Animal Pre-Clinical Study of an Inactivated SARS-CoV-2 Vaccine candidate (Osvid-19 ): Immunogenicity, Protective, and Safety Aspects

Background: This study aimed to evaluate the outcomes of preclinical studies on the safety and immunogenicity of an inactivated COVID-19 vaccine candidate to warrant further clinical evaluation. Method(s): SARS-CoV-2 positive nasopharyngeal swab specimens were confirmed by real-time polymerase chain reaction and next-generation sequencing. The safety and immunogenicity tests of the COVID-19 vaccine were carried out in rats and Rhesus monkeys, and Balb/C mice and Rhesus monkeys, respectively. Result(s): The candidate vaccine was well tolerated and induced promising levels of SARS-CoV-2- specific IgG1, IgG2a, and Granzyme B in Balb/C mice, and anti-SARS-CoV-2 spike IgG and neutralizing antibodies in Rhesus monkeys. Based on cVNT results, the inactivated vaccine in 0.5 and 1 microg/100 microL doses was able to induce a neutralizing effect against the SARS-CoV-2 virus up to a dilution of 1:512 and 1:1000. The protective efficacy of the vaccine candidate was challenged with 2 x108 PFU of live viruses and confirmed by lung CT scan and histopathological evaluations compared to the control group. Repeated intramuscular injection of the candidate vaccine was generally well-tolerated in Rats and Rhesuses. No significant side effects were observed in rats injected with ten full human doses and in the Rhesus monkeys with three full human doses. Conclusion(s): Based on the findings presented in this study, it is recommended that this vaccine be moved into human testing commencing with a phase I clinical trial.Copyright © 2021 Muslim OT et al.

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.

BASELINE AND TEMPORAL DIFFERENCES IN PROTEOMICS FOLLOWING SARS-CoV-2 INFECTION IN PWH

Background: COVID-19 may be more severe in persons with HIV (PWH). However, underlying biological mechanisms associated with the development of COVID-19 and its clinical severity among antiretroviral therapy (ART) treated PWH are largely unknown. Therefore, we wished to evaluate temporal changes in plasma proteins following SARS-CoV-2 infection and identify pre-infection proteomic markers associated with future COVID-19. Method(s): We analyzed the data of clinical, antibody-confirmed COVID-19 ARTtreated PWH from the global Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE). Individuals were matched on geographic region, age, and sample timing to antibody-negative controls. For cases and controls, pre-COVID-19 pandemic specimens were obtained prior to January 2020 to assess temporal changes and baseline differences in protein expression in relationship to COVID-19 severity, using mixed effects models adjusted for false-discovery rate. Result(s): We compared 257 unique plasma proteins (Olink Proteomics) in 94 COVID-19 antibody-confirmed clinical cases and 113 matched antibody-negative controls, excluding COVID-19 vaccinated participants (median age 50 years, 73% male). 40% of cases were characterized as mild;60% moderate to severe. Median time from COVID-19 infection to follow-up sampling was 4 months. Temporal changes in protein expression differed based on COVID-19 disease severity. Among moderate to severe cases vs. controls, NOS3 increased, whereas ANG, CASP-8, CD5, GZMH, GZMB, ITGB2, and KLRD1 decreased. Higher baseline circulating concentrations of granzymes A, B and H (GZMA, GZMB and GZMH) were associated with the future development of moderate-severe COVID-19 in PWH and were related to immune function, including CD4, CD8 and the CD4/ CD8 ratio. Conclusion(s): We identified temporal changes in novel proteins in closely linked inflammatory, immune, and fibrotic pathways which may relate to COVID-19-related morbidity among ART-treated PWH. Further, we identified key granzyme proteins, serine proteases expressed by cytotoxic T lymphocytes and NK cells in response to foreign antigens, associated with future COVID-19 in PWH. Our results provide unique insights into the biological susceptibility and responses to COVID-19 infection in PWH. (Figure Presented).

