Dynamic γδ T-cell Receptor remodeling and antigen-induced T-cell IFN-γ responses after SARS-CoV-2 infection during pregnancy: insights for γδ T-cell immunotherapy

Introduction Pregnancy requires coordinated immune adaptation to maintain fetal tolerance while preserving antiviral defense. However, the temporal dynamics of maternal cellular immunity and maternal-fetal antibody transfer after SARS-CoV-2 infection during pregnancy remain incompletely defined. Methods We enrolled 52 pregnant women with laboratory-confirmed SARS-CoV-2 infection and stratified them by infection-to-delivery interval: <90 days, 90–120 days, and >120 days. Maternal peripheral blood mononuclear cells were analyzed by multiparametric flow cytometry. Basal and Omicron BA.5.2 antigen-induced IFN-γ production by CD3 + , CD4 + , and CD8 + T cells were assessed, and SARS-CoV-2-specific S1/RBD IgM and IgG levels were measured in paired maternal and cord blood by ELISA. Results Baseline characteristics and major perinatal outcomes were broadly comparable among groups. Maternal T cells retained antigen-inducible IFN-γ responses, with the strongest responses observed in the 90–120-day group. Immune phenotyping revealed interval-associated remodeling of adaptive T-cell subsets, γδ T-cell receptor phenotypes, NK-cell subsets, and selected B-cell compartments. Cord blood IgM remained consistently low, providing no immunological evidence of intrauterine SARS-CoV-2 infection. In contrast, maternal and cord blood IgG levels were positively correlated, indicating preserved transplacental IgG transfer without clear time-dependent changes in transfer efficiency. Conclusions These results extend current understanding of post-infection immune adaptation during pregnancy and provide an immunological basis for future longitudinal studies aimed at defining the timing and durability of maternal and neonatal immune protection.