[Immune-based therapies and HIV infection]

The aim of immune-based therapies in HIV infection is to enhance numbers and function of CD4 and CD8 T lymphocytes especially specific anti-HIV cellular immune responses in order to allow immune control of viral replication. Interleukin-2 (IL-2) has been extensively studied in phase II trials. Intermittent administration of subcutaneous IL-2 results in substantial increases in CD4 cell counts in most HIV-patients. Two large-scale phase III international studies are addressing the key remaining question of the clinical benefit associated with CD4 cell expansions in HIV-infected patients receiving IL-2. Other cytokines including interferon-alpha are currently under investigation in phase II trials. The goal of therapeutic immunizations is to enhance and broaden the immune system's ability to recognize HIV. Several vaccine candidates, also tested as immunogens for preventive vaccines, are currently studied in phase II trials in patients exhibiting viral suppression under highly active antiretroviral therapy. It has been demonstrated in rhesus monkeys'models that therapeutic immunizations can result in the induction of strong CD4 and CD8 responses associated with viral control and prevention of clinical AIDS, following challenge with a highly pathogenic strain of chimeric SIV-HIV. The clinical efficacy of immune-based strategies remains to be demonstrated in randomized controlled clinical trials. Participation of immune system to control of viral replication may allow simplification of antiretroviral treatment which results in long-term adverse effects having impact in life quality of persons living with HIV.