A mouse placental immunoregulatory factor different from transforming growth factor beta.
Of the growth-promoting factors, transforming growth factor beta (TGF-beta) has been most clearly shown to act as a potent regulator of inflammation and immunity. It is highly suppressive for T and B lymphocyte proliferation, cytotoxic T lymphocyte generation, and lymphokine-activated killer cell development, as well as natural killer cell activity. Moreover, there is accumulating evidence that TGF-beta also may contribute to impaired immune surveillance of tumor development. In previous work, we isolated and described a 40 kD glycoprotein extracted from mouse placenta. This placental factor (PF) is also a potent immune modulator in vivo: it is highly inhibitory of secondary antibody responses as well as cellular responses, such as local graft-versus-host reactions. Because placenta has been shown to be a major source of TGF-beta and several reports have indicated an important role for TGF-beta in the immunosuppressive mechanisms taking place during the course of mammalian gestation, we have looked for the presence of TGF-beta in our placental factor preparations. Our results clearly indicate that they do not contain TGF-beta or TGF-beta-like molecules by the following criteria: (1) no inhibition of Mv-1 Lu cell proliferation at any dose tested; (2) no band detected by immunoblotting using different polyclonal reagents specific for TGF-beta 1; and (3) no activity retained on or eluted from an affinity column made of immobilized monoclonal antibody against TGF-beta 2. Aliquots of the same preparations retained their full immune inhibitory capacity in vivo throughout the various assays.(ABSTRACT TRUNCATED AT 250 WORDS)
Bleux
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Department of Developmental Biology, Institut Jacques Monod, CNRS, Paris, France.
Bobe
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Kanellopoulos-Langevin
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D000818:Animals; D000911:Antibodies, Monoclonal; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002846:Chromatography, Affinity; D005260:Female; D015151:Immunoblotting; D007166:Immunosuppressive Agents / Q000032:analysis*; D008431:Maternal-Fetal Exchange; D051379:Mice; D008808:Mice, Inbred CBA; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy; D016212:Transforming Growth Factor beta / Q000032:analysis* / Q000276:immunology
D000911:Antibodies, Monoclonal; D007166:Immunosuppressive Agents; D016212:Transforming Growth Factor beta