The standard human peripheral blood mononuclear cell isolation media like that of lymphoprep or Nycoprep 1.077 are less effective for the isolation of these cells from the blood of certain experimental animals. The density of the Peripheral blood mononuclear cell from mice, rats and rabbits is actually slightly higher than that from humans. Some commercial media simply address this problem by having an equally raised density. This simple solution however fails to address the instantaneous problem that the density of the polymorphonuclear leukocytes is the same. Thus although recoveries of Peripheral blood mononuclear cells are satisfactory, contamination from PMNs can be important. The basic aim or the background of the study is to investigate the role of peripheral blood mononuclear cells in embryo invasion at the implantation site and to estimate the effect on PBMC function of human chorionic gonadotrophin that is secreted from the human embryo.

Occurrence of peripheral blood mononuclear cell

The interaction of commensal bacteria with immunocompetent cells might occur in definite compartments of the mucosal immune system, as limited translocation through the epithelial barrier cannot be excluded. A variety of bacterial strains induced a differential cytokine pattern. Whereas L. johnsonii and L. sakei strongly induced gamma interferon and interleukin-12, E. coli and lipopolysaccharide preferentially induced IL-10 after 16 h of stimulation. Expression of activation antigens CD69 and CD25 was experimented on natural killer cells after stimulation of total human peripheral blood mononuclear cells. All bacteria mediated the proliferation of human peripheral blood mononuclear cells, and the strongest proliferative reaction was observed with L. johnsonii.

Methods and results

The consequence of PBMC on the invasiveness of murine embryos was examined using an invasion assay. PBMC obtained from women in early pregnancy considerably enhanced both spreading of murine embryos on Matrigel and invasion beneath the gel. These effects were greater than those of PBMC acquired from non-pregnant women in the secretory phase and the control. When PBMC obtained from non-pregnant women were incubated with recombinant HCG for 2 days and were subjected to invasion assay using murine embryos, PBMC treated with HCG appreciably promoted both spreading and invasion of murine embryos as compared with the non-treated PBMC.