Different reactivity of activated human B cells to B-cell growth factor and interleukin 2 in the costimulation assay with anti-IgM antibody and in the preactivation assay with staphylococcus bacteria

• Published in: Cellular immunology Vol. 95; no. 2; pp. 358 - 367
• Main Authors: Almerigogna, F., Biagiotti, Roberta, Giudizi, Grazia M., Del Prete, G.F., Maggi, E., Mazzetti, M., Alessi, Anna, Ricci, M., Romagnani, S.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.10.1985; Elsevier
• Subjects: Analysis of the immune response. Humoral and cellular immunity; Antibodies, Anti-Idiotypic - physiology; B-Lymphocytes - immunology; Biological and medical sciences; Clone Cells - immunology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Growth Substances - physiology; Humans; Immunobiology; Immunoglobulin M - physiology; Interleukin-2 - physiology; Interleukin-4; Lymphocyte Activation; Lymphokines - physiology; Lymphokines, interleukins ( function, expression); Recombinant Proteins - pharmacology; Regulatory factors and their cellular receptors; Staphylococcus aureus - immunology; T-Lymphocytes - immunology; Time Factors; Human; Immune response; Interleukin 2; Antibody; Micrococcales; Bacteria; Stimulation; Micrococcaceae; Activation; B-Lymphocyte; Lymphokine; Staphylococcus aureus
• ISSN: 0008-8749; 1090-2163
• DOI: 10.1016/0008-8749(85)90323-5

The two main assay systems which have been developed for the study of lymphokine-mediated human B-cell proliferation, i.e., the costimulation assay with anti-μ antibody and the preactivation assay with Staphylococcus aureus Cowan I (SAC) bacteria, were compared. Purified interleukin 2 (IL-2), obtained by the recombinant DNA technology (r-IL-2), enhanced the proliferative response of anti-μ-stimulated human B cells in the costimulation assay with anti-μ antibody and maintained the B-cell proliferation induced by preactivation with SAC bacteria. Although the majority of T-cell clones, established from normal peripheral blood T lymphocytes, showed production of both IL-2 and B-cell growth factor (BCGF) following phytohemagglutinin (PHA)-stimulation, some T-cell clones were found whose supernatants (PHA-SN), apparently free of IL-2, manifested strong BCGF activity in the costimulation assay with anti-μ antibody. However, the same clonal, IL-2-free, T-cell SN displayed no BCGF activity in the preactivation assay with SAC bacteria. When B cells were activated for 3 days with anti-μ antibody, followed by the addition of r-IL-2 or clonal T-cell SN containing BCGF for an additional 3 days, r-IL-2 showed the ability to maintain B-cell proliferation, whereas clonal SN containing BCGF had virtually no effect. These data indicate that the costimulation assay with anti-μ antibody explores the reactivity of normal human B cells to both BCGF and IL-2, whereas the preactivation assay with SAC bacteria, due to a shorter reactivity to BCGF of activated human B cells, essentially represents a probe for the study of IL-2-promoted B-cell proliferation.