We have investigated the effects of cleavage of factor B by its activating enzyme, factor D, as well as its activation fragments Bb and Ba, on the growth of mouse spleen B lymphocytes preactivated by LPS. Neither factor B nor factor D show any growth-supporting activity when tested alone. The coaddition of factor B and factor D to serum-free cultures of LPS-preactivated B cell blasts increased the proliferation of the responding cells up to the level obtained by restimulation with LPS. Such growth-supporting activity was shown to be mediated by Ba, whereas Bb did not show any significant effect. Furthermore, this effect was not restricted to the LPS-preactivated B cell blasts; in fact, Ba also supported the growth of in vivo, activated B cell blasts of unprimed mice of the LPS-nonresponder C3H/HeJ strain. In contrast, Ba did not maintain growth of Con A-activated T cells or TCGF-dependent CTL cells. Taken together, these results describe the first biological activity of human Ba as a B cell stimulatory factor.
Article| May 01 1986
Growth-supporting activity of fragment Ba of the human alternative complement pathway for activated murine B lymphocytes.
Online Issn: 1540-9538
Print Issn: 0022-1007
J Exp Med (1986) 163 (5): 1349–1354.
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F Praz, E Ruuth; Growth-supporting activity of fragment Ba of the human alternative complement pathway for activated murine B lymphocytes.. J Exp Med 1 May 1986; 163 (5): 1349–1354. doi: https://doi.org/10.1084/jem.163.5.1349
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