High Salt-Induced Hyperosmolality Reduces in Vitro Survival and Proliferation of Pre-B Cells

Abstract

Aim: B cells of the adaptive immunity are critical for protection against the vast majority of pathogens through the production of specific antibodies. A number of signaling pathways and transcription factors control B cell development. Environmental factors, including diet, are also important in determining how B cell develop and function. Here, the effects of hyperosmolality induced by elevated salt on the survival, IL-7-induced proliferation and differentiation of pre-B cells were tested in vitro. 
 Material and Methods: The wk3 pre-B cell line generated from SLP65–/– mice was used. Hyperosmolality in the cell culture medium was created by increasing the salt concentration with the addition of 40 mM NaCl. Wk3 pre-B cells were cultured in standard (normal NaCl) and high salt (+40 mM NaCl) medium, followed by flow cytometric analysis.
 Results: It was found that hyperosmolality caused by high salt reduced survival and induced apoptosis in wk3 pre-B cells. In addition, hyperosmolality inhibited IL-7-induced proliferation of pre-B cells. Conversely, pre-B cells treated with high salt were able to differentiate normally into IgM+ immature B cells when IL-7 was removed. 
 Conclusion: These findings suggest that the hyperosmolar microenvironment induced by high salt may play a key role in B cell development in the bone marrow.