This is a competitive renew of a grant that has uncovered the essential roles of a heat shock protein (HSP) gp96 (also known as grp94 and HSP90b1) in chaperoning multiple TLRs in the endoplasmic reticulum. TLRs are critical sensors for pathogens in the initiation of innate immunity and for subsequent activation of adaptive immunity. Until recently, research in TLR biology has been focused primarily on downstream signaling events. It is increasingly appreciated that TLR biogenesis and trafficking are also tightly regulated to prevent inflammation and autoimmunity. My laboratory is at the forefront to address the function of gp96 using genetic approaches. We have discovered and published in the last funding period that: (i) gp96 is a master chaperone for both cell surface and intracellula TLRs;(ii) gp96 is not required for the assembly of immunoglobulin but it plays critical roles in te proper compartmentalization of B1 cells and marginal zone B cells due to its ability to also chaperone integrins;(iii) the Drosophila gp93 is the gp96 ortholog in that it can rescue the expression of both TLRs and integrins in gp96 KO murine cells;(iv) gp96 is critical for T and B lymphopoiesis but not myelopoiesis;(v) the folding of TLRs by gp96 is dependent on a substrate (TLR)-specific co-chaperone, CNPY3 (also known as PRAT4A). Unexpectedly, we have made two additional novel observations. First, gp96 plays critical roles in canonical Wnt signaling such that when gp96 is deleted from the gut, mice develop a profound and lethal enterocolitis. Second, when gp96 was selectively knocked down from macrophages, we observed a significant attenuation of inflammation-associated colon cancer and a concurrent reduction of IL23 and IL17. We thus hypothesize that gp96 provide a crucial link for multiple processes including inflammation, tissue homeostasis and cancer. We will tackle our hypothesis with the following three specific aims: (1) Determine the molecular mechanisms of gp96 in folding TLRs with specific focus on the roles of co-chaperones. (2) Establish the roles and mechanisms of gp96 in gut homeostasis. (3) Dissect the macrophage-intrinsic roles and mechanisms of gp96 in inflammation-associated colon cancer. Successful execution of our proposal shall significantly advance the field of chaperone biology, innate immunity, inflammation and tumor immunology.

Public Health Relevance

Proteins need to be folded into proper three-dimensional structure in order to have their biological function, which is often carried out by proteins called molecular chaperones. This project addresses the function and mechanism of one such chaperone that is particularly important in folding immune sensors to regulate inflammation and cancer. Knowledge learnt from this proposal should facilitate the development of novel drugs for the treatment of a variety of diseases such as sepsis, cancer and autoimmune disease.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Transplantation, Tolerance, and Tumor Immunology (TTT)
Program Officer
Palker, Thomas J
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Medical University of South Carolina
Schools of Medicine
United States
Zip Code
Wu, Bill X; Li, Anqi; Lei, Liming et al. (2017) Glycoprotein A repetitions predominant (GARP) positively regulates transforming growth factor (TGF) ?3 and is essential for mouse palatogenesis. J Biol Chem 292:18091-18097
Thaxton, Jessica E; Wallace, Caroline; Riesenberg, Brian et al. (2017) Modulation of Endoplasmic Reticulum Stress Controls CD4+ T-cell Activation and Antitumor Function. Cancer Immunol Res 5:666-675
Hong, Feng; Liu, Bei; Wu, Bill X et al. (2017) CNPY2 is a key initiator of the PERK-CHOP pathway of the unfolded protein response. Nat Struct Mol Biol 24:834-839
Morales, Crystal; Li, Zihai (2017) Drosophila canopy b is a cochaperone of glycoprotein 93. J Biol Chem 292:6657-6666
Hong, Feng; Mohammad Rachidi, Saleh; Lundgren, Debbie et al. (2017) Mapping the Interactome of a Major Mammalian Endoplasmic Reticulum Heat Shock Protein 90. PLoS One 12:e0169260
Wang, Jun; Yuan, Ruirong; Song, Wenru et al. (2017) PD-1, PD-L1 (B7-H1) and Tumor-Site Immune Modulation Therapy: The Historical Perspective. J Hematol Oncol 10:34
Liu, Xiaojuan; Kwon, Hyunwoo; Li, Zihai et al. (2017) Is CD47 an innate immune checkpoint for tumor evasion? J Hematol Oncol 10:12
Ansa-Addo, Ephraim A; Zhang, Yongliang; Yang, Yi et al. (2017) Membrane-organizing protein moesin controls Treg differentiation and antitumor immunity via TGF-? signaling. J Clin Invest 127:1321-1337
Rachidi, Saleh; Metelli, Alessandra; Riesenberg, Brian et al. (2017) Platelets subvert T cell immunity against cancer via GARP-TGF? axis. Sci Immunol 2:
Huck, John D; Que, Nanette L; Hong, Feng et al. (2017) Structural and Functional Analysis of GRP94 in the Closed State Reveals an Essential Role for the Pre-N Domain and a Potential Client-Binding Site. Cell Rep 20:2800-2809

Showing the most recent 10 out of 47 publications