Association of SARS-COV-2 viral RNAemia, IL- 6 gene polymorphism, serum IL-6 and peripheral blood lymphocytes and monocytes with disease severity in COVID-19 patients

Coronavirus disease 2019 (COVID-19) is a fatal pandemic viral disease caused by the severe acute respiratory syndrome corona virus type-2 (SARS-CoV-2). The aim of this study is to observe the associations of IL-6, SARS-COV-2 viral load (RNAemia), IL- 6 gene polymorphism and lymphocytes and monocytes in peripheral blood with disease severity in COVID-19 patients. This study was carried out from March 2021 to January 2022. RT-PCR positive 84 COVID-19 patients and 28 healthy subjects were enrolled. Blood was collected to detect SARS-COV-2 viral RNA (RNAemia) by rRT-PCR, serum IL-6 level by chemiluminescence method, SNPs of IL-6 by SSP-PCR, immunophenotyping of lymphocytes and monocyte by flow cytometry. Serum IL-6 level (pg/ml) was considerably high among critical patients (102.02 +/- 149.7) compared to severe (67.20 +/- 129.5) and moderate patients (47.04 +/- 106.5) and healthy controls (3.5 +/- 1.8). Serum SARS-CoV-2 nucleic acid positive cases detected mostly in critical patients (39.28%) and was correlated with extremely high IL-6 level and high mortality (R =.912, P < 0.001). Correlation between IL-6 and monocyte was statistically significant with disease severity (severe group, p < 0.001, and 0.867*** and critical group p < 0.001 and 0.887***). In healthy controls, moderate, severe and critically ill COVID-19 patients, IL-6 174G/C (rs 1800795) GG genotype was 82.14%, 89.20%, 67.85% and 53.57% respectively. CC and GC genotype had strong association with severity of COVID-19 when compared with GG genotype. Significant statistical difference found in genotypes between critical and moderate groups (p < 0.001, OR-10.316, CI-3.22-23.86), where CC genotype was associated with COVID-19 severity and mortality. The absolute count of T cell, B cell, NK cell, CD4+ T cells and CD8+ T cells were significantly decreased in critical group compared to healthy, moderate and severe group (P < 0.001). Exhaustion marker CD94/NKG2A was increased on NK cells and CD8+ cytotoxic T cell among critical and severe group. Absolute count of monocyte was significantly increased in critical group (P < 0.001). Serum IL-6, IL-6 174 G/C gene and SARS-CoV-2 RNAaemia can be used in clinical practice for risk assessment;T cell subsets and monocyte as biomarkers for monitoring COVID-19 severity. Monoclonal antibody targeting IL-6 receptor and NKG2A for therapeutics may prevent disease progression and decrease morbidity and mortality.Copyright © 2023 Elsevier Inc.

Heterologous prime-boost viral vector vaccines for the treatment of a P1A-expressing BGL-1 glioblastoma model

Glioblastoma is an extremely aggressive and difficult cancer to treat, which may partly be due to its limited ability to induce T-cell responses. However, combining viral vector vaccines with other therapies to generate tumor-specific T cells may provide a meaningful benefit to patients. Here, we investigated whether heterologous prime-boost vaccination with chimpanzee-derived adenoviral vector ChAdOx1 and modified vaccinia Ankara (MVA) vaccines could generate therapeutically effective CD8+ T-cell responses against a model antigen P1A, a mouse homolog of human tumorassociated Melanoma Antigen GenE (MAGE)-type antigens, expressed by a BGL-1 mouse glioblastoma cell line. We demonstrated that heterologous prime-boost vaccination with ChAdOx1/MVA vaccines targeting P1A generated a high magnitude of CD8+ T cells specific for the P1A35-43 epitope presented by the MHC class I molecule H-2Ld . Prophylactic vaccination with ChAdOx1/MVA-P1A significantly prolonged the survival of syngeneic mice subcutaneously challenged with P1A-expressing BGL-1 tumors. Furthermore, different vaccination schedules significantly impact the magnitude of antigen-specific CD8+ T-cell responses and may impact protective efficacy. However, the substantial induction of myeloid-derived suppressor cells (MDSCs) by this tumor model presents a significant challenge in the therapeutic setting. Future work will investigate the efficacy of this vaccination strategy on intracranial P1A-expressing BGL-1 models.

Glucosaminylmuramyl dipeptide efficacy in post-COVID-19 patient rehabilitation treatment.

