HIV Molecular Immunology 2005

HIV specific cytotoxic T lymphocytes (CTL) and T-helper cells (Th) remain one of the cornerstones of a potential HIV vaccine, and a number of vaccine trials and recent in vitro studies point towards the importance of the close interplay between these two arms of the cellular immune response in HIV infection. As more and more vaccine candidates find their way to clinical trials, not only the question of vaccine immunogen selection but also that of the appropriate in vitro monitoring of vaccine success become increasingly critical issues. The chosen approaches will need to balance the optimal sensitivity with the need of inter-trial comparability, and several efforts are under way to establish widely applicable in vitro antigen test sets to monitor several parallel vaccine trials in the future. The challenge for this undertaking is considerable, given that many vaccine trials are based on non-clade B immunogens, and thus require a comprehensive knowledge of immunogenic regions in various HIV clades, with the most pressing one likely being clade C. Part of this characterization will be the detailed delineation of the optimal CTL epitopes and their HLA restriction that are contained in these regions, so that reliable predictions can be made in terms of population coverage and how well local viral diversity is reflected by the vaccine sequence(s). Thus, although few laboratories nowadays follow through on identifying the precise nature of the targeted, optimal CTL epitopes in their various immunogens, we feel that epitope definition is not only desirable but actually urgently needed for an optimal vaccine design and appropriate analyses of induced responses. As in the past years, we here present an updated compilation of optimally defined CTL epitopes in all regions of HIV, which increasingly also includes epitopes defined in non-clade B infection. As argued above, especially non-clade B derived CTL epitopes will be most