The role of IL-4 in the generation of B lymphocytes in the bone marrow.
It has been indicated that IL-4 supports the maturation of pre-B cells to B lymphocytes. The present study was designed to investigate the mechanism by which IL-4 influences this maturational process. In order to determine whether IL-4 acts directly on pre-B cells, we sorted out B220+, sIg- cells from bone marrow of young adult (C3H X C57BL/6)F1 mice. These purified populations of pre-B cells (greater than 95%) were incubated with and without 4 to 200 U/ml of rIL-4, and the generation of new B lymphocytes in these cultures was followed for several days. We found that the frequency of newly generated B lymphocytes (%sIg+) was similar in control and in IL-4-containing cultures. However, the total number of B lymphocytes was significantly higher in IL-4-containing cultures. This high number of B lymphocytes was a result of an increased survival of cells in IL-4-containing cultures. The effect was IL-4 specific because anti-IL-4 antibodies completely prevented this phenomenon. We thus conclude that IL-4 does not induce the maturation of pre-B cells but may be important in the process of B lymphocytes generation by providing a signal for survival of these cells.
Simons
A
A
Department of Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
Zharhary
D
D
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000502:physiology; D001853:Bone Marrow / Q000276:immunology* / Q000502:physiology; D002454:Cell Differentiation; D002470:Cell Survival; D002478:Cells, Cultured; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000502:physiology; D015847:Interleukin-4 / Q000494:pharmacology / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction
D011994:Recombinant Proteins; D015847:Interleukin-4