The COVID-19 pandemic has altered people's lifestyles around the world. Prevention of recurrent episodes of the disease and mitigation of its consequences are especially associated with effective post-COVID-19 rehabilitation in patients. The aim of the study was to evaluate the effects of the drug Likopid (glucosaminylmuramyl dipeptide, GMDP) for post-COVID-19 rehabilitation in patients. Material and methods. Patients who recovered from mild to moderate COVID-19 (n=60, mean age 54+/- 11.7 years) were randomized into the observation group (n=30, 15 men and 15 women) who received 2 courses of Licopid (1 mg twice a day) and the comparison group (n=30, 15 men and 15 women). Analysis of the phenotypic and functional characteristics of the innate immune cellular factors was carried out before the start of immunomodulatory therapy, immediately after the end of the course, and also after 6 months observations. In order to assess the quality of life of all patients, we used the SF-36 Health Status Survey and the Hospital Anxiety and Depression Scale questionnaires. Results. During assessing the effect of immunomodulatory therapy on the parameters of innate immunity of patients at the stage of rehabilitation after COVID-19, an increase in the protective cytolytic activity of CD16+ and CD8+Gr+ cells, as well as a persistent increase in TLR2, TLR4 and TLR9 expression was found, which indicates the antigen recognition recovery and presentation at the level of the monocytic link of the immune system. The use of GMDP as an immunomodulatory agent resulted in an 8-fold reduction in the frequency and severity of respiratory infections due to an increase in the total monocyte count. As a result of assessing patients' quality of life against the background of the therapy, a positive dynamic in role functioning was revealed in patients. In the general assessment of their health status, an increase in physical and mental well-being was noted during 6 months of observation. The comparison group showed no improvement in the psychoemotional state. Discussion. The study demonstrated the effectiveness of GMDP immunomodulatory therapy in correcting immunological parameters for post-COVID-19 rehabilitation in patients. The data obtained are consistent with the previously discovered ability of GMDP to restore impaired functions of phagocytic cells and induce the expression of their surface activation markers, which in turn contributes to an adequate response to pathogens. Conclusion. The study revealed that the correction of immunological parameters with the use of GMDP in COVID-19 convalescents contributed not only to a decrease in the frequency and severity of respiratory infections, but also to an improvement in the psycho-emotional state of patients, and a decrease in anxiety and depression.Copyright © Eco-Vector, 2023. All rights reserved.

Primary immunodeficiency associated with a SAMD9L mutation

Background: SAMD9L is a tumor suppressor involved in regulating the proliferation and maturation of cells, particularly those derived from the bone marrow, and appears to play an important role in cerebellar function. It can be activated in hematopoietic stem cells by type I and type II interferons. It has been hypothesized to act as a critical antiviral gatekeeper regulating interferon dependent demand driven hematopoiesis. Gain of function mutations can present with an immunodeficiency due to transient severe cytopenias during viral infection. Case presentation: We report a 3-year-old boy born full term with a history of severe thrombocytopenia requiring transfusions, developmental delay, ataxia, seizure disorder, and recurrent severe respiratory viral infections. His infectious history was significant for respiratory syncytial virus with shock requiring extracorporeal membrane oxygenation complicated by cerebral infarction and a group A streptococcus empyema, osteomyelitis requiring a left below the knee amputation, and infections with rhinovirus, COVID-19, and parainfluenza requiring hospitalizations for respiratory support. Initial immunologic evaluation was done during his hospitalization for parainfluenza. His full T cell subsets was significant for lymphopenia across all cell lines with CD3 934/microL, CD4 653/microL, CD8 227/microL, CD19 76/microL, and CD1656 61/microL. His mitogen stimulation assay to phytohemagglutinin and pokeweed was normal. Immunoglobulin panel showed a mildly decreased IgM of 25 mg/dL, but normal IgA and IgG. Vaccine titers demonstrated protective titers to 12/22 pneumococcus serotypes, varicella, diphtheria, mumps, rubella, and rubeola. Repeat full T cell subsets 6 weeks later revealed marked improvement in lymphocyte counts with CD3 3083/microL, CD4 2101/microL, CD8 839/microL, CD19 225/microL, and CD1656/microL. A primary immunodeficiency genetic panel was ordered and positive for a heterozygous SAMD9L c.1549T>C (p.Trp517Arg) mutation classified as a variant of unknown significance. Discussion(s): This patient's history of severe viral infections, ataxia, thrombocytopenia, and severe transient lymphopenia during infection is suggestive of a SAM9DL gain of function mutation. Protein modeling done by the laboratory suggests this missense mutation would affect protein structure. The mutation found has been observed in individuals with thrombocytopenia. This case highlights the importance of immunophenotyping both during acute illness and once recovered.Copyright © 2023 Elsevier Inc.

COMPARISON OF HOMOLOGOUS AND HETEROLOGOUS BOOSTER SARS-CoV-2 VACCINATION IN AUTOIMMUNE RHEUMATIC AND MUSCULOSKELETAL PATIENTS

