T-cell responses to ancestral SARS-CoV-2 and Omicron variant among unvaccinated pregnant and postpartum women living with and without HIV in South Africa

Sci Rep. 2024 Sep 2;14(1):20348. doi: 10.1038/s41598-024-70725-8.

Abstract

SARS-CoV-2 cell-mediated immunity remains understudied during pregnancy in unvaccinated Black African women living with HIV (WLWH) from low- and middle-income countries. We investigated SARS-CoV-2-specific T-cell responses 1 month following infection in 24 HIV-uninfected women and 15 WLWH at any stage during pregnancy or postpartum. The full-length spike (FLS) glycoprotein and nucleocapsid (N) protein of wild-type (WT) SARS-CoV-2, as well as mutated spike protein regions found in the Omicron variant (B.1.1.529) were targeted by flow cytometry. WT-specific CD4+ and CD8+ T cells elicited similar FLS- and N-specific responses in HIV-uninfected women and WLWH. SARS-CoV-2-specific T-lymphocytes were predominantly TNF-α monofunctional in pregnant and postpartum women living with and without HIV, with fever cells producing either IFN-γ or IL-2. Furthermore, T-cell responses were unaffected by Omicron-specific spike mutations as similar responses between Omicron and the ancestral virus were detected for CD4+ and CD8+ T cells. Our results collectively demonstrate comparable T-cell responses between WLWH on antiretroviral therapy and HIV-uninfected pregnant and postpartum women who were naïve to Covid-19 vaccination. Additionally, we show that T cells from women infected with the ancestral virus, Beta variant (B.1.351), or Delta variant (B.1.617.2) can cross-recognize Omicron, suggesting an overall preservation of T-cell immunity.

MeSH terms

  • Adult
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • COVID-19* / immunology
  • COVID-19* / virology
  • Female
  • HIV Infections* / immunology
  • HIV Infections* / virology
  • Humans
  • Postpartum Period* / immunology
  • Pregnancy
  • Pregnancy Complications, Infectious / immunology
  • Pregnancy Complications, Infectious / virology
  • SARS-CoV-2* / immunology
  • South Africa / epidemiology
  • Spike Glycoprotein, Coronavirus* / genetics
  • Spike Glycoprotein, Coronavirus* / immunology
  • T-Lymphocytes / immunology

Substances

  • Spike Glycoprotein, Coronavirus
  • spike protein, SARS-CoV-2

Supplementary concepts

  • SARS-CoV-2 variants