Histoplasmosis and SARS-CoV-2 infection in a critically ill patient

Introduction: Histoplasmosis is caused by the dimorphic fungus Histoplasma capsulatum, whose clinical manifestations range from asymptomatic to disseminated and highly fatal disease. Objective: To present the case of a patient diagnosed with disseminated histoplasmosis and SARS-CoV-2 infection. Clinical case: The case of a 79-year-old man is presented with a history of systemic arterial hypertension and type 2 diabetes mellitus. He was admitted for a week with nonproductive cough, dyspnea, and fatigue on moderate exertion, and reported having a positive antigen test for SARS-CoV-2. During hospitalization, he presented clinical deterioration, needing mechanical ventilation due to respiratory infection associated with COVID-19. Despite this, he presented lymphadenopathy, hepatosplenomegaly, and umbilicated skin-colored papules suggestive of disseminated fungal infection. Suspecting co-infection, infection by Histoplasma capsulatum was confirmed by means of mini-bronchoalveolar lavage and antifungal treatment was initiated;however, the patient presented persistent clinical deterioration and died. Conclusion: Cases of co-infections with COVID-19 in patients without chronic diseases or immunosuppressive states are rare, their diagnosis being a challenge for medical personnel and requiring consideration of pulmonary fungal infections such as cryptococcosis or histoplasmosis in associated respiratory failure. to SARS-CoV-2 infection. © 2023, Editorial Ciencias Medicas. All rights reserved.

The immunopathology of COVID-19 placentitis: A multi-omic spatial approach

Problem: COVID-19 placentitis is a rare complication of maternal SARS-CoV-2 respiratory infection associated with serious adverse obstetric outcomes, including intra-uterine death. The precise role of SARS-CoV-2 in COVID-19 placentitis is uncertain, as trophoblast infection is only observed in around one-half of the affected placenta. Method of Study: Through multi-omic spatial profiling, including Nanostring GeoMX digital spatial profiling and Lunaphore COMET multiplex IHC, we provide a deep characterization of the immunopathology of placentitis from obstetrically complicated maternal COVID-19 infection. Result(s):We show that SARS-CoV-2 infection of placental trophoblasts is associated with a distinct innate and adaptive immune cell infiltrate, florid cytokine expression and upregulation of viral restriction factors. Quantitative spatial analyses reveal a unique microenvironment surrounding virus-infected trophoblasts characterizedd by multiple immune evasion mechanisms, including immune checkpoint expression, cytotoxic T-cell exclusion, and interferon blunting. Placental viral loads inversely correlated with the duration of maternal infection consistent with progressive virus clearance, potentially explaining the absence of virus in some cases. Conclusion(s): Our results demonstrate a central role for placental SARS-CoV-2 infection in driving the unique immunopathology of COVID-19 placentitis.

Exploration of potential mechanism of SARS-CoV-2 induced immune inflammatory response leading to progression of atherosclerosis and prediction of traditional Chinese medicine for preventing and treating based on bioinformatics.

Objective To explore the core targets and important pathways of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) induced atherosclerosis (AS) progression from the perspective of immune inflammation, so as to predict the potential prevention and treatment of traditional Chinese medicine (TCM). Methods Microarray data were obtained from the Gene Expression Omnibus (GEO) database for coronavirus disease 2019 (COVID-19) patients and AS patients, and the "limmar" and "Venn" packages were used to screen out the common differentially expressed genes (DEGs) genes in both diseases. The gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analyses were performed on the common DEGs to annotate their functions and important pathways. The two gene sets were scored for immune cells and immune function to assess the level of immune cell infiltration. The protein-protein interaction (PPI) network was constructed by STRING database, and the CytoHubba plug-in of Cytoscape was used to identify the hub genes. Two external validation datasets were introduced to validate the hub genes and obtain the core genes. Immuno-infiltration analysis and gene set enrichment analysis (GSEA) were performed on the core genes respectively. Finally the potential TCM regulating the core genes were predicted by Coremine Medical database. Results A total of 7898 genes related to COVID-19, 471 genes related to AS progression;And 51 common DEGs, including 32 highly expressed genes and 19 low expressed genes were obtained. GO and KEGG analysis showed that common DEGs, which were mainly localized in cypermethrin-encapsulated vesicles, platelet alpha particles, phagocytic vesicle membranes and vesicles, were involved in many biological processes such as myeloid differentiation factor 88 (MyD88)-dependent Toll-like receptor signaling pathway transduction, interleukin-8 (IL-8) production and positive regulation, IL-6 production and positive regulation to play a role in regulating nicotinamide adenine dinucleotide phosphate oxidase activity, Toll-like receptor binding and lipopeptide and glycosaminoglycan binding through many biological pathways, including Toll-like receptor signaling pathways, neutrophil extracellular trap formation, complement and coagulation cascade reactions. The results of immune infiltration analysis demonstrated the state of immune microenvironment of COVID-19 and AS. A total of 5 hub genes were obtained after screening, among which Toll-like receptor 2 (TLR2), cluster of differentiation 163 (CD163) and complement C1q subcomponent subunit B (C1QB) genes passed external validation as core genes. The core genes showed strong correlation with immune process and inflammatory response in both immune infiltration analysis and GSEA enrichment analysis. A total of 35 TCMs, including Chuanxiong (Chuanxiong Rhizoma), Taoren (Persicae Semen), Danggui (Angelicae Sinensis Radix), Huangqin (Scutellariae Radix), Pugongying (Taraxaci Herba), Taizishen (Pseudostellariae Radix), Huangjing (Polygonati Rhizoma), could be used as potential therapeutic agents. Conclusion TLR2, CD163 and C1QB were the core molecules of SARS-CoV-2-mediated immune inflammatory response promoting AS progression, and targeting predicted herbs were potential drugs to slow down AS progression in COVID-19 patients.Copyright © 2023 Editorial Office of Chinese Traditional and Herbal Drugs. All rights reserved.

