Interferon-gamma (IFN-gamma) can counteract the in vitro inhibitory effect of an HIV p24 immunosuppressive heptapeptide.
Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7), corresponding to a conserved sequence of HIV core protein p24 (aa 232-238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). In the present study we show that Ch7 did not inhibit the induction of IFN-gamma-secreting cells nor the accumulation of IFN-gamma mRNA in antigen-stimulated cultures. However, delayed addition of recombinant human IFN-gamma to Ch7-suppressed cultures was able to restore fully the capacity to mount an antigen-specific antibody response. Thus, although the Ch7 immunosuppressive effect may not be directly related to a decreased production of IFN-gamma, an increased level of this cytokine is certainly able to counteract the negative effect of the peptide.
Luzzati
A L
AL
Department of Immunology, Istituto Superiore di Sanità, Rome, Italy.
Boirivant
M
M
Giacomini
E
E
Giordani
L
L
Di Modugno
F
F
Chersi
A
A
D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D000918:Antibody Specificity; D002478:Cells, Cultured; D016655:HIV Core Protein p24 / Q000187:drug effects* / Q000494:pharmacology; D006801:Humans; D007166:Immunosuppressive Agents / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D007371:Interferon-gamma / Q000096:biosynthesis / Q000187:drug effects / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D009842:Oligopeptides / Q000037:antagonists & inhibitors* / Q000494:pharmacology*
D000911:Antibodies, Monoclonal; D016655:HIV Core Protein p24; D007166:Immunosuppressive Agents; D009842:Oligopeptides; D007371:Interferon-gamma