J Acquir Immune Defic Syndr. 2000 Jan 1;23(1):1-7. Unique Identifier :
Neutralizing antibodies and specific cytotoxic T lymphocytes (CTL) may
contribute to controlling viral spread, and ideally, to virus clearance
in HIV infection. Both effector mechanisms depend on specific CD4
T-helper (Th) cells. Nevertheless, HIV hypervariability facilitates
appearance of escape mutants for antibodies and for CTL responses. Here
we also show that natural mutations (i.e., from sequences of different
HIV strains) in an immunodominant Th epitope recognized by human CD4
clones specific for the envelope glycoprotein gp120 escape CD4 T-cell
recognition. Furthermore, several natural analogue peptides exert an
antagonistic function by inhibiting proliferative response of T cells
specific to gp120 with a wild-type sequence. If similar events occur in
vivo, they may represent an additional escape mechanism for HIV. In
fact, antagonism for CD4 Th response may occur during superinfection
with a different strain, or with the appearance of a variant carrying a
mutated antagonistic sequence. In both cases, impaired Th cell function
could lead to reduced immune control of HIV infection by interfering
with CTL and antibody response.
JOURNAL ARTICLE Amino Acids/IMMUNOLOGY Clone Cells CD4-Positive
T-Lymphocytes/*DRUG EFFECTS Epitopes Human HIV Envelope Protein
gp120/GENETICS/*IMMUNOLOGY HIV-1/GENETICS/*IMMUNOLOGY Immunodominant
Epitopes Mutation Oligopeptides/IMMUNOLOGY/*PHARMACOLOGY Support,
Non-U.S. Gov't T-Lymphocytes, Helper-Inducer/*IMMUNOLOGY