HIGH RNAemia ASSOCIATES WITH SKEWED T-CELL RESPONSE IN PLWH HOSPITALIZED FOR COVID-19

Background: Severe COVID-19 outcomes have been reported in people living with HIV (PLWH). High SARS-CoV-2 RNAemia has emerged as a hallmark of severe COVID-19, yet its pathogenic role in the context of COVID-19 in PLWH is currently unknown. We hereby measured SARS-CoV-2 RNAemia and explored its association with T-cell/humoral responses and clinical severity in PLWH. Method(s): Unvaccinated PLWH and age/sex-matched people living without HIV (PLWOH) hospitalized for radiologically-confirmed COVID-19 pneumonia were consecutively enrolled (March 2020-January 2021). We measured: SARS-CoV-2 RNAemia (RT-qPCR);T-cell activation (HLA-DR+CD-38+), cytotoxic T-cells [granzyme-B(GRZB)+perforin(PRF)+], GRZB/PRF production (MFI) by cytotoxic T-cells (flow cytometry);SARS-CoV-2-specific cytokines (IFN-gamma/ TNF-alpha/IL-2/IL-4/IL-17A)-producing T-cells, after SARS-CoV-2 spike peptides challenge (flow cytometry);anti-RBD antibodies (ELISA), Spike-ACE2 binding inhibition (receptor binding inhibition assay). Statistics: Mann-Whitney test and Spearman's correlation. Result(s): 18 PLWH (16 on cART;median CD4 361.5/mL;HIV-RNA< 50 cp/ mL in 15/18) and 18 PLWOH were included at a median of 10 days from symptoms onset (Fig.1A). PLWH had lower PaO2/FiO2 [140 (122-151.5) vs. 207 (156.3-309.3);P=0.0005] and higher SARS-CoV-2 RNAemia (Fig.1B). While humoral responses were comparable between groups ( Fig.1C-D), as was T-cell activation, PLWH showed skewed T-cell responses: higher perforin production by cytotoxic T-cells (Fig.1E);fewer SARS-CoV-2-specific IFN-gamma+ and IL-4+ CD4 T-cells (Fig.1F);lower Th1 tri-functional (IFN-gamma+TNF-alpha+IL-2+) and bi-functional (IFN-gamma+TNF-alpha+) CD4 T-cells (Fig.1G);reduced TNF-alpha+ CD8 T-cells (Fig.1H). Interestingly, SARS-CoV-2 RNAemia correlated negatively with PaO2/FiO2 nadir and SARS-CoV-2-specific T-cells, yet positively with perforin production by cytotoxic T-cells (Fig.1I-M). No correlations between RNAemia and humoral responses were found. Conclusion(s): As compared to HIV-uninfected patients, PLWH hospitalized for COVID-19 pneumonia feature high SARS-CoV-2 RNAemia which is linked to respiratory failure and skewed T-cell responses, with higher perforin production by cytotoxic T-cells, and yet fewer polyfunctional SARS-CoV-2-specific T-cells. Our data suggest a link between HIV-related T-cell dysfunction and poor control over circulating SARS-CoV-2 that may in turn influence COVID-19 severity in PLWH. (Figure Presented).

Immune response and allergenic components of COVID-19 vaccines induced delayed cutaneous reactions

Background: Delayed-type cutaneous adverse reactions (DCARs) are potential adverse reactions induced by COVID-19 vaccinations. Objective(s): To investigate the immune pathomechanism of COVID-19 vaccination-related DCARs. Method(s): We conducted a prospective observational study on patients with COVID-19 vaccine-DCARs and tolerant subjects. Serum immune molecules and high-parameter blood cell analysis were analyzed.In vitro lymphocyte activation test (LAT) was performed to evaluate the causative allergens of COVID-19 vaccines for DCARs. Result(s): We enrolled 103 patients with COVID-19 vaccine-DCARs. Patients suffered from DCARs mainly after the first vaccination dose (75.7%). Compared to the tolerant controls, patients with DCARs showed significantly higher serum levels of IL-4, IL-6, IL-8, IL-17A, IL-18, IFN-gamma, IP-10, MIG, granulysin, PARC and TARC(P=3.40x10-5-0.028). High-parameter flow cytometric analysis revealed significant increased CD4+Th2, CD4+Th17, CD4+Th22, CD4+LAG-3+, CD4+CD103+Trm, Tfr, CD8+CXCR3+, CD8+Tc2, CD8+Tc17 and CD8+CTLA4+cell populations relative to total DCARs and specific phenotypes(P=0.001-0.042). In vitro LAT assays measuring IFN-gamma, granulysin, and granzyme B showed that patients with AZD1222-DCARs were significantly reactive to polysorbate 80 and spike protein;BNT162b2-DCARs were significantly reactive to polyethene glycol(PEG) 2000, and spike protein;while mRNA-1273-DCARs were significantly reactive to PEG 2000, tris and spike protein(P<0.05). Conclusion(s): We demonstrated a distinct immune response related to variable clinical phenotypes involved in the immune mechanism of COVID-19 vaccines-DCARs. In vivo LAT assays showed that COVID-19 vaccines excipients and spike protein were potential major components related to the COVID-19 vaccines-induced DCARs.Copyright © 2023

Identification of pre-infection markers and differential plasma protein expression following SARS-CoV-2 infection in people living with HIV.

