Human lymphocyte-activating properties of a purified polysaccharide from Candida albicans: B and T cell cooperation in the mitogenic response.

Purified human T and B lymphocytes were tested for their ability to show a mitogenic response to a purified polysaccharide (MPPS) extracted from C. albicans. It was found that neither T nor B cells alone could respond to MPPS. When a mixture of these two types of cells was tested, a normal response (comparable to the one of unfractionated peripheral blood lymphocytes) was observed. This response was not affected by prior depletion of macrophages. Results obtained with normal B or T cells mixed with mitomycin C-treated T or B cells indicated that a reciprocal helper effect exists between these two types of cells in their response to MPPS. This response could be inhibited by antisera against HL-A and Ia-like antigens.