ANALYSIS OF EPITOPE-SPECIFIC T CELLS IN SARS-CoV-2 INFECTION AND VACCINATION

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.

Mobile Learning for teaching journalism from a remote television set during COVID-19

This research describes the implementation of a system that allows a television studio to operate through cell phones and mobile applications, this innovation was developed in a university in Peru for television journalism courses. This is an applied research with a qualitative approach, which describes the development of this innovation from the experience of its creator and details how different technologies were made to converge so that students could broadcast news programs from their homes by operating the equipment located on the television set of tv. The results allow us to conclude that the pandemic has led to the invention of educational solutions that hybridize television technologies, cell phones, mobile applications and the Internet, from this convergence it was possible for students to develop journalistic educational skills remotely. © 2022 Latin American and Caribbean Consortium of Engineering Institutions. All rights reserved.

Technological Innovations in the Production of Peruvian Television Newscasts During the Emergence of Covid-19

The outbreak of Covid-19 imposed radical changes in all human activities and television journalism was no exception. This study aims to analyze the innovations that were applied by television journalists in Peru in order to continue practicing their work in one of the countries hardest hit by the pandemic. The applied methodology was qualitative, semi-structured interviews were carried out which allowed knowing the innovations that were applied to overcome the dangers and sanitary restrictions. As a result, it was obtained that the journalists hybridized their teams and production methods with non-television technologies such as video calls, mobile phones, or the implementation of telework to continue producing television news in a context for which they were never prepared. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Transformations in Framing and the Journalistic Production of Peruvian Television Newscasts During the covid-19 Pandemic

As soon as the spread of the covid-19 began, the media's information production was affected by social distancing restrictions and journalists were exposed health hazards in an attempt to carry out their jobs. This study aims at learning about the transformations undergone by the television newscasts production in Peru, one of the most affected countries by the pandemic at a global level. Qualitative methods were applied through semi-structured interviews with journalists working during the said period, obtaining results that evince the implementation of several devices and unconventional or unsuitable television processes. This issue is cross-sectional through the three audiovisual production stages—namely, pre-production, media coverage, and post-production—a situation that has never taken place so intensely and permanently. All this leads to the conclusion that the newscasts production had to resort to the hybridization of technologies and procedures to continue performing their duties in such an unexpected and complex context. © 2023, Universidad del Rosario. All rights reserved.

The percentage of CD39+ monocytes is higher in pregnant COVID-19+ patients than in nonpregnant COVID-19+ patients.

Current medical guidelines consider pregnant women with COVID-19 to be a high-risk group. Since physiological gestation downregulates the immunological response to maintain "maternal-fetal tolerance", SARS-CoV-2 infection may constitute a potentially threatening condition to both the mother and the fetus. To establish the immune profile in pregnant COVID-19+ patients, a cross-sectional study was conducted. Pregnant women with COVID-19 (P-COVID-19+; n = 15) were analyzed and compared with nonpregnant women with COVID-19 (NP-COVID-19+; n = 15) or those with physiological pregnancy (P-COVID-19-; n = 13). Serological cytokine and chemokine concentrations, leucocyte immunophenotypes, and mononuclear leucocyte responses to polyclonal stimuli were analyzed in all groups. Higher concentrations of serological TNF-α, IL-6, MIP1b and IL-4 were observed within the P-COVID-19+ group, while cytokines and chemokines secreted by peripheral leucocytes in response to LPS, IL-6 or PMA-ionomicin were similar among the groups. Immunophenotype analysis showed a lower percentage of HLA-DR+ monocytes in P-COVID-19+ than in P-COVID-19- and a higher percentage of CD39+ monocytes in P-COVID-19+ than in NP-COVID-19+. After whole blood polyclonal stimulation, similar percentages of T cells and TNF+ monocytes between groups were observed. Our results suggest that P-COVID-19+ elicits a strong inflammatory response similar to NP-COVID19+ but also displays an anti-inflammatory response that controls the ATP/adenosine balance and prevents hyperinflammatory damage in COVID-19.

TCR SEQUENCING of EPITOPE-SPECIFIC T CELLS from SARS-CoV-2 CONVALESCENT INDIVIDUALS

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.

Characterization and epitope mapping of SARS-CoV-2-specific t cells

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.

SARS-CoV-2 reinfection of health personnel in Mexico?

OBJECTIVE: To communicate probable cases of COVID-19 reinfection in medical personnel. MATERIALS AND METHODS: A prospective, observational study performed from June to October 2020, in which information was collected on the cases of doctors who had COVID-19 reinfection. RESULTS: Twenty-four doctors with COVID-19 reinfection were included. The most frequent comorbidity in this group of cases was overweight or obesity in 15 patients (62%);7 individuals did not report any comorbidity and 3 of the cases suffered from systemic arterial hypertension, of which 2 also had obesity. CONCLUSIONS: The reinfection of COVID-19 is very likely and the SARS-CoV-2 virus does not provoke a perennial immunological memory in all infected individuals. © 2021 Comunicaciones Cientificas Mexicanas S.A. de C.V.. All rights reserved.

Cyclosporine A plus low-dose steroid treatment in COVID-19 improves clinical outcomes in patients with moderate to severe disease: A pilot study.

BACKGROUND: COVID-19 pandemic causes high global morbidity and mortality and better medical treatments to reduce mortality are needed. OBJECTIVE: To determine the added benefit of cyclosporine A (CsA), to low-dose steroid treatment, in patients with COVID-19. METHODS: Open-label, non randomized pilot study of patients with confirmed infection of SARS-CoV-2 hospitalized from April to May 2020 at a single centre in Puebla, Mexico. Patients were assigned to receive either steroids or CsA plus steroids. Pneumonia severity was assessed by clinical, laboratory, and lung tomography. The death rate was evaluated at 28 days. RESULTS: A total of 209 adult patients were studied, 105 received CsA plus steroids (age 55.3 ± 13.3; 69% men), and 104 steroids alone (age 54.06 ± 13.8; 61% men). All patients received clarithromycin, enoxaparin and methylprednisolone or prednisone up to 10 days. Patient's death was associated with hypertension (RR = 3.5) and diabetes (RR = 2.3). Mortality was 22 and 35% for CsA and control groups (P = 0.02), respectively, for all patients, and 24 and 48.5% for patients with moderate to severe disease (P = 0.001). Higher cumulative clinical improvement was seen for the CsA group (Nelson Aalen curve, P = 0.001, log-rank test) in moderate to severe patients. The Cox proportional hazard analysis showed the highest HR improvement value of 2.15 (1.39-3.34, 95%CI, P = 0.0005) for CsA treatment in moderate to severe patients, and HR = 1.95 (1.35-2.83, 95%CI, P = 0.0003) for all patients. CONCLUSION: CsA used as an adjuvant to steroid treatment for COVID-19 patients showed to improve outcomes and reduce mortality, mainly in those with moderate to severe disease. Further investigation through controlled clinical trials is warranted.