title: Murine CD7 shares antigenic cross-reactivity with HSP-60.
abstract: Human (h) CD7 is a 40 kDa single chain Ig superfamily molecule that is expressed on thymocytes, a major subunit of peripheral T cells, and most natural killer cells. Ligands for hCD7 include the epithelial cell-produced molecule, K-12, and galectin. Mice deficient in CD7 have been shown to be resistant to LPS-induced endotoxic shock syndromes. However, monoclonal antibodies (MAb) to mouse (m) CD7 have yet to be produced, nor is the distribution of mCD7 protein in mice known. We have raised a panel of three rat MAbs to mCD7 by immunizing rats with recombinant mCD7 protein. However, using Western blot and immunoprecipitation of tissue extracts from mouse thymus, spleen, liver, brain, lymph node and skin, these anti-mouse CD7 MAbs bound only to murine heat shock protein 60 (HSP-60) present both in wild-type (CD7+/+) and CD7-deficient (CD7-/-) mice. Epitope mapping of the sites on HSP-60 and recombinant mCD7 recognized by mCD7 MAbs demonstrated non-homologous amino acid sequence epitopes recognized by anti-CD7 MAbs on both proteins. These data demonstrated molecular mimicry of mCD7 with HSP-60, and leave open the question of surface expression of mCD7.
authors.affiliation: Departments of Medicine, Duke University Medical Center, Duke Human Vaccine Institute, Durham, North Carolina, USA.
authors.forename: Brandon A
authors.initials: BA
authors.lastname: Howard
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Sempowski
authors.forename: Richard M
authors.initials: RM
authors.lastname: Scearce
authors.forename: Hua-Xin
authors.initials: HX
authors.lastname: Liao
authors.forename: David M
authors.initials: DM
authors.lastname: Lee
authors.forename: Gordon K
authors.initials: GK
authors.lastname: Lam
authors.forename: Haiyen
authors.initials: H
authors.lastname: Chen
authors.forename: Patrick
authors.initials: P
authors.lastname: Fadden
authors.forename: Timothy
authors.initials: T
authors.lastname: Haystead
authors.forename: Barton F
authors.initials: BF
authors.lastname: Haynes
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D019011:Antigens, CD7 / Q000276:immunology* / Q000378:metabolism*; D002460:Cell Line; D018834:Chaperonin 60 / Q000096:biosynthesis / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D006825:Hybridomas; D007421:Intestine, Small / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000276:immunology; D011817:Rabbits; D051381:Rats; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D019011:Antigens, CD7; D018834:Chaperonin 60