Antibodies against a peptide sequence within the HIV envelope protein crossreacts with human interleukin-2

Recent investigations have identified a homologous sequence between the lymphokine interleukin 2 (IL-2) and the envelope protein of HIV. This homology is one of six amino acids corresponding to interleukin-2 (IL-2) residues 14-19 (Leu-Glu-His-Leu-Leu-Leu) and to the carboxy terminal six amino acids of HIV envelope protein gp41 (Leu-Glu-Arg-Ile-Leu-Leu). Thus, it is conceivable that an anti-HIV antibody response would generate antibodies which would crossreact with IL-2. We show here that the two peptides are recognized by the immune system as being almost identical. More importantly, antibodies against the HIV envelope peptide bind IL-2. Thus, these studies are the first step in investigating what could be characterized as an HIV-induced autoimmune response, that is, the induction of antibodies to the HIV envelope protein which also crossreact with IL-2.