BACKGROUND: Mechanisms contributing to COVID-19 severity in people with HIV (PWH) are poorly understood. We evaluated temporal changes in plasma proteins following SARS-CoV-2 infection and identified pre-infection proteomic markers associated with future COVID-19. METHODS: We leveraged data from the global Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE). Antiretroviral therapy (ART)-treated PWH with clinical, antibody-confirmed COVID-19 as of September 2021 were matched on geographic region, age, and sample timing to antibody negative controls. For cases and controls, pre COVID-19 pandemic specimens were obtained prior to January 2020 to assess change over time and relationship to COVID-19 severity, using false-discovery adjusted mixed effects modeling. FINDINGS: We compared 257 unique plasma proteins in 94 COVID-19 antibody-confirmed clinical cases and 113 matched antibody-negative controls, excluding COVID-19 vaccinated participants (age 50 years, 73% male). 40% of cases were characterized as mild; 60% moderate to severe. Median time from COVID-19 infection to follow-up sampling was 4 months. Temporal patterns of protein changes differed based on COVID-19 disease severity. Among those experiencing moderate to severe disease vs. controls, NOS3 increased whereas ANG, CASP-8, CD5, GZMH, GZMB, ITGB2, and KLRD1 decreased. Higher pre-pandemic levels of granzymes A, B and H (GZMA, GZMB and GZMH) were associated with the future development of moderate-severe COVID-19 and were related to immune function. INTERPRETATION: We identified temporal changes in proteins closely linked to inflammatory, immune, and fibrotic pathways which may relate to COVID-19-related morbidity among ART-treated PWH. Further we identified key granzyme proteins associated with future COVID-19 in PWH. FUNDING: This study is supported through NIH grants U01HL123336, U01HL123336-06 and 3U01HL12336-06S3, to the clinical coordinating center, and U01HL123339, to the data coordinating center as well as funding from Kowa Pharmaceuticals, Gilead Sciences, and a grant award through ViiV Healthcare. The NIAID supported this study through grants UM1 AI068636, which supports the AIDS Clinical Trials Group (ACTG) Leadership and Operations Center, and UM1 AI106701, which supports the ACTG Laboratory Center. This work was also supported by NIAID through grant K24AI157882 to MZ. The work of IS was supported by the intramural research program of NIAID/NIH.

Prolonged fever and inflammation in a young child in the midst of the pandemic - it's not always MIS-C

Case Report: Prolonged fever in children is a symptom that is seen in many different diseases, infections, malignancies, and autoimmune conditions. This can, at times, make the correct diagnosis challenging. A previously healthy 10-year-old male was transferred to our institution with one week history of fever, fatigue, abdominal pain, and vomiting. Laboratory studies demonstrated pancytopenia, transaminitis, electrolyte abnormalities, elevated pro-inflammatory markers & D-Dimer, and hypoalbuminemia. COVID-19 IgG was reactive. Due to the severity in presentation the patient was transferred to the ICU with a presumptive diagnosis of MIS-C. Hewas started on IVIG as well as a five-day course of high-dose methylprednisolone per protocol. Aspirin was added, but later discontinued, due to worsening thrombocytopenia. CT imaging with contrast showed small bilateral pleural effusions & periportal edema, mild splenomegaly, and echocardiogram showed diffuse dilation of the left main and left anterior descending arteries. Given the laboratory findings the differential diagnosis was expanded, Ehrlichia caffeensis serology was sent and empiric Doxycycline started. EBV Nuclear Antigen IgG antibody and EBV Viral Capsid Antigen IgM Antibody resulted as positive suggesting recent or reactivated infection. Respiratory viral PCR with COVID-19, Cytomegalovirus and Parvovirus PCR were negative. Despite initial treatment, the patient continued to have persistent fever, severe pancytopenia, and high ferritin up to 24 426 ng/mL, raising suspicion for Haemophagocytic Lymphohistiocytosis (HLH). Soluble interleukin-2 level was elevated & his presentation was then considered to be more consistent with HLH given that he met 6/8 criteria. Screening for primary HLH including CD107a, perforin and granzyme B, SAP, and XIAP resulted in the latter three being normal but CD107a was abnormal. Next generation sequencing for primary criteria was negative. E. Chaffeensis resulted positive: IgM 1:80, IgG 1:256. MIS-C and HLH have overlapping features but differ in some clinical manifestations. Timely recognition and management is paramount as the management differs. This case illustrates the importance of performing a broad search for potential causes, allowing for appropriate and timely treatment. COVID-19 serology alone should not be the basis for diagnosis of MIS-C in a patient with fever and inflammation. This is important as SARS-CoV2 becomes endemic. Infections such as EBV and Ehrlichiosis should be on the differential particularly in endemic areas and during seasons of higher prevalence for the latter, as these have been well documented to cause HLH. Copyright © 2023 Southern Society for Clinical Investigation.

Residual persistence of cytotoxicity lymphocytes and regulatory T cells in patients with severe coronavirus disease 2019 over a 1-year recovery process.

Aim: To clarify the immune cellular changes in critically ill patients recovering from coronavirus disease 2019 (COVID-19). Methods: The immune response of peripheral blood mononuclear cells from patients with severe COVID-19 in different stages of recovery (3, 6, and 12 months from hospitalization) was evaluated by single-cell mass cytometry. Immunological changes in patients were compared with those in age-matched healthy donors. Results: Three patients with severe COVID-19 were compared with four healthy donors. In the patients, there was an increase in the cell density of CD4- and CD8-positive T lymphocytes, and B cells, over the course of the recovery period. CD4- and CD8-positive T lymphocytes expressing T-bet and granzyme B (Gzm B) in patients were abundant during all recovery periods. The level of regulatory T cells remained high throughout the year. The levels of natural killer (NK) cells in patients were higher than in those in the healthy donors, and the frequency of CD16+ NK cells expressing Gzm B increased throughout the year. Conclusion: Patients recovering from severe COVID-19 showed persistence of cytotoxic lymphocytes, NK cells, and regulatory T cells throughout the posthospitalization year of recovery.

