Restriction in the usage of variable beta regions in T-cells infiltrating valvular tissue from rheumatic heart disease patients.
Rheumatic Heart Disease (RHD) is a delayed consequence of a pharyngeal infection with group A streptococcus (GAS), usually ascribed to a cross-reactive immune response to the host's cardiac tissues. Several GAS proteins have been reported to be superantigens, also raising the possibility that T cells in RHD could be driven by superantigens. We therefore analysed the variable beta (V beta) repertoire of T cells infiltrating heart valves from chronic RHD patients undergoing elective valvular surgery. We analysed 15 valve specimens from patients with longstanding quiescent RHD and control valves from four non-rheumatic individuals. Total RNA was extracted from fresh valve tissue and employed to amplify 22 V beta genes by RT-PCR. In valvular tissue, a restricted number of only 2 to 9 V beta regions were detected as opposed to the findings in control valves. In 8 RHD valves, the expression of V beta1, 2, 3, 5.1, 7, 8, 9 or 14 was marked. These V beta regions have been related to GAS superantigens. Our results evidence the presence of a restricted set of T lymphocytes in valvular tissue from a majority of patients with chronic RHD and suggest that valvular sequelae in these patients might be related to a local antigen or superantigen driven inflammatory process that persists even many years after the initial triggering event.
Figueroa
F
F
Laboratory of Immunology, Faculty of Medicine, Universidad de los Andes, Santiago, Chile. ffigueroa@uandes.cl
González
M
M
Carrión
F
F
Lobos
C
C
Turner
F
F
Lasagna
N
N
Valdés
F
F
D000328:Adult; D000368:Aged; D005260:Female; D006351:Heart Valves / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D012214:Rheumatic Heart Disease / Q000276:immunology* / Q000503:physiopathology; D013601:T-Lymphocytes / Q000276:immunology*
D007135:Immunoglobulin Variable Region; D011948:Receptors, Antigen, T-Cell