BackgroundVaccine-induced immunity is very important for controlling the COVID-19 infection. The vaccination supports humoral and cellular immunity, and this is one of the main strategy for us. Various vaccines approved in the countries have been shown to reduce infection rates, severity, and mortality.ObjectivesWe aimed to compare humoral and cellular immune responses after homologous or heterologous vaccination among patients with aiRMDs at their third vaccination with BNT162b2 or with two vaccinations followed by COVID-19 infection. We detected the anti-SARS-CoV2 antibody levels and measured the SARS-CoV-2 reactive B-, or T-cell mediated immunity in aiRMDs receiving homologous (Hom.), heterologous (Het.) vaccines or became infected (Inf.).MethodsA single center observational study evaluated immunogenicity and safety of the third dose vaccines or after two-dose regimen of vaccine and COVID infection in patients with aiRMDs. Neutralizing anti-RBD antibodies and specific T-cell response were measured.ResultsWe showed that following 4 months of the booster vaccination with the third dose of mRNA-based vaccine or after COVID infection, the positive (>21.8 BAU/mL) neutralizing anti-RBD IgG antibody response was outstanding in all three patient groups, 95.5%, 100% and 100% of the homologous and heterologous as well as the SARS-CoV-2 infected groups. Taken together booster vaccinations or SARS-CoV-2 infection after completing 2 doses of the vaccination can lead to the production of neutralizing antibodies still protective in RMD cases after 4 months of the third antigen exposition. The booster vaccination reduces the frequency of hospital admissions and mortality with ai RMDs. The vaccinations are effective independently from the type of vaccine, the SARS-CoV-2 specific memory B-cell populations showed a statistically not significant but lower frequency in the infection group. Clinical activity of aiRMDs was not increased following booster vaccination.ConclusionPatients, who received a heterologous booster vaccine had a higher level of peripheral memory B-cells compared to those who had COVID-19 infection. Biologic therapy decreased the level of B-cells. Patients with a disease duration of more than 10 years had higher level of CD8+TNF-α+ and CD8+IFN-γ+ T-cells compared to patients who were diagnosed less than 10 years ago. The third booster mRNA-based vaccine was as much effective as in the homologous and heterologous patients groups compared who had COVID infection.References[1] Szebeni, G.J.;Gemes, N.;Honfi, D.;Szabo, E.;Neuperger, P.;Balog, J.A.;Nagy, L.I.;Szekanecz, Z.;Puskas, L.G.;Toldi, G.;et al. Humoral and Cellular Immunogenicity and Safety of Five Different SARS-CoV-2 Vaccines in Patients With Autoimmune Rheumatic and Musculoskeletal Diseases in Remission or With Low Disease Activity and in Healthy Controls: A Single Center Study. Front. Immunol. 2022, 13, 846248.[2]Honfi, D.;Gémes, N.;Szabó, E.;Neuperger, P.;Balog, J.Á.;Nagy, L.I.;Toldi, G.;Puskás, L.G.;Szebeni, G.J.;Balog, A. Comparison of Homologous and Heterologous Booster SARS-CoV-2 Vaccination in Autoimmune Rheumatic and Musculoskeletal Patients. Int. J. Mol. Sci. 2022, 23, 11411Acknowledgements:NIL.Disclosure of InterestsNone Declared.

Scientific rationale of Indian AYUSH Ministry advisory for COVID-19 prevention, prophylaxis, and immunomodulation

The current outbreak of COVID-19 is caused by the SARS-CoV-2 virus that has affected > 210 countries. Various steps are taken by different countries to tackle the current war-like health situation. In India, the Ministry of AYUSH released a self-care advisory for immunomodulation measures during the COVID-19 and this review article discusses the detailed scientific rationale associated with this advisory. Authors have spotted and presented in-depth insight of advisory in terms of immunomodulatory, antiviral, antibacterial, co-morbidity associated actions, and their probable mechanism of action. Immunomodulatory actions of advised herbs with no significant adverse drug reaction/toxicity strongly support the extension of advisory for COVID-19 prevention, prophylaxis, mitigations, and rehabilitation capacities. This advisory also emphasized Dhyana (meditation) and Yogasanas as a holistic approach in enhancing immunity, mental health, and quality of life. The present review may open-up new meadows for research and can provide better conceptual leads for future researches in immunomodulation, antiviral-development, psychoneuroimmunology, especially for COVID-19.Copyright © 2021, Institute of Korean Medicine, Kyung Hee University.

Viruses and the risk of lung cancer: prevention and treatment

Lung cancer is the most common cancer in males and the second most common among females both in Europe and worldwide. Moreover, lung cancer is the leading cause of death due to cancer in males. The European region accounts for 23% of total cancer cases and 20% of cancer-related deaths. Relationships have been described between a number of infectious agents and cancers, but our knowledge of the role of viruses, both respiratory and systemic, in the pathogenesis of lung cancer is still rudimentary and has been poorly disseminated. In this chapter, we review the available evidence on the involvement of HPV, Epstein-Barr virus, HIV, cytomegalovirus and measles virus in the epidemiology and pathogenesis of lung cancer.Copyright © ERS 2021.

REVACCINATION OF PATIENTS WITH SLE OR RA WITHOUT AN INITIAL COVID-19 VACCINE RESPONSE ELICITS SEROCONVERSION IN HALF OF THE PATIENTS