ANTI-TNF THERAPY for IMMUNE MEDIATED INFLAMMATORY DISEASES MAY BE ASSOCIATED with LOWER ANTIBODY LEVELS and VIRUS NEUTRALIZATION EFFICACY FOLLOWING SARS-COV-2 MRNA VACCINATION

Background: The impact of immunosuppressants on COVID-19 vaccination response and durability in patients with immune-mediated infammatory diseases (IMID) is yet to be fully characterized. Humoral response may be attenuated in these patients especially those on B cell depleting therapy and higher doses of corticosteroids, but data regarding other immunosuppressants are scarce. Objectives: We aimed to investigate antibody and T cell responses and durability to SARS-CoV-2 mRNA vaccines (BNT162b and/or mRNA 1273) in IMID patients on immunomodulatory maintenance therapy other than B-cell depleting therapy and corticosteroids. Methods: This prospective observational cohort study examined the immuno-genicity of SARS-CoV-2 mRNA vaccines in adult patients with IMIDs (psoriatic arthritis, psoriasis, infammatory bowel disease and rheumatoid arthritis) with or without maintenance immunosuppressive therapies (anti-TNF, methotrexate/azathioprine [MTX/AZA], anti-TNF + MTX/AZA, anti IL12/23, anti-IL-17, anti-IL23) compared to healthy controls. Automated ELISA for IgGs to spike trimer, spike receptor binding domain (RBD) and the nucleocapsid (NP) and T-cell release of 9 cytokines (IFNg, IL2, IL4, IL17A, TNF) and cytotoxic molecules (sFasL, GzmA, GzmB, Perforinin) in cell culture supernatants following stimulation with spike or NP peptide arrays were conducted at 4 time points: T1=pre vaccination, T2=me-dian 26 days after dose 1, T3=median 16 days after dose 2 and T4=median 106 days after dose 2. Neutralization assays against four SARS-CoV-2 variants (wild type, delta, beta and gamma) were conducted at T3. Results: We followed 150 subjects: 26 healthy controls and 124 IMID patients: 9 untreated, 44 on anti-TNF, 16 on anti-TNF with MTX/AZA, 10 on anti-IL23, 28 on anti-IL12/23, 9 on anti-IL17, 8 on MTX/AZA (Table 1). Most patients mounted antibody and T cell responses with increases from dose 1 to dose 2 (100% sero-conversion at T3) and some decline by T4, with variability within groups. Antibody levels and neutralization efficacy was lower in anti-TNFgroups (anti-TNF, anti-TNF + MTX/AZA) compared to controls and waned by T4 (Figure 1). T cell responses were not consistently different between groups. Pooled data showed a higher antibody response to mRNA-1273 compared to BNT162b. Conclusion: Following 2 doses of mRNA vaccination there is 100% seroconver-sion in IMID patients on maintenance therapy. Antibody levels and neutralization efficacy in anti-TNF group are lower than controls, and wane substantially by 3 months after dose 2. These fndings highlight the need for third dose in patients undergoing treatment with anti-TNF therapy and continued monitoring of immunity in these patient groups, taking into consideration newer variants and additional vaccine doses.

A case of acute hepatitis and morbilliform eruption after mRNA COVID-19 vaccination

Objectives: A 36-year-old Caucasian woman developed acute hepatitis and morbilliform eruption arising ten days after the first dose of the mRNA BNT162b2 SARS-CoV-2 vaccine. Materials and Methods: The patient was asymptomatic apart from the skin rash. Liver function tests showed predmoninantly severe transaminitis (AST 523 U/L, ALT 1550 U/L, GGT 151 U/L, ALP 128 U/L, bilirubin 12 umol/L). Only the ANA 1:160 was abnormal. Other serology for autoimmune and infectious diseases were negative. Multiphase computed tomography of the abdomen was unremarkable. The SARS-CoV-2 anti-spike IgG titre was 67.5 AU/mL (cut-off[15 AU/mL). The skin histology revealed spongiotic reaction pattern with focal interface lymphocytic inflammation. Multiple eosinophils and a few plasma cells were present. The epidermal lymphocytes were composed of CD2, CD3, C4, CD5, CD7 and CD8-positive T cells, with a CD4:CD8 ratio of 1:5. A small number stained positive with TIA1, PD1 and granzyme B. CD56 staining was negative. A liver biopsy was performed after 2 days of steroids. Liver histology showed mild steatosis and mild inflammatory portal infiltrate comprising mainly of small lymphocytes that were CD3 positive with retained staining for CD7 and CD8. Lobular architecture was preserved with inconspicuous interface hepatitis or piecemeal necrosis. Results: The patient was treated with intravenous hydrocortisone (400 mg/day) followed by prednisone (50 mg/day). There was rapid improvement in her liver function tests and cutaneous manifestations (Fig. 1). Conclusion: mRNA COVID-19 vaccine induced hepatitis is a rare phenomenon that is steroid-responsive and has associations with cutaneous eruptions. Our patient's lack of hepatic histological abnormalties is most likely due to early immunosuppression. She had epidermal lymphocytosis with predominance of CD8-positive T cells that were not of cytotoxic phenotype and we are uncertain as to their significance. There is limited guidance on the safety of SARS-CoV-2 vaccination in those who have had developed significant hepatic and cutaenous reactions. Further work is needed.

