Pediatric Rheumatology Online Journal → August 2003 →  Basic Immunology  → Abstract #171  

B CELL RETENTION IN THE SPLENIC MARGINAL ZONE

T. T. Lu,¹ J. G. Cyster.¹

¹Microbiology and Immunology, University of California San Francisco, San Francisco, CA

The B cells of the splenic marginal zone mediate early responses to blood-borne encapsulated organisms and are enriched in autoreactive cells. Control of the localization of these cells may have implications for the function of these cells. The factors regulating marginal zone B cell localization have not been well understood. We investigated the role of integrins, and found that the integrins alph4beta1 and LFA-1 are expressed at high levels and are active on these B cells. Blocking antibodies to these integrins causes complete displacement of the cells from the their niche. Furthermore, we show that the integrin ligands, ICAM-1 and VCAM-1, are expressed in the marginal zone n a lymphotoxin-dependent manner. By identifying some of the key regulators of marginal zone B cell localization, these results suggest a number of potential methodologies for purging potentially autoreactive lymphocytes.