A placenta-derived suppressor factor with a T-cell bias.
OBJECTIVE
Functional and mechanistic aspects of immunosuppression by murine placental supernatants (MPS) were investigated.


METHODS
MPS and a low molecular weight fraction of the supernatant (MPSf) were tested for suppressive action on T-cell reactivity in vitro and in vivo, on B-cell responses and on T-cell activation events.


RESULTS
MPS and MPSf suppress mitogen-induced proliferation and mixed lymphocyte reactions of human and murine lymphocytes, antigen-induced proliferation of T cells in vitro and in vivo, proliferation of CD8+ lymphocytes, proliferation induced by cross-linking of surface CD3 and the in vivo response of mice to allogeneic stimuli. MPSf affects cell cycling of activated T cells and blocks interleukin (IL)-2 production. MPSf does not affect antibody production or the induction of MHC class II expression on B cells.


CONCLUSIONS
MPSf is a potent inhibitor of T-cell responses in vitro and in vivo, with no demonstrable effect on B-cell function.
Raghupathy
R
R
Department of Microbiology, Faculty of Medicine, Kuwait University. raj@hsc.kuniv.edu.kw
Khan
S F
SF
Syamasundar
P V
PV
Bansal
P
P
Azizieh
F
F
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D015847:Interleukin-4 / Q000494:pharmacology; D020014:K562 Cells; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology / Q000494:pharmacology; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000302:isolation & purification / Q000502:physiology*; D015375:Receptors, Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D013491:Suppressor Factors, Immunologic / Q000302:isolation & purification / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology*
D017252:CD3 Complex; D007376:Interleukin-2; D011257:Pregnancy Proteins; D015375:Receptors, Interleukin-2; D013491:Suppressor Factors, Immunologic; D015847:Interleukin-4; D007371:Interferon-gamma; D010047:Ovalbumin