Structural and functional characterization of IL 2 receptors on activated human B cells.
After activation, B cells express the IL 2 receptor as determined by their reactivity with monoclonal anti-IL 2 receptor antibodies. In this report we show that anti-IL 2 receptor antibodies precipitated comparable 60,000 to 65,000 dalton proteins from highly purified B and T cells. Limited peptide mapping suggested that the receptors on B and T cells were identical. Moreover, activated B cells could be induced to proliferate by IL 2, but not to secrete Ig. Anti-IL 2R antibody blocked the effect of IL 2 but not the proliferative response induced by B cell growth factor (BCGF), suggesting independent growth factor receptors. Investigation of the kinetics of the B cell response to growth factor indicated that BCGF acts within 24 hr, whereas IL 2 was virtually devoid of activity for 48 hr. Nevertheless, after 72 to 96 hr, the effect of IL 2 was equal to or greater than that obtained with BCGF. These studies suggest that the initial stages of B cell proliferation involves a sequential interaction of BCGF and IL 2 with their respective receptors.
D000911:Antibodies, Monoclonal / Q000502:physiology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D001667:Binding, Competitive; D002454:Cell Differentiation; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006133:Growth Substances / Q000502:physiology; D006801:Humans; D015847:Interleukin-4; D007399:Interphase; D007700:Kinetics; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000502:physiology; D011971:Receptors, Immunologic / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D015375:Receptors, Interleukin-2; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000378:metabolism
D000911:Antibodies, Monoclonal; D006133:Growth Substances; D008222:Lymphokines; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D015847:Interleukin-4