BackgroundTreatment with Rituximab (RTX) in patients with rheumatic diseases (RD) has presented a challenge during the COVID-19 pandemic, as RTX leads to markedly reduced and often undetectable antibody responses after COVID-19 vaccination (1).ObjectivesTo investigate the effect of COVID-19 mRNA revaccination (two doses) on the antibody response in patients with RD who were initial vaccine non-responders. Further, to examine if B-cell levels or T-cell responses before revaccination predicted seroconversion.MethodsFrom a RD cohort (COPANARD) vaccinated with the standard two-dose COVID-19 vaccinations, we enrolled cases without detectable antibody responses (n=17) and controls with detectable antibody response (n=29). Blood donors (n=32) were included as additional controls. Samples were collected before and six weeks after completed revaccination. Total antibodies (abs) and specific IgG, IgA, and IgM against SARS-CoV-2 spike protein, SARS-CoV-2 neutralizing abs, and SARS-CoV-2 reacting CD4+ and CD8+ T-cells were measured before and after revaccination. B-cells (CD19+CD45+) were quantified before revaccination. This study was funded by the Danish Rheumatism Association.ResultsPatient demographics are given in Table 1. Forty-seven percent of cases had detectable total SARS-CoV-2 abs and neutralizing abs after revaccination. However, antibody levels were significantly lower than in controls and blood donors (p<0.008), Figure 1A+B. Revaccination induced an antibody class switch in cases with a decrease in detectable IgM abs (Baseline 11/17, Followup 3/17) and increase in IgG. No significant difference was observed in T-cell responses before and after revaccination between the three groups, Figure 1C. The proportion of cases with detectable CD4+ T cells increased from 69% to 88% (p=0.25), and for CD8+ T cells, the proportion decreased from 88% to 82% (p=1.00). Only 29% of cases had measurable B-cells compared to 100% of controls and blood donors, Figure 1D. Fifty percent of revaccinated cases who seroconverted had measurable B-cells before revaccination, Figure 1D.Univariate logistic regression analysis was performed to analyze if active RTX treatment, the presence of B-cells, or a positive T-cell response prior to revaccination predicted seroconversion of total SARS-CoV-2-abs in the patient cohort. We did not find a significant explanatory effect of either variable in the univariate logistic models, data not shown.Table 1.DemographicsCases Revaccination, n=17Controls Boost, n=29Female sex, no(%)1482%2172%Age, median (IQR)6549 - 706762 - 72Disease duration, years1510 - 18229 - 31Rheumatoid Arthritis/SLE13/410/19None DMARD529%828%Prednisone424%13%Methotrexate741%1241%Hydroxychloroquine212%414%None biologic treatment424%931%Rituximab1271%0TNF-inhibitors16%724%JAK-inhibitors0621%IL-6-inhibitors, Abatacept, Benlysta0724%Previous rituximab treatmentAny rituximab treatment1694%13%RTX within the last 15 months, no1488%0Cumulative total dose, mg134-242Time from RTX to revaccination, months95-1249Figure 1.ConclusionIn conclusion, forty-seven percent of initial non-responders were able to seroconvert after two-dose revaccination. However, plasma concentrations of the antibodies against SARS-COV-2 and the levels of neutralizing capacity remained significantly lower than in immunocompetent blood donors. B-cell levels or T-cell responses before revaccination did not predict seroconversion. Our study suggests that patients with RDs who did not mount a detectable serological response to a COVID-19 mRNA vaccine have a T cell response similar to immunocompetent controls. Future studies should establish the antibody levels that identify RD patients without sufficient protection against SARS-CoV-2 infection.References[1]Troldborg A, et al. Time Since Rituximab Treatment Is Essential for Developing a Humoral Response to COVID-19 mRNA Vaccines in Patients With Rheumatic Diseases. J Rheumatol. 2022.AcknowledgementsThe Danish Rheumatism Association [grant number R203-A7217]. We acknowledge all patients and blood donors contributing to the stud for their invaluable participation. The authors would like to thank Sif Kaas Nielsen and Mads Engelhardt Knudsen, the Laboratory of Molecular Medicine at Rigshospitalet, for their excellent technical assistance in analyzing the samples.Disclosure of InterestsNone Declared.

CELLULAR AND HUMORAL IMMUNOGENICITY OF THE NEOANTIGEN S1 FROM SARS-COV-2 VACCINES IN PATIENTS WITH AUTOIMMUNE RHEUMATIC DISEASES

BackgroundData on cellular and humoral immunogenicity triggered by SARS-CoV-2 vaccines in patients with autoimmune rheumatic diseases (ARDs) are limited. While current vaccine efforts have focused on the induction of neutralizing antibodies against SARS-CoV-2, T-cell immunity may also provide protection against infection. Experimental data suggest that CD8+ T cell responses may have a protective role in the presence of decreasing or sub protective antibody titers [1].ObjectivesThe aim of this project is to describe the serological and T cell responses to the third dose of vaccine (either with BNT162b2 mRNA or ChAdOx1 nCoV-19 replication-deficient adenoviral vector vaccines) in a cohort of patients with ARDs (rheumatoid arthritis and spondyloarthropathies) treated with biologic therapies, to describe the impact of these treatments on vaccine response in this patient population. As a second objective, we will describe the characteristics of patients who did not present an adequate immunogenic response.MethodsCase-control study. We studied in 79 patients with ARDs and in 31 healthy controls, anti-SARS-CoV-2 specific interferon-gamma (IFN-γ) production measured by IGRA between 8-12 weeks after the third dose of anti-SARS-CoV-2 vaccine. In addition, humoral response was measured by anti-S1 IgG antibody production measured by chemiluminescent microparticle immunoassay. Statistical comparison between categorical variables was performed by Fisher's or χ2 test. For quantitative variables by Kruskal-Wallis test or Mann-Whitney test.Results79 patients with ARDs (48 women, 31 men;mean age 58±11.4) 43 (54%), with rheumatoid arthritis and 36 (45.6%) with spondyloarthropathies. 32 (49.5%) of them were on glucocorticoid treatment (mean dose 4.92 mg/day), 25 (31.6%) on methotrexate and 56 (70.9%) on anti-TNF. Post-vaccination results showed positive T-cell immune responses in 68 of 79 (86.1%) ARDs patients with mean IFN- γ anti-SARS-CoV-2 titers of 1,606.85 mUI/ml. 7 (8.9%) of ARDs patients showed negative IFN-γ SARS-CoV-2 levels, while 4 (5%) had borderline titers. 100% of patients with previous COVID 19 disease had positive cellular responses. Within the group of negative or borderline cellular responses, 7 of 10 were men (70%), with no significant differences in terms of diagnosis, comorbidities or immunosuppressive treatments used. In the control group, 100% presented positive cellular responses. Anti-Spike IgG antibodies were detectable in all patients with ARDs as in the control group.ConclusionOur preliminary data show that most patients with ARD were able to generate an adequate specific cellular response after vaccination against SARS-CoV-2, emphasizing the relevance of vaccination in this group. Specific antibody responses secondary to anti-SARS-CoV-2 vaccination were detected in all patients with ARD. Our data could support the relevance of these immune responses to personalize prevention, vaccination decision-making and treatment in this subgroup of patients.References[1]Sieiro Santos C, Calleja Antolin S, Moriano Morales C, Garcia Herrero J, Diez Alvarez E, Ramos Ortega F, et al. Immune responses to mRNA vaccines against SARS-CoV-2 in patients with immune-mediated inflammatory rheumatic diseases. RMD Open. 2022 Jan 5;8(1).Figure 1.Specific anti-SARS-CoV-2-IFN- γ responses measured by IGRA. Dotted lines represent positivity cut-off: ≥200mUI/ml. HC: Healthy controls. AIRDs: Autoimmune rheumatic diseases.[Figure omitted. See PDF]Acknowledgements:NIL.Disclosure of InterestsNone Declared.

