title: Immunochemical characteristics of a novel cell death receptor and a decoy receptor on granulosa cells of porcine ovarian follicles.
abstract: Previously, we prepared an IgM monoclonal antibody(PFG-1) which specifically recognized a cell-membraneglycoprotein (PFG-1 antigen; 55 kD, pI 5.9),immunohistochemically reacted with granulosa cells ofhealthy follicles but not of atretic follicles, andinduced granulosa cell apoptosis. In the presentstudy, an IgM monoclonal antibody (PFG-3) capable ofinducing granulosa cell apoptosis and an IgGmonoclonal antibody (PFG-4) not capable of inducingapoptosis were produced against granulosa cellsprepared from healthy antral follicles of porcineovaries. Two-dimensional Western blotting analysisrevealed that PFG-3 specifically recognized twocell-membrane proteins (named PFG-3-1 andPFG-3-2/PFG-1 antigens; 42 kD, pI 5.2 and 55 kD, pI5.9, respectively) of healthy granulosa cells, andthat PFG-4 recognized the same two cell-membraneproteins. In atretic granulosa cells, PFG-3-2/PFG-1antigen disappeared. Immunochemical reactions of theseantibodies were only detected in follicular granulosacells but not any other ovarian tissues or organs.PFG-3 and PFG-4 immunohistochemically reacted withgranulosa cells of healthy and atretic follicles. Whenthe isolated granulosa cells prepared from healthyfollicles were cultured in medium containing PFG-3,the cells underwent apoptosis, and co-incubation withPFG-4 inhibited PFG-3-inducible apoptosis. Theseobservations suggested that PFG-3-2/PFG-1 antigen isa novel cell death receptor which is different fromthe apoptosis-mediating receptors (Fas/Apo-1/CD95 orTNF receptor), and that PFG-3-1 antigen may act as adecoy receptor and inhibit apoptotic signal transmission.
authors.affiliation: Unit of Anatomy and Cell Biology, Department of Animal Sciences, Kyoto University, Kyoto, 606-8502, Japan, manabe@jkans.jkans.kais.kyoto-u.ac.jp.
authors.forename: N
authors.initials: N
authors.lastname: Manabe
authors.forename: A
authors.initials: A
authors.lastname: Myoumoto
authors.forename: C
authors.initials: C
authors.lastname: Tajima
authors.forename: M
authors.initials: M
authors.lastname: Fukumoto
authors.forename: M
authors.initials: M
authors.lastname: Nakayama
authors.forename: K
authors.initials: K
authors.lastname: Uchio
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: H
authors.initials: H
authors.lastname: Miyamoto