Since human cytomegalovirus (HCMV) was first recognized as a threat to the developing fetus, there have been repeated calls for a vaccine that could protect from the damaging effects of HCMV infection in those at risk for HCMV disease. The long quest for a HCMV vaccine that could prevent congenital infection and fetal sequelae, as well as end-organ disease in immune compromised individuals, remains unfulfilled. The primary objective measure for evaluating the efficiency of any vaccine is whether protective levels of immunity are generated and sustained in the vaccinees. An important issue for HCMV is the definition of what constitutes protective immunity. Using a stringent threshold, an immune response can be considered protective only if the vaccinees are absolutely protected from infection following repeated exposure to virus. Alternatively, a vaccine could still be considered protective if the course of challenge virus infection was so dramatically altered that the potential for transmission (horizontal and vertical) and pathogenesis of challenge virus was essentially eliminated. The difference between the two involves the level of virus replication at the primary site of challenge and the extent of dissemination beyond. The former definition requires the generation and maintenance of sterilizing immunity with no spread of the virus. The latter does not, but it does require that the immune system maintain a lifelong restriction on replication of a virus with a complex natural history of persistence in immune competent hosts. The hypothesis is presented that immunization against CMV can generate protective immune responses, although the degree of protection (sterilizing versus limited dissemination) will be dependent on both the titer of challenge virus and the frequency of exposure. According to this hypothesis, immunization can protect completely against infrequent exposure to a low titer CMV challenge. Protection will become more variable as the titer and/or the frequency of exposure to challenge virus increases. Vaccination should shift the virus-host balance decidedly in favor of the host such that both reactivation and shedding are significantly diminished. The hypothesis will be tested in the rhesus macaque model of HCMV infection through the following Aims. (I) Genetic immunization of seronegative macaques with plasmid expression vectors for RhCMV gB, pp65, and IE1, followed by immunization with formalin-inactivated virus. (II) Subcutaneous challenge of vaccinees and controls by experimental inoculation with either high or low titers of RhCMV. (III) Immunization of macaques followed by challenge of vaccinees and controls by natural routes with natural titers of RhCMV by co-housing vaccinees with seropositive, virus-excreting macaques. (IV) Alterations of RhCMV gene expression patterns to induce novel protective immune responses. A CMV vaccine can be considered protective if it results in a dead-end infection. This proposal will stringently test whether a combination of genetic immunization and formalin-inactivated virus can effectively eliminate horizontal spread of RhCMV following either experimental or natural infection. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI063356-03
Application #
7162536
Study Section
Special Emphasis Panel (ZRG1-VMD (01))
Program Officer
Beisel, Christopher E
Project Start
2005-01-01
Project End
2009-12-31
Budget Start
2007-01-01
Budget End
2007-12-31
Support Year
3
Fiscal Year
2007
Total Cost
$359,716
Indirect Cost
Name
University of California Davis
Department
Pathology
Type
Schools of Medicine
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
Wussow, Felix; Chiuppesi, Flavia; Meng, Zhuo et al. (2018) Exploiting 2A peptides to elicit potent neutralizing antibodies by a multi-subunit herpesvirus glycoprotein complex. J Virol Methods 251:30-37
Wussow, Felix; Chiuppesi, Flavia; Contreras, Heidi et al. (2017) Neutralization of Human Cytomegalovirus Entry into Fibroblasts and Epithelial Cells. Vaccines (Basel) 5:
Fan, Qihua; Nelson, Cody S; Bialas, Kristy M et al. (2017) Plasmablast Response to Primary Rhesus Cytomegalovirus (CMV) Infection in a Monkey Model of Congenital CMV Transmission. Clin Vaccine Immunol 24:
Nelson, Cody S; Cruz, Diana Vera; Tran, Dollnovan et al. (2017) Preexisting antibodies can protect against congenital cytomegalovirus infection in monkeys. JCI Insight 2:
Yue, Yujuan; Kaur, Amitinder; Lilja, Anders et al. (2016) The susceptibility of primary cultured rhesus macaque kidney epithelial cells to rhesus cytomegalovirus strains. J Gen Virol 97:1426-1438
Cavicchioli, Laura; Zanetti, Rossella; Ferraresso, Serena et al. (2015) Expression of recipient cytomegalovirus in immunosuppressed and xenotransplanted Macaca fascicularis may be related to more severe gastrointestinal lesions. Xenotransplantation 22:135-43
Davis, Zachary B; Cooley, Sarah A; Cichocki, Frank et al. (2015) Adaptive Natural Killer Cell and Killer Cell Immunoglobulin-Like Receptor-Expressing T Cell Responses are Induced by Cytomegalovirus and Are Associated with Protection against Cytomegalovirus Reactivation after Allogeneic Donor Hematopoietic Cell Transpla Biol Blood Marrow Transplant 21:1653-62
Oxford, Kristie L; Dela Pena-Ponce, Myra Grace A; Jensen, Kara et al. (2015) The interplay between immune maturation, age, chronic viral infection and environment. Immun Ageing 12:3
Gibson, Laura; Barysauskas, Constance M; McManus, Margaret et al. (2015) Reduced frequencies of polyfunctional CMV-specific T cell responses in infants with congenital CMV infection. J Clin Immunol 35:289-301
Chiuppesi, Flavia; Wussow, Felix; Johnson, Erica et al. (2015) Vaccine-Derived Neutralizing Antibodies to the Human Cytomegalovirus gH/gL Pentamer Potently Block Primary Cytotrophoblast Infection. J Virol 89:11884-98

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