Identification of a T cell-derived b cell growth factor distinct from interleukin 2.

We report here a factor (B cell growth factor) found in induced supernatants of the mouse thymoma EL4 that co-stimulates with anti-IgM antibodies in short-term cultures of purified B lymphocytes to induce polyclonal B cell proliferation but not antibody-forming cell production. The factor is not mitogenic for resting B cells and interacts with anti-IgM-activated B cells in a non-H-2-restricted manner. Absorption studies and molecular weight analysis reveal the factor is distinct from interleukin 2. This factor synergises with antigen, interleukin 2, and an interleukin 2-free, B cell growth factor-free T cell supernatant that contains T cell-replacing factor to produce erythrocyte-specific plaque-forming cells in cultures of highly purified B cells.

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Interleukin 2 and low molecular weight B cell growth factor are T cell-replacing factors for different subpopulations of human B cells*

European Journal of Immunology ◽

10.1002/eji.1830181026 ◽

1988 ◽

Vol 18 (10) ◽

pp. 1635-1638 ◽

Cited By ~ 9

Author(s):

Robin E. Callard ◽

Susan H. Smith

Keyword(s):

Molecular Weight ◽

T Cell ◽

B Cells ◽

Growth Factor ◽

Cell Growth ◽

B Cell ◽

Interleukin 2 ◽

Low Molecular Weight ◽

Human B Cells ◽

B Cell Growth Factor

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Development of a human T-T cell hybridoma secreting B cell growth factor.

Journal of Experimental Medicine ◽

10.1084/jem.157.1.60 ◽

1983 ◽

Vol 157 (1) ◽

pp. 60-68 ◽

Cited By ~ 75

Author(s):

J L Butler ◽

A Muraguchi ◽

H C Lane ◽

A S Fauci

Keyword(s):

T Cell ◽

B Cells ◽

Growth Factor ◽

Cell Growth ◽

B Cell ◽

Interleukin 2 ◽

Lymphocyte Function ◽

B Cell Growth Factor ◽

Normal Human

The success of long-term culture of normal human and murine B cells has been hampered by the limited availability of soluble factors capable of maintaining proliferation of activated B lymphocytes. Previous experiments using various culture-derived supernatants in a human system were unable to separate the activities of B cell growth factor (BCGF) and interleukin 2 (IL-2) by immunochemical means. Thus, purified factors with BCGF activity in the absence of IL-2 activity have not been available for study. In the present study, normal human peripheral blood T cells were fused with the hypoxanthine/aminopterin/thymidine-sensitive human T-leukemic cell line, CEM-6. Supernatants from the resulting hybrid cells were tested for the ability to maintain proliferation of normal human B cells in a recently described assay system for human BCGF. Hybrids demonstrating BCGF activity were cloned by limiting dilution. One hybrid clone, 2B11, continued to support proliferation of B cells in both long-term cultures and 6-d assays at a level significantly above that seen with conventionally produced growth factors. No IL-2 activity was found in the supernatant from hybrid 2B11. The hybridoma supernatant was fractionated by gel filtration, and maximum proliferation of B cells was supported by the 18-20,000 mol wt protein fraction. Thus, a human T-T cell hybridoma that has BCGF activity in the absence of any demonstrable IL-2 activity has been developed. Human T-T cell hybridomas secreting discrete immunoregulatory factors should prove to be powerful tools in dissecting the mechanisms of immunoregulation of human lymphocyte function.

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