title: Detection of immunologically cross-reacting capsid protein of alphaviruses on the surfaces of infected L929 cells.
abstract: Hyperimmune, but not normal immune, monospecific antiserum made to capsid protein of Sindbis virus (SIN) was found to cause cytolysis equally well of both SIN- and Semliki Forest virus-infected L929 cells in antibody-dependent, complement-mediated cytotoxicity assays. The cell surface reactivity of the hyperimmune antiserum was also demonstrated by solid-phase radioimmune assays with unfixed infected cells or infected cells fixed with low concentrations of glutaraldehyde (0.025%) before reactivity with antisera. Higher concentrations of glutaraldehyde lowered the sensitivity of detection. Purified SIN capsid protein specifically inhibited antibody-dependent, complement-mediated cytotoxicity by the monospecific anti-capsid protein serum on SIN- and Semliki Forest virus-infected target cells. That hyperimmune anti-SIN serum also cross-reacts with capsid protein on the surface of Semliki Forest virus-infected cells was suggested by the fact that capsid protein inhibited cross-cytolysis in the antibody-dependent, complement-mediated cytotoxicity assay. The latter antiserum was collected after repeated injections of purified virions over a 9-month period. The results suggest that hyperimmune monospecific antisera made to SIN capsid protein or hyperimmune antisera to SIN or Semliki Forest virions detect homologous and cross-reacting capsid protein determinants on the surface of infected cells.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D002213:Capsid / Q000032:analysis* / Q000276:immunology; D002472:Cell Transformation, Viral; D002642:Chick Embryo; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts; D007106:Immune Sera; D007739:L Cells / Q000276:immunology; D051379:Mice; D011863:Radioimmunoassay; D012845:Sindbis Virus / Q000032:analysis* / Q000276:immunology
chemical_list: D000936:Antigen-Antibody Complex; D007106:Immune Sera