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Background: The rapid development of SARS-CoV-2 mRNA vaccines has been a remarkable success of the COVID-19 pandemic, but vaccine-induced immunity is heterogeneous in immunocompromised populations. We sought to determine the immunogenicity of SARS-CoV-2 mRNA vaccines in a cohort of people with idiopathic CD4 lymphopenia (ICL). Method(s): 25-patients with ICL followed at the National Institutes of Health on a natural history protocol were evaluated between 2020-2022. Blood and serum was collected within 4-12 weeks after their second and/or third SARS-CoV-2 mRNA vaccine dose. Twenty-three matched healthy volunteers (HVs) provided blood samples at similar timepoints post-mRNA vaccination on a separate clinical protocol. Pre-vaccine blood samples were also used when available. Anti-spike and anti-receptor binding domain antibodies were measured. T-cell stimulation assays were performed to quantify SARS-CoV-2 specific T-cell responses. Comparisons were made with Wilcoxon test. Result(s): Twenty-participants with ICL had samples collected after their second mRNA vaccine and 7-individuals after the third dose. Median age at vaccination was 51-years (IQR: 44-62) and 12 were women (48%). Median CD4 T-cell count was 150 cells/muL (IQR: 85-188) at the time of vaccination, and 11-individuals (44%) had a baseline CD4 count <=100 cells/muL. HVs had a median age of 54-years (IQR: 43-60) with 13-women (56.5%). Anti-spike IgG antibody levels were significantly greater in HVs than those with ICL after 2-doses. Lower SARS-CoV-2 IgG antibody production was primarily observed in those with baseline CD4 T-cells <=100 cells/mul (Figure-1A). The decreased production in ICL remained after a third vaccine dose (Figure-1B). There was a significant correlation between anti-spike IgG and baseline CD4 count. Spike-specific CD4 T-cell responses in volunteers compared to those with ICL demonstrated similar levels of activation induced markers (CD154+CD69+) and cytokine production (IFNgamma+, TNFalpha+, IL2+) after two or three mRNA vaccine doses. Quantitatively the smallest responses were observed in those with lower baseline CD4 T-cells (Figure 1C-D). Minimal SARS-CoV-2 CD8 T-cell responses were detected in both groups. Conclusion(s): Patients with ICL and baseline CD4 T-cells >100 mount similar humoral and cellular immune responses to SARS-CoV-2 vaccination as healthy volunteers. Those with baseline CD4 T-cells <=100 have impaired vaccine- induced immunity and should be prioritized to additional boosters and continue other risk mitigation strategies. (Figure Presented).
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Background: T cells play a critical role in the adaptive immune response to SARS-CoV-2 in both infection and vaccination. Identifying T cell epitopes and understanding how T cells recognize these epitopes can help inform future vaccine design and provide insight into T cell recognition of newly emerging variants. Here, we identified SARS-CoV-2 specific T cell epitopes, analyzed epitope-specific T cell repertoires, and characterized the potency and cross-reactivity of T cell clones across different common human coronaviruses (HCoVs). Method(s): SARS-CoV-2-specific T cell epitopes were determined by IFNgamma ELISpot using PBMC from convalescent individuals with mild/moderate disease (n=25 for Spike (S), Nucleocapsid (N) and Membrane (M)), and in vaccinated individuals (n=27 for S). Epitope-specific T cells were isolated based on activation markers following a 6-hour peptide stimulation, and scRNAseq was performed for TCR repertoire analysis. T cell lines were generated by expressing recombinant TCRs in Jurkat cells and activation was measured by CD69 upregulation. Result(s): We identified multiple immunodominant T cell epitopes across S, N and M proteins in convalescent individuals. In vaccinated individuals, we detected many of the same dominant S-specific epitopes at similar frequencies as compared to convalescent individuals. T cell responses to peptide S205 (amino acids 817-831) were observed in 56% and 59% of individuals following infection and vaccination, respectively, while 20% and 19% of individuals responded to S302 (a.a. 1205-1219) following infection and vaccination, respectively. For S205, a CD4+ T cell response, we confirmed 8 unique TCRs and determined the minimal epitope to be a 9mer (IEDLLFNKV). While TCR genes TRAV8-6*01 and TRBV30*01 were commonly utilized across the TCRs, we did identify TCRs with unique immunogenetic properties with different potencies of cross-reactivity to other HCoVs. For S302, a CD8+ T cell response, we identified two unique TCRs with different immunogenetic properties that recognized the same 9mer (YIKWPWYIW) and cross-reacted with different HCoV peptides (Figure 1). Conclusion(s): These data identify immunodominant T cell epitopes following SARS-CoV-2 infection and vaccination and provide a detailed analysis of epitope-specific TCR repertoires. The prospect of developing a vaccine that broadly protects against multiple human coronaviruses is bolstered by the identification of conserved immunodominant SARS-CoV-2 T cell epitopes that cross react with multiple other HCoVs.
