GAMMA-DELTA T-CELLS IN HUMAN DECIDUA

OBJECTIVE: Our purpose was to assess the presence and frequency of gammadelta T cells in the decidua of term and first-trimester pregnancies. STUDY DESIGN: Term and first-trimester placentas were obtained from normal subjects. Frozen sections and cell suspensions were prepared from decidual tissue and stained with monoclonal antibodies to T cell markers. Cell sorter analysis was performed. RESULTS: Gammadelta T cells in term decidual cell preparations were enriched 2.4-fold compared with peripheral blood. Immunohistochemical staining of term decidual tissue demonstrated many gammadelta+ and CD3+ T cells, fewer CD8+ cells, and rare CD4+ cells. In contrast, first-trimester decidua was found to be devoid of gammadelta+ T cells, by both cell sorter analysis and immunohistochemical methods. CONCLUSIONS: Term, but not early, decidua harbors a resident T-cell population that is significantly enriched in gammadelta T cells compared with blood. These lymphocytes may provide an added defense mechanism against infection during the peripartum.