Heterophile antigen detectable by infectious mononucleosis sera on bone marrow cells

By means of mixed agglutination test and indirect immunofluorescence test, reactions of infectious mononucleosis sera with bone marrow cells were investigated. Positive reactions were observed with bovine, murine and rat bone marrow cells, but negative results were obtained with cells of monkeys and guinea pigs. Absorption studies demonstrated that the observed reactions are due to interaction of the Paul-Bunnell antigen on bone marrow cells with its corresponding antibodies in infectious mononucleosis sera. Whereas all cells of bovine bone marrow gave positive results, only 50% of murine or rat cells were positive and these cells were shown to be neutrophilic granulocytes. Evidence was also presented that the Paul-Bunnell antigen and Fc receptor are present, apart from each other, on murine neutrophilic granulocytes.