Extracorporeal cytokine hemadsorption in severe COVID-19 respiratory failure

Background: At least 20% of coronavirus disease 2019 (COVID-19) patients develop acute hypoxemic respiratory failure requiring admission to intensive care unit in 5-32% of the cases. Hyper-inflammatory activation characterized by immune cell infiltration and elevated levels of cytokines was reported as the main mechanism leading to critical illness and severe acute respiratory distress syndrome (ARDS). CytoSorb is currently used for all the conditions where elevated levels of cytokines are present. Along with the beneficial effect on systemic inflammation, CytoSorb can be easily integrated with all extracorporeal circulation systems. Case Presentation: Here, we present the laboratory and clinical outcomes of 11 patients with microbiological confirmed SARS-CoV-2 infection. These patients were treated with CytoSorb to remove the excess of cytokine. All patients were male, overweight and only 3 (27%) were over 70 years old. Median age was 62 years and median body mass index was 28. Best supportive care was provided according to hospital guidelines of that moment and included antibiotic therapy, antiretroviral therapy and protective ventilation. Result(s): Cytokines levels were evaluated before and after treatment. A significant reduction of IL-6, IL-8, IL-10 and IL-1beta was observed. A significant drop of C-reactive protein (CRP) median levels was observed starting from 48 hours after treatment start levels. The decrease in the inflammatory status was associated with a progressive improvement in the respiratory function, with a significant increase in P/F from the first day after the end of the therapy. A similar trend was observed for procalcitonin. Conclusion(s): CytoSorb therapy proved to be safe in COVID-19 patients. A clinical improvement was observed in most of the treated patients despite the severity of the disease. In this study CytoSorb was used empirically for 24- 48 hours based on previous experience in septic shock. The persistence of significant levels of IL-6 and CRP after CytoSorb treatment may suggest that a prolonged treatment can improve the efficacy in controlling COVID-19 hyperinflammatory status.

Pulmonary influenza infection promotes the awakening of dormant metastatic breast cancer cells

Breast cancer is the most common form of cancer and the second cancer-causing death in females. Although remission rates are high if detected early, survival rates drop substantially when breast cancer becomes metastatic. The most common sites of metastatic breast cancer are bone, liver and lung. Respiratory viral infections inflict illnesses on countless people. The latest pandemic caused by the respiratory virus, SARS-CoV-2, has infected more than 600 million worldwide, with documented COVID-related death upward of 1 million in the United States alone. Respiratory viral infections result in increased inflammation with immune cell influx and expansion to facilitate viral clearance. Prior studies have shown that inflammation, including through neutrophils, can contribute to dormant cancer cells reawakening and outgrowth. Moreover, inhibition of IL6 has been shown to decrease breast cancer lung metastasis in mouse models. However, how respiratory viral infections contribute to breast cancer lung metastasis remains to be unraveled. Using MMTV/PyMT and MMTV/NEU mouse models of breast cancer lung metastasis and influenza A virus as a model respiratory virus, we demonstrated that acute influenza infection and the accompanying inflammation and immune cell influx awakens and dramatically increased proliferation and expansion of dormant disseminated cancer cells (DCC) in the lungs. Acute influenza infection leads to immune influx and expansion, including neutrophils and macrophages, with increased proportion of MHCII+ macrophages in early time points, and a sustained decrease in CD206+ macrophages starting 6 days post-infection until 28 days after the initial infection. Additionally, we observed a sustained accumulation of CD4+ T cells around expanding tumor cells for as long as 28 days after the infection. Notably, neutrophil depletion or IL6 knockout reversed the flu-induced dormant cell expansion in the lung. Finally, awakened DCC exhibited downregulation of vimentin immunoreactivity, suggesting a role for phenotypic plasticity in DCC outgrowth following viral infection. In conclusion, we show that respiratory viral infections awaken and increase proliferation of dormant breast cancer cells in the lung, and that depletion of neutrophils or blocking IL6 reverses influenza-induced dormant cell awakening and proliferation.

