1480 Regulation of TLR Signaling in B-Cell Activation and Survival

Saturday, March 24, 2012: 9:45 a.m. - 11 a.m.
Presentation Type: Poster Session
X. YU, D. QIU, Z. LI, M. KAJIYA, T. KAWAI, M. TAUBMAN, and X. HAN, Department of Immunology, Forsyth Institute, Cambridge, MA
Objectives: Toll-Like Receptors (TLRs) play a key role in innate and adaptive immune responses in periodontal disease. While B lymphocytes express multiple TLRs, the role of TLR signaling in B cell activation and survival is unclear. In this study we have determined the role of TLR2 and TLR4 signaling in Porphyromonas gingivalis (P. gingivalis) LPS-induced B-cell activation and survival. Methods: Three groups of mice (6-8 weeks old) of C57/BL6 background were used: Wild Type (WT), TLR2 knockout (KO) and TLR4 KO. Splenocytes were extracted from mouse spleen and were stained with FITC-labeled anti-CD19 antibody. B cells were isolated from each splenocytes suspension using flow cytometry cell sorting (FACS, BD FACSAria III). Purified B cells were cultured in 96-well plate at a concentration of 105/well in the presence or absence of P. gingivalis LPS (strain: ATCC 33277). After various time of incubation, Cell Titer 96 AQueous One solution was added to each well and B cell proliferation was determined after 4 hours using microplate reader. Results: After cultured for 48 hours, the percentage of live B cells decreased more sharply in TLR2 KO mice (37.7%) compared to those in WT (21.6%) or TLR4 KO (24.8%) mice. Addition of anti-CD19 antibody did not change the B cell proliferation rate and the percentage of live B cells in culture. B cells from WT or TLR4 KO mice showed increased proliferation after LPS stimulation. However, B cells from TLR2 KO mice did not demonstrate any increase in cell proliferation after LPS stimulation. In the absence of LPS, B cells from TLR4 KO mice showed reduced rate of proliferation as compared to those from WT mice or TLR2 KO mice under normal culture conditions. Conclusions: TLR2 signaling may play a role in B cell proliferation and survival in response to P. gingivalis LPS.
This abstract is based on research that was funded entirely or partially by an outside source: NIH NIDCR DE021837

Keywords: Animal, Apoptosis, Cell culture, Immune response and Periodontal disease
See more of: Immunology
See more of: Microbiology / Immunology
Previous Abstract | Next Abstract >>