LitCovid-sentences  

PMC:7200337 / 33677-38411 JSONTXT 10 Projects

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Id Subject Object Predicate Lexical cue
T188 0-39 Sentence denotes Induction of Antiviral T Cell Responses
T189 40-182 Sentence denotes Available information about SARS-CoV-1-specific T cell immunity may serve as an orientation for further understanding of SARS-CoV-2 infection.
T190 183-380 Sentence denotes Immunogenic T cell epitopes are distributed across several SARS-CoV-1 proteins (S, N, and M, as well as ORF3), although CD4 T cell responses were more restricted to the S protein (Li et al., 2008).
T191 381-655 Sentence denotes In SARS-CoV-1 survivors, the magnitude and frequency of specific CD8 memory T cells exceeded that of CD4 memory T cells, and virus-specific T cells persisted for at least 6–11 years, suggesting that T cells may confer long-term immunity (Ng et al., 2016, Tang et al., 2011).
T192 656-922 Sentence denotes Limited data from viremic SARS patients further indicated that virus-specific CD4 T cell populations might be associated with a more severe disease course, since lethal outcomes correlated with elevated Th2 cell (IL-4, IL-5, IL-10) serum cytokines (Li et al., 2008).
T193 923-1051 Sentence denotes However, the quality of CD4 T cell responses needs to be further characterized to understand associations with disease severity.
T194 1052-1141 Sentence denotes Few studies have thus far characterized specific T cell immunity in SARS-CoV-2 infection.
T195 1142-1540 Sentence denotes In 12 patients recovering from mild COVID-19, robust T cell responses specific for viral N, M, and S proteins were detected by IFN-γ ELISPOT, weakly correlated with neutralizing antibody concentrations (similar to convalescent SARS-CoV-1 patients; Li et al., 2008), and subsequently contracted with only N-specific T cells detectable in about one-third of the cases post recovery (Ni et al., 2020).
T196 1541-1716 Sentence denotes In a second study, PBMCs from COVID-19 patients with moderate to severe ARDS were analyzed by flow cytometry approximately 2 weeks after ICU admission (Weiskopf et al., 2020).
T197 1717-2059 Sentence denotes Both virus-specific CD4 and CD8 T cells were detected in all patients at average frequencies of 1.4% and 1.3%, respectively, and very limited phenotyping according to CD45RA and CCR7 expression status characterized these cells predominantly as either CD4 Tcm (central memory) or CD8 Tem (effector memory) and Temra (effector memory RA) cells.
T198 2060-2522 Sentence denotes This study is notable for the use of large complementary peptide pools comprising 1,095 SARS-Cov-2 epitopes (overlapping 15-mers for S protein as well as computationally predicted HLA-I- and -II-restricted epitopes for all other viral proteins) as antigen-specific stimuli that revealed a preferential specificity of both CD4 and CD8 T cells for S protein epitopes, with the former population modestly increasing over ∼10–30 days after initial onset of symptoms.
T199 2523-2775 Sentence denotes A caveat, however, pertains to the identification of specific T cells by induced CD69 and CD137 co-expression, since upregulation of CD137 by CD4 T cells, in contrast to CD154, may preferentially capture regulatory T cells (Treg) (Bacher et al., 2016).
T200 2776-2957 Sentence denotes Further analyses of S protein-specific T cells by ELISA demonstrated robust induction of IFN-γ, TNF-α, and IL-2 concomitant with lower levels of IL-5, IL-13, IL-9, IL-10, and IL-22.
T201 2958-3184 Sentence denotes A third report focused on S-specific CD4 T cell responses in 18 patients with mild, severe, or critical COVID-19 using overlapping peptide pools and induced CD154 and CD137 co-expression as a readout for antiviral CD4 T cells.
T202 3185-3349 Sentence denotes Such cells were present in 83% of cases and presented with enhanced CD38, HLA-DR, and Ki-67 expression indicative of recent in vivo activation (Braun et al., 2020).
T203 3350-3484 Sentence denotes Of note, the authors also detected low frequencies of S-reactive CD4 T cells in 34% of SARS-CoV-2 seronegative healthy control donors.
T204 3485-3905 Sentence denotes However, these CD4 T cells lacked phenotypic markers of activation and were specific for C-terminal S protein epitopes that are highly similar to endemic human CoVs, suggesting that crossreactive CD4 memory T cells in some populations (e.g., children and younger patients that experience a higher incidence of hCoV infections) may be recruited into an amplified primary SARS-CoV-2-specific response (Braun et al., 2020).
T205 3906-4029 Sentence denotes Similarly, endemic CoV-specific CD4 T cells were previously shown to recognize SARS-CoV1 determinants (Gioia et al., 2005).
T206 4030-4150 Sentence denotes How previous infections with endemic CoV may affect immune responses to SARS-CoV-2 will need to be further investigated.
T207 4151-4477 Sentence denotes Finally, in general accordance with the above findings on the induction of SARS-CoV-2-specific T cells, using TCR sequencing (TCR-seq), Huang et al. and Liao et al. reported greater TCR clonality of peripheral blood (Huang et al., 2020c) as well as BAL T cells (Liao et al., 2020) in patients with mild versus severe COVID-19.
T208 4478-4734 Sentence denotes Moving forward, a comprehensive identification of immunogenic SARS-CoV-2 epitopes recognized by T cells (Campbell et al., 2020), as well as further studies on convalescent patients who recovered from mild and severe disease, will be particularly important.