RESUMO
The present investigation assesses the possible role of apoptosis and necrosis in intracellular antigen exposure of kidneys from Balb/c mice. Renal tissues were cultured and treated with chemicals to induce apoptosis and /or necrosis. The expression of intracellular antigens Sm, RNP, Ro and La were monitored with antibodies against these antigens. Main results confirm that renal intracellular antigens are released and exposed onto the surface of apoptotic and necrotic cells, therefore these antigens become an easy target of autoantibodies. This mechanism may be important in the lupus nephritis pathogenesis.
Assuntos
Autoantígenos/biossíntese , Rim/imunologia , Rim/patologia , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Necrose/induzido quimicamente , Técnicas de Cultura de Tecidos , Proteínas Centrais de snRNP , Antígeno SS-BRESUMO
OBJECTIVE: Present study addresses the issue whether apoptosis and necrosis increases the antigenicity of proteins recognized by antinuclear antibodies. MATERIAL AND METHODS: HEp-2 cells were cultured in standard conditions; apoptosis was induced by camptothecin and necrosis by mercuric chloride. Protein antigenicity of cell extracts was tested onto nitrocellulose membranes and probed with positive or negative sera for antinuclear antibodies by a luminescent-dot-ELISA system. RESULTS: Apoptotic changes in HEp-2 cells appeared by 24 hours of camptothecin exposure, meanwhile the necrotic features become visible earlier. Luminescence was significantly superior in ANA positive sera than in ANA negative controls. Antinuclear antibody sera recognized better the antigens from the apoptotic and necrotic cells than controls without chemical treatments. CONCLUSIONS: Apoptosis and necrosis increase the ANA binding by better availability of intracellular antigens, or by disclosing cryptic epitopes.
