Increased levels of antibodies against interferon-alpha in HIV-1 positive individuals may be explained by a common immunological epitope on the human interferon-alpha and HIV-1 gp41.
Based on the similar effects of HIV-1 gp41 and human type I interferons on inhibition of lymphocyte proliferation and modulation of MHC class I and II molecule expression, we compared amino acid sequences of human interferons with HIV-1 gp41 and found sequence-similarity existing between gp41 and IFN-alpha. Anti-gp41-antibodies affinity-purified from sera of HIV-1-infected individuals (stage A) using rsgp41-Sepharose column could recognize human IFN-alpha in ELISA, but no antibody against IFN-alpha was detected if immunoglobulins were prepared in the same way from pooled HIV-negative serum. Besides, a sheep polyclonal anti-human IFN-alpha antibody bound weakly to recombinant soluble gp41 (rsgp41) of HIV-1IIIB. These results indicate that gp41 may share an immunological epitope with IFN-alpha. We examined 40 sera from healthy and asymptomatic HIV-1-infected individuals and AIDS-patients for IFN-alpha antibody levels by ELISA. The levels of anti-IFN-alpha antibody in sera from asymptomatic HIV-infected individuals (stage A, n = 6) was increased by about 150% in comparison with HIV-negative, but the antibody levels were obviously reduced in the case of symptomatic HIV-infected individuals (stage B, n = 7) and AIDS-patients (stage C, n = 7) in comparison with asymptomatic HIV-infected individuals (stage A). We suppose that the increased IFN-alpha-antibody level in HIV-1-infected individuals (stage A) may be due to this common immunological epitope and cross-reaction of antibodies to HIV-1 gp41 with IFN-alpha.
Chen
Y H
YH
Department of Biological Science and Technology, Tsinghua University, Beijing, China.
Stoiber
H
H
Dierich
M P
MP
D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology; D000328:Adult; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology*; D015483:HIV Antibodies / Q000276:immunology*; D015488:HIV Antigens / Q000276:immunology*; D015700:HIV Envelope Protein gp41 / Q000276:immunology*; D006679:HIV Seropositivity / Q000276:immunology*; D015497:HIV-1; D006801:Humans; D016898:Interferon-alpha / Q000276:immunology*; D008875:Middle Aged; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D000939:Epitopes; D015483:HIV Antibodies; D015488:HIV Antigens; D015700:HIV Envelope Protein gp41; D016898:Interferon-alpha