Human cytomegalovirus (HCMV) is a medically significant pathogen associated with severe clinical disease in immune deficient people. In recent years, medical researchers have gained appreciation that HCMV infection is also associated with a number of proliferative diseases such as cardiovascular disease, chronic bowel inflammatory disease and gastro-intestinal cancer. At the core of these manifestations is a virally programmed highjacking of cellular machinery. HCMV directly modulates signal transduction pathways, promotes changes in cellular processes, globally alters gene expression and induces disease mediators such as inflammatory cytokines. Interactions of HCMV envelope proteins with cellular receptors are the initiators of many of these changes. HCMV envelope glycoprotein B (gB) plays several fundamental roles in infection including receptor binding, membrane fusion, and activation of signal transductionpathways. Correspondingly, gB is under intense host surveillance. gB is recognized by pathogen sensors known as Toll-like receptors and serves as a trigger of host innate immunity, a discovery made by our laboratory in the previous funding period. Both branches of the adaptive immune system also recognize gB. It elicits potent neutralizing antibodies and has multiple epitopes recognized by cytotoxic T cell responses. The goal of these studies is to define the molecular underpinnings of the interactions of gB with cellular molecules. We also seek to characterize the consequences and cellular responses to these interactions in hopes that this knowledge will yield valuable insights into HCMV pathogenesis. In the previous funding period, we discovered that HCMV engages cellular integrins as entry mediators and signaling molecules. We also detected a novel disintegrin-like domain in the amino terminus of gB that had homology to cellular integrin binding proteins. Strikingly, this domain is very highly conserved in all beta and many gamma herpesviruses suggesting that integrins may serve as co-receptors for this medically significant group of pathogens. Studies proposed herein will test the hypothesis that the gB disintegrin-like domain directly mediates engagement of cellular integrins and that the consequence of this interaction is to prime downstream events such as membrane fusion, capsid-tegument translocation and/or gene expression. We also discovered that heptad repeat regions predictive of alpha helical coil-coils are present in gB and are important in the penetration stage of infection. Both the disintegrin-like domain and heptad repeat region will be subject to genetic analysis. In collaborative studies with Dr. Sam Gellman, a pioneer in beta-peptide technology, we will synthesize and characterize beta-peptide mimics of the gB coiled-coil domain. These data will be used to develop rational design of anti-fusogenic mimics that may ultimately be useful in treatment of HCMV disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI034998-14
Application #
7754046
Study Section
Virology - B Study Section (VIRB)
Program Officer
Beisel, Christopher E
Project Start
1995-04-01
Project End
2011-12-31
Budget Start
2010-01-01
Budget End
2011-12-31
Support Year
14
Fiscal Year
2010
Total Cost
$301,169
Indirect Cost
Name
University of Wisconsin Madison
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Feire, Adam L; Roy, Rene M; Manley, Kate et al. (2010) The glycoprotein B disintegrin-like domain binds beta 1 integrin to mediate cytomegalovirus entry. J Virol 84:10026-37
Isaacson, Marisa K; Compton, Teresa (2009) Human cytomegalovirus glycoprotein B is required for virus entry and cell-to-cell spread but not for virion attachment, assembly, or egress. J Virol 83:3891-903
Isaacson, Marisa K; Feire, Adam L; Compton, Teresa (2007) Epidermal growth factor receptor is not required for human cytomegalovirus entry or signaling. J Virol 81:6241-7
English, Emily Payne; Chumanov, Robert S; Gellman, Samuel H et al. (2006) Rational development of beta-peptide inhibitors of human cytomegalovirus entry. J Biol Chem 281:2661-7
Lam, Vy; Boehme, Karl W; Compton, Teresa et al. (2006) Spatial patterns of protein expression in focal infections of human cytomegalovirus. Biotechnol Bioeng 93:1029-39
Boehme, Karl W; Guerrero, Mario; Compton, Teresa (2006) Human cytomegalovirus envelope glycoproteins B and H are necessary for TLR2 activation in permissive cells. J Immunol 177:7094-102
Lopper, Matthew; Compton, Teresa (2004) Coiled-coil domains in glycoproteins B and H are involved in human cytomegalovirus membrane fusion. J Virol 78:8333-41
Lopper, Matthew; Compton, Teresa (2002) Disulfide bond configuration of human cytomegalovirus glycoprotein B. J Virol 76:6073-82
Singh, J; Compton, T (2000) Characterization of a panel of insertion mutants in human cytomegalovirus glycoprotein B. J Virol 74:1383-92
Boyle, K A; Pietropaolo, R L; Compton, T (1999) Engagement of the cellular receptor for glycoprotein B of human cytomegalovirus activates the interferon-responsive pathway. Mol Cell Biol 19:3607-13

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