Efficient B cell responses to Borrelia hermsii infection depend on BAFF and BAFFR, but not TACI. Infect Immun. 2013 Nov 11. [Epub ahead of print] ncbi.nlm.nih.gov/pubmed/24218480 Dickinson GS, Sun G, Bram RJ, Alugupalli KR. Source Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107. Abstract T cell-independent antibody responses develop rapidly within 3-4 days and are critical for preventing blood-borne pathogens from evolving into life-threatening infections. Interaction of BAFF, also known as BLyS, with its receptors, BAFFR and TACI, on B cells is critical for B cell homeostasis and function. Using a synthetic polysaccharide antigen, it has previously been shown that TACI is critical for T cell-independent antibody responses. To examine the role of BAFFR and TACI in T cell-independent antibody responses to an active infection, we utilized the B. hermsii infection system. In this infection system T cell-independent responses mediated by the B1b cell subset are critical for controlling bacteremia. We found that B1b cells express BAFFR and TACI and surface expression of both receptors is upregulated on B1b cells following exposure to whole B. hermsii. Surprisingly, we found that TACI-/- mice are neither impaired in specific antibody responses to B. hermsii, nor in controlling B. hermsii bacteremia. In contrast, TACI-deficient mice immunized with heat-killed type 3 serotype pneumococcus are impaired in generating pneumococcal polysaccharide-specific responses and succumb to challenge with live type 3 serotype pneumococcus, indicating that TACI is required for T cell-independent antibody responses to bacteria-associated polysaccharides. Although we have found that TACI is dispensable for controlling B. hermsii infection, mice deficient in BAFFR or BAFF exhibit impairment in B.hermsii-specific IgM responses and clearance of bacteremia. Collectively these data indicate a disparity in the role for TACI and BAFFR in primary T cell-independent antibody responses to bacterial pathogens.
Posted on: Thu, 14 Nov 2013 03:53:44 +0000
Trending Topics
Recently Viewed Topics
© 2015