CD21+CD27+ memory B cells could be associated with the persistence of viral antigen in the gut and/or gut dysbiosis. Moreover, the decrease in CD4+ TEMRA cells could be related to autoantibodies against G-protein coupled receptors (GPCRs), since this cell population can express GPR56, and autoantibodies against GPCRs were previously reported to be elevated in adults with long COVID.

SARS-CoV-2 Kerala Isolate Spike Protein Induces Cancer Proliferating Markers for Lung and Breast Cancer: An In Silico Approach

Background: Coronavirus disease (COVID 19) has been emerging as a major threat to humans all over the world. Severe Acute Respiratory Syndrome CoronaVirus 2 (nSARS-CoV-2) is the causative agent for the disease resulting in severe acute respiratory illness. Earlier, it took several years to come up with a vaccine or other sorts of treatments for viral diseases. But now with the advent of biotechnology and development of bio-informatic tools, the process has been accelerated. The WHO reports 39,806,488 affected cases and 1,112,208 deaths till today all over the world (17 Oct 2020). nSARS-CoV-2 has a greater influence on people with comorbidities mainly cancer. Objective(s): The study herein attempts to understand the binding affinity of the spike protein of the novel coronavirus with the lung and breast cancer marker proteins by docking and ClusPro analysis. Method(s): The analysis was conducted in reference to hACE2 (human Angiotensin Converting Enzyme 2), the receptor of nSARS-CoV-2. Total 22 different marker proteins were analyzed using ClusPro. Result(s): BRCA1 (Breast Cancer type 1 susceptibility protein) and CXCR4 (a chemokine receptor belong-ing to the G protein coupled receptor family) were found to exhibit higher binding affinities.-73.82 kcal/mol and-66.45 kcal/mol were the global energies they showed upon binding to S protein respective-ly. Conclusion(s): Therefore, novel SARS-CoV-2 has a higher chance of inducing cancer in non-cancerous individuals and aids in cancer acceleration in cancer patients. This poses a threat to cancer patients and immunocompromised individuals. The study can be exploited to identify the optimal drug delivery system for novel SARS CoV2.Copyright © 2022 Bentham Science Publishers.

Human T2R38 Bitter Taste Receptor Expression and COVID-19: From Immunity to Prognosis

Background: Bitter taste-sensing type 2 receptor (T2Rs or TAS2Rs) found on ciliated epithelial cells and solitary chemosensory cells have a role in respiratory tract immuni-ty. T2Rs have shown protection against SARS-CoV-2 by enhancing the innate immune response. The purpose of this review is to outline the current sphere of knowledge re-garding this association. Method(s): A narrative review of the literature was done by searching (T2R38 OR bitter taste receptor) AND (COVID-19 OR SARS-CoV-2) keywords in PubMed and google scholar. Result(s): T2R38, an isoform of T2Rs encoded by the TAS2R38 gene, may have a potential association between phenotypic expression of T2R38 and prognosis of COVID-19. Current studies suggest that due to different genotypes and widespread distributions of T2Rs within the respiratory tract and their role in innate immunity, treatment protocols for COVID-19 and other respiratory diseases may change accordingly. Based on the phenotypic expression of T2R38, it varies in innate immunity and host response to respiratory infection, systemic symptoms and hospitalization. Conclusion(s): This review reveals that patients' innate immune response to SARS-COV-2 could be influenced by T2R38 receptor allelic variations.Copyright © 2023, Avicenna Journal of Medical Biotechnology.

Polysaturated fatty acids and their derivatives regulate respiratory infections.

The regulation of inflammation is a complex pathophysiological process that depends on the production of oxygenated lipid derivatives essential polyunsaturated fatty acids, like omega-3 and omega-6, among which are the lipoxins resolvins and protectins, called specialized pro-resolving lipid mediators (SPM). Their activity is associated with the control of respiratory infection processes to modulate the production of proinflammatory cytokines, avoiding damage due to inflammation-associated necrosis, reducing microbial loads, and promoting tissue remodeling. Therefore, we review some of the biochemical, physiological and immunological aspects of SPM in the regulation of inflammation in respiratory infections.Copyright © 2022, Instituto Nacional de Enfermedades Respiratorias. All rights reserved.

Clostridium butyricum-induced ω-3 fatty acid 18-HEPE elicits anti-influenza virus pneumonia effects through interferon-λ upregulation.