Impaired immunity in elderly, vaccinated residents of an long-term care facility affected by a COVID-19 outbreak

The ongoing COVID-19 pandemic has hit long-term care facilities (LTCF), with outbreaks affecting both residents and health care workers (HCWs). Elderly persons have been prioritized in the implementation of vaccination programs. Here we investigated a COVID-19 outbreak, caused by the Beta variant (B.1.351) in a LTCF where residents and HCWs had received 2 doses of Comirnaty vaccine (Pfizer/BioNTech) until one month before the outbreak. Samples from 14 residents (SARS-CoV-2 PCR-negative: n = 8, PCR-positive: n = 6) and 10 HCWs (PCR-negative: n = 10) were collected at a median of 54 days following the second vaccine dose. IgG antibodies to SARS-CoV-2 spike glycoprotein and neutralizing antibody (NAb) titers were measured. Additionally, functional responses of PBMCs to SARS-CoV-2 spike and nucleocapsid proteins were investigated. We observed that Comirnaty induced higher IgG concentrations and NAb titers in HCWs compared to residents. PBMCs of HCWs responded vigorously to stimulation with SARS-CoV-2 spike glycoprotein, with the secretion of interferon gamma, granzyme B and perforin-1 into supernatants. In comparison, only 3 of 9 samples from residents showed positive cellular responses to spike glycoprotein. Group-level cellular responses directed at SARS-CoV-2 nucleoprotein remained low both in HCWs and in residents. Only 2 of 2 PCR-positive residents showed a positive response consistent with exposure to SARS-CoV-2 breakthrough infection. Our results show that elderly persons are at increased risk for breakthrough infection after vaccination. Weak vaccine-directed responses in the elderly need to be addressed in vaccination protocols.

Antibody patterns and T-cell responses to SARS-CoV-2 in Swedish primary health care workers during the Covid-19 pandemic

During the first period of the Covid-19 pandemic, most of the immunological studies on SARS-CoV-2 were based on hospitalized-and intensive care unit patients. In this study, a healthy population continuously exposed to the virus, Swedish primary health care workers (n = 156), were monitored for 6 months and the development of antibody patterns and T-cell responses to SARS-CoV-2 were evaluated. In addition to blood sampling, demographic-and clinical information such as PCR-tests, self-reported symptoms, underlying medical conditions, and medications were collected. Multivariate statistical analysis using OPLS-DA showed that Covid-19 infection was associated with SARS-CoV-2 specific IgG antibodies, T-cell responses, male sex, hypertension, and higher BMI and contrary, that not contracting the infection, was associated with female sex, no-or only SARS-CoV-2 specific IgA antibodies, smoking and airborne allergy. Analysis with Cytometry by Time-of-flight (CyTOF) revealed a unique cytotoxic CD4+ T cell population in participants with IgG-dominated antibody responses which expressed CD25, CD38, CD69, CD194, CD279, CTLA-4 and granzyme B. 10% of the study participants had only SARS-CoV-2 specific IgA antibodies with no detectable SARS-CoV-2 specific IgG antibodies. These IgA antibodies could partially neutralize the virus in vitro and none of the participants with this antibody pattern contracted Covid-19 during the study period. These results have the potential to further help us understand the immunological responses to SARS-CoV-2 infection.

Faster cytotoxicity with age: Increased perforin and granzyme levels in cytotoxic CD8+ T cells boost cancer cell elimination.

A variety of intrinsic and extrinsic factors contribute to the altered efficiency of CTLs in elderly organisms. In particular, the efficacy of antiviral CD8+ T cells responses in the elderly has come back into focus since the COVID-19 pandemic outbreak. However, the exact molecular mechanisms leading to alterations in T cell function and the origin of the observed impairments have not been fully explored. Therefore, we investigated whether intrinsic changes affect the cytotoxic ability of CD8+ T cells in aging. We focused on the different subpopulations and time-resolved quantification of cytotoxicity during tumor cell elimination. We report a surprising result: Killing kinetics of CD8+ T cells from elderly mice are much faster than those of CD8+ T cells from adult mice. This is true not only in the total CD8+ T cell population but also for their effector (TEM ) and central memory (TCM ) T cell subpopulations. TIRF experiments reveal that CD8+ T cells from elderly mice possess comparable numbers of fusion events per cell, but significantly increased numbers of cells with granule fusion. Analysis of the cytotoxic granule (CG) content shows significantly increased perforin and granzyme levels and turns CD8+ T cells of elderly mice into very efficient killers. This highlights the importance of distinguishing between cell-intrinsic alterations and microenvironmental changes in elderly individuals. Our results also stress the importance of analyzing the dynamics of CTL cytotoxicity against cancer cells because, with a simple endpoint lysis analysis, cytotoxic differences could have easily been overlooked.

