title: A subpopulation of human B lymphocytes that rosette with mouse erythrocytes.
abstract: A proportion of human peripheral blood lymphocytes form rosettes with mouse erythrocytes (M-RFC). It is confirmed that the proportion of such rosette-forming cells is high in chronic lymphocytic leukaemia (CLL). Analysis of normal lymphocyte populations revealed that M-RFC belong to the B-lymphocyte subclass exclusively. Analysis of their surface markers showed: (a) complement receptors in 50% as compared to 71% of the total B-cell population; (b) a distribution of surface immunoglobulins G, A, M and E typical of the lymphocyte sources; (c) lack of sheep erythrocyte receptor. No differences in the ratio of M-RFC to total B cells was found between lymphocyte population from tonsils, bone marrow and peripheral blood although a significantly higher ratio was seen in cord blood and in chronic lymphocytic leukaemia. Investigation of the properties of mouse erythrocyte rosette formation revealed the following: (a) incubation of lymphocyte mouse erythrocyte mixtures at 37degreesC before centrifugation inhibited rosette formation when CLL lymphocytes were used; (b) treatment of mouse erythrocytes with neuraminidase or trypsin increased their adhesiveness to lymphocytes; (c) treatment of lymphocytes with neuraminidase promoted M-rosette formation but trypsin treatment had an inhibitory effect; (d) cyanide and fluoride at concentrations which strongly inhibited E-rosette formation had no inhibitory effect on M rosettes; (e) M-rosette formation was inhibited by anti-immunoglobulin serum but not by anti-lymphocyte serum; and (f) M-rosette formation was also inhibited by the presence of staphylococci. E-rosette formation was unaffected. The nature of the bond in mouse rosettes is discussed in the light of these findings. The evidence indicates that the lymphocyte receptor may be a part of an immunoglobulin molecule.
mesh_terms: D000818:Animals; D000961:Antilymphocyte Serum; D001402:B-Lymphocytes / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D003486:Cyanides / Q000494:pharmacology; D004912:Erythrocytes / Q000276:immunology; D005459:Fluorides / Q000494:pharmacology; D006801:Humans; D051379:Mice / Q000276:immunology; D009439:Neuraminidase / Q000494:pharmacology; D014066:Palatine Tonsil / Q000276:immunology; D013210:Staphylococcus / Q000276:immunology; D013696:Temperature; D014357:Trypsin / Q000494:pharmacology
chemical_list: D000961:Antilymphocyte Serum; D003486:Cyanides; D009439:Neuraminidase; D014357:Trypsin; D005459:Fluorides