Highly Conserved but Activation‐Dependent CCR5, CCR6, and CXCR4 Chemokine Receptor Expression and Trophoblast‐Mediated Cytokine Profile of Peripheral Gamma‐Delta T Cells During Early Human Pregnancy

Pregnancy requires balanced maternal immune regulation for healthy fetal development, in which γδT cells contribute at the feto‐maternal interface; however, mechanisms guiding decidual γδT‐cell accumulation remain unclear. We analyzed chemokine receptor (ChR) expression (C‐C motif ChR [CCR]5, CCR6, and C‐X‐C motif ChR [CXCR]4) and cytokine profiles of peripheral γδT cells from first‐trimester pregnant and nonpregnant women by multicolor flow cytometry under baseline and antigen‐independent activation, while cytokine modulation was assessed in isolated γδT cells co‐cultured with trophoblasts using cytometric bead array (CBA). While the frequency of ChR‐expressing γδTCR ⁺ cells was largely preserved, CCR6 and CXCR4 expression intensities were slightly elevated during pregnancy. Although single ChR expression did not differ between conventional and natural killer (NK)‐like γδT cell subsets, the proportions of some ChR co‐expressing populations were slightly but significantly higher among NK‐like γδT cells. Within the observed co‐expression patterns, CCR5/CCR6 was the most frequent combination on γδT cell subsets. Furthermore, different stimulation models differently shaped ChR expression on conventional γδT cells, with physiological activation maintaining CCR5 ⁺ dominance alongside elevated CXCR4 ⁺ cell ratios, whereas PMA/Ionomycin stimulation was characterized by a predominance of CXCR4 ⁺ cells and a low proportion of CCR5 ⁺ cells. In terms of cytokine production γδT cells exhibited a broad Th1‐like cytokine profile dominated by IL‐2, TNF‐α, and IFN‐γ, with modest reductions in TNF‐α and IFN‐γ during pregnancy. Trophoblast contact further attenuated this response by inhibiting IL‐2, TNF‐α, and IL‐17A release, while markedly enhancing IL‐6 production. Our findings suggest that γδT cell subsets slightly differ in ChR co‐expression patterns, and ChRs are differentially regulated by distinct activation processes. The modest differences observed during first‐trimester pregnancy indicate a conserved migratory capacity, with pregnancy‐specific migratory phenotypes likely shaped at the materno‐fetal interface. Additionally, γδT cells exhibited an inflammatory cytokine milieu that was modulated upon trophoblast contact, which may contribute to trophoblast‐mediated immune adaptations during human pregnancy.