The precise mechanism by which butyrate-producing bacteria in the gut contribute to resistance to respiratory viral infections remains to be elucidated. Here, we describe a gut-lung axis mechanism and report that orally administered Clostridium butyricum (CB) enhances influenza virus infection resistance through upregulation of interferon (IFN)-λ in lung epithelial cells. Gut microbiome-induced ω-3 fatty acid 18-hydroxy eicosapentaenoic acid (18-HEPE) promotes IFN-λ production through the G protein-coupled receptor (GPR)120 and IFN regulatory factor (IRF)-1/-7 activations. CB promotes 18-HEPE production in the gut and enhances ω-3 fatty acid sensitivity in the lungs by promoting GPR120 expression. This study finds a gut-lung axis mechanism and provides insights into the treatments and prophylaxis for viral respiratory infections.

Dysregulated autoantibodies targeting vaso- and immunoregulatory receptors in Post COVID Syndrome correlate with symptom severity.

Most patients with Post COVID Syndrome (PCS) present with a plethora of symptoms without clear evidence of organ dysfunction. A subset of them fulfills diagnostic criteria of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Symptom severity of ME/CFS correlates with natural regulatory autoantibody (AAB) levels targeting several G-protein coupled receptors (GPCR). In this exploratory study, we analyzed serum AAB levels against vaso- and immunoregulatory receptors, mostly GPCRs, in 80 PCS patients following mild-to-moderate COVID-19, with 40 of them fulfilling diagnostic criteria of ME/CFS. Healthy seronegative (n=38) and asymptomatic post COVID-19 controls (n=40) were also included in the study as control groups. We found lower levels for various AABs in PCS compared to at least one control group, accompanied by alterations in the correlations among AABs. Classification using random forest indicated AABs targeting ADRB2, STAB1, and ADRA2A as the strongest classifiers (AABs stratifying patients according to disease outcomes) of post COVID-19 outcomes. Several AABs correlated with symptom severity in PCS groups. Remarkably, severity of fatigue and vasomotor symptoms were associated with ADRB2 AAB levels in PCS/ME/CFS patients. Our study identified dysregulation of AAB against various receptors involved in the autonomous nervous system (ANS), vaso-, and immunoregulation and their correlation with symptom severity, pointing to their role in the pathogenesis of PCS.

Possible Impact of functional active GPCRautoantibodies on retinal microcirculation in Long-COVID

Purpose : Long-COVID is assumed to have an autoimmune component. As a seropositivity of functional active autoantibodies against G-protein coupled receptors (GPCR-AAb) and an impaired retinal microcirculation, measured by OCT-angiography (OCT-A), was observed after COVID-19 infection, it was the aim of the present study to investigate the impact of GPCR-AAbs on retinal microcirculation in patients with LongCOVID. Methods : Seventy-six patients with Long-COVID (COVID-19 infection was confirmed by real time rt-PCR) were recruited. A seropositivity for GPCR-AAbs (Nociceptin-AAb, ß2-AAb, AT1-AAb, α1-AAb, MAS-AAb, M2-AAb, ETA-AAb) was analyzed by a specific rat cardiomyocyte bioassay in vitro. Macular (superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP)) and peripapillary vessel density (VD) were measured by OCT-A (Spectralis II, Heidelberg, Germany). VD analysis was done by the Erlangen-Angio tool, including an APSifyed and Bruch's membrane opening (BMO) based analysis. Data were analyzed by mixed model (SAS version 9.4). Gender and age were set as covariates. The study was approved by the local ethics committee and was done in accordance with the tenets of the Declaration of Helsinki. Informed consent was achieved. Results : All patients with Long-COVID showed a seropositivity for GPCR-AAbs (100%). Female patients with Long-COVID showed lower macular and peripapillary VD compared to men. A significant effect of a seropositivity of AT1-AAb on age-corrected least squares means (LS-means) overall VD of DCP ([CI: 0,25;6.07], p=0.03). A seropositivity of α1-AAb showed a significant effect on age-corrected LS-mean overall VD of SVP ([CI: 0.07;2.69], p=0.04), of DCP ([CI: 0.36;3.25], p=0.01), and of PH ([CI: 1.17;5.59], p=0.01), respectively. A seropositivity of MAS-AAb yielded a significant effect on age-corrected LS-mean overall VD of DH (CI: 1.48;6.07, p=0.001). A seropositivity of ß2-AAb has a significant effect on agecorrected LS-mean overall VD of MH (CI: 0,02;1,94, p=0.04). For those effects, the covariate age was significant in the type III tests (p<0.05), thus analysis was done considering this age-effect. Conclusions : As autoimmune mechanisms were reported to be involved in the pathogenesis of Long-COVID, we postulate that functional active GPCR-AAb may have an impact on retinal microcirculation, being a propable correlate to systemic disease.

