HIV-1-induced immune suppression may result from autoimmune disorders including anti-SLWDQ autoantibodies.
We have previously unravelled the striking SLWDQ pentapeptide identity between HIV-1 env gp120 and the CD4 molecule. We show here that this pentapeptide is required for the functioning of the co-stimulatory MHC-CD4 signal in T4-cell activation since it suppresses antigen-induced T-cell proliferation. Moreover, concerning the MHC class II counterpart, the LNGQEETGVVSTN sequence which strongly inhibits T-cell immune activation is likely to be part of the functional site of the molecule. Interestingly the MHC/gp120 homology described by Young overlaps this MHC region. We further report that the gp120 SLWDQ peptide triggers an immune reaction which is both humoral (anti-SLWDQ antibodies) and cellular (CTLs against autologous targets carrying the pentapeptide) in HIV-1 infected individuals. Finally, anti-SLWDQ antibodies from patients sera purified by column chromatography strongly inhibit antigen-induced immune T-cell activation. This result led us to postulate that these antibodies found in high titers in HIV-1 infected individuals could contribute to set up the progressive systemic immune T-cell suppression characterizing AIDS.
Zagury
J F
JF
Université Pierre et Marie Curie, Paris.
Bernard
J
J
Achour
A
A
Astgen
A
A
Lachgar
A
A
Fall
L
L
Carelli
C
C
Issing
W
W
Mbika
J P
JP
Cantalloube
H
H
D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D000917:Antibody Formation / Q000187:drug effects; D001323:Autoantibodies / Q000276:immunology*; D015704:CD4 Antigens / Q000276:immunology; D015483:HIV Antibodies / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D016867:Immunocompromised Host / Q000276:immunology*; D008285:Major Histocompatibility Complex / Q000276:immunology
D001323:Autoantibodies; D015704:CD4 Antigens; D015483:HIV Antibodies