Autoimmune Acute Myelitis with Guillain-Barré Syndrome and Cerebellar Ataxia after COVID-19 Infection: a Case Report

Objective: We aim to report clinical characteristics of an extremely rare case of myelitis with Guillain-Barré syndrome (GBS) and cerebellar ataxia (CA) after COVID-19 infection. Background: There have been many reports about neurological complications following the world pandemic of COVID-19. We found about 100 GBS, 50 myelitis, and 10 CA cases after COVID-19 infection. To best our knowledge, this is the first report of myelitis with GBS and CA accompanied by multiple autoantibodies. Design/Methods: NA Results: A 60-year-old man with fever and cough was diagnosed with mild COVID-19 infection. Fourteen days later from the onset, he developed gait disturbance and fell frequently. On hospitalization, he exhibited fever, hypoxemia, mild consciousness disturbance, flaccid paraplegia, mild numbness and severe deep sensory disturbance in the lower limbs, bladder and bowel disturbance, mild muscle weakness in the fingers, myoclonus in the extremities, and CA. The PCR of COVID-19 was negative. Blood investigations showed elevated inflammatory markers with dehydration, rhabdomyolysis, and hypercoagulation. Cerebrospinal fluid (CSF) analysis presented mild pleocytosis and elevated protein without anti-COVID-19 antibodies. Contrast-enhanced CT showed massive pulmonary embolisms and deep venous thromboses. Brain SPECT showed cerebellar hypoperfusion despite no abnormalities in brain MRI. Spine MRI revealed longitudinal hyperintense lesions mainly in the dorsal white matter, compatible with myelitis. Additional investigations of autoantibodies realized anti-GM3, TPI, GluR, and NMDAR IgG antibodies in serum, and anti-GluR and NMDAR IgG antibodies with increased granzyme B in CSF. Treatments of corticosteroid and intravenous immunoglobulin resulted in complete recovery to consciousness disturbance, muscle weakness of fingers, myoclonus, and CA, while paraparesis with deep sensory and bladder and bowel disturbance remained. Conclusions: We highlight the possibility of the coexistence of several post-infectious autoimmune neurological complications in patients of COVID-19. It is important to search autoantibodies carefully corresponding to clinical manifestations for appropriate treatments and understanding of pathophysiology.

Longitudinal Assessment of SARS-CoV-2-Specific T Cell Cytokine-Producing Responses for 1 Year Reveals Persistence of Multicytokine Proliferative Responses, with Greater Immunity Associated with Disease Severity.

Cell-mediated immunity is critical for long-term protection against most viral infections, including coronaviruses. We studied 23 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected survivors over a 1-year post-symptom onset (PSO) interval by ex vivo cytokine enzyme-linked immunosorbent spot assay (ELISpot) assay. All subjects demonstrated SARS-CoV-2-specific gamma interferon (IFN-γ), interleukin 2 (IL-2), and granzyme B (GzmB) T cell responses at presentation, with greater frequencies in severe disease. Cytokines, mainly produced by CD4+ T cells, targeted all structural proteins (nucleocapsid, membrane, and spike) except envelope, with GzmB and IL-2 greater than IFN-γ. Mathematical modeling predicted that (i) cytokine responses peaked at 6 days for IFN-γ, 36 days for IL-2, and 7 days for GzmB, (ii) severe illness was associated with reduced IFN-γ and GzmB but increased IL-2 production rates, and (iii) males displayed greater production of IFN-γ, whereas females produced more GzmB. Ex vivo responses declined over time, with persistence of IL-2 in 86% and of IFN-γ and GzmB in 70% of subjects at a median of 336 days PSO. The average half-life of SARS-CoV-2-specific cytokine-producing cells was modeled to be 139 days (~4.6 months). Potent T cell proliferative responses persisted throughout observation, were CD4 dominant, and were capable of producing all 3 cytokines. Several immunodominant CD4 and CD8 epitopes identified in this study were shared by seasonal coronaviruses or SARS-CoV-1 in the nucleocapsid and membrane regions. Both SARS-CoV-2-specific CD4+ and CD8+ T cell clones were able to kill target cells, though CD8 tended to be more potent. IMPORTANCE Our findings highlight the relative importance of SARS-CoV-2-specific GzmB-producing T cell responses in SARS-CoV-2 control and shared CD4 and CD8 immunodominant epitopes in seasonal coronaviruses or SARS-CoV-1, and they indicate robust persistence of T cell memory at least 1 year after infection. Our findings should inform future strategies to induce T cell vaccines against SARS-CoV-2 and other coronaviruses.

