title: Cross protection among togaviruses in nude mice and littermates.
abstract: After immunization with Sindbis virus, T-cell deficient nude mice, compared to normal littermates, were equally protected against challenge with Sindbis virus. However, the nude mice showed about one-tenth the protection observed with normal littermates after challenge with Semliki Forest virus at a dose of 100 LD50. This consistent with our previous interpretation that sensitized T-cell populations play a major role in cross protection between the two togaviruses. The remaining low level of specific cross protection in nude mice (detectable only at a challenge dose of 10 LD50) could not be attributed to an anamnestic response of neutralizing antibody to the challenge virus or to an effective antibody-dependent, complement-mediated cytolysis of infected cells in vivo. Other possible compensatory mechanisms to explain the low level of specific cross protection in nude mice are discussed.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D001102:Arbovirus Infections / Q000276:immunology*; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D007114:Immunization; D007156:Immunologic Memory; D051379:Mice; D008819:Mice, Nude; D012672:Semliki forest virus / Q000276:immunology*; D012845:Sindbis Virus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral