Microorganisms (Apr 2024)

A Comparative Analysis of Innate Immune Responses and the Structural Characterization of Spike from SARS-CoV-2 Gamma Variants and Subvariants

  • Aline Miranda Scovino,
  • Elizabeth Chen Dahab,
  • Israel Diniz-Lima,
  • Etiele de Senna Silveira,
  • Shana Priscila Coutinho Barroso,
  • Karina Martins Cardoso,
  • Dirlei Nico,
  • Gustavo José Makhoul,
  • Elias Barbosa da Silva-Junior,
  • Celio Geraldo Freire-de-Lima,
  • Leonardo Freire-de-Lima,
  • Leonardo Marques da Fonseca,
  • Natalia Valente,
  • Valeria Nacife,
  • Ana Machado,
  • Mia Araújo,
  • Gustavo Fioravanti Vieira,
  • Alex Pauvolid-Corrêa,
  • Marilda Siqueira,
  • Alexandre Morrot

DOI
https://doi.org/10.3390/microorganisms12040720
Journal volume & issue
Vol. 12, no. 4
p. 720

Abstract

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The SARS-CoV-2 P.1 variant, responsible for an outbreak in Manaus, Brazil, is distinguished by 12 amino acid differences in the S protein, potentially increasing its ACE-2 affinity and immune evasion capability. We investigated the innate immune response of this variant compared to the original B.1 strain, particularly concerning cytokine production. Blood samples from three severe COVID-19 patients were analyzed post-infection with both strains. Results showed no significant difference in cytokine production of mononuclear cells and neutrophils for either variant. While B.1 had higher cytopathogenicity, neither showed viral replication in mononuclear cells. Structural analyses of the S protein highlighted physicochemical variations, which might be linked to the differences in infectivity between the strains. Our studies point to the increased infectivity of P.1 could stem from altered immunogenicity and receptor-binding affinity.

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