SARS-CoV-2 mRNA VACCINATION EXPOSES LATENT HIV to Nef-SPECIFIC CD8+ T CELLS

Background: The kinetics and functional profiles (granzyme-B production) of HIV-specific T-cell responses support that those targeting the early viral gene product Nef disproportionately recognize residual antigen expression during long-term antiretroviral therapy (ART). Here, we leveraged this insight to test whether SARS-CoV2 mRNA vaccines-which activate TLR and inflammatory signaling pathways-would reactivate latent HIV, stimulating T-cell responses with these characteristics. Methods: T-cell responses to individual HIV gene products were measured by IFN-g or granzyme B ELISPOT, and by activation induced marker (AIM) assays at baseline and ∼2 weeks after SARS-CoV-2 mRNA vaccine prime and boost, in 13 long-term ART treated adults. Total and unspliced HIV mRNA, as well as intact and defective (IPDA) HIV DNA were measured in parallel by digital droplet PCR (ddPCR). Results: We observed transient increases Nef-specific T-cell responses following vaccine prime by granzyme B ELISPOT (3.1-fold increase, p=0.002) and a trend by AIM assay (1.5-fold increase, p=0.06). Such increases were not observed in granzyme B responses to late gene products nor in any IFN-g responses. Both unspliced and total HIV mRNA decreased significantly across the study, unspliced-1.6-fold decrease p = 0.03;total-1.5-fold decrease p = 0.05. Changes in total HIV mRNA correlated inversely with Nef-specific granzyme B-producing (spearman's ρ =-0.73, p = 0.006) and Nef-specific CD8+ AIM T-cell responses (ρ =-0.76, p = 0.006) following vaccine prime. These reductions in HIV RNA were not accompanied by significant changes in total or intact HIV DNA. Conclusion: Consistent with our hypothesis, a restricted profile of HIV-specific T-cell responses showed significant increases following SARS-CoV-2 vaccine prime, each of which were then correlated with reductions in HIV RNA. This supports that vaccination promoted productive interactions between Nef-specific CTL and HIV-infected cells in vivo. We propose three scenarios for why this was not reflected in reductions in intact or total HIV DNA: i) meaningful depletions in inducible proviruses occurred but were lost against the background of non-inducible proviruses ii) interactions with CTL involved only a fraction of inducible proviruses, or iii) substantive proviral depletions occurred, but were counterbalanced by clonal expansion of HIV-infected cells.

Intracellular Cytokine Profiling by High-Dimensional Flow Cytometry Demonstrates Highly Augmented Cytotoxicity and Overly Activated NK cells in COVID-19 Patients

Background: COVID-19 pandemic has caused more than 4.7 million deaths worldwide to date and still continues globally unabated. Numerous studies have linked the mortality in COVID-19 to aggressive immune response and cytokine storm. However, little is known about the cytokine profiles of individual immune cells that are directly involved in tissue damage. Here we investigate intracellular cytokines in individual T and NK cells of COVID-19 patients. Design: We studied 50 blood samples from 22 COVID-19 patients, 4 with mild, 6 moderate and 12 severe disease. There were 6 healthy controls. We performed high-dimensional 30-color spectral flow cytometry to characterize the immune cell subsets. For cytokine study, cells were stimulated for 6 hours, and stained for surface antigens and intracellular cytokines (IL1b, IL2, IL4, IL6, IL8, IL10, IL12, IL17a, IL21, INFg, GnzB, TNFa, and GMCSF). Data ware acquired on FACSymphony 50-parameter analyzer and analysis performed using FlowJo. Results: Our studies revealed significant differences in lymphocyte cytokine profiles between COVID+ and healthy controls (Fig 1). CD4+ and CD8+ T-cells exhibited increased percentages of IL2+ and IFNg+ cells, indicating a shift towards Th1 reaction. Granzyme B is highly upregulated in all T and NK cell subsets, demonstrating highly armed cytotoxic cells in COVID patients. The most prominent changes were noted in NK cells, 7 cytokines were highly expressed, most are proinflammatory cytokines. Of particular interest are IL-21 and GMCSF, both are known to play important roles in inflammatory cell recruitment, activation and renewal, which can lead to augmented tissue inflammation and injury. These changes were already evident in patients with mild disease, but there is heightened cytokine production in severe cases. Conclusions: Using high-dimensional flow cytometry we demonstrated for the first time significantly increased production of multiple proinflammatory cytokines and cytotoxic molecules in individual T and NK cells of COVID-19 patients. NK cells are most drastically activated. It is conceivable that when recruited to the target tissue such as lung, these highly primed cells will play a major role in tissue injury and ultimately organ failure via their direct cytotoxicity and cytokine secretion. This is consistent with previous reports of increased NK cells in the COVID lungs. Analysis of NK cell cytokine profiles may serve to predict disease progression, and reveal new targets for immune-therapy for severe COVID patients. (Table Presented).

