PROBLEM: @entity1420 -dependent immunomodulation is one of the mechanisms that enables pregnancy to proceed to term. Immunologic effects of @entity1420 are mediated by a protein named the @entity1420 -induced blocking factor (PIBF). Among other effects this protein inhibits natural killer (NK) activity and displays an anti-abortive effect in @entity19 . Recently, we have shown that PIBF induces a Th2 shift in vitro. The present study was aimed at investigating the in vivo effect of PIBF on cytokine production, as well as the relationship between cytokine production, NK activity, and @entity393 . METHOD OF STUDY: Balb-c @entity19 on day 8.5 of pregnancy were injected intraperitoneally with 0.5 mg of rabbit anti-PIBF immunoglobulin G (IgG). Another group of @entity19 was simultaneously treated with anti-NK monoclonal antibodies. Mice treated with the same amount of normal rabbit serum or untreated @entity19 of similar gestational age were used as controls. The animals were sacrificed and their uteri were inspected. The ratio of living and resorbed embryos was determined. NK activity as well as cytokine expression on the spleen cells were determined by immunocytochemistry and enzyme-linked immunoadsorbent assay (ELISA). RESULTS: Mitogen-activated spleen cells from anti-PIBF-treated @entity19 produced significantly (P < 0.001) less @entity1618 than those of pregnant control @entity19 . A significantly higher percentage (P < 0.001) of spleen cells from anti-PIBF-treated @entity19 expressed @entity60 ( @entity60 ) as determined by immunocytochemistry, than those of untreated pregnant @entity19 . There was a positive relationship between the percentage of @entity60 -positive spleen cells and resorption rates, and an inverse relationship between the latter and @entity1618 ( @entity1618 ) production. All these effects were corrected by treatment with anti-NK antibodies. CONCLUSION: Our data suggest that PIBF contributes to the success of gestation via cytokine-mediated inhibition of NK activity.

XXXX and non-specific immunologic mechanisms in pregnancy.

@entity1420 :: ('MESH:D011374', 'Chemical') :: ['progesterone', 'Progesterone'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity60 :: ('15978(Tax:10090)', 'Gene') :: ['interferon-gamma', 'IFN gamma'] @entity1618 :: ('16153(Tax:10090)', 'Gene') :: ['interleukin-10', 'IL-10'] @entity393 :: ('MESH:D034381', 'Disease') :: ['pregnancy loss']
@entity1420 :: (MESH:D011374,Chemical) :: ['Progesterone']
