[Expression of Fc receptors for IgG in peripheral blood leucocytes from hepatitis C virus infected individuals].
The immune response represents a fundamental element in the control of Hepatitis C virus (HCV) infection. Viral and cellular host factors may modulate this response. In the present study, we characterized immune complexes (cryoprecipitates) isolated form HCV-infected patients and evaluated the expression of Fc receptors for IgG (FcgammaR) in peripheral blood leucocytes of these patients. Twelve HCV (+) patients and 12 healthy control individuals were selected for this study. For each group, sera samples were collected for cryoglobulins isolation and characterization and EDTA-anticoagulated venous blood samples were collected for flow cytometry analysis of FcgammaR, CD64 (FcgammaRI), CD32 (FcgammaRII) and CD16 (FcgammaRIII) expression. Presence of HCV RNA in serum and cryoprecipitates was analysed by RT-PCR. Results show that 50% of HCV-infected patients present high levels of cryoglobulins mainly constituted by IgG. Three out of 5 cryoglobulins analyzed by RT-PCR were positive for HCV-RNA. Expression of CD64 was observed mainly in monocytes (80%), CD32 in monocytes, B lymphocytes and neutrophils (> 90%) and CD16 in NK cells and neutrophils (85% and 95% respectively). No differences were observed in the percentage of FcgammaR expression when comparing HCV-infected patients with healthy controls. On the contrary, density of expression of CD32 in monocytes and neutrophils cell populations of HCV patients was significantly lower than that observed in healthy controls (p < 0.05). We concluded that low density expression of FcgammaRII in HCV-infected patients may have implications in the physiopatholgy of HCV infection.
Peinado
María
M
Instituto de Inmunología, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
Conesa
Angela
A
Dávila
Luisana
L
De Sanctis
Juan Bautista
JB
Deibis
Leopoldo
L
Toro
Félix
F
D000328:Adult; D005260:Female; D006526:Hepatitis C / Q000097:blood* / Q000276:immunology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D017452:Receptors, IgG / Q000096:biosynthesis*
D017452:Receptors, IgG