Advances in immunosuppressive therapy, which have led to the application of transplantation for a wide spectrum of diseases, have been limited in part by the development of infectious complications. Despite the development of effective antiviral therapy, CMV represents the most common viral infection following transplantation resulting in loss of life and graft, as well as significant cost. In addition, the emergence of viral mutants has resulted in increasing resistance to antiviral therapy, underscoring the importance of preventive strategies. Reactivation of CMV from latency requires the virus to become transcriptionally active, and culminates in replication of infectious virus resulting in active infection. A crucial first step is expression of the Immediate Early (IE) genes to activate expression of other viral genes. The investigators hypothesize that reactivation of latent MCMV occurs in latently infected cells as a result of induction of IE gene expression. They further hypothesize that inflammatory cytokines such as TNF-a, released as a result of ischemia/reperfusion injury and/or allogeneic stimulation, activate the transcription factor NF-kB which in turn induces IE gene expression, an essential first step in MCMV reactivation. The investigators will induce transcription of MCMV genes in latently infected organs by intraperitoneal injection of TNF-a, ischemia/reperfusion injury, and allogeneic stimulation. They anticipate that this will be accompanied by activation of NF-kB, AP-1, and ATF. Immunophenotyping in combination with in situ amplification of RNA will be used to identify the cell types in which induction of viral transcripts occurs. The mechanism of induction of IE transcription will be investigated using transgenic mice that express beta -gal under the control of the IE promoter. The investigators propose to show that these mice are a valid model for viral reactivation by demonstrating that treatments which induce IE gene expression in latently infected mice also induce beta -gal expression in the IE-beta -gal transgenic mice. They will investigate the role of TNF in induction of IE gene expression by breeding IE-B-gal mice to mice deficient in TNF receptors. The requirement for NF-kB in activation of IE gene expression will be confirmed by using inhibitors that prevent activation of NF-kB. By defining the specific cytokine/transcription factor interactions that govern upregulation of relevant CMV gene expression, future strategies which modulate gene expression may be designed that prevent reactivation of CMV from latency, therefore eliminating the direct and indirect sequelae of CMV infection.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI042898-01A1
Application #
2747650
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Beisel, Christopher E
Project Start
1999-01-05
Project End
2002-12-31
Budget Start
1999-01-05
Budget End
1999-12-31
Support Year
1
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Northwestern University at Chicago
Department
Surgery
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
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Zhang, Zheng; Kim, Soo Jung; Varghese, Thomas et al. (2008) TNF receptor independent activation of the cytomegalovirus major immediate early enhancer in response to transplantation. Transplantation 85:1039-45
Liu, Xue-feng; Yan, Shixian; Abecassis, Michael et al. (2008) Establishment of murine cytomegalovirus latency in vivo is associated with changes in histone modifications and recruitment of transcriptional repressors to the major immediate-early promoter. J Virol 82:10922-31
Hummel, Mary; Yan, Shixian; Li, Zhigao et al. (2007) Transcriptional reactivation of murine cytomegalovirus ie gene expression by 5-aza-2'-deoxycytidine and trichostatin A in latently infected cells despite lack of methylation of the major immediate-early promoter. J Gen Virol 88:1097-102
Kim, Soo Jung; Varghese, Thomas K; Zhang, Zheng et al. (2005) Renal ischemia/reperfusion injury activates the enhancer domain of the human cytomegalovirus major immediate early promoter. Am J Transplant 5:1606-13
Hummel, Mary; Abecassis, Michael M (2002) A model for reactivation of CMV from latency. J Clin Virol 25 Suppl 2:S123-36
Hummel, M; Zhang, Z; Yan, S et al. (2001) Allogeneic transplantation induces expression of cytomegalovirus immediate-early genes in vivo: a model for reactivation from latency. J Virol 75:4814-22