Efficient generation of human anti-cytomegalovirus IgG monoclonal antibodies from preselected antigen-specific B cells.

Human anti-cytomegalovirus (CMV) specific B cells were enriched to a purity of up to 38% on CMV-coated dishes and subsequently clonally expanded in the presence of human T cell supernatant and irradiated murine thymoma helper cells. The expanded cells were immortalized by a mini-electrofusion with K6H6B5 myeloma cells. Twenty-two anti-CMV positive B cell clones could be obtained from as little as 1.5 ml donor blood. The majority of these clones produced anti-CMV antibodies of the IgG class. Ten anti-CMV positive B cell clones were submitted to separate mini-electrofusions yielding stable, human anti-CMV IgG-producing hybridomas in six out of ten fusions. These antibodies recognized different proteins of the CMV virus, as deduced from the immunofluorescence staining pattern on infected human fibroblasts.