DENDRITIC CELLS ARE POTENT ANTIGEN-PRESENTING CELLS FOR IN-VITRO INDUCTION OF PRIMARY HUMAN CD4(-CELL LINES SPECIFIC FOR HIV GP120() T)

Activation of T helper cells specific for viral antigens is critical f or antibody production and for generation of cytotoxic cells during th e immune response to HIV. Since T-cell activation depends on antigen-p resenting cells (APCs), it is important to define the cells that have a role in presentation of HIV antigens in general and of gp120 in part icular. Peripheral blood mononuclear cells (PBMCs), adherent monocytes (AMs), dendritic cells (DCs) and Epstein Barr virus-transformed B-cel l lines (LCLs) were tested for the capacity to present gp120 to a spec ific T-cell clone. DCs proved to be the most effective APC. Primary T- cell lines were generated from uninfected and unprimed individuals by using different APCs in the presence of gp120 or an immunodominant pep tide. T-cell lines specific for gp120 were obtained with PBMCs or DCs as APCs, but not with AMs or LCLs. The data showed that (a) DCs are th e most effective APCs for presentation of gp120 to specific T cells an d (b) DCs are necessary for in vitro induction of primary T-cell lines specific for gp120.