Greice Carolina Santos da Silva , Victoria Cruz Paraná , Filipe Ferreira de Almeida Rego , Mariana Maciel Portela , Mariana Barros Queiroz , Raimundo Coutinho Junior , Carlos Gustavo Regis da Silva , Luana Leandro Gois , Maria Fernanda Rios Grassi
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引用次数: 0
Abstract
Background
This study aimed to investigate whether mutations in the immunodominant regions of the S, M, and N proteins of the Gamma, Delta, and Omicron SARS-CoV-2 variants that circulated in Brazil affect the recognition of viral antigens by Brazilian HLA-I-restricted CD8+ T cell epitopes, using an in silico approach.
Methods
Sequences of the Gamma (n = 36,174), Delta (n = 35,129), and Omicron (n = 336) variants were retrieved using GISAID. Consensus sequences were generated using Geneious software with NC045512 as a reference. Epitopes for the S, M, and N proteins of both the original and variant sequences were predicted using NetCTLpan 1.1, NetMHCpan 4.0, and VaxiJen v2.0. The positions occupied by these epitopes, with high probability of presentation, affinity to HLA molecules, and antigenicity, were identified as potentially immunodominant regions.
Results
The S protein of the reference sequence (NC045512) and its variants contained 17 immunodominant regions. Delta showed the highest conservation (94.1 %, 16), followed by Gamma (82.3 %, 14) and Omicron (70.5 %, 12). Omicron exhibited the greatest mutational variability and had regions of increased antigenicity and two novel immunodominant regions with broader human leukocyte antigen (HLA) recognition. Additionally, Omicron lost two previously identified immunodominant regions and had one region of reduced antigenicity that did not affect HLA recognition. Gamma had mutations in three regions that increased both antigenicity and HLA recognition. Delta had only one mutated region with lower antigenicity, which did not affect HLA recognition. Notably, new immunodominant regions for the M and N proteins appeared in the Omicron variant.
Conclusions
Brazilian HLA-I-restricted CD8+ T cell epitopes from SARS-CoV-2 immunodominant regions are partially conserved in the Gamma, Delta, and Omicron variants circulating in Brazil, suggesting effective a cross-protective immune response that may help reduce COVID-19 severity and mortality.
期刊介绍:
The Journal of Infection and Public Health, first official journal of the Saudi Arabian Ministry of National Guard Health Affairs, King Saud Bin Abdulaziz University for Health Sciences and the Saudi Association for Public Health, aims to be the foremost scientific, peer-reviewed journal encompassing infection prevention and control, microbiology, infectious diseases, public health and the application of healthcare epidemiology to the evaluation of health outcomes. The point of view of the journal is that infection and public health are closely intertwined and that advances in one area will have positive consequences on the other.
The journal will be useful to all health professionals who are partners in the management of patients with communicable diseases, keeping them up to date. The journal is proud to have an international and diverse editorial board that will assist and facilitate the publication of articles that reflect a global view on infection control and public health, as well as emphasizing our focus on supporting the needs of public health practitioners.
It is our aim to improve healthcare by reducing risk of infection and related adverse outcomes by critical review, selection, and dissemination of new and relevant information in the field of infection control, public health and infectious diseases in all healthcare settings and the community.