Cardiac injury in myocarditis induced by Coxsackievirus group B, type 3 in Balb/c mice is mediated by Lyt 2 + cytolytic lymphocytes.
Male Balb/c mice inoculated with a heart-adapted variant of Coxsackievirus, group B, type 3 (CVB3) develop severe myocarditis 7 days later. The lesions are characterized by mononuclear cell inflammation and myocyte necrosis. Infected T-lymphocyte-deficient mice show either minimal or no cardiac injury, although virus concentrations in the hearts of T-cell-deficient and -sufficient animals are similar. Adoptive transfer of 2 X 10(6) CVB3 immune Thy 1+ cells into CVB3-infected T-cell-deficient mice effectively restored myocarditis to levels observed in intact animals. Similar reconstitution with immune Ig+ cells or serum resulted in only a minimal increase in cardiac injury. To determine whether T-lymphocyte-dependent humoral or cellular immunity was responsible for myocarditis. T lymphocytes were obtained from Balb/c mice 6 days after infection with CVB3, separated into Lyt 1+2- (helper) and Lyt 1-2+ (cytolytic/suppressor) cell populations, and 2 X 10(6) of the enriched helper and cytolytic cells were adoptively transfused into infected T-cell-deficient recipients. Animals receiving the immune Lyt2+ cells developed severe myocarditis, had cytolytic T lymphocytes to both CVB3-infected and uninfected myocytes, but lacked a detectable IgG antibody response. Recipients of the Lyt 1+ cells failed to develop either myocarditis or cytolytic T cells but had normal serum IgG antibody titers to the virus. These results demonstrate that cardiac myocarditis is the product of cellular immune mechanisms.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D001853:Bone Marrow / Q000276:immunology; D016026:Bone Marrow Transplantation; D003384:Coxsackievirus Infections / Q000276:immunology*; D029822:Enterovirus B, Human / Q000276:immunology; D007518:Isoantibodies / Q000032:analysis*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009205:Myocarditis / Q000276:immunology / Q000382:microbiology*; D013601:T-Lymphocytes / Q000528:radiation effects; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013934:Thymectomy
D007518:Isoantibodies; C029805:Lyt antibodies