A high-affinity human monoclonal IgM antibody reacting with multiple strains of Mycoplasma hominis

Human monoclonal antibodies were produced against Mycoplasma hominis by in vitro immunization of peripheral blood lymphocytes from a healthy seropositive donor using low amounts of antigen (5 ng/ml). The immune B lymphocytes were subsequently immortalized by Epstein-Barr virus transformation followed by somatic cell fusion. Using this procedure, several specific anti-M. hominis monoclonal antibodies of mu isotype were obtained exhibiting apparent affinity constants as high as 3 x 10(9)M-1. The productivity of a number of different hybridomas was determined to be in the range 7-22 micrograms x (24 hr x 10(6) cells)-1. The specificity of one antibody, 129.1, was further characterized by enzyme-linked immunosorbent assay against several different species of Mycoplasma and by Western blot analysis. The antibody specifically bound to a protein of Mr 100,000 present in 10 of 12 different strains of M. hominis.