Cellular and humoral immune responses after SARS-CoV-2 vaccination in pediatric kidney recipients

Objective: Humoral and cellular immune responses to SARS-CoV-2 vaccination are reduced in adult kidney recipients. After pediatric kidney transplantation there are only few data available - mostly limited to monitoring of SARS-CoV-2 antibodies. Method(s): Cellular and humoral immune responses have been monitored before and after SARS-CoV-2 vaccination in pediatric kidney recipients. After in vitro stimulation with SARS-CoV-2 antigen (spike glycoprotein) virus-specific CD4 and CD8 T cells (SARS-CoV-2-Tvis) have been identified by cytokine flow cytometry. SARS-CoV-2 IgG was measured by CMIA. Result(s): Immune response after SARS-CoV-2 vaccination was analyzed in a total of 30 pediatric kidney recipients (age at 1st vaccine dose 5.2 - 17.8 years, median 14.8 years;43% male;30/30 2 vaccine doses;23/30 3 vaccine doses). At time of vaccination 22 patients (73%) received a tacrolimus (Tac)-based immunosuppression combined with mycophenolate mofetil (MMF;n = 15) or everolimus (n = 6) or neither of them (n = 1);3 patients were exposed to cyclosporine A and 5 patients to a calcineurin inhibitor (CNI)- free immunosuppression. MMF was used in 18/30 patients. After 1st dose of mRNA vaccine SARS-CoV-2 antibodies were detectable in 50% of pediatric kidney recipients, after 2nd dose in 78% and after 3rd dose in 88%. After the 2nd vaccine dose absence of humoral immune response (< 33.8 BAU/ml) was only found in case of MMF use (predominately combined with Tac). Peak IgG values (> 2,080 BAU/ml) were only detected in MMF-free regimens (6/7). Cellmediated response partially differed from humoral response, e. g., in some patients SARS-CoV2-Tvis were found despite lack of virus-specific antibodies. After 1st vaccine dose SARS-CoV-2-Tvis were detectable in 50% of pediatric kidney recipients, after 2nd dose in 92%. After 2nd vaccine dose absence or very low levels of SARS-CoV-2-Tvis (< 0.3 cells/mul) were only found in Tac-based immunosuppressive regimens, whereas higher levels (> 1.3 cells/mul) were exclusively detected in patients with MMFfree medication. Conclusion(s): After pediatric kidney transplantation humoral and cellular immune responses to SARS-CoV-2 vaccination were suboptimal, but more pronounced than in adult kidney recipients. Use of Tac and MMF was associated with impaired immune response to vaccination. SARS-CoV-2-specific humoral response corresponded only partially to cell-mediated response. Additional monitoring of SARS-CoV- 2-Tvis might be recommendable to improve assessment of the individual vaccine response and thereby to personalize the decision on the necessity of further vaccine doses.

Regulatory CD4+ and CD8+ T cells are negatively correlated with CD4+ /CD8+ T cell ratios in patients acutely infected with SARS-CoV-2.

Regulatory T cell can protect against severe forms of coronaviral infections attributable to host inflammatory responses. But its role in the pathogenesis of COVID-19 is still unclear. In this study, frequencies of total and multiple subsets of lymphocytes in peripheral blood of COVID-19 patients and discharged individuals were analyzed using a multicolor flow cytometry assay. Plasma concentration of IL-10 was measured using a microsphere-based immunoassay kit. Comparing to healthy controls, the frequencies of total lymphocytes and T cells decreased significantly in both acutely infected COVID-19 patients and discharged individuals. The frequencies of total lymphocytes correlated negatively with the frequencies of CD3- CD56+ NK cells. The frequencies of regulatory CD8+ CD25+ T cells correlated with CD4+ /CD8+ T cell ratios positively, while the frequencies of regulatory CD4+ CD25+ CD127- T cells correlated negatively with CD4+ /CD8+ T cell ratios. Ratios of CD4+ /CD8+ T cells increased significantly in patients beyond age of 45 years. And accordingly, the frequencies of regulatory CD8+ CD25+ T cells were also found significantly increased in these patients. Collectively, the results suggest that regulatory CD4+ and CD8+ T cells may play distinct roles in the pathogenesis of COVID-19. Moreover, the data indicate that NK cells might contribute to the COVID-19 associated lymphopenia.

