T helper cell immunity in pregnancy and influence on autoimmune disease progression - Graham 2021

The maternal immune system faces a unique challenge during pregnancy as it needs to protect against pathogens while also tolerating paternal allo-antigens expressed by fetal tissues. T helper (Th) cells play a crucial role in modulating immune responses, and recent advancements have identified distinct contributions of various Th cell subsets in each phase of human pregnancy. Dysregulation of Th cell responses is associated with multiple obstetrical complications. Modulation of Th cell immunity during gestation is largely mediated by oscillations in sex hormone concentrations, in addition to localized decidual mechanisms. Aberrant Th cell responses are also implicated in several autoimmune disorders, whereas changes in the balance of Th cell immunity during pregnancy have been shown to be beneficial in Th1 and Th17-driven autoimmune conditions, followed by postpartum exacerbations in disease.

Graham JJ, Longhi MS, Heneghan MA. T helper cell immunity in pregnancy and influence on autoimmune disease progression. J Autoimmun. 2021 Jul;121:102651. doi: 10.1016/j.jaut.2021.102651. Epub 2021 May 18. PMID: 34020252; PMCID: PMC8221281.