INCREASED PROTEASE-ACTIVATED RECEPTOR 1 AUTOANTIBODIES ARE ASSOCIATED with SEVERE COVID-19

Background: In acute COVID-19 infection, growing evidence hints towards a broad activation of plasma cells and the presence of pathologic autoantibodies (abs). A systematic screening for abs confrmed induction of diverse functional abs by SARS-CoV-2 infection (1, 2). Immune-mediated thrombosis, involving platelet activation, has been identifed as one of the key pathogenic mechanisms in COVID-19 and is linked to morbidity and mortality (3). As natural abs against G protein-coupled receptors, functional abs against the thrombin receptor type-1 (PAR-1) might predispose for increased activation of the coagulation system present in COVID-19 infection. Objectives: The aim of this study is to identify the diagnostic value of anti-PAR1 antibodies and their capacity to predict the outcome of COVID-19 infection. Methods: 82 serum samples from 55 individuals with COVID-19 derived from three different hospitals in Schleswig-Holstein, Germany, and 88 single time point samples from healthy controls were subjected to ELISA-based quantifcation of anti-PAR-1 abs (CellTrend GmbH Luckenwalde, Germany). The levels of anti-AT1R abs were compared with clinical and laboratory parameters. Results: COVID-19 patients revealed markedly increased levels of circulating anti-PAR1 abs in hospitalized patients particularly in those required intensive care treatment in comparison to controls (p < 0.0001, Figure 1a). Anti-PAR1 ab levels were highest in patients with fatal outcome (p = 0.006, Figure 1a). Receiver operating characteristic (ROC) analysis of PAR1 abs levels in COVID-19 patients revealed a sensitivity of 84.00% and a specifcity 79.25% for patients requiring intensive care unit (ICU) treatment and a sensitivity of 87.50 % and a specifcity 84.51 % to distinguish fatal vs. non-fatal disease outcome (Figure 1b). We found correlation of circulating anti-PAR1 abs with D dimers. Conclusion: The increased anti-PAR1 abs, their prediction to identify patients requiring ICU and fatal outcome, and the correlation with markers for blood clotting suggest a role for antibodies against PAR1 in the disease development of blood clotting in COVID-19.

21stRSC/SCI Medicinal Chemistry Symposium Cambridge/Virtual - September 13-15, 2021

The Royal Chemistry Society/Society of Chemistry Industry (RSC/SCI) Medicinal Chemistry Symposium is a key symposium in the field of medicinal chemistry that takes place every 2 years at the University of Cambridge, U.K., under the auspices of the RSC and the SCI. This year, in its 21st edition, it was run as a hybrid event, simultaneously attended by both in-person and virtual attendees. Its theme was 'Improving Success', and 25 orals and 30 posters were presented. The scientific program covered recent medicinal chemistry achievements in major therapeutic areas, with a few first-time structure disclosure presentations and particular emphasis on emerging early-stage drug discovery and lead optimization strategies, including reports of successful case studies illustrating fragment-based screening and phenotypic target engagement approaches. Applications of artificial intelligence (AI), mass spectrometry and photochemistry in drug design and discovery were also highlighted. This report will cover some of the medicinal chemistry presentations delivered at the meeting.

Role of adenosine receptors in cardiovascular disorders and novel corona virus infection

Objective: To assess the importance of adenosine signaling in cardiovascular disorders (thrombosis, ischemia) and novel corona virus infection. Methodology: A specified web search was done to gather the relevant information using different scientific research forums and databases like WHO database, Pubmed and Google Scholar etc. Results: Adenosine receptors are P1 type of purinergic receptors and belong to G protein-coupled receptors (GPCRs), which is the largest family of integral membrane bound proteins receptors. Adenosine receptors are further classified into four subclasses known as A1, A2A, A2B, and A3. All four subclasses are being mediated by extracellular adenosine and perform a key role in a wide range of physiological functions such as immune system modulation, angiogenesis and sleep regulation. Adenosine receptors are thought to play a significant role in many pathophysiological conditions including cardiovascular disorders such as ischemia and thrombosis and novel corona virus infection making it a key target against these disorders. Conclusion: We suggest that modulation of adenosine receptor activity could increase the regenerative phase in these disorders by increasing the proliferation and differentiation rates of damaged tissue.

TALQUETAMAB, A G PROTEIN-COUPLED RECEPTOR FAMILY C GROUP 5 MEMBER D X CD3 BISPECIFIC ANTIBODY, IN PATIENTS WITH RELAPSED/REFRACTORY MULTIPLE MYELOMA (RRMM): UPDATED PHASE 1 RESULTS FROM MONUMENTAL-1