Immune Responses and Pathogenesis following Experimental SARS-CoV-2 Infection in Domestic Cats.

Several reports demonstrated the susceptibility of domestic cats to SARS-CoV-2 infection. Here, we describe a thorough investigation of the immune responses in cats after experimental SARS-CoV-2 inoculation, along with the characterization of infection kinetics and pathological lesions. Specific pathogen-free domestic cats (n = 12) were intranasally inoculated with SARS-CoV-2 and subsequently sacrificed on DPI (days post-inoculation) 2, 4, 7 and 14. None of the infected cats developed clinical signs. Only mild histopathologic lung changes associated with virus antigen expression were observed mainly on DPI 4 and 7. Viral RNA was present until DPI 7, predominantly in nasal and throat swabs. The infectious virus could be isolated from the nose, trachea and lungs until DPI 7. In the swab samples, no biologically relevant SARS-CoV-2 mutations were observed over time. From DPI 7 onwards, all cats developed a humoral immune response. The cellular immune responses were limited to DPI 7. Cats showed an increase in CD8+ cells, and the subsequent RNA sequence analysis of CD4+ and CD8+ subsets revealed a prominent upregulation of antiviral and inflammatory genes on DPI 2. In conclusion, infected domestic cats developed a strong antiviral response and cleared the virus within the first week after infection without overt clinical signs and relevant virus mutations.

Immune response induced by novel coronavirus infection.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has been prominent around the world since it was first discovered, affecting more than 100 million people. Although the symptoms of most infected patients are not serious, there is still a considerable proportion of patients who need hospitalization and even develop fatal symptoms such as cytokine storms, acute respiratory distress syndrome and so on. Cytokine storm is usually described as a collection of clinical manifestations caused by overactivation of the immune system, which plays an important role in tissue injury and multiorgan failure. The immune system of healthy individuals is composed of two interrelated parts, the innate immune system and the adaptive immune system. Innate immunity is the body's first line of defense against viruses; it can quickly perceive viruses through pattern recognition receptors and activate related inflammatory pathways to clear pathogens. The adaptive immune system is activated by specific antigens and is mainly composed of CD4+ T cells, CD8+ T cells and B cells, which play different roles in viral infection. Here, we discuss the immune response after SARS-CoV-2 infection. In-depth study of the recognition of and response of innate immunity and adaptive immunity to SARS-CoV-2 will help to prevent the development of critical cases and aid the exploration of more targeted treatments.

CD71+ erythroid cells suppress T-cell effector functions and predict immunotherapy outcomes in patients with virus-associated solid tumors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer. However, only a portion of patients respond to such treatments. Therefore, it remains a prevailing clinical need to identify factors associated with acquired resistance or lack of response to ICIs. We hypothesized that the immunosuppressive CD71+ erythroid cells (CECs) within the tumor and/or distant 'out-of-field' may impair antitumor response. METHODS: We studied 38 patients with cancer through a phase II clinical trial investigating the effects of oral valproate combined with avelumab (anti-programmed death-ligand 1 (PD-L1)) in virus-associated solid tumors (VASTs). We quantified the frequency/functionality of CECs in blood and biopsies of patients. Also, we established an animal model of melanoma (B16-F10) to investigate the possible effects of erythropoietin (EPO) treatment on anti-PD-L1 therapy. RESULTS: We found a substantial expansion of CECs in the blood of patients with VAST compared with healthy controls. We noted that the frequency of CECs in circulation was significantly higher at the baseline and throughout the study in non-responders versus responders to PD-L1 therapy. Moreover, we observed that CECs in a dose-dependent manner suppress effector functions of autologous T cells in vitro. The subpopulation of CD45+CECs appears to have a more robust immunosuppressive property compared with their CD45- counterparts. This was illustrated by a stronger expression of reactive oxygen species, PD-L1/PD-L2, and V-domain Ig suppressor of T-cell activation in this subpopulation. Lastly, we found a higher frequency of CECs in the blood circulation at the later cancer stage and their abundance was associated with anemia, and a poor response to immunotherapy. Finally, we report the expansion of CECs in the spleen and tumor microenvironment of mice with melanoma. We found that although CECs in tumor-bearing mice secret artemin, this was not the case for VAST-derived CECs in humans. Notably, our results imply that EPO, a frequently used drug for anemia treatment in patients with cancer, may promote the generation of CECs and subsequently abrogates the therapeutic effects of ICIs (eg, anti-PD-L1). CONCLUSIONS: Our results demonstrate that anemia by the expansion of CECs may enhance cancer progression. Notably, measuring the frequency of CECs may serve as a valuable biomarker to predict immunotherapy outcomes.

GRAd-COV2 vaccine provides potent and durable humoral and cellular immunity to SARS-CoV-2 in randomized placebo-controlled phase 2 trial.

