Selective compartmentalization of gammadelta-T lymphocytes in human breastmilk

In human breastmilk, T lymphocytes with gammadelta-receptor (TCR) are more frequent than those with alphabeta-TCR, in comparison with peripheral blood. Differential representation has also been demonstrated for subpopulations of gammadelta-T cells. Reactivity was visualized with three monoclonal antibodies against Vdelta1, Vdelta2 and Vgamma2 on T cells from the breastmilk and peripheral blood of 12 women who had recently given birth. Confirming the results with Vdelta1, it was found that Vdelta1 (p < 0.01) and Vgamma2 (p < 0.05) but not Vdelta2 were overrepresented on T cells in milk as compared with blood. This selective compartmentalization seems to reflect the homing of certain cells to the mammary gland.