G protein-coupled receptor family C group 5 member D (GPRC5D) has limited expression in healthy human tissue but is highly expressed in malignant plasma cells, making it a promising target for immunotherapy approaches for MM. Talquetamab (JNJ-64407564) is a first-in-class bispecific antibody that binds to both GPRC5D and CD3 receptors to redirect T cells to kill MM cells. Updated and new results of talquetamab at the recommended phase 2 doses (RP2Ds) are reported (NCT03399799). Eligible patients had RRMM or were intolerant to standard therapies. Patients who were previously treated with B-cell maturation antigen (BCMA)-directed therapies were eligible. This analysis focuses on patients who received talquetamab subcutaneously (SC;range: 5.0-800 μg/kg) weekly (QW) or biweekly (Q2W) with step-up dosing. The primary objectives were to identify the RP2D (part 1) and assess talquetamab safety and tolerability at the RP2Ds (part 2). Adverse events (AEs) were graded by CTCAE v4.03;cytokine release syndrome (CRS) was graded per Lee et al 2014 criteria. Responses were investigator-assessed per IMWG criteria. As of July 19, 2021, 95 patients had received SC talquetamab. The original RP2D was 405 μg/kg SC talquetamab QW with step-up doses, and a second RP2D of 800 μg/kg SC talquetamab Q2W with step-up doses was also identified. 30 patients received 405 μg/kg QW (median 61.5 years [range 46-80];63% male;100% triple-class exposed;80% penta-drug exposed;77% triple-class refractory, 20% penta-drug refractory;30% prior BCMA-directed therapy;median follow-up [mF/U]: 7.5 mo [range 0.9-15.2]). 23 patients received 800 μg/kg Q2W (median 60.0 years [range 47-84];48% male;96% triple-class exposed;70% penta-drug exposed;65% triple-class refractory, 22% penta-drug refractory;17% prior BCMA-directed therapy;mF/U: 3.7 mo [range 0.0-12.0]). No treatment discontinuations due to AEs were reported at either RP2Ds. Most common AEs at the 405 μg/kg QW were CRS (73%;1 grade 3 CRS), neutropenia (67%;grade 3/4: 60%), and dysgeusia (60%;grade 2: 29%). Skin-related AEs occurred in 77% of patients and were all grade 1/2 (nail disorders: 30%). Infections occurred in 37% of patients (1 grade 3 COVID-19 pneumonia). Most common AEs at 800 μg/kg Q2W were CRS (78%;all grade 1/2), dry mouth (44%;all grade 1/2), and neutropenia (44%;grade 3/4: 35%). Skin-related AEs occurred in 65% of patients with grade 3 events in 13% (nail disorders: 17%). Infections occurred in 13% of patients (1 grade 3 pneumococcal sepsis). In 30 response-evaluable patients treated at 405 μg/kg QW, the overall response rate (ORR) was 70% (very good partial response or better [≥VGPR]: 57%). In 17 response-evaluable patients treated at 800 μg/ kg Q2W, the ORR was 71% (≥VGPR: 53%). Responses were durable and deepened over time with both RP2Ds (Figure). Median duration of response (DOR) was not reached at either RP2D;6-month DOR rate was 67% (95% CI: 41-84) at 405 μg/kg QW. Serum trough levels of talquetamab were comparable at both RP2Ds. Pharmacodynamic data at both RP2Ds showed peripheral T cell activation and induction of cytokines. SC talquetamab is well tolerated and highly effective at both RP2Ds. Preliminary data suggest that less frequent, higher doses of SC talquetamab do not negatively impact the safety profile. Further evaluation of talquetamab as monotherapy (phase 2;NCT04634552) and in combination with other therapies in patients with RRMM is underway. (Figure Presented) .

High-throughput drug screening allowed identification of entry inhibitors specifically targeting different routes of SARS-CoV-2 Delta and Omicron/BA.1.

The Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2) has continuously evolved, resulting in the emergence of several variants of concern (VOCs). To study mechanisms of viral entry and potentially identify specific inhibitors, we pseudotyped lentiviral vectors with different SARS-CoV-2 VOC spike variants (D614G, Alpha, Beta, Delta, Omicron/BA.1), responsible for receptor binding and membrane fusion. These SARS-CoV-2 lentiviral pseudoviruses were applied to screen 774 FDA-approved drugs. For the assay we decided to use CaCo2 cells, since they equally allow cell entry through both the direct membrane fusion pathway mediated by TMPRSS2 and the endocytosis pathway mediated by cathepsin-L. The active molecules which showed stronger differences in their potency to inhibit certain SARS-CoV-2 VOCs included antagonists of G-protein coupled receptors, like phenothiazine-derived antipsychotic compounds such as Chlorpromazine, with highest activity against the Omicron pseudovirus. In general, our data showed that the various VOCs differ in their preferences for cell entry, and we were able to identify synergistic combinations of inhibitors. Notably, Omicron singled out by relying primarily on the endocytosis pathway while Delta preferred cell entry via membrane fusion. In conclusion, our data provide new insights into different entry preferences of SARS-CoV-2 VOCs, which might help to identify new drug targets.