The Diagnosis, Pathophysiology, and Treatment of Chronic Hepatitis E Virus Infection-A Condition Affecting Immunocompromised Patients.

Hepatitis E is a zoonosis caused by hepatitis E virus (HEV), which was first discovered 40 years ago. Twenty million HEV infections worldwide are estimated each year. Most hepatitis E cases are self-limiting acute hepatitis, but the virus has been recognized to cause chronic hepatitis. Following the first case report of chronic hepatitis E (CHE) in a transplant recipient, CHE has recently been identified as associated with chronic liver damage induced by HEV genotypes 3, 4, and 7-usually in immunocompromised patients such as transplant recipients. In addition, patients infected with HIV and those receiving chemotherapy for malignancy, along with patients with rheumatic disease and COVID-19, have recently been reported as having CHE. CHE can be easily misdiagnosed by usual diagnostic methods of antibody response, such as anti-HEV IgM or IgA, because of the low antibody response in the immunosuppressive condition. HEV RNA should be evaluated in these patients, and appropriate treatments-such as ribavirin-should be given to prevent progression to liver cirrhosis or liver failure. While still rare, cases of CHE in immunocompetent patients have been reported, and care must be taken not to overlook these instances. Herein, we conduct an overview of hepatitis E, including recent research developments and management of CHE, in order to improve our understanding of such cases. The early diagnosis and treatment of CHE should be performed to decrease instances of hepatitis-virus-related deaths around the world.

A case of COVID-19-associated rhino-orbito-cerebral mucormycosis caused by Apophysomyces variabilis with a review of the literature.

A fatal case of COVID-19-associated mucormycosis (CAM) affected a 40-year-old woman who was initially admitted to our hospital due to a SARS-CoV-2 infection. Her clinical condition worsened, and she finally died because of respiratory failure, hemodynamic instability, and mucormycosis with invasion into the orbit and probably the brain. According to DNA sequence analysis of the fungus isolated from the patient, Apophysomyces variabilis was involved. This is the first published case of CAM and the third case of mucormycosis due to this mold.

COVID-19-associated pulmonary aspergillosis in immunocompetent patients: a virtual patient cohort study.

The opportunistic fungus Aspergillus fumigatus infects the lungs of immunocompromised hosts, including patients undergoing chemotherapy or organ transplantation. More recently however, immunocompetent patients with severe SARS-CoV2 have been reported to be affected by COVID-19 Associated Pulmonary Aspergillosis (CAPA), in the absence of the conventional risk factors for invasive aspergillosis. This paper explores the hypothesis that contributing causes are the destruction of the lung epithelium permitting colonization by opportunistic pathogens. At the same time, the exhaustion of the immune system, characterized by cytokine storms, apoptosis, and depletion of leukocytes may hinder the response to A. fumigatus infection. The combination of these factors may explain the onset of invasive aspergillosis in immunocompetent patients. We used a previously published computational model of the innate immune response to infection with Aspergillus fumigatus. Variation of model parameters was used to create a virtual patient population. A simulation study of this virtual patient population to test potential causes for co-infection in immunocompetent patients. The two most important factors determining the likelihood of CAPA were the inherent virulence of the fungus and the effectiveness of the neutrophil population, as measured by granule half-life and ability to kill fungal cells. Varying these parameters across the virtual patient population generated a realistic distribution of CAPA phenotypes observed in the literature. Computational models are an effective tool for hypothesis generation. Varying model parameters can be used to create a virtual patient population for identifying candidate mechanisms for phenomena observed in actual patient populations.

