Apoptosis and necrosis increase antigenicity of proteins recognized by antinuclear antibodies.
OBJECTIVE
Present study addresses the issue whether apoptosis and necrosis increases the antigenicity of proteins recognized by antinuclear antibodies.


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.
Herrera-vanOostdam
D A
DA
Department of Immunology, Institute for Experimental Biology, Universidad Autónoma de Zacatecas, Guadalupe, Zac. 98040, Mexico.
Esparza-Ibarra
E
E
Ramírez-Sandoval
R
R
Ortíz
V
V
Bollain-y-Goitia
J J
JJ
Avalos-Diaz
E
E
Herrera-Esparza
R
R
D000974:Antibodies, Antinuclear / Q000097:blood / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D000951:Antigens, Neoplasm / Q000276:immunology; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology* / Q000473:pathology; D002166:Camptothecin / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000473:pathology; D045744:Cell Line, Tumor / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D020287:In Situ Nick-End Labeling; D007822:Laryngeal Neoplasms / Q000276:immunology / Q000473:pathology; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology; D008627:Mercuric Chloride / Q000494:pharmacology; D008947:Mixed Connective Tissue Disease / Q000097:blood / Q000276:immunology; D009336:Necrosis; D009363:Neoplasm Proteins / Q000276:immunology; D045743:Scleroderma, Diffuse / Q000097:blood / Q000276:immunology; D012859:Sjogren's Syndrome / Q000097:blood / Q000276:immunology
D000974:Antibodies, Antinuclear; D000951:Antigens, Neoplasm; D001324:Autoantigens; D007140:Immunoglobulin Fab Fragments; D009363:Neoplasm Proteins; D008627:Mercuric Chloride; D002166:Camptothecin