Targeting mucormycosis polyprotein (RVT_1 region) through antifungal phytochemicals: An in-silico perspective

Mucormycosis has become a global issue due to its potential to infect and destroy organs, as well as its high fatality rate. Co-infecting with Covid 19 or when infecting after Covid 19, it becomes more lethal. Several antifungal medicines have been utilized to treat this illness, but they come with a slew of dangerous side effects. Hence, using various computational tools;the current study was attempted to determine several antifungal plant metabolites that can act as inhibitory agents of Rhizopus oryzae, which is responsible for 70% of mucormycosis cases. In total, 56 antifungal plant metabolites were evaluated against Rhizopus oryzae polyprotein (RVT_1 region). Four metabolites, i.e., emetine, jatrorrhizine, isoboldine, and 6-a-hydroxymedicarpin showed maximum binding affinity with the targeted polyprotein (RVT_1 region) according to the lowest global binding energy and binding energy. The fungal protein's critical binding sites and drug surface hotspots were uncovered. The best candidates were gone through an ADME (absorption, distribution, metabolism, and excretion) analysis to observe their drug profiles. According to the findings, none have any side effects that could interfere with their drug likeness efficiency as well as no significant toxic effects and allergenicity were found. The majority of the target classes for proposed drug candidates were enzyme groups (e.g., oxidoreductase, family a g protein-coupled receptor, enzyme, protease). Furthermore, emetine and jatrorrhizine have been proposed to have inhibitory potency against covid 19 in several studies. Hence, we strongly propose additional in vivo trials in order to experimentally validate our findings, based on the optimistic results.

Preparation and characterization of immobilized 5-HT1A receptor stationary phase for high throughput screening of the receptor-binding ligands from complex systems like Curcuma wenyujin Y. H. Chen et C. Ling extract.

The incidence of depression has increased significantly during the COVID-19 pandemic. This disease is closely associated with serotonin 1A (5-HT1A) receptor and often treated by complex prescription containing Curcuma wenyujin Y. H. Chen et C. Ling. Therefore, we hypothesized that this herb contains bioactive compounds specially binding to the receptor. However, the rapid discovery of new ligands of 5-HT1A receptor is still challenging due to the lack of efficient screening methods. To address this problem, we developed and characterized a novel approach for the rapid screening of ligands by using immobilized 5-HT1A receptor as the chromatographic stationary phase. Briefly, haloalkane dehalogenase was fused at the C-terminal of 5-HT1A receptor, and the modified 5-HT1A receptor was immobilized on amino-microspheres by the reaction between haloalkane dehalogenase and 6-chlorohexanoic acid linker. Scanning electron microscope and X-ray photo-electron were used to characterize the morphology and element of the immobilized receptor. The binding of three specific ligands to 5-HT1A receptor was investigated by two different methods. Moreover, we examined the feasibility of 5-HT1A receptor colume in high throughput screening of new ligands from complex systems as exemplified by Curcuma wenyujin Y. H. Chen et C. Ling. Gweicurculactone, 2-hydroxy-1-(3,4-dihydroxybenzene)-7-(4'-hydroxybezene)-heptane and curcuminol F were identified as the ligands of 5-HT1A receptor with the binding energies of -7.06 kcal/mol, -7.77 kcal/mol and -5.26 kcal/mol, respectively. Collectively, these results indicated that the immobilized 5-HT1A receptor was capable of screening bioactive compound from complex system, providing an effective methodology for high throughput screening.

Updated Phase 1 Results from MonumenTAL-1: First-in-Human Study of Talquetamab, a G Protein-Coupled Receptor Family C Group 5 Member D x CD3 Bispecific Antibody, in Patients with Relapsed/Refractory Multiple Myeloma

