No abstract

The following reactions of serum antibodies with cell surface antigens were studied by means of an enzyme immunoassay with cell suspensions: (1) Rh antiserum with human red blood cells; (2) H-2 antisera with murine red blood cells; (3) H-2 antisera with murine thymocytes and hepatocytes; (4) Thy-1 antiserum with murine thymocytes; (5) polyvalent and monovalent HLA alloantisera with human leukocytes and human mononuclear cells, and (6) antisera of murine origin with human and marmoset lymphoid cell lines. In all instances, with the exception of monovalent HLA antisera, the assay proved to be a sensitive and highly specific procedure.

Infectious mononucleosis sera gave positive results in enzymoimmunoassay with glutaraldehyde-treated human erythrocytes. This unexpected reaction appeared to be caused by the interaction of Paul-Bunnell (P-B) antibodies with a partial P-B antigen that apparently appears on human red blood cells in a hidden form and becomes exposed by the treatment with glutaraldehyde.

Two cell lines secreting Paul-Bunnell antibodies were established by means of Epstein-Barr virus-induced immortalization of B lymphocytes from patients with infectious mononucleosis. Progressive loss of antibody production, most probably due to a shutdown of antibody secretion by individual cells was, however, observed. The first of the established cell lines lost its secretion ability after 10 weeks, and the second after 33 weeks of culture. Further improvements of the technique are necessary to stabilize the antibody secretion.