Caracterização das variantes do gene tlr9 (rs5743836 e rs187084), associado ao perfil de citocinas em indivíduos vacinados com a CoronaVac

Abstract

Introduction: COVID-19 is an infectious disease caused by the SARS-CoV-2 virus, responsible for the last pandemic, declared in March 2020. It has killed approximately 7 million people worldwide; in Brazil, more than 700,000 deaths have been confirmed due to the disease. Immunization against COVID-19 is ongoing and is the main prophylaxis strategy available against the virus. Worldwide, more than 13 billion vaccine doses have already been administered; in Brazil, more than 500 million vaccine doses have already been applied to the population. Several studies have evaluated the immune response and efficacy of COVID-19 vaccines in order to understand the immunological mechanisms triggered by the immunizers. The immune response induced by the vaccine can be influenced by several factors, ranging from environmental to genetic, hence the importance of studying these polymorphisms, single nucleotide variations in genes of immune response pathways that may be associated with differences in response presented by immunized individuals. Objectives: This study aims to analyze possible influences of single nucleotide polymorphisms in the TLR-9 receptor gene (rs5743836 and rs187084), which may be associated with the cytokine profile in individuals vaccinated with CoronaVac. Material and Methods: For this study, samples were collected from 170 employees of the HEMOAM Foundation. Samples were collected at three time points: T0 or pre-vaccination (n=170), T1 60 days after the second dose (n=170) and T2 90 days after the second dose (n=170), for genotyping (PCR-RFLP) and cytokine analysis (Flow Cytometry). Results: In the collaborators of this study, there was a significant increase in the serum levels of Th1 (IL-6), Th2 (IL-4) and Th17 (IL-17) and regulatory (IL-10) cytokines when compared to time T0 to times T1 and T2, carriers of the homozygous genotypes C/C, C/T and T/T of both variants had a significant magnitude of cytokines, since the C/C genotype of TLR9 1486 we observed at time T1 a greater concentration compared to the other genotypes. Conclusion: These results infer that a balance of the Th1 (IL-6) and regulatory (IL-10) profile is possibly occurring in individuals vaccinated with CoronaVac, thus avoiding a more severe course of the disease.