Introduction: Despite recent advances in treatment, patients with multiple myeloma (MM) continue to relapse. G protein-coupled receptor family C group 5 member D (GPRC5D) is a promising target for immunotherapy in patients with MM due to its high expression in malignant plasma cells and limited expression in normal human tissue;unlike other antigens targeted by MM therapies, there is no indication that GPRC5D sheds into the periphery. Talquetamab (JNJ-64407564) is a first-in-class bispecific IgG4 antibody that redirects T cells to kill MM cells by binding to both GPRC5D and CD3 receptors. Here we report updated and new results of talquetamab at the recommended phase 2 doses (RP2Ds) from a phase 1 trial in relapsed/refractory MM (RRMM;NCT03399799). Methods: Eligible patients with MM had relapsed or refractory disease or were intolerant to standard therapies;patients previously treated with B-cell maturation antigen (BCMA)-directed therapies were eligible. This analysis focuses on patients who received talquetamab subcutaneously (SC;range 5.0-800 µg/kg) weekly or biweekly. Step-up dosing was used as a patient management strategy to minimize the severity of cytokine release syndrome (CRS). The primary objectives were to identify the RP2D (part 1) and assess talquetamab safety and tolerability at the RP2Ds (part 2). Adverse events (AEs) were graded by CTCAE v4.03 with CRS events graded per Lee et al 2014 criteria. Responses were investigator-assessed per International Myeloma Working Group criteria. Results: As of July 19, 2021, 95 patients have received SC talquetamab. The RP2D was originally identified as a weekly SC dose of 405 µg/kg talquetamab with step-up doses. However, alternative dosing schedules that require less frequent administration continue to be investigated. A biweekly RP2D was also identified as an SC dose of 800 µg/kg talquetamab with step-up doses. 30 patients received the 405 µg/kg weekly dosing schedule (median age: 61.5 years [range 46-80];63% male;100% triple-class exposed;80% penta-drug exposed;77% triple-class refractory, 20% penta-drug refractory;30% prior BCMA-directed therapy;median follow-up: 7.5 mo [range 0.9-15.2]). 23 patients received the 800 µg/kg biweekly dosing schedule (median age: 60.0 years [range 47-84];48% male;96% triple-class exposed;70% penta-drug exposed;65% triple-class refractory, 22% penta-drug refractory;17% prior BCMA-directed therapy;median follow-up 3.7 mo [range 0.0-12.0]). There were no treatment discontinuations due to AEs at either of the RP2Ds. The most common AEs at the 405 µg/kg weekly dose were CRS (73%;1 patient had grade 3 CRS), neutropenia (67%;grade 3/4: 60%), and dysgeusia (60%;grade 2: 29%);skin-related AEs occurred in 77% (all grade 1/2;nail disorders: 30%) of patients, and infections occurred in 37% of patients (1 patient had grade 3 COVID-19 pneumonia). The most common AEs at the 800 µg/kg biweekly dose were CRS (78%;all grade 1/2), dry mouth (44%;all grade 1/2), and neutropenia (44%;grade 3/4: 35%);skin-related AEs occurred in 65% of patients (grade 3: 13%;nail disorders: 17%) and infections occurred in 13% of patients (1 patient had grade 3 pneumococcal sepsis). In 30 response-evaluable patients treated with the 405 µg/kg weekly dose, the overall response rate (ORR) was 70% (very good partial response or better [≥VGPR] rate: 57%). In 17 response-evaluable patients treated with the 800 µg/kg biweekly dose, the ORR was 71% (≥VGPR rate: 53%). Responses were durable and deepened over time in both cohorts (Figure). Median duration of response (DOR) was not reached at either RP2D;the 6-month DOR rate for patients who received the 405 µg/kg weekly dose was 67% [95% CI: 41-84]. Serum trough levels of talquetamab were comparable at both RP2Ds. Consistent with the mechanism of action for talquetamab, pharmacodynamic data from cohorts treated at both dose levels showed peripheral T-cell activation and induction of cytokines. Conclusions: These findings indicate that SC talquetamab is well tolerated and highly effective at both RP2Ds. Preliminary data from the 800 µg/kg biweekly cohorts indicate that less frequent, higher doses of SC talquetamab do not have a negative impact on the previously described safety profile. Further investigation of talquetamab as monotherapy (phase 2;NCT04634552) and in combination with other therapies in patients with RRMM is underway. [Formula presented] Disclosures: Krishnan: MAGENTA: Consultancy;BMS: Consultancy, Current equity holder in publicly-traded company, Speakers Bureau;JANSSEN: Consultancy, Research Funding;City of Hope Cancer Center: Current Employment;REGENERON: Consultancy;SANOFI: Consultancy;GSK: Consultancy;Amgen: Speakers Bureau. Minnema: Celgene: Other: Travel expenses;Alnylam: Consultancy;Cilag: Consultancy;BMS: Consultancy;Janssen: Consultancy;Kite/Gilead: Consultancy. Berdeja: Lilly, Novartis: Research Funding;Abbvie, Acetylon, Amgen: Research Funding;Celularity, CRISPR Therapeutics: Research Funding;EMD Sorono, Genentech: Research Funding;Poseida, Sanofi, Teva: Research Funding;Bluebird bio, BMS, Celgene, CRISPR Therapeutics, Janssen, Kite Pharma, Legend Biotech, SecuraBio, Takeda: Consultancy;GSK, Ichnos Sciences, Incyte: Research Funding. Oriol: Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Karyopharm: 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;GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;BMS/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. van de Donk: Roche: Consultancy;Takeda: Consultancy;Cellectis: Research Funding;Amgen: Consultancy, Research Funding;Janssen: Consultancy, Research Funding;BMS/Celgene: Consultancy, Honoraria;Novartis /bayer/servier: Consultancy. Rodriguez-Otero: Clínica Universidad de Navarra: Current Employment;Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Celgene-BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Pfizer: Consultancy;Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees;Kite: Honoraria, Membership on an entity's Board of Directors or advisory committees;Amgen: Honoraria;Regeneron: Honoraria. Askari: Janssen: Research Funding. Mateos: Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees;Sea-Gen: Honoraria, Membership on an entity's Board of Directors or advisory committees;Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees;Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees;Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees;Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees;Celgene - Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees;Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees;Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees;Oncopeptides: Honoraria;Bluebird bio: Honoraria;AbbVie: Honoraria;GSK: Honoraria;Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees;Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Costa: BMS: Consultancy, Honoraria, Research Funding;Janssen: Consultancy, Honoraria, Research Funding;Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau;Karyopharm: Consultancy, Honoraria;Pfizer: Consultancy, Honoraria;Sanofi: Consultancy, Honoraria, Speakers Burea . Verona: Janssen: Current Employment. Ma: Janssen: Current Employment, Current holder of individual stocks in a privately-held company. Girgis: Janssen: Current Employment, Current holder of individual stocks in a privately-held company. Yang: Janssen: Current Employment. Hilder: Janssen: Current Employment, Current holder of individual stocks in a privately-held company. Russell: Janssen: Ended employment in the past 24 months. Goldberg: Janssen: Current Employment, Current holder of individual stocks in a privately-held company. Chari: Shattuck Labs: 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;Karyopharm: 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;Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees;Takeda: Consultancy, Research Funding;Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Pharmacyclics: Research Funding;Secura Bio: 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;AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees;GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees;Novartis: Consultancy, Research Funding;Genentech: Consultancy, Membership on an entity's Board of Directors or advisorycommittees;Janssen Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Flow Cytometric Detection of Procoagulant Properties of Plasma from Patients with Clinically Confirmed Vaccine-Induced Immune Thrombotic Thrombocytopenia

