This chapter provides an overview of B cell growth and their differentiation factors. The growth and differentiation of B lymphocytes is mediated by soluble products released by T cells and macrophages. B cell trophic cytokines include interleukin-1 (IL-1) which is secreted by macrophages, B cell stimulatory factor I (BSF-1; previously known as B cell growth factor I or BCGF I), B cell growth factor II (BCGF II), T cell replacing factor (TRF), interleukin-2 (IL-2), and several B cell differentiation and maturation factors (BCDF or BMF) which are secreted by T cells. The chapter further discusses preparation of supernatants containing BSF-1. BSF-l-containing supernatants are derived from T cells stimulated either with mitogens, or phorbol myristate acetate (PMA). The initial step in purifying BSF-1 involves concentration of crude supernatants by ammonium sulfate precipitation. The bulk of the BSF-1 activity is found in the 50-100% saturated ammonium sulfate fractions. The next purification step varies among laboratories but involves either Phenyl Sepharose chromatography. In addition, BCGF II is also described with its purification.
ASJC Scopus subject areas
- Molecular Biology