The mouse lymph node homing receptor is identical with the lymphocyte cell surface marker Ly-22: role of the EGF domain in endothelial binding.
The lymph node homing receptor core polypeptide (mLHRc) is composed of a tandem collection of domains: a lectin domain, an epidermal growth factor (EGF) domain, and two repeats common in complement regulatory proteins. Here we demonstrate localization of mLHRc to chromosome 1, the portion syntenic with chromosome 1 in man. This locus is inseparable in mouse strains from the murine lymphocyte cell surface marker Ly-22. The data indicate that Ly-22 is an allelic determinant on the LHR resulting from a single amino acid interchange within the EGF domain. Cross-blocking experiments demonstrate that anti-Ly-22 and MEL-14 recognize independent epitopes and that Ly-22 is distinct from the carbohydrate binding region. Application of anti-Ly-22 in the in vitro binding assay shows inhibition of binding of lymphocytes to high endothelial venules (HEVs). The localization of the Ly-22 epitope in this novel chimeric protein suggests direct participation of the EGF domain in the adhesion of lymphocytes to HEV.
Department of Pathology, Stanford University School of Medicine, California 94305.
M H
MH
Siegelman
I C
IC
Cheng
I L
IL
Weissman
E K
EK
Wakeland
D000595:Amino Acid Sequence; D000818:Animals; D000950:Antigens, Ly / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics*; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D004730:Endothelium, Vascular / Q000276:immunology*; D004815:Epidermal Growth Factor / Q000235:genetics; D000939:Epitopes / Q000032:analysis; D015870:Gene Expression; D006801:Humans; D008198:Lymph Nodes / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D011233:Precipitin Tests; D011971:Receptors, Immunologic / Q000235:genetics*; D016201:Receptors, Lymphocyte Homing; D014162:Transfection
D000950:Antigens, Ly; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D000939:Epitopes; D011971:Receptors, Immunologic; D016201:Receptors, Lymphocyte Homing; D004815:Epidermal Growth Factor