Background: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe prothrombotic complication of adenoviral vaccines including ChAdOx1 nCoV-19 (AstraZeneca) vaccine. The putative mechanism involves formation of pathological anti-PF4 antibodies that activate platelets via the FcγRIIa receptor to drive thrombosis and the associated thrombocytopenia. Functional assays are important in the VITT diagnostic pathway as not all detectable PF4 antibodies are pathogenic. Detection of procoagulant platelets (platelets supporting thrombin generation) in presence of PF4 has been proposed as a diagnostic assay for VITT (Althaus et al). Procoagulant platelets are not typically generated in response to low level agonist stimulation;however, combination of ligand binding of G-protein coupled receptors (GPCR) (eg. PAR1) and ITAM linked receptors (eg. GPVI, CLEC2 and FcγRIIa) synergistically induce procoagulant platelet formation. Here, we describe an alternative flow cytometric assay to diagnose VITT. We hypothesized that priming of platelets with a PAR1 agonist at a level sufficient to release PF4, but insufficient to generate a significant procoagulant response in donor platelets, would provide a platform in which procoagulant response would be dependent on presence of FcγRIIa dependent procoagulant antibodies in patient plasma, without requirement for additional PF4. Methods: Our previously established flow cytometry-based procoagulant platelet assay (using cell death marker GSAO and P-selectin) was modified to incorporate exogenous patient plasma and performed on whole blood from healthy donors screened for FcγRIIa responsiveness (aggregation response to anti-CD9 antibody, ALB6), primed with 5 μM SFLLRN. The assay was performed on Australian patients referred for confirmatory VITT testing with probable VITT (confirmed thrombosis within 4-42 days of ChAdOx1 nCov-19 vaccination, D-Dimer > 5x ULN, platelets < 150 x 10 9/L or falling platelet count) after screening on PF4/heparin ELISA (Asserachrom HPIA IgG Assay, Stago Diagnostics). Procoagulant response was also measured in presence of 0.5 U/mL and 100 U/mL heparin, monoclonal FcγRIIa blocking antibody, IV.3, and intravenous immunoglobulin, IVIg. Some plasmas were incubated with ChAdOx1 nCoV-19 or SARS-CoV-2 spike protein. Flow cytometry positive patients were also tested by serotonin release assay (SRA) and multiplate aggregometry. Clinical correlation was obtained. Results: Citrated plasma from 49 unique patients with suspected VITT are reported. Plasma from ELISA+ve patients with clinical picture consistent with VITT (n=31), significantly increased the procoagulant platelet proportions in healthy donors in presence of 5 μM SFLLRN (p<0.0001, Figure 1A). This increase was not seen with plasma from healthy donors (n=14);or individuals exposed to ChAdOx1 nCov-19 vaccine without VITT: thrombocytopenic thrombosis patients who were ELISA-ve and SRA-ve (n=14);or low-level ELISA+ve patients without thrombocytopenia who were negative by either multiplate or SRA (n=4). The procoagulant platelet response induced by VITT positive plasma was reduced with low dose heparin (0.5 U/mL, p<0.01) except for 3 patients who showed a heparin-enhancing effect (Figure 1B). High dose heparin (100 U/mL, p<0.0001), IV.3 (10 µg/mL, p<0.0001) or IVIg (10 mg/mL, p<0.0001) abolished the procoagulant response (Figures 1C-D). The in vitro effect of IVIg was predictive of the in vivo response to IVIg therapy (Figure 1E). Addition of SARS-CoV-2 spike protein had no effect on the procoagulant platelet response. ChAdOx1 nCov-19 had an inconsistent effect on procoagulant platelet formation in presence of VITT plasma. Use of donors without a robust aggregation response to ALB6 resulted in false negative results. Conclusion: Induction of FcγRIIa dependent procoagulant response by patient plasma, suppressible by high dose heparin and IVIg, is highly indicative of VITT in the correct clinical circumstance. This assay modification of priming donor platelets from known FcγRIIa responsive donors ith a GPCR agonist to potentiate the ITAM signaling from platelet activating immune complexes, results in a sensitive and specific assay. This may represent a functional platform that can be adopted into diagnostic laboratories to identify patients with platelet-activating antibodies and potentially predict treatment responses. [Formula presented] Disclosures: No relevant conflicts of interest to declare.