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Introduction:: The COVID pandemic and public health restrictions significantly impacted those living with neurological conditions such as Parkinson’s Disease due to the curtailment of therapies. Patients attending a single centre movement disorders clinic reported reduced physical activity and quality of life during the pandemic. This study aimed to assess the impact of pandemic restrictions on Parkinson’s Disease symptom severity in people with mild to moderate Parkinson’s Disease. Method:: A cross-sectional study design with a convenience sample of 20 people living with mild to moderate Parkinson’s Disease was adopted. A telephone survey questionnaire was completed to measure changes in symptom severity on the 14 most common Parkinson’s Disease symptoms. Data were analysed using descriptive statistics. Results:: Nineteen participants completed the survey. Participants frequently reported a decline in nine symptoms of Parkinson’s Disease;bradykinesia, rigidity, walking, sleep, mood, memory, quality of life and fatigue. Nil changes in freezing were reported. No change was reported in the nonmotor symptoms of constipation, speech and pain in 75, 65 and 95% of participants, respectively. Conclusion:: Findings of this study acknowledge the negative impact of restrictions on the motor and nonmotor symptoms of Parkinson’s Disease. Flexibility to access and delivery of service should be considered to mitigate any future potential restrictions.
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Background: COVID-19 has been a devastating disease and a major public health concern mainly to susceptible populations. Methods: We accessed two groups of pregnant women at the time of delivery: SARS-CoV2 active infection and convalescents. To investigate the factors contributing to COVID19 severity we have assessed several immunological parameters including cytokines/chemokine levels in the maternal and cord blood plasma. We have evaluated 33 cytokines. Our findings were validated in vitro in HTBE (Human tracheobronchial epithelial) cells infected with live SARS-COV2 (wild type). Results: Our cohort was enriched in high-risk subjects, including African American and obese women. Only 6% had severe or critical disease, contrasting with the 20-25% reported in some pregnant cohorts. TGFb2 levels were significantly associated with asymptomatic/mild disease in both active and convalescent cohorts, and inversely correlated with IP10, IL6 and IL8, known to be part of the cytokine storm post-infection. Pre-treatment of HTBE with TGFb2 for 48 hours led to a significant decay in viral loads at 72h post-infection. This control was associated with significantly higher IL-6 (IFNb2) levels prior to infection, and significantly higher expression of anti-viral genes at 72h pi (MX1, IFNA1, IFNA2, IFNL1, STAT1). Additionally, TGFb2 pre-treatment suppressed the expression of the cytokines IP-10, IL1b and IL8. Conclusion: Altogether this data suggested that TGFB2 plays a protective role in SARS-COV2 infection in this high-risk population by improving epithelial cells intrinsic antiviral function and by modulating the expression of the cytokines associated to the heightened inflammation in severe cases.
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Background: T cells have been shown to play a role in the immune response to SARS-CoV-2. Identification of T cell epitopes and a better understanding of the T cell repertoire will provide important insights into how T cells impact antiviral immunity. Here, we identified T cell epitopes within the Spike (S), Nucleocapsid (N) and Membrane (M) proteins from SARS-CoV-2 convalescent individuals and performed TCR sequencing on epitope-specific T cells. Methods: Epitope mapping was performed by IFNγ ELISpot on PBMC from SARS-CoV-2 convalescent patients with mild/moderate disease (n = 19 for S;n=15 for N and M), and minimum epitopes were determined using truncated peptides and ICS. TCR sequence analysis was performed on a subset of individuals (n=9 donors;2-3 epitopes/donor), with longitudinal samples for 7 donors (2-3 time points/donor;33 to 236 days post-symptom onset). T cells were stimulated with individual peptides for 6 hours and sorted based on the expression of activation markers (CD4+: CD69, CD40L;CD8+: CD69, CD107a, surface TNF). scRNAseq was performed on sorted cells for TCR repertoire and transcriptome analysis. Results: We identified several peptides recognized by multiple individuals, including S42 (amino acids 165-179;7/19 donors), S302 (a.a. 1205-1219;6/19 donors), N27 (a.a. 106-120;6/14 donors) and M45 (a.a. 177-191;10/14 donors). S42 elicited both CD4+ (n=5) and CD8+ (n=1) T cell responses, with one individual having both a CD4+ and CD8+ response. The minimum epitope for S42 was determined to be a 9mer (FEYVSQPFL) for both CD4+ and CD8+ cells. TCR sequencing of S42-specific T cells identified a dominant gene pairing for TCRα across multiple donors (TRAV35;TRAJ42) and for both CD4+ and CD8+ T cells (Figure 1). In general, epitope-specific CD4+ responses (S42, M45) were more clonally diverse than CD8+ responses (S42, S302, N27). For both CD4+ and CD8+ T cells, conserved TCR gene usage and gene pairings could be identified within multiple donors responding to the same epitope. Conclusion: These data suggest that in SARS-CoV-2 convalescent people, epitope-specific CD4+ and CD8+ T cells can differ in their clonal diversity and that related TCRs can be identified across multiple donors. S42-specific T cell studies are ongoing to determine their transcriptional profile and pMHC presentation. Ongoing longitudinal analysis will provide a better understanding of different epitope-specific TCR repertoires and T cell transcriptional profiles, and how they evolve after infection.
