Innate immune mechanisms in the pathogenesis of systemic lupus erythematosus (SLE).
Immune imbalance in SLE increases the susceptibility to infectious diseases. The aim of this study was to analyze several mechanisms related to non-specific immunity in this autoimmune disorder. We studied in vivo CD11b expression, phagocytosis, and chemotaxis in polymorphonuclear cells (PMN) from SLE patients. All tests were also performed under hrIL-8 stimulating conditions and analyzed by flow cytometry. Intracellular leucocyte (monocytes and PMN) enzyme activity was evaluated using specific substrates for cathepsin B and D, collagenase, and oxidative burst by flow cytoenzymology. An exaggerated in vivo CD11b expression was observed on PMN from SLE patients without noticeably in vitro effect upon hrIL-8. Similarly both, phagocytosis and chemotaxis were diminished and showed no response to hrIL-8 stimulation. The opposite was found in PMN from controls. Intracellular enzyme activity was comparable between groups as far as cathepsin B and D are concerned. A tendency of decreased oxidative-burst induction was noted in monocytes and PMN from SLE patients, whereas collagenase activity was found clearly increased in both leucocyte subpopulations. Our results may represent a deficient ability of the innate immune mechanisms for the clearance of infectious agents, immune complexes, satisfactory resolution of inflammatory processes and tissue repair in SLE.
de la Fuente
H
H
Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Tlalpan 14000, D.F., México, Mexico.
Richaud-Patin
Y
Y
Jakez-Ocampo
J
J
González-Amaro
R
R
Llorente
L
L
D000293:Adolescent; D000328:Adult; D002401:Cathepsin B / Q000378:metabolism; D002402:Cathepsin D / Q000378:metabolism; D002634:Chemotaxis, Leukocyte; D017364:Collagenases / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007113:Immunity, Innate; D016209:Interleukin-8 / Q000494:pharmacology; D008180:Lupus Erythematosus, Systemic / Q000201:enzymology / Q000276:immunology*; D016177:Macrophage-1 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism; D009504:Neutrophils / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism; D010587:Phagocytosis; D011994:Recombinant Proteins / Q000494:pharmacology; D016897:Respiratory Burst
D016209:Interleukin-8; D016177:Macrophage-1 Antigen; D011994:Recombinant Proteins; D002401:Cathepsin B; D002402:Cathepsin D; D017364:Collagenases