Does immune recognition of SARS-CoV2 epitopes vary between different ethnic groups?

Abstract

The SARS-CoV2 mediated Covid-19 pandemic has impacted humankind at an unprecedented scale. While substantial research efforts have focused towards understanding the mechanisms of viral infection and developing vaccines/ therapeutics, factors affecting the susceptibility to SARS-CoV2 infection and manifestation of Covid-19 remain less explored. Given that the Human Leukocyte Antigen (HLA) system is known to vary among ethnic populations, it is likely to affect the recognition of the virus, and in turn, the susceptibility to Covid-19. To understand this, we used bioinformatic tools to probe all SARS-CoV2 peptides which could elicit T-cell response in humans. We also tried to answer the intriguing question of whether these potential epitopes were equally immunogenic across ethnicities, by studying the distribution of HLA alleles among different populations and their share of cognate epitopes. Results indicate that the immune recognition potential of SARS-CoV2 epitopes tend to vary between different ethnic groups. While the South Asians are likely to recognize higher number of CD8-specific epitopes, Europeans are likely to identify higher number of CD4-specific epitopes. We also hypothesize and provide clues that the newer mutations in SARS-CoV2 are unlikely to alter the T-cell mediated immunogenic responses among the studied ethnic populations. The work presented herein is expected to bolster our understanding of the pandemic, by providing insights into differential immunological response of ethnic populations to the virus as well as by gauging the possible effects of mutations in SARS-CoV2 on efficacy of potential epitope-based vaccines through evaluating ∼40000 viral genomes.

Determinants of antibody responses to two doses of ChAdOx1 nCoV-19 or BNT162b2 and a subsequent booster dose of BNT162b2 or mRNA-1273: population-based cohort study (COVIDENCE UK)

“…20,24 We demonstrate for the first time that higher anti-spike titres among vaccinated people of South Asian origin are not attributable to the higher rates of pre-vaccination SARS-CoV-2 infection that we have previously reported. 20,24 The reasons for this phenomenon require further investigation: ethnic variation in recognition of SARS-CoV-2 T cell epitopes is recognised, 32 and it may be that analogous variation in B cell epitopes underlies the ethnic differences in antibody responses to vaccination seen here. By contrast with ethnicity, several studies have investigated the impact of BMI on post-vaccination antibody titres.…”

Haplotype distribution of SARS-CoV-2 variants in low and high vaccination rate countries during ongoing global COVID-19 pandemic in early 2021

“…Although sub-haplotypes 2A_3 and 2B_1 were less easily neutralized than original SARS-CoV-2, there was no good evidence that these variants could evade the vaccination. The new sub-haplotypes appeared in the amino acid substitutions in B- and T-cell epitopes of Spike protein predicted ( Bhattacharya et al, 2020 ), which might alter the immune recognition potential SARS-CoV2 epitopes by HLA alleles among different populations ( Bose et al, 2021 ). Therefore, the new sub-haplotypes could trigger the differential T-cell-based immunological responses to SARS-CoV-2 infection in different ethnic populations and reduce the efficacy of SARS-CoV-2 epitope-based vaccines in the future.…”

Renin-angiotensin system blocker and the COVID-19 aggravation in patients with hypertension, diabetes, renal failure, Cerebro-cardiovascular disease, or pulmonary disease: Report by the COVID-19 Registry Japan

“…Although the detailed mechanism of the host response to SARS-CoV-2 is still insufficient, the immune system for viral invasion can be broadly divided into the innate immune response and the adaptive immune response. Innate immunity not only induces an inflammatory response and the production of interferon, but also has a role of initiating an adaptive immune response by antibodies and cytotoxic T lymphocytes for each specific virus [ 32 ]. Cytotoxic T lymphocytes recognize the viral epitope presented on human leukocyte antigen (HLA) on virus-infected cells and suppress virus infection by destroying the virus-infected cells.…”

“…Using the SARS-Cov-2 peptide that can activate cytotoxic T lymphocytes as a probe, the relationship between epitope presentation by SARS-CoV-2 infection and activated T lymphocytes has been evaluated. South Asians frequently recognize CD8-specific epitopes, Europeans frequently recognize CD4-specific epitopes, and East Asians, Africans, and Oceanians have low ability to recognize both CD4/CD8 epitopes [ 32 ]. Although these findings do not directly prove the association with the onset and aggravation of COVID-19, they are considered to be one of the footholds for COVID-19 treatment including vaccine development.…”