Morphological Changes in Blood Cells as Indicators for Disease Progression in COVID-19

BACKGROUND: COVID-19 as a pandemic has caused an alarming increase in mortality and morbidity. Viral-induced morphologic changes in the peripheral blood cells are well characterized in certain infections and can direct diagnostic workup to ensure timely therapeutic intervention. This study describes the morphological changes of blood cells in various stages of COVID disease. MATERIALS AND METHODS: A total of thousand COVID-positive patients admitted in the tertiary care center were taken for the study. They were classified as mild, moderate, and severe based on the clinical criteria suggested by World Health Organization. Peripheral smears of the patients were analyzed, and the morphological changes in various blood cells were correlated with the disease stage and coagulation parameters. RESULT(S): The study demonstrated significant morphological changes in the blood cells of COVID patients during the course of disease progression and during the onset of COVID-associated coagulopathy. Leukocytosis, neutrophilia, and toxic changes in neutrophils were seen in the severe stage of the disease and in COVID coagulopathy suggesting these are important indicators of disease severity. Activated lymphocyte was found to be the most common morphological presentation seen in all patients irrespective of the disease stage, whereas plasmacytoid lymphocytes were an important finding in severe-stage disease. Schistocytes an important finding in any other coagulopathy was present only in 1% of cases of COVID coagulopathy. CONCLUSION(S): The study demonstrated significant morphological changes in the blood cells of COVID-positive patients during the course of disease progression. Comprehensive daily complete blood count and peripheral smear examination should be undertaken in patients hospitalized with COVID-19 to predict potential clinical deterioration and signs of disease progression. These morphological changes in peripheral smear can be used as one of the factors indicating disease progression which can formulate for further evaluation. Since follow-up and post-COVID morphological examination were not done, additional research in this aspect can shed light on the clinical categorization of COVID patients based on the morphological findings.Copyright © 2023 Journal of Applied Hematology Published by Wolters Kluwer - Medknow.

Pre-existing Immunocompromised Status as a Preventer of Mortality in COVID-19 Patients: Friend or Foe?

Objective COVID-19 has been negatively impacted by a number of comorbidities. Aside from that, some conditions or treatments that cause immunosuppression can alter the course of the disease, leading to worse outcomes. The primary goal of this study is to compare the clinical presentation, laboratory analysis, radiological findings, and outcomes of patients with COVID-19 with and without immunosuppression. Materials and methods The study includes patients with pre-existing immunosuppression and COVID-19 infection who were admitted and received inpatient treatment at Marmara University Hospital, Istanbul, Pulmonary Medicine ward between April 2020 and June 2020. Data on demographics, epidemiology, clinical course, laboratory analysis, radiological findings, length of hospital stay, morbidity, and mortality were collected from all patients. Results The study group consisted of 23 patients who had pre-existing immunosuppression, and the control group consisted of 207 immunocompetent patients, making a total of 230 patients. Significant differences in lymphocyte count, ROX (respiratory-rate oxygenation) index on Day 0, and fibrinogen levels were discovered between the two groups. SARI (severe acute respiratory infection) was more common in the control group than in the study group (p<0.022), but there was no difference in mortality. Conclusion The mean number and percentage of lymphocytes were lower in immunocompromised COVID-19 patients at the time of diagnosis. Higher ROX index values and a lower risk of developing SARI could explain the hypothesis that these patients may be benefiting from a pre-existing corticosteroid regimen. Additional research with larger numbers of patients may be beneficial in drawing a more definitive conclusion.

Single-Cell Analysis Reveals Characteristics of Myeloid Cells in Pulmonary Pasc

Background: Although our understanding of immunopathology in the risk and severity of COVID-19 disease is evolving, a detail of immune response in long-term consequences of COVID-19 infection remains unclear. Recently, few studies have detailed the immune and cytokine profiles associated with PASC. However, dysregulation of immune system driving pulmonary PASC is still largely unknown. Method(s): To characterize the immunological features of PPASC, we performed droplet-based scRNA-sequencing using 10X genomics to study the transcriptomic profiles of peripheral blood mononuclear cells (PBMCs) from participants naive to SARS-CoV-2 (NP, n=2) and infected with SARS-CoV-2 with chronic pulmonary symptoms (PPASC, n=2). Result(s): Analysis of more than 34,000 PBMCs by integrating our dataset with previously reported control datasets generated cell distribution and identified 11 immune cell types based on canonical gene expression. The proportion of myeloid-lineage cells (CD14+monocyte, CD16+monocyte, and dendritic cells) and platelets were increased in PPASC compared with those of NP. Specifically, PPASC displayed up-regulation of VEGFA and transcription factors, such as ATF2, ELK, and SMAD in myeloid-lineage cells. Also, TGF-beta and WNT signaling pathways were up-regulated in these cell population. Cell-cell interaction analysis identified that myeloid-lineage cells in PPASC participated in regulation of fibrosis and immune response, such as VEGFA (increased) and MIF (decreased) interactions. Conclusion(s): Together, this study provides high-resolution insights into immune landscape in PPASC. Our results emphasize differences in myeloid lineage-mediated fibrosis and immunity between PPASC and NP, suggesting they could act as potential pathological drivers of PPASC. (Figure Presented).