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and heterologous immunization approaches implemented worldwide for booster doses call for diversified vaccine portfolios. GRAd-COV2 is a gorilla adenovirus-based COVID-19 vaccine candidate encoding prefusion-stabilized spike. The safety and immunogenicity of GRAd-COV2 is evaluated in a dose- and regimen-finding phase 2 trial (COVITAR study, ClinicalTrials.gov: NCT04791423) whereby 917 eligible participants are randomized to receive a single intramuscular GRAd-COV2 administration followed by placebo, or two vaccine injections, or two doses of placebo, spaced over 3 weeks. Here, we report that GRAd-COV2 is well tolerated and induces robust immune responses after a single immunization; a second administration increases binding and neutralizing antibody titers. Potent, variant of concern (VOC) cross-reactive spike-specific T cell response peaks after the first dose and is characterized by high frequencies of CD8s. T cells maintain immediate effector functions and high proliferative potential over time. Thus, GRAd vector is a valuable platform for genetic vaccine development, especially when robust CD8 response is needed.

Effector memory T cell subset CD45RA-CCR7-CD27-CD28- EM3 increases in direct proportion to the disease severity of COVID-19

COVID-19, which emerged in December 2019 and continues to wreak havoc, has led to the death of many people around the world. In this study, we aimed to uncover the variables underlying the exacerbation of the disease by considering the changes in T cell subsets in adults and juveniles with different disease severity of COVID-19. Peripheral blood samples of 193 patients (128 adults and 65 juveniles) diagnosed with COVID-19 were evaluated in a flow cytometer, and a broad T cell profile was revealed by examining T cell subsets in terms of exhaustion and senescence. We found remarkable differences in the effector memory (EM;CD45RA-CCR7-) cell subsets of severe pneumonia cases. The frequencies of EM2 CD4+ T, EM3 CD4+ T, EM3 CD8+ T, EM2 DN T and EM3 DN T cells were found to increase in severe pneumonia cases. Consistently, these cells were found in juveniles and uncomplicated adults in similar or lower proportions to healthy controls. The findings of our study provide a view of the T cell profile that may underlie differences in the course of COVID-19 cases in juveniles and adults and may provide new insights into the development of effective treatment strategies.

Immune Responses to Mrna Vaccines against Sars-Cov2 in Patients with Immune-Mediated Inflammatory Rheumatic Diseases

Background/Aims Patients with immune-mediated rheumatic diseases (IMRD) are commonly treated with immunosuppressors and are prone to infections. Recently introduced mRNA SARS-Cov2 vaccines have demonstrated extraordinary efficacy across all ages. Immunosuppressed patients were excluded from phase III trials with SARS-We aim to fully characterize B and T cell immune responses elicited by mRNA SARS-Cov2 vaccines in patients with rheumatic diseases under immunotherapies, and to identify which drugs reduce vaccine's immunogenicity. Methods Humoral, CD4 and CD8 immune responses were investigated in 147 SARS-Cov2-naive patients with selected rheumatic diseases under immunosuppression after a two-dose regimen of SARS-Cov2 mRNA vaccine. Responses were compared with age, gender, and diseasematched IMRD patients not receiving immunosuppressors and with healthy controls Results IMRD patients showed decreased seroconversion rates (63% vs 100%, p=0.04) and cellular immune responses (59% vs 100%, p=0.007). Patients on methotrexate achieved seroconversion in 62% of cases and cellular responses in 80% of cases. Abatacept deeply affected humoral and cellular responses. Rituximab (31% responders) and belimumab (50% responders) showed severely impaired humoral responses but cellular responses were often preserved. Antibody titers were reduced with mycophenolate and azathioprine but preserved with leflunomide. Conclusion IMRD patients exhibit impaired SARS-CoV-2 vaccine-immunogenicity, variably reduced with immunosuppressors. Among commonly used therapies, abatacept and B-cell depleting therapies show the most deleterious effects, while anticytokines preserved immunogenicity. The effects of cumulative methotrexate and glucocorticoid doses on immunogenicity should be considered. Humoral and cellular responses are weakly correlated, but CD4 and CD8 tightly correlate. Seroconversion alone might not reflect the vaccine's immunogenicity.

Neutralising antibodies (NAbs) against SARS-CoV-2 in BNT162b2 vaccine recipients with a history of advanced HIV infection: cPass as a simpler alternative to gold-standard tests

Background: Established SARS-CoV-2 NAb tests are labor-intensive. We prospectively measured NAbs vs Wuhan-1 and Omicron BA.2 using the novel GenScript cPass assay and examined correlations with responses measured by gold-standard plaque reduction neutralisation test (PRNT) (Cotugno, Ruggiero et al. Cell Rep 2021) and with anti-Spike IgG quantified by Roche Elecsys. Given the paucity of data, we selected BNT162b2 vaccine recipients with a history of advanced HIV infection (prior AIDS-defining conditions and/or nadir CD4 <200 cells). Method(s): In Mar 2021-Apr 2022, 55 PWH received 2 vaccine doses median 3 weeks apart [IQR 3-3] and a 3rd dose 27 weeks later [23-31]. Plasma samples (n=147) were stored immediately before dose-1 (T0), median 4 weeks [3-5] after dose-2 (T1) and median 13 weeks [9-19] after dose-3 (T2) for batch testing. Result(s): Participants' characteristics: 74% male, 85% white, all on ART, 82% HIV-RNA <50 cps/ml;median age 55 years, ART duration 7 years, nadir CD4 83 cells [36-211], current CD4 440 cells [270-710], CD4:CD8 ratio 0.6 [0.4-1.0];73% had a history of advanced HIV infection;15% received a COVID-19 diagnosis during the study. At T0, T1 and T2, proportions with quantifiable anti-S IgG (>0.8 U/ml) were 11/49 (22%), 50/54 (93%) and 43/43 (100%), respectively;their median anti-S IgG titres were 30 [15-124], 15949 [596-3389] and 8527 [3146-17190] U/ml. Proportions showing Wuhan-1 neutralisation by cPass were 6/50 (12%), 45/53 (85%) and 40/43 (93%), with median neutralisations of 67% [47-70], 97% [91-98] and 98% [98-98] and corresponding NAb titres of 1332 [792-1436], 5354 [3529-6187] and 6242 [5765-6766] U/ml. At T2, 25/28 (89%) showed BA.2 neutralisation by cPass (median 83% [68-93];NAb titre 7836 [3172-12173] U/ml) (Fig 1A). Two participants lacking NAbs at T2 had a history of advanced HIV infection. cPass data were highly correlated with anti-S IgG titres (rho 0.82;p<0.0001) and with PRNT data for both Wuhan-1 (n=27, Fig 1B) and Omicron BA.2 (n=28, Fig 1C). Conclusion(s): cPAss offers a simple methodology for measuring SARS-CoV-2 NAbs. Despite prior advanced HIV infection, neutralising activity improved with successive vaccinations and most participants showed NAbs against both Wuhan-1 and Omicron BA.2 after 3 vaccine doses. (Figure Presented).

