An HIV-1 infection-related idiotype/clonotype (1F7) is expressed on antibodies directed to envelope glycoprotein in simian immunodeficiency virus- and chimeric simian/human immunodeficiency virus-infected rhesus monkeys.

An antiidiotypic/clonotypic marker, designated 1F7, is restricted to antibodies directed to human immunodeficiency virus type 1 (HIV-1) envelope, core, and reverse transcriptase proteins. 1F7-Id is shared by more than 70% of HIV-infected individuals, arising early and persisting throughout all disease stages. To study the specificity and biological function of this cross-reactive idiotypic marker, and to explore its potential in therapeutics, we have sought an appropriate animal model. 1F7-Id+ antiviral antibodies are found among experimentally HIV-1 IIIB-infected chimpanzees; however, these rare and expensive animals do not develop acquired immunodeficiency syndrome (AIDS), and so are not an appropriate model. We now report the presence in rhesus monkeys of 1F7-Id on antibodies to the external envelope glycoproteins of simian immunodeficiency virus (SIV). This may be surprising, in view of the genetic and serologic differences between SIV and HIV-1, but is in accord with the occurrence of 1F7-Id on antibodies reacting with a broad range of HIV-1 strains. We also found 1F7-Id on anti-gp120 antibodies in rhesus monkeys infected with chimeric immunodeficiency viruses (SHIV) expressing the env, tat, and rev genes of HIV-1 on a backbone of SIV. Both SIV and SHIV cause AIDS in these monkeys. Thus, SIV- and SHIV-infected rhesus monkeys are suitable models for exploring the role of 1F7 in AIDS pathogenesis and prevention. Experiments are underway using MAb 1F7 to test the hypothesis of deceptive imprinting in AIDS.