CBD Treatment Improves Fatal Inflammatory Response Exhibited in SEB-Induced ARDS

The novel SARS-CoV-2 virus known to cause the COVID-19 outbreak has resulted in a global healthcare crisis that has persisted the past 3 years. Thus, understanding the mechanisms underlying this disease are vital at this time. While there are issues of research infrastructure to handle the virus and because of the refractoriness of rodents to this disease, the availability of these tools is still limited. The cytokine storm and fatality presented in patients with severe COVID-19 can be mimicked with Staphylococcal enterotoxin B (SEB)-induced Acute Respiratory Distress Syndrome (ARDS). Within ~7 days, the survival rate drops to 0% for C3H/HeJ mice exposed to a dual dose of SEB. In this study, we administered cannabidiol (CBD) intraperitoneally for 3 days pre- and post-SEB dosing and found that the clinical outcomes improved significantly. Initial evaluation of scRNASeq data from lungs comparing naive to SEB-induced ARDS mice illustrated an increase in infiltrating immune cells, and a loss in pulmonary epithelial cells in the latter group. When evaluating the effect of CBD treatment on SEB-induced ARDS, we were able to demonstrate that CBD reduced the macrophage population. To characterize the mechanism by which CBD treatment ameliorated the inflammatory response, we found that CBD treated mice had significant reduction in infiltrating immune cells and alveolar thickening. This same histology and infiltration is presented in ARDS. MicroRNA expression analysis showed a significant increase in the expression mmu-miR-298-5p and mmu-miR- 566 with CBD treatment. Ingenuity Pathway Analysis (IPA) indicated that the dysregulated miRNAs were also implicated in pathways associated with macrophage activation, respiratory disease and inflammation, interferon stimulated genes, as well as genes which have been upregulated in the disease state of this model. These targets include but are not limited to Cebpb, Efhd2, Stat3, Socs3, Cxcl5, Gbp2, and Birc3. This finding offers insights for the development of preventive and therapeutic strategies in the treatment of ARDS, including that induced in COVID-19. Supported by NIH grants P01AT003961, P20GM103641, R01ES003961, R01AI129788, R01AI123947, R01AI160896 to MN and PSN and K99GM147910 to KW.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

SARS-CoV-2 VARIANTS-DEPENDENT INFLAMMASOME ACTIVATION

Background: Innate immunity is the first line of defense in response to pathogens, which acts locally and also leads the stimulation of adaptive immunity through at least with IL-1beta secretion. It has been shown that SARSCoV- 2 infection triggered the NLRP-3 inflammasome activation and the IL-1beta secretion. The aim of this study was to analyze and compare the level of IL-1beta secretion that is one of the most important innate immunity cytokines, in monocyte-like cells infected with 6 different variants of the SARS-CoV-2. Method(s): Six SARS-CoV-2 variants (historical (B.1, D614G), Alpha, Beta, Gamma, Delta and Omicron BA.1) were isolated from COVID-19 hospitalized patients. Viral stocks were obtained by inoculation in Vero and Vero-TRMPSS2 cells. THP-1 monocyte-like cells were cultured with RPMI-hepes 10% FBS-0.05 mM 2-mercaptoethanol. A total of 5 x 104 of THP-1 cells was plated per well in 96-wells plate and differentiated with 10nM of PMA for 24h. Differenciated- THP-1 were first primed with LPS 1mug/ml for 2h and infected with different SARS-CoV-2 variants with a MOI 0.1. IL-1beta was measured by luminescence in the supernatant after 24 h of infection. Result(s): We analyzed and compared IL-1beta secretion between SARS-CoV-2 virus 6 sublineages after infection of monocytes like THP-1. We observed that THP-1 cells infected with SARS-CoV-2 variants presented a significantly higher IL-1beta secretion than non-infected cells. Moreover, some SARS-CoV-2 variants led to a stronger IL-1beta secretion, and particularly we observed a significantly higher level of IL-1beta cells infected with Omicron BA.1 sublineage compared to other variants. Indeed, Omicron BA.1 infected cells presented the higher IL-1beta secretion (median 385.7 pg/ml IQR[302.6-426.3]) follows by the Delta variants and the historical variants (median 303.6 [266.3-391.9] and 281.9 [207.2-410], respectively). Alpha, Beta and Gamma variants presented the lowest IL-1beta secretion (median 228.1 [192.5-276.4], 219.1 [185.1-354.2] and 211 [149.8- 228.8]). Conclusion(s): We observed the inflammasome activation for the 6 SARS-CoV-2 sublineages with a variation in level of IL-1beta secretion. Indeed, our results suggested that Omicron BA.1 was more recognized by the innate immune cells than other SARS-CoV-2, which could in part, with its upper respiratory tract tropism, possibly explain its less clinical virulence. Taking together, these results suggest that the innate immunity response and precisely, IL-1beta secretion pathways were activated in a SARS-CoV-2 variants-dependent manner.

