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

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-specifc 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-specifc 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.
Description
Keywords
T- Cell, SARS‑CoV‑2, Omicron variant, Pregnant women, Postpartum women, HIV, South Africa
Citation
McMahon, W. C., Kwatra, G., Izu, A., Jones, S. A., Mbele, N. J., Jafta, N., Lala, R., Shalekoff, S., Tiemessen, C. T., Madhi, S. A., & Nunes, M. C. (2024). 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. Scientific reports, 14(1), 20348. https://doi.org/10.1038/s41598-024-70725-8