SARS-CoV-2-specific T cell responses and immune regulation in infected pregnant women Journal of Reproductive Immunology

We studied the T cell response to SARS-CoV-2 spike and non-spike peptide epitopes in eight convalescent pregnant women together with the immune monitoring that included innate tolerogenic dendritic cell populations important to maintain the immunological mother/fetus interface to address a potential risk for the antiviral cellular response in the outcome of pregnancy. Four subjects had pre-existing chronic inflammatory conditions that could have potentially affected the SARS-CoV-2-specific T cell response. Seven of eight subjects responded to SARS-CoV-2 peptides with differences within CD4 + T helper (Th) and CD8 + cytotoxic T cells (CTL). SARS-CoV-2-specific inducible regulatory T cells (iTreg) were numerous in circulation. CD4 + T cell memory included central memory T cells (T CM ) and effector memory (T EM ). As far as the CD8 + memory repertoire, T CM and T EM were very low or absent in eight of eight subjects and only effector cells that revert to CD45RA + , defined as T EMRA were measurable in circulation. T cells were in the normal range in all subjects regardless of pre-existing inflammatory conditions. The immune phenotype indicated the expansion and acti- vation of tolerogenic myeloid dendritic cells including CD14 + cDC2 and CD4 + ILT-4 + tmDC. In summary, SARS-CoV-2 infection induced a physiological anti-viral T cell response in pregnant women that included SARS-CoV-2- specific iTreg with no negative effects on the tolerogenic innate dendritic cell repertoire relevant to the immune homeostasis of the maternal-fetal interface. All eight subjects studied delivered full-term, healthy infants. DC leads to the polarization of T cell lineages