Covid-19 Vaccination Impacts Functional Immune Responses and Plasma Proteome in Plwh

Background: The impact of COVID-19 infection or COVID-19 vaccination on the immune system of people living with HIV (PLWH) is unclear. We therefore studied the effects of COVID-19 infection or vaccination on functional immune responses and systemic inflammation in PLWH. Method(s): Between 2019 and 2021, 1985 virally suppressed, asymptomatic PLWH were included in the Netherlands in the 2000HIV study (NCT039948350): 1514 participants enrolled after the start of the COVID-19 pandemic were separated into a discovery and validation cohort. PBMCs were incubated with different stimuli for 24 hours: cytokine levels were measured in supernatants. ~3000 targeted plasma proteins were measured with Olink Explore panel. Past COVID-19 infection was proven when a positive PCR was reported or when serology on samples from inclusion proved positive. Compared were unvaccinated PLWH with and without past COVID-19 infection, and PLWH with or without anti-COVID-19 vaccination excluding those with past COVID-19 infection. Result(s): 471 out of 1514 participants were vaccinated (median days since vaccination: 33, IQR 16-66) and 242 had a past COVID-19 infection (median days since +PCR: 137, IQR 56-206). Alcohol, smoking, drug use, BMI, age, latest CD4 count and proportion with viral blips were comparable between groups. Systemic inflammation as assessed by targeted proteomics showed 89 upregulated and 43 downregulated proteins in the vaccinated participants. In contrast, individuals with a past COVID-19 infection display lower levels of 138 plasma proteins compared to the uninfected group (see figure). 'Innate immune system' and 'cell death' were upregulated in pathway analysis in vaccinated PLWH, but downregulated in COVID-19 infected participants. The increased systemic inflammation of the COVID-19 vaccinated group was accompanied by lower TNF-alpha and IL-1beta production capacity upon restimulation with a range of microbial stimuli, while production of IL-1Ra was increased. In COVID-19 infected PLWH only a reduced production of TNF-alpha to S. pneumonia was significant. Vaccinated PLWH also showed upregulation of platelet aggregation pathways. Conclusion(s): COVID-19 vaccination in PLWH leads to an increased systemic inflammation, but less effective cytokine production capacity of its immune cells upon microbial stimulation. This pattern is different from that of COVID-19 infection that leads to a decreased inflammatory profile and only minimal effects on cytokine production capacity. (Figure Presented).

Development of a Lymphoid Organ-Chip to Evaluate Covid Vaccine Boosting Strategies