Adenosine: a partially discovered medicinal agent.

BACKGROUND: A plethora of chemicals exists in human body which can alter physiology in one way or other. Scientists have always been astounded by such abilities of chemicals but as the technology advances, even the chemical which was once expected to be well known changes its status to not really well known. Adenosine is one of the chemicals which is in consonance with the aforementioned statements, although previous articles have covered vast information on role of adenosine in cardiovascular physiology, bacterial pathophysiology and inflammatory diseases. In this review we have discussed adenosine and its congeners as potential promising agents in the treatment of Huntington's disease, post-traumatic stress disorder, erectile dysfunction, viral infections (SARS-CoV) and anxiety. MAIN TEXT: Adenosine is a unique metabolite of ATP; which serves in signalling as well. It is made up of adenine (a nitrogenous base) and ribo-furanose (pentose) sugar linked by ß-N9-glycosidic bond. Adenosine on two successive phosphorylation forms ATP (Adenosine Triphosphate) which is involved in several active processes of cell. It is also one of the building blocks (nucleotides) involved in DNA (Deoxy-ribonucleic Acid) and RNA (Ribonucleic Acid) synthesis. It is also a component of an enzyme called S-adenosyl-L-methionine (SAM) and cyano-cobalamin (vitamin B-12). Adenosine acts by binding to G protein-coupled receptor (GPCR: A1, A2A, A2B and A3) carries out various responses some of which are anti-platelet function, hyperaemic response, bone remodelling, involvement in penile erection and suppression of inflammation. On the other hand, certain microorganisms belonging to genus Candida, Staphylococcus and Bacillus utilize adenosine in order to escape host immune response (phagocytic clearance). These microbes evade host immune response by synthesizing and releasing adenosine (with the help of an enzyme: adenosine synthase-A), at the site of infection. CONCLUSION: With the recent advancement in attribution of adenosine in physiology and pathological states, adenosine and its congeners are being looked forward to bringing a revolution in treatment of inflammation, viral infections, psychiatric and neurodegenerative disorders.

Ectopic Odorant Receptor Responding to Flavor Compounds: Versatile Roles in Health and Disease.

Prompted by the ground-breaking discovery of the rodent odorant receptor (OR) gene family within the olfactory epithelium nearly 30 years ago, followed by that of OR genes in cells of the mammalian germ line, and potentiated by the identification of ORs throughout the body, our appreciation for ORs as general chemoreceptors responding to odorant compounds in the regulation of physiological or pathophysiological processes continues to expand. Ectopic ORs are now activated by a diversity of flavor compounds and are involved in diverse physiological phenomena varying from adipogenesis to myogenesis to hepatic lipid accumulation to serotonin secretion. In this review, we outline the key biological functions of the ectopic ORs responding to flavor compounds and the underlying molecular mechanisms. We also discuss research opportunities for utilizing ectopic ORs as therapeutic strategies in the treatment of human disease as well as challenges to be overcome in the future. The recognition of the potent function, signaling pathway, and pharmacology of ectopic ORs in diverse tissues and cell types, coupled with the fact that they belong to G protein-coupled receptors, a highly druggable protein family, unequivocally highlight the potential of ectopic ORs responding to flavor compounds, especially food-derived odorant compounds, as a promising therapeutic strategy for various diseases.