T cells and subgroups in children with COVID-19

Objective: In COVID-19 disease, it was observed that T lymphocytes decreased numerically, both CD4+ and CD8+ could decrease, and sometimes the CD8+ level increased significantly. The virus-specific CD8+ T-cells are thought to be TEM or TEMRA cells. However, the characteristics of these cells, particularly their role in the pathogenesis of SARS-CoV-2 infection or COVID-19 disease, are unclear. Therefore, this study aimed to examine the flow cytometric changes observed in T helper, T cytotoxic cells, and subtypes during diagnosis in pediatric patients diagnosed with COVID-19 infection with SARS-CoV-2 PCR positivity. Methods: Twenty-two children aged 0-18, diagnosed with COVID-19, with flow cytometry;T Helper Cell (TH), T Cytotoxic Cell (TC), T Naive Cells (TN), Central Memory (TCM), Effector Memory (TEM), RA + Effector memory (TEMRA) and Recent Thymic Emigrants (RTEs) were studied. Results: T cell counts were found to be expected in all age groups. The CD4/CD8 ratio increased in the under-five and over 16 age group. While TCM among CD4+T cells decreased in the group above 16 years of age, TEM decreased in all age groups. RTEs decreased in all except the age group 16+. Naive CD8+ T cells (TN) were found to be high in all age groups. Conclusion: A low number of CD4+ and CD8+ lymphocytes have been reported as a distinctive laboratory finding in 2019 Coronavirus disease (COVID-19). Having enough naive T cells is essential for the immune system to respond consistently to unknown pathogens. This study found that these cells were higher than expected in children.

POLYFUNCTIONAL SARS-CoV-2-SPECIFIC T CELLS PERSIST IN TISSUE OF COVID-19 CONVALESCENTS

Background: T cells play an essential role in SARS-CoV-2 immunity, including in defense against severe COVID-19. However, most studies analyzing SARSCoV- 2-specific T cells have been limited to analysis of blood. Furthermore, the role of T cells in SARS-CoV-2 immunity in pregnant women, which are at disproportionately higher risk of severe COVID-19, is poorly understood. Method(s): Here, we quantitated and deeply phenotyped SARS-CoV-2-specific T cells from convalescent women (n=12) that had mild (non-hospitalized) COVID-19 during pregnancy. Endometrial, maternal blood, and fetal cord blood specimens were procured at term, which ranged from 3 days to 5 months post-infection. SARS-CoV-2-specific T cells were deeply analyzed by CyTOF using a tailored phenotyping panel designed to assess the effector functions, differentiation states, and homing properties of the cells. Result(s): SARS-CoV-2-specific T cells were more abundant in the endometrium than in maternal or fetal cord blood. In a particularly striking example, in one donor sampled 5 months after infection, SARS-CoV-2-specific CD8+ T cells comprised 4.8% of total endometrial CD8+ T cells, while it only reached 1.4% in blood. Endometrial SARS-CoV-2-specific T cells were more frequently of the memory phenotype relative to their counterparts in maternal and fetal cord blood, which harbored higher frequencies of naive T cells. Relative to their counterparts in blood, endometrial SARS-CoV-2-specific T cells exhibited unique phenotypic features, including preferential expression of the T resident memory marker CD69, inflammatory tissue-homing receptor CXCR4, and the activation marker 4-1BB. Endometrial T cells were highly polyfunctional, and could secrete IFNg, TNFa, MIP1b, IL2, and/or IL4 in response to spike peptide stimulation. By contrast, their counterparts in blood preferentially produced the cytolytic effectors perforin and granzyme B. Conclusion(s): Polyfunctional SARS-CoV-2-specific T cells primed by prior exposure to the virus are abundant and persist in endometrial tissue for months after infection. These cells exhibit unique phenotypic features including preferential expression of select chemokine receptors and activation molecules. Compared to their blood counterparts, the effector functions of these cells are more cytokine-driven and less cytolytic. The long-term persistence of these cells in the endometrium may help protect future pregnancies from SARS-CoV-2 re-infection.