Background: Secondary lymphoid organs provide the adequate microenvironment for the development of antigen (Ag)-specific immune responses. The tight collaboration between CD4+ T cells and B cells in germinal centers is crucial to shape B cell fate and optimize antibody maturation. Dissecting these immune interactions remains challenging in humans, and animal models do not always recapitulate human physiology. To address this issue, we developed an in vitro 3D model of a human lymphoid organ. The model relies on a microfluidic device, enabling primary human cells to self-organize in an extracellular matrix (ECM) under continuous fluid perfusion. We applied this Lymphoid Organ-Chip (LO chip) system to the analysis of B cell recall responses to SARS-CoV-2 antigens. Method(s): We used a two-channel microfluidic Chip S1 from Emulate, where the top channel is perfused with antigen (spike protein or SARS-CoV-2 mRNA vaccine), while the bottom channel contains PBMC (n = 14 independent donors) seeded at high-density in a collagen-based ECM. Immune cell division and cluster formation were monitored by confocal imaging, plasmablast differentiation and spike-specific B cell amplification by flow cytometry, antibody secretion by a cell-based binding assay (S-flow). Result(s): Chip perfusion with the SARS-CoV-2 spike protein for 6 days resulted in the induction CD38hiCD27hi plasmablast maturation compared to an irrelevant BSA protein (P< 0.0001). Using fluorescent spike as a probe, we observed a strong amplification of spike-specific B cell (from 3.7 to 140-fold increase). In line with this rapid memory B cell response, spike-specific antibodies production could be detected as early as day 6 of culture. Spike perfusion also induced CD4+ T cell activation (CD38+ ICOS+), which correlated with the level of B cell maturation. The magnitude of specific B cell amplification in the LO chip was higher than in 2D and 3D static cultures at day 6, showing the added value of 3D perfused culture for the induction of recall responses. Interestingly, the perfusion of mRNA-based SARS-CoV-2 vaccines also led to strong B cell maturation and specific B cell amplification, indicating that mRNA-derived spike could be expressed and efficiently presented in the LO chip. Conclusion(s): We developed a versatile Lymphoid Organ-Chip model suitable for the rapid evaluation of B cell recall responses. The model is responsive to protein and mRNA-encoded antigens, highlighting its potential in the evaluation of SARS-CoV-2 vaccine boosting strategies.

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.

A feasibility study on a digital device, SAT-008, as an influenza vaccine adjuvant

Background: Viral infections such as influenza and COVID-19 pose a serious threat to human health, which increases the demand for a new approach to enhance the host immunity. Previous studies showed that exercise activities could enhance the anti-viral neutralizing antibody titers after vaccination. We developed a novel digital device, SAT-008, as a mobile application based on an algorithm to regulate physical activity which are related to boosting innate and adaptive immune systems against virus. SAT-008 aimed to improve the activity of immune cells and the immune response in the body, which can be induced by software -designed -intensity levels of daily physical activities. Method(s): A randomized, open-label, and controlled study was conducted for 13 weeks (Oct 20 to Jan 21). A total of 42 healthy adults aged 24 to 46 years were recruited for this study and 32 among them served for analysis. Subjects were administered a single-dose quadrivalent influenza vaccine. The control group maintained daily life without using SAT-008, while the experimental group used SAT-008 during the study. Result(s): Compared to the control group, the experimental group showed a significant increase in neutralizing antibody titers of antigen subtype B Yamagata lineage after 4 weeks of vaccination and antigen subtype B Victoria lineage after 12 weeks of vaccination (P < 0.05), whereas the controls did not reach a significant level in any antibody titer. In the case of type 'A' influenza, there was no significant difference in neutralizing antibody titers between control and experimental groups. Stimulated NK cells of subjects in the control group decreased significantly between 4 weeks and 12 weeks after the vaccination (P < 0.05) while the subjects in the experimental group slightly increase the NK activity between 4 weeks and 12 weeks after the vaccination, however, there was no significance. The interaction effect was observed between control and experimental groups at weeks 4 and 12 by subsequent analysis (P < 0.05). Conclusion(s): We conclude that a novel approach using the digital device may play an important role to enhance the host immune system to act as a vaccine adjuvant against viral diseases such as influenza.

