Expression of the CD85j (leukocyte Ig-like receptor 1, Ig-like transcript 2) receptor for class I major histocompatibility complex molecules in idiopathic inflammatory myopathies.
OBJECTIVE
Expression of class I major histocompatibility complex (MHC) molecules on the surface of muscle cells is a biologic feature of idiopathic inflammatory myopathies (IIM). Class I MHC-transgenic mouse models support a causative role for class I MHC expression by muscle cells in the pathogenesis of IIM. The muscle lesions are characterized by leukocyte infiltration. We undertook this study to analyze the expression in muscle lesions of various class I MHC-specific receptors on leukocytes and natural killer (NK) cells.


METHODS
We generated a panel of cell transfectants to control the immunofluorescence analysis of class I MHC receptor expression. We then analyzed the expression of CD158 (killer cell Ig-like receptors [KIRs]) and CD85j (leukocyte Ig-like receptor 1, Ig-like transcript 2) on muscle sections prepared from 14 patients with IIM (5 with dermatomyositis [DM], 5 with polymyositis [PM], and 4 with sporadic inclusion body myositis [IBM]).


RESULTS
We could not detect the presence of NK cells in inflammatory lesions. However, the class I MHC receptor CD85j, but no KIRs, was expressed by inflammatory cells infiltrating muscle lesions in IIM.


CONCLUSIONS
CD85j is expressed in PM and sporadic IBM at the sites of partial invasion and in DM in perivascular inflammation, paving the way for dissecting the role of CD85j in the pathogenesis of inflammatory myopathies.
Schleinitz
Nicolas
N
Department of Internal Medicine, CHU La Conception, Marseille, France. nicolas.schleinitz@ap-hm.fr
Cognet
Celine
C
Guia
Sophie
S
Laugier-Anfossi
Fanny
F
Baratin
Myriam
M
Pouget
Jean
J
Pelissier
Jean-Francois
JF
Harle
Jean-Robert
JR
Vivier
Eric
E
Figarella-Branger
Dominique
D
D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D009220:Myositis / Q000276:immunology / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*
D015703:Antigens, CD; C105299:LILRB1 protein, human; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D011971:Receptors, Immunologic