1. Ambrus, J. L., Pippin, J., Joseph, A., Xu, C., Blumenthal, D., Tamayo, A., Claypool, K., McCourt, D., Srikiatchatochorn, A., and Ford, R. J., 1993, Identification of a cDNA for a human high-molecular-weight B-cell growth factor, Proc. Natl. Acad. Sci. U.S.A. 90: 6330–6334.
2. Armitage, R. J., Macduff, B. M., Spriggs, M. K., and Fanslow, W. C., 1993, Human B cell proliferation and 1g secretion induced by recombinant CD40 ligand are modulated by soluble cytokines. J. Immunol. 150: 3671–3680.
3. Arpin, C., Dechanet, J., van Kooten, K., Merville, P., Grouard, G., Brière, E, Banchereau, J., and Liu, Y-J., 1995, In vitro generation of memory B cells and plasma cells, Science 268: 720–722.
4. Aversa, G., Punnonen, J., and de Vries, J.E., 1993, The 26-kD transmembrane form of tumor necrosis factor a on activated CD4+ T cell clones provides a costimulatory signal for human B cell activation, J. Exp. Med. 177: 1575–1585.
5. Azuma, M., Ito, D., Yagita, H., Okumura, K., Phillips, J. H., Lanier, L. L., and Somoza, C., 1993, B70 antigen is a second ligand for CTLA-4 and CD28, Nature 366: 76–79.