Cells of the B-cell lineage play an essential part in the immune response,
not only as the producers of antigen-specific antibodies, but also as antig
en-presenting cells. Unlike T cells, however, the establishment of long-ter
m normal B-cell lines has proved to be exceedingly difficult. In this paper
we demonstrate that cell membrane-expressed CD154 (CD40 ligand) is able to
support the continual growth of porcine mesenteric lymph node B-cell cultu
res for more than 4 months without the addition of exogenous cytokines, suc
h as interleukin-4 (IL-4). Addition of IL-4, but not interferon-gamma (IFN-
gamma) or IL-13, to these cultures enhanced proliferation, as, to a lesser
extent, did addition of IL-2. Interestingly, however, whilst IFN-gamma-supp
lemented cultures largely consisted of immunoglobulin M (IgM)-positive cell
s, cultures with IL-13 or IL-4 contained a significantly increased proporti
on of IgG-positive cells.