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A re-evaluation of the role of C3 in B-cell activation
1National Institute for Medical Research, Mill Hill, London NW7, UK.
There is considerable evidence that, in vivo, C3 is required for the induction and maintenance of memory cells of the B-cell lineage. Recent data from in-vitro systems indicate that ligation of C3 receptors on B cells can activate these cells, and that appropriately presented C3 split products can act as B-cell growth factors. Here, Gerry Klaus and John Humphrey propose that in vivo these growth-promoting effects of C3 may operate within the microenvironment of germinal centres, where B cells encounter antigen-antibody-C3 complexes on the surfaces of follicular dendritic cells.
There is considerable evidence that, in vivo, C3 is required for the induction and maintenance of memory cells of the B-cell lineage. Recent data from in-vitro systems indicate that ligation of C3 receptors on B cells can activate these cells, and that appropriately presented C3 split products can act as B-cell growth factors. Here, Gerry Klaus and John Humphrey propose that in vivo these growth-promoting effects of C3 may operate within the microenvironment of germinal centres, where B cells encounter antigen-antibody-C3 complexes on the surfaces of follicular dendritic cells.
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