IMMUNOPHENOTYPICAL CHARACTERISTICS OF CELLULAR COMPOSITION IN BREAST MILK

The morphology and immunophenotype of female colostrum adherent cells with the help of CD3, CD31, CD34, CD45, CD68, vimentin, and osteocalcin antibodies panel was studied in short-term (6—7 days) culture in vitro. Approximately equal (1 : 1) ratio of fibroblast-like and rounded cells was observed in 20 % of cultural flasks. The cells with regular shape mixed with single fibroblasts were noted in 80 % of cultural flasks. The diameter of spreaded cells varied within 10—100 mm. All cells adhered to plastics did not express CD3 and interacted slightly (sl) with antibodies to CD31, CD34, and CD45. At the same time, adherent cells with intensive CD68, vimentin and osteocalcin staining have been revealed. Literature data allows to interpret CD68+CD3–CD31slCD34slCD45sl immunophenotype of significant part of mother colostrum adherent cells as belonging to monocyte-macrophage lineage. Marked expression of stromal antigens (vimentin, osteocalcin) in 40—45 % adherent cells in cultural medium without osteogenic supplements (beta-glycerophosphate, ascorbic acid, dexamethasone) proposes an existence of osteoblasts fraction differentiated in colostrum from mesenchymal stem cells under an action of breast milk humoral factors.