The role of B7-2 (CD86) in tumour immunity

Tumour cells engineered to express co-stimulatory molecules on their surface provide researchers with powerful new tools to manipulate antitumour responses. It has been demonstrated that B7-1⁺ and B7-2⁺ tumour cells can elicit effective responses against their wild-type counterparts. This response is primarily mediated by CD8⁺ cytolytic T-lymphocytes. The co- stimulatory ability of B7-2⁺ tumour cells is comparable to that of B7-1⁺ tumour cells, though with some exceptions. However, on host antigen- presenting cells (APC), B7-2 plays a dominant role in inducing T-cell- mediated immune responses. Up-regulation of B7-2 on host APC may, therefore, present an effective means of generating potent antitumour immunity.