eprintid: 10202 rev_number: 4 userid: 6 dir: disk0/00/01/02/02 datestamp: 2011-11-10 20:09:21 lastmod: 2016-11-15 13:53:53 status_changed: 2011-11-10 20:09:21 type: thesis_degree metadata_visibility: show contact_email: nab31@pitt.edu, nab1320@yahoo.com item_issues_count: 0 eprint_status: archive creators_name: Biswas, Nabanita creators_email: nab31@pitt.edu, nab1320@yahoo.com creators_id: NAB31 title: CHARACTERIZATION OF BIOLOGICAL FUNCTION OF INTERACTION BETWEEN TLR4 AND PLIC-1 ispublished: unpub divisions: sch_gsph_infectiousdiseasesmicrobiology full_text_status: public keywords: mutation abstract: Toll-like receptors (TLRs) are key innate immune receptors that recognize non-self pathogens and trigger host responses. Activation of these receptors results in the release of antimicrobial peptides, inflammatory cytokines, and co stimulatory molecules that initiate adaptive immunity for infections with gram-negative bacteria, lipopolysaccharide is the main source of inflammation, and toll-like receptor 4 (TLR4) is crucial in mediating its effects. TLR4 is expressed on cardiomyocytes, macrophages, airway epithelia, endothelial, smooth-muscle cells and in small amounts in most other tissue. But, uncontrolled activation of TLR signaling molecules may cause auto immune diseases, sepsis, and tissue damage so the activation of TLR4 should be under control. Ubiquitin¨Cdependent receptor degradation as well as stabilization was recently suggested as a novel regulatory mechanism in controlling several TLR activations. We have recently found that an ubiquitin-like protein named protein linking integrin associated protein to cytoskeleton 1 (PLIC-1) interacts with the cytoplasmic domain of TLR4. The interaction between TLR4 and PLIC-1 was verified by western blot and immunoprecipitation. Further mapping of the interacting domain was done and we observed that the N terminal fragment of PLIC-1 is interacting with TLR4. PLIC-1 has been reported to stabilize proteins by interfering with proteosomal degradation. Consistent with this finding, we observed that over expression of PLIC-1 accumulated ubiquitinated TLR4. By flow cytometric analysis we observed that over expression of PLIC-1 is stabilizing TLR4. Reporter studies show that PLIC-1 inhibits the TRIF-dependent IFN-¦Â pathway. When endogenous PLIC-1 was knocked down by RNAi, the activation of TRIF-dependent IFN-¦Â luc was further increased. The same effect was observed in J774 mouse macrophages. Taken together our results suggest that PLIC-1 is a negative regulator of TLR pathway. This knowledge may be applied in immunotherapy as a means to modulate TLR activation in diseases such as septic shock, thus provides benefit for public health. date: 2007-02-15 date_type: completed institution: University of Pittsburgh refereed: TRUE etdcommittee_type: committee_chair etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_name: Wang, Tianyi etdcommittee_name: Hackam, David etdcommittee_name: Martinson, Jeremy etdcommittee_email: tywang@pitt.edu etdcommittee_email: hackamd@upmc.edu etdcommittee_email: jmartins@pitt.edu etdcommittee_id: TYWANG etdcommittee_id: etdcommittee_id: JMARTINS etd_defense_date: 2006-12-15 etd_approval_date: 2007-02-15 etd_submission_date: 2006-12-08 etd_access_restriction: immediate etd_patent_pending: FALSE assigned_doi: doi:10.5195/pitt.etd.2011.10202 thesis_type: thesis degree: MS committee: Tianyi Wang, PhD, (tywang@pitt.edu) - Committee Chair committee: David Hackam, MD, PhD, (hackamd@upmc.edu) - Committee Member committee: Jeremy Martinson, PhD, (jmartins@pitt.edu) - Committee Member etdurn: etd-12082006-125251 other_id: http://etd.library.pitt.edu/ETD/available/etd-12082006-125251/ other_id: etd-12082006-125251 citation: Biswas, Nabanita (2007) CHARACTERIZATION OF BIOLOGICAL FUNCTION OF INTERACTION BETWEEN TLR4 AND PLIC-1. Master's Thesis, University of Pittsburgh. (Unpublished) document_url: http://d-scholarship-dev.library.pitt.edu/10202/1/BiswasNabanita2006.pdf