Macrophage MHC receptor 2: a novel receptor on allograft (H-2D(d)K(d))-induced macrophage (H-2D(b)K(b)) recognizing an MHC class I molecule, H-2K(d), in mice.
We previously reported that a population of allograft (H-2D(d)K(d))-induced macrophages (AIM) in C57BL/6 (H-2D(b)K(b)) mice exhibited major histocompatibility complex (MHC) haplotype (H-2D(d)) specific killing of the allograft (e.g., BALB/c skin and Meth A cells; H-2D(d)K(d)) in a macrophage MHC receptor (MMR)-dependent manner. In the present study, we isolated a cDNA clone encoding a novel receptor (MMR2) on AIM recognizing another MHC class I molecule, H-2K(d), by the expression cloning method using H-2K(d) tetramer and a monoclonal antibody (mAb; R12) specific for AIM. The cDNA (2359-bp) encoded a 677-amino acid polypeptide of a calculated molecular mass of 87 kDa and was found to be expressed exclusively on AIM among cells infiltrating into allografts on days 0-9 after transplantation. Confocal microscopy showed that HEK293T cells transfected with this cDNA were reactive toward the H-2K(d) molecule but not toward other MHC class I molecules such as H-2D(d), H-2D(b), H-2D(k), H-2K(b), H-2K(k), and H-2L(d) molecules. The binding of the H-2K(d) molecule to the transfectants was inhibited by the addition of R12 or anti-H-2K(d), but not by R15 (a mAb specific for H-2D(d) receptor) or anti-H-2D(d), mAb. Flow cytometric analysis revealed specific binding of H-2K(d) molecules to AIM (K(d)=2.7x10(-9) M); and the binding was completely suppressed by the addition of R12 mAb. These results demonstrate that a novel receptor (MMR2) for H-2K(d) molecules was induced on effector macrophages responsible for allograft (H-2D(d)K(d)) rejection by H-2D(b)K(b) mice.
Tashiro-Yamaji
Junko
J
Department of Physiology, Osaka Medical College, Takatsuki 569-8686, Japan.
Kubota
Takahiro
T
Yoshida
Ryotaro
R
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D045744:Cell Line, Tumor; D018076:DNA, Complementary; D005260:Female; D006183:H-2 Antigens / Q000276:immunology; D064532:Histocompatibility Antigen H-2D; D006825:Hybridomas / Q000637:transplantation; D008264:Macrophages / Q000276:immunology* / Q000637:transplantation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D051381:Rats; D011971:Receptors, Immunologic / Q000235:genetics* / Q000276:immunology*; D013047:Specific Pathogen-Free Organisms; D014184:Transplantation, Homologous / Q000276:immunology*
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D006183:H-2 Antigens; C024755:H-2K(K) antigen; D064532:Histocompatibility Antigen H-2D; C516324:MMR2 protein, mouse; D011971:Receptors, Immunologic