No abstract

B-cell heterogeneity studies have historically focused upon BALB/c mice and their derivatives. In contrast, the B cells of DBA/2J mice, a prototype strain for the study of the endogenous minor lymphocyte stimulatory (Mls) viral superantigen Mls-1a, have not been extensively investigated. DBA/2J B cells, by functioning as Mls-1a antigen-presenting cells, influence their own differentiation and diversity by inducing the proliferation and differentiation of specific CD4 T-cell subsets. In this report, the B cells of DBA/2J and BALB/c mice were compared for their ability to restore B-cell function in severe combined immunodeficient (SCID) recipients. Although spleen and bone marrow cells from these strains exhibited similar restoration of serum IgM production, the transfer of DBA/2J B cells into SCID mice led to greater IgG1 production. The peritoneal cells of DBA/2J mice consisted of a lower percentage of B-1 B cells and were less capable of restoring B-cell function after transfer into SCID recipients. These differences are discussed with respect to the possible role of viral superantigens in influencing B-lymphocyte diversity.

A new case of IgE lambda paraproteinaemia is described in which the immunoproliferative disorder was lympho-plasmacytoid, rather than myelomatous in type. The patient, an 81-year-old woman, lacked both organomegaly and bone lesions. The peripheral white blood count was 30 X 10(9)/l (43% lymphocytes and 37% lymphoplasmacytoid cells) and the bone marrow was heavily infiltrated with mononuclear cells with 50% lymphocytes and 50% lymphoplasmacytoid cells). Detailed immunological marker analysis of both peripheral blood and marrow showed an increased population of morphologically normal T cells, together with neoplastic population of B cells. The neoplastic cells were shown to re-express surface immunoglobulin after stripping with anti-E anti-serum, and to synthesis Ig in radio-incorporation experiments. The immunological characteristics of the neoplastic cells are considered in relation to B-cell maturation and it is shown that the immunological phenotype was of the intermediate type to be expected in association with a lympho-plasmacytoid proliferation.