Adenosine-based cancer immunotherapy for COVID-19

Cancer immunotherapy has shaped the way in which we design cancer treatments, introducing the paradigm of taking advantage of our immune system to fight cancer. We propose that the same concept could be applied to infectious diseases and, especially, to those that hamper the immune system like COVID-19. It is well known that an adaptive immune response is able to eradicate viral infections and CD8+ T-cells are key in such anti-viral response. Furthermore, several studies reported that the number of CD8+ T-cells is reduced in COVID-19 patients since the beginning of SARS-CoV-2 infection and further decreased in severe cases. CD8+ T-cells often show signs of exhaustion, loss of T-cell functions and suppression in COVID-19 patients, suggesting that hampering CD8+ T-cells could be a way by which SARS-CoV-2 infection progresses. Importantly, the number of CD8+ T cells appears to re-increase in patients that are recovering from COVID-19, suggesting that CD8+ T-cells could be a key factor that determines whether our body can recover from the disease. We propose that therapies that boost CD8+ T cells could be effective in clearing SARS-CoV-2 infection in COVID-19. To test this, we will take advantage of the adenosine-mediated immunomodulation. Adenosine, an ATP metabolite that is produced during inflammation, hypoxia and in the tumor microenvironment, was found to suppress the immune response through activation of adenosine receptors present on immune cells. Small molecules antagonists that block one of these receptors, adenosine A2A receptor (A2AR) antagonists, are currently being studied to boost anti-cancer T-cell mediated immune responses. Our data show that treatment with an A2AR antagonist restores and stabilizes Notch1, a key pathway for T-cell functions, along with production of INF-gamma and Granzyme B and proliferation in CD8+ T-cells. As a proof of concept, our data indicates that treatment with an A2AR antagonist increases CD8+ T-cells anti-cancer response in tumor-derived organoids, suggesting that the treatment boosts CD8+ T-cells-mediated immune response. Ongoing work aims to test whether the A2AR antagonist treatment restores several parameters of T-cell function that are specifically modified in COVID-19. This analysis will help to predict the action of the A2AR antagonist on T-cells in vivo and we ultimately aim to test this treatment in a mouse model for COVID-19. Overall, our work could introduce a new paradigm and new therapies for COVID-19 and other infectious diseases.

Allogeneic, Off-the-Shelf, SARS-CoV-2-specific T Cells Demonstrate Reactivity Against Emerging Variant Strains

Background. The impact of COVID-19 has been profound with >170,000,000 confirmed cases worldwide and emerging variants being a cause of global concern. Defects in T-cell function and trafficking have been described among those with severe illness, and immunodeficiency is a risk factor for persistent viral shedding and prolonged symptoms. Because of our prior clinical data demonstrating that allogeneic, off-the-shelf virus-specific T cells (VSTs) can safely and effectively treat viral infections, we investigated the feasibility of targeting COVID-19 using banked, SARS-CoV-2-specific VSTs. Methods. We first screened PBMCs from convalescent individuals against 18 structural and non-structural/accessory (NSPs/APs) SARS-CoV-2 proteins and identified 5 [Spike (S), Membrane (M), Nucleoprotein (N), NSP4, and AP7a] as immunodominant which were then advanced to our VST production process. Results. Using overlapping peptide libraries spanning these antigens as a stimulus, we achieved a mean 7.6±0.9 fold expansion (n=13) of VSTs (96±0.5%), with a mixture of cytotoxic (CD8+) and helper (CD4+) T cells that expressed activation and central/effector memory markers. These VSTs were potent, Th1-polarized and polyfunctional, producing IFNγ, TNFα, GM-CSF and Granzyme B. Moreover, the VSTs were able to kill pepmix-loaded autologous targets with no evidence of auto- or alloreactivity, attesting to their virus selectivity and safety for clinical use (Figure 1). Finally, though initially generated against the reference strain NC-045512.2 (Wuhan), these VSTs were able to recognize other clinically important variants including B1.1.7 (UK), B1.351 (South Africa) and P1 (Brazil). This demonstrates the cross-reactive potential of these polyclonal and diverse VSTs, which were developed to provide potent antiviral effects and minimize the risk of immune escape due to sequence variation. Figure 1: SARS-CoV-2 Specific T cells Have Demonstrated Selective Cytolytic Activity against SARS-CoV-2 While Leaving Non-Virus Infected Targets Intact. Conclusion. In conclusion, it is feasible to generate polyclonal SARS-CoV-2 VSTs that provide coverage against variant strains using GMP-compliant manufacturing methodologies. We have advanced this product to the bedside for administration in a Phase I, randomized clinical trial [VSTs+ standard of care (SOC) vs SOC] in high-risk patients hospitalized with COVID-19 (NCT04401410).

Prolonged enhancement of cytotoxic T lymphocytes in the post-recovery state of severe COVID-19.

We evaluated the peripheral blood immune responses of lymphocytes in severe Coronavirus disease 2019 (COVID-19) patients in different stages of recovery using single-cell mass cytometry. The patients with prolonged hospitalization did not show recovery of B lymphocyte counts and CD4-positive T lymphocyte counts but did show abundant CD8-positive T lymphocytes. CD4 and CD8 T cells expressing high levels of T-bet and Granzyme B were more abundant in post-recovery patients. This study showed that cytotoxic Th1 and CD8 T cells are recruited to the peripheral blood long after recovery from COVID-19.