title: Immune response to a hepatitis C virus nonstructural protein in chronic hepatitis C virus infection.
abstract: The immune responses to a hepatitis C virus nonstructural protein (T3Ag) overlapping with the C100-3 antigen were examined in three groups of patients with chronic non-A, non-B hepatitis. Group I included 20 cases positive for both anti-C100-3 and the second-generation anti-HCV test (anti-HCV-II): Group II, five cases with anti-C100-3(-)/anti-HCV-II(+); and Group III, seven cases negative for both tests. HCV RNA was detectable in 20 (100%), 4 (80%) and 0 (0%) patients in each group, respectively. Proliferative responses of peripheral blood mononuclear cells to T3Ag were present in 16 (80%), 3 (60%) and 0 (0%) cases in each group, respectively (p < 0.05). Removal of CD8+ T cells from peripheral blood mononuclear cells resulted in a conversion of unresponsiveness to significant proliferation to T3Ag in the remaining cases in groups I and II, but not in group III. This change paralleled the antigen-induced production of interferon-gamma and interleukin-2, but not interleukin-4. The removal also enhanced the T3Ag-stimulated anti-C100-3 antibody production from cultured peripheral blood mononuclear cells in group II patients. These results indicate that the T3Ag-specific type 1 T helper cells play an important role in regulating anti-C100-3 antibody secretion in hepatitis C patients.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei.
authors.forename: S L
authors.initials: SL
authors.lastname: Tsai
authors.forename: P J
authors.initials: PJ
authors.lastname: Chen
authors.forename: L H
authors.initials: LH
authors.lastname: Hwang
authors.forename: J H
authors.initials: JH
authors.lastname: Kao
authors.forename: J H
authors.initials: JH
authors.lastname: Huang
authors.forename: T H
authors.initials: TH
authors.lastname: Chang
authors.forename: D S
authors.initials: DS
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D001483:Base Sequence; D002478:Cells, Cultured; D002908:Chronic Disease; D004279:DNA, Viral / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D005260:Female; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000096:biosynthesis*; D006526:Hepatitis C / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D018937:Hepatitis C Antibodies; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; C064544:C100 protein, hepatitis C virus; D004279:DNA, Viral; D006508:Hepatitis Antibodies; D018937:Hepatitis C Antibodies; D007376:Interleukin-2; D012367:RNA, Viral; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; D015847:Interleukin-4; D007371:Interferon-gamma