Novel Translational Animal Model Of Pediatric Viral Myocarditis

Myocarditis is a heart condition characterized by inflammation of cardiac myocytes. This inflammation is instigated by the activation of both the innate and acquired immune responses and is most often caused by viruses (flu, hand foot and mouth and COVID-19). Myocarditis may progress to dilated cardiomyopathy (DCM), a chronic heart condition in which fibrosis and remodeling weakens the ability of the heart to effectively pump. Myocarditis is a leading cause of sudden death in children and young adults. In this study, we investigated the progression and severity of myocarditis within the pediatric population as compared to an adult population. Prior to this study there were no mouse models for pediatric myocarditis but a large percent of patients with myocarditis are children. We utilized our knowledge from our adult mouse model of coxsackievirus B3 (CVB3) myocarditis to create a pediatric CVB3 myocarditis model in order to better understand the development of myocarditis in children. We hypothesized that myocarditis would have sex-specific differences in the manifestation and severity similar to the adult model but the mechanisms of disease would very between ages. We utilized 4-week-old male and female BALB/c mice to model pediatric myocarditis as compared to 8-week-old mice. Mice were be infected with heart-passaged CVB3 intraperitoneally (ip) on day (d) 0. Disease severity and progression was evaluated during acute myocarditis (d8-12 pi) and during DCM (d35pi). After anesthesia, body weight, heart weight and tibia length, blood, hearts, pancreas and spleens were harvested. Echocardiography was conducted on mice at the chronic DCM timepoint. We found that adult male and female mice develop myocarditis with male mice have more severe disease and progress to DCM as compared to female mice. The main immune cells and pathways involved in myocarditis severity were macrophages, complement and the inflammasome in male adult mice. This increase in disease was driven by testosterone and reduced by estrogen as seen utilizing gonadectomies. In the pediatric population we did not see as drastic of differences in sex hormone levels as the mice are pre-pubescent, this led to less dramatic sex differences in disease and altered immune mechanisms leading to disease in the pediatric population compared to the adults. We do see induction of myocarditis in both male and female pediatric mice compared to uninfected controls but severity in the pediatric population is less than adult population. Successful development of a pediatric translational mouse model of viral myocarditis will significantly impact the myocarditis field by allowing the ability to assess differences between pediatric and adult populations and develop targeted diagnostics and treatments.Copyright © 2022

Sars-Cov-2 Associated Myopathy

An association between SARS-CoV-2 infection and myopathy was suspected early in the pandemic: patients with severe COVID-19 showed increased levels of creatine kinase that could not be solely explained by cardiac affection. On the other hand, myalgia and muscle weakness are frequent symptoms in patients with mild or moderate COVID-19 - as with many other viral infections -and subsets of infected patients report persistent muscular weakness and fatigue even months after the initial infection. We performed a case-control autopsy comparing patients with severe COVID-19 to patients with other critical illnesses and assessed inflammation of skeletal muscle tissue by quantification of immune cell infiltrates, expression of major histocompatibility complex (MHC) class I and class II antigens on the sarcolemma. Relevant expression of MHC class I antigens on the sarcolemma was present in 23 of 42 specimens from patients with COVID-19 (55%) and upregulation of MHC class II antigens in 7 of 42 specimens from patients with COVID-19 (17%), but neither were found in any of the controls. In a subset of patients, MHC class I and MHC class II expression showed a clear perifascicular pattern. Signs of degenerating and necrotic fibers could also be found, however there was no statistically significant difference in the frequency of occurrence when compared to non-COVID-19 critically ill patients. We interpreted this as non-specific signs of muscular damage in critically ill patients. Numbers of macrophages, lymphocytes and natural killer cells were found to be increased in muscles from patients with COVID-19. Interestingly, no relevant expression of MxA on myofibers could be found by immunohistochemistry, but in some cases, expression of MxA was found on capillaries. Ultrastructural analysis of selected muscles with perifascicular MHC-expression did not show tubuloreticular inclusions. However, capillaries of the analyzed samples showed basement membrane alterations and signs of ongoing regenerative processes. In addition, we evaluated inflammation of cardiac muscles by quantification of immune cell infiltrates in the same patients, and found that skeletal muscles showed more inflammatory features than cardiac muscles. Moreover, inflammation was most pronounced in patients with COVID-19 with chronic courses. In some muscle specimens, SARS-CoV-2 RNA was detected by reverse transcription-polymerase chain reaction, but no evidence for a direct viral infection of myofibers was found by immunohistochemistry or electron microscopy. This suggests that SARS-CoV-2 may be associated with a postinfectious, immune-mediated myopathy.

Summer Meeting of the Anatomical Society

The proceedings contain 71 papers. The topics discussed include: experience of learning human anatomy and histology during COVID-19 pandemic in Kharkiv National Medical University;using musculoskeletal modelling to investigate the functional significance of craniofacial form variation within the genus homo;a morphometric analysis of the cranial fossae in patients with scaphocephaly;exploring the thalamus in young adolescents with psychotic experiences;to replace or not replace that is the question: addressing fate decisions during minipig tooth replacement;anatomy of termination of popliteal artery: a multidetector CT angiographic study;anatomical variation between populations of British red squirrels: the potential impact of supplementary feeding;revealing the biomechanics of the masticatory muscles in the eastern grey squirrel (Sciurus carolinensis) using multibody dynamics analysis;and myoepithelial and immune cell dynamics in the ovine mammary gland during postnatal development.