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[Figure: see text].
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Background: The development of a preventive vaccine remains a critical priority for ending the HIV/AIDS pandemic. Critical improvements in mRNA technology, as attested by recent successes in preventing COVID-19 disease, led us to develop an mRNA platform for HIV vaccines. Methods: In this regard, we designed an mRNA vaccine with different HIV-1 envelope mRNAs from 3 different clades co-formulated with SIV gag mRNA, which can assemble virus like particles (VLPs) in vivo. Rhesus macaques were primed with a transmitted-founder clade-B Env lacking the 276 N-glycan followed by multiple glycan-repaired autologous and bivalent heterologous (clades A and C) booster immunizations. Results: Immunized animals rapidly developed autologous neutralizing antibodies and eventually, after the second heterologous boost, cross-reactive tier-2 neutralizing antibodies, albeit at low titers. Vaccinated animals were protected from repeated low-dose rectal challenges with a heterologous tier-2 simian-human immunodeficiency virus (AD8). Protection was correlated with the presence of antibodies to the CD4-binding site. Conclusion: Thus, the Gag-Env VLP mRNA platform offers a promising strategy for the development of an HIV-1 vaccine.
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Background: The role that CD4+ and CD8+ T cells play in the protection from and disease severity of COVID-19 is not completely understood. A better understanding of T cell function and the epitopes that they target will be invaluable in the development of the next generation of vaccines and therapeutics. To better understand the role of T cells, we characterized the frequency, effector functions and phenotype of SARS-CoV-2-specific CD4+ and CD8+ T cells in a cohort of patients who recovered from COVID-19, and identified multiple peptides that contain T cell epitopes within the Spike protein (S), Nucleocapsid protein (N) and Membrane protein (M). Methods: The frequency and phenotype of SARS-CoV-2-specific T cells from convalescent patients with mild or moderate disease (n=27, 25 to 92 days post-symptom onset) were determined by polychromatic flow cytometry and intracellular cytokine staining (ICS). Cells were stimulated for 6 hours with peptide pools corresponding to S, N and M. Cytokine production, memory phenotype, chemokine receptor expression and PD-1 expression were analyzed. For a subset of individuals (n = 19 for S;n=14 for N and M), IFNg ELISpot assays and peptide matrices were utilized to identify peptides that contain T cell epitopes. Results: CD4+ T cell responses to S, N and/or M were detected in almost all donors by ICS and were predominantly a Th1-type response as determined by cytokine production (IFNg, IL-2 or TNF) and expression of CXCR3. A majority of the antigen-specific CD4+ cells were found in the effector memory compartment. Although less robust than the CD4+ T cell response, antigenspecific CD8+ T cells were detected in a majority of donors, were found within the effector memory compartments and displayed modest PD-1 upregulation. Multiple peptides that contain T cell epitopes were identified by IFNg ELISpot (Figure 1). Some of the most commonly identified peptides include S42 (amino acids 165-179;7/19 donors), S205 (a.a. 817-831;10/19 donors), N83 (a.a. 329-343;7/14 donors), M37 (a.a. 145-159;8/14 donors) and M45 (a.a. 177-191;10/14 donors). Conclusion: These data suggest that T cells that target S, N and M play an important role in the immune response to SARS-CoV-2 and should be considered in future vaccine development. Further studies such as transcriptomic analysis and the TCR usage in longitudinal samples will provide a better understanding of epitope-specific T cells and their longevity.
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Introduction: The impact of the novel Coronavirus (Covid-19) has been felt around the world. The need for resource reallocation and increased Covid-associated risks have meant that elective surgeries are rationalised, resulting in many cancellations. Many organisations have put forth guidelines on how to triage these cases, but no universally accepted protocol exists and the effect of delays on patient outcomes remains uncertain (1). The aim of this study was to review the impact of Covid-19 on the urology waiting lists in 3 Dublin centres. Methods: A database of all patients awaiting a urological procedure in either Connolly Hospital, St Joseph's Hospital Raheny or Beaumont University Hospital was created and prospectively maintained from the 16th of March 2020. Results: A total of 77 urological procedures have been postponed between the two hospitals. Of these, 52% (n = 40) were flexible cystoscopies for haematuria or bladder cancer surveillance, 10% (n = 8) were ureteroscopies for patients with indwelling ureteric stents and 8% (n = 6) were transurethral resection of bladder tumours. During this time, 5 patients phoned the service complaining of urological symptoms, one patient attended their general practitioner, and one patient presented to emergency department directly. To date, 4 urology patients have tested positive for Covid-19 between the two institutions. Conclusions: While this study is ongoing, it has highlighted that several urgent cases have already been postponed. Though the full impact of these delays on patient outcomes remains to be seen, many patients have already sought medical advice for ongoing symptoms as a result.