Increased level of serum HLA class I antigens in patients with systemic lupus in patients with systemic lupus erythematosus. Correlation with disease activity.
The level of soluble beta2-mu-associated HLA Class I heavy chains (sHLA-I) and of soluble beta2-mu-free HLA Class I heavy chains (sHLA-FHC) was found to be significantly higher in sera from 58 patients with systemic lupus erythematosus (SLE) than in those from 82 age and sex-matched controls. The level of serum sHLA-I in patients with SLE was significantly correlated to disease activity. Western blotting analysis showed that the 44-kDa isoform represents the major component in the antigens immunoprecipitated by anti-beta2-mu mAb NAMB-1 and by anti-beta2-mu-free HLA Class I heavy chain mAb HC-10 from sera of patients with SLE. These results suggest that the increased serum levels of sHLA-I and of sHLA-FHC in patients with SLE reflect their increased shedding from cell membrane. In view of the ability of sHLA-I and of sHLA-FHC to induce apoptosis of activated T cells, it is suggested that their increased serum levels in patients with SLE is triggered by dysregulation of the immune system leading to T-cell activation. The increased serum levels of sHLA-I and of sHLA-FHC may be used by the immune system to control the pool of activated T cells by inducing apoptosis. If this possibility is proven to be correct, modulation of the serum level of sHLA-I and of sHLA-FHC may be utilized to develop strategies to treat SLE.
Servizio di Oncologia Sperimentale C-Immunologia, Istituto Tumori Fondazione Pascale, Napoli, Italy.
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A
Bresciani
G
G
Pirozzi
M
M
Spera
M L
ML
Lombardi
L
L
Ambrosone
S
S
Migliaresi
S
S
Ferrone
C
C
Manzo
D000293:Adolescent; D000328:Adult; D015153:Blotting, Western; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms
D015395:Histocompatibility Antigens Class I; D007143:Immunoglobulin Heavy Chains; D020033:Protein Isoforms