Serological evidence for antigenic differences between the Mason-Pfizer monkey virus (MPMV) and an MPMV-like virus (PMFV) detected in a malignant permanent human cell line.

Abstract Mason-Pfizer monkey virus (MPMV) and an MPMV-like virus (PMFV) detected in a human continuous cell line were compared in immunofluorescence tests. Antisera against MPMV and PMFV revealed cross-reacting antigens in the cytoplasm of cells infected with either MPMV or PMFV. Immunofluorescence absorption showed that, in addition to the common specificities, both viruses have distinct antigens. MPMV and PMFV must therefore be regarded as different types of a closely related virus group.