This proposal represents a close collaborative effort between the Jardetzky and Longnecker laboratories focusing on understanding Epstein-Barr virus (EBV) entry into target cells and in particular defining how receptor binding triggers fusion mediated by EBV-encoded glycoproteins. EBV is a causative agent in endemic Burkitt's lymphoma, Hodgkin's lymphoma, and undifferentiated nasopharyngeal carcinoma (NPC). EBV is also recognized as an important pathogen in immunosuppressed individuals including HIV/AIDS patients causing a variety of proliferative disorders such as immunoblastic lymphomas, oral hairy leukoplakia, and other pathologies. Fusion of EBV with a cellular membrane minimally requires a complex of viral proteins that includes gB, gH/gL, and gp42 for B cells and gB and gH/gL for epithelial cells. In the previous funding period, we made substantial progress in understanding how EBV as well as other herpesviruses bind to and ultimately fuse with target cells. In the past funding period, we solved three key structures - gp42 alone, which allowed comparison to our previous structure of gp42 bound to the receptor HLA, gH/gL, and the post fusion form of gB. In addition, in the previous funding period, we began to identify functional domains of these key glycoproteins providing considerable momentum to our proposed studies in the new funding period. Overall, in our two aims, we plan to elucidate how receptor binding to EBV triggers changes in viral glycoprotein interactions that ultimately result in refolding of gB and fusion of the virion envelope with a cellular membrane. Clarifying the interactions between cellular receptors and viral glycoproteins, and the steps that lead from receptor binding to membrane fusion, is essential for understanding the tropisms behind EBV associated diseases.
This proposed research represents a collaborative research program between Dr. Longnecker and Dr. Jardetzky to define the molecular mechanisms involved in Epstein-Barr virus (EBV) entry into B lymphocytes and epithelial cells - the major cellular targets of EBV infection in human hosts. EBV is associated with a variety of hematopoietic, epithelial, and lymphoproliferative diseases and the proposed research will lead to a better understanding of EBV and herpesvirus entry in general and may result in the identification of new targets for herpesvirus therapeutics.
|MÃ¶hl, Britta S; Chen, Jia; Sathiyamoorthy, Karthik et al. (2016) Structural and Mechanistic Insights into the Tropism of Epstein-Barr Virus. Mol Cells 39:286-91|
|Sathiyamoorthy, Karthik; Hu, Yao Xiong; MÃ¶hl, Britta S et al. (2016) Structural basis for Epstein-Barr virus host cell tropism mediated by gp42 and gHgL entry glycoproteins. Nat Commun 7:13557|
|MÃ¶hl, Britta S; SchrÃ¶ter, Christina; Klupp, Barbara G et al. (2016) Comparative Mutagenesis of Pseudorabies Virus and Epstein-Barr Virus gH Identifies a Structural Determinant within Domain III of gH Required for Surface Expression and Entry Function. J Virol 90:2285-93|
|Chen, Jia; Jardetzky, Theodore S; Longnecker, Richard (2016) The Cytoplasmic Tail Domain of Epstein-Barr Virus gH Regulates Membrane Fusion Activity through Altering gH Binding to gp42 and Epithelial Cell Attachment. MBio 7:|
|Rowe, Cynthia L; Chen, Jia; Jardetzky, Theodore S et al. (2015) Membrane anchoring of Epstein-Barr virus gp42 inhibits fusion with B cells even with increased flexibility allowed by engineered spacers. MBio 6:|
|Chen, Jia; Zhang, Xianming; Jardetzky, Theodore S et al. (2014) The Epstein-Barr virus (EBV) glycoprotein B cytoplasmic C-terminal tail domain regulates the energy requirement for EBV-induced membrane fusion. J Virol 88:11686-95|
|Sathiyamoorthy, Karthik; Jiang, Jiansen; Hu, Yao Xiong et al. (2014) Assembly and architecture of the EBV B cell entry triggering complex. PLoS Pathog 10:e1004309|
|MÃ¶hl, Britta S; Sathiyamoorthy, Karthik; Jardetzky, Theodore S et al. (2014) The conserved disulfide bond within domain II of Epstein-Barr virus gH has divergent roles in membrane fusion with epithelial cells and B cells. J Virol 88:13570-9|
|Zago, Anna; Connolly, Sarah A; Spear, Patricia G et al. (2013) The fusion loops and membrane proximal region of Epstein-Barr virus glycoprotein B (gB) can function in the context of herpes simplex virus 1 gB when substituted individually but not in combination. Virus Res 171:227-30|
|Garcia, Nicholas J; Chen, Jia; Longnecker, Richard (2013) Modulation of Epstein-Barr virus glycoprotein B (gB) fusion activity by the gB cytoplasmic tail domain. MBio 4:e00571-12|
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