Partial purification and some properties of BB7.2. A cytotoxic monoclonal antibody with specificity for HLA-A2 and a variant of HLA-A28.

The purification and properties of a cytotoxic mouse monoclonal anti-HLA-A2 antibody are described. This antibody, BB7.2, can be used as an HLA-A2 typing reagent with little modification of current typing techniques. It also recognizes a low frequency variant of HLA-A28. BB7.2 provides an example of an antibody which requires bivalent attachment to a polymeric antigen, e.g., a cell, to produce a readily detectable complex. This is due to a high rate of dissociation of the complex formed between a single BB7.2 combining sites and HLA-A2. The consequences of this property were investigated and some complications for potential uses of such monoclonal antibodies are discussed.