Rotavirus (RV) is the major cause of severe gastroenteritis in infants and young children worldwide. The failure of rotavirus vaccines to consistently induce protection against disease in infants and animals underscores a need for more effective vaccines. Our goal is an improved understanding of disease pathogenesis and mucosal immune responses to human rotaviruses (HRV) and identification of correlates of protective immunity in the gnotobiotic (Gn) pig model. The Gn pig is an ideal animal model because of its susceptibility to infection and disease (including intestinal lesions) with HRV, a lack of previous exposure or maternal antibodies to RV and its similarity to human infants in size, milk diet, gastrointestinal physiology and ontogeny of mucosal immune responses. To study disease pathogenesis, the putative role of the RV nonstructural protein, NSP4 as a viral enterotoxin and virulence determinant or target for induction of protective immune responses will be investigated in Gn pigs inoculated with recombinant NSP4 and NSP 4 peptides from virulent and attenuated pairs of RV. Expression of NSP4 and induction of immune responses to NSP4 will be further analyzed in Gn pigs infected with the respective virulent and attenuated pairs of HRV. In previous studies, the magnitude of the intestinal igA antibody secreting cell and lymphoproliferative immune responses coincided with the degree of RV replication and diarrhea induction, and were positively correlated with the level of protection induced. Hence we will further explore the role that viral replication and virulence (lesions and/or diarrhea) play in induction of mucosal immunity and protection against HRV. To assess which viral proteins are targets of protective immunity, B cell responses to RV and to RV structural and nonstructural proteins will be measured by virus neutralization, ELISA and ELISPOT assays and T cell responses will be examined by lymphoproliferative assays and analysis of cytokine profiles (RT- PCR,ELISA,ELISPOT). The type, magnitude, kinetics and correlation with protection of these mucosal immune responses will be compared in Gn pigs inoculated orally with virulent HRV (induces diarrhea and lesions and mimics natural infection) or candidate HRV vaccines including: attenuated HRV (no diarrhea or lesions); or the viral subunits, NSP4 (from virulent RV, induces diarrhea; attenuated RV, no diarrhea) and rotavirus-like particles (VLP) (no diarrhea or lesions), and challenged with virulent homotypic HRV. Finally we will examine if selected immunoenhancers (microencapsulation, mucosal adjuvants) can augment the mucosal immune responses to the attenuated and subunit HRV vaccines and increase vaccine efficacy in the Gn pig model.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI033561-07
Application #
6169945
Study Section
Experimental Virology Study Section (EVR)
Project Start
1992-09-30
Project End
2002-06-30
Budget Start
2000-07-01
Budget End
2002-06-30
Support Year
7
Fiscal Year
2000
Total Cost
$175,996
Indirect Cost
Name
Ohio State University
Department
Zoology
Type
Schools of Earth Sciences/Natur
DUNS #
098987217
City
Columbus
State
OH
Country
United States
Zip Code
43210
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Wen, Ke; Li, Guohua; Zhang, Wei et al. (2011) Development of ?? T cell subset responses in gnotobiotic pigs infected with human rotaviruses and colonized with probiotic lactobacilli. Vet Immunol Immunopathol 141:267-75
Gonzalez, Ana M; Azevedo, Marli S P; Jung, Kwonil et al. (2010) Innate immune responses to human rotavirus in the neonatal gnotobiotic piglet disease model. Immunology 131:242-56
Wen, Ke; Azevedo, Marli S P; Gonzalez, Ana et al. (2009) Toll-like receptor and innate cytokine responses induced by lactobacilli colonization and human rotavirus infection in gnotobiotic pigs. Vet Immunol Immunopathol 127:304-15
Zhang, Wei; Wen, Ke; Azevedo, Marli S P et al. (2008) Lactic acid bacterial colonization and human rotavirus infection influence distribution and frequencies of monocytes/macrophages and dendritic cells in neonatal gnotobiotic pigs. Vet Immunol Immunopathol 121:222-31
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Zhang, Wei; Azevedo, Marli S P; Wen, Ke et al. (2008) Probiotic Lactobacillus acidophilus enhances the immunogenicity of an oral rotavirus vaccine in gnotobiotic pigs. Vaccine 26:3655-61
Yuan, Lijuan; Wen, Ke; Azevedo, Marli S P et al. (2008) Virus-specific intestinal IFN-gamma producing T cell responses induced by human rotavirus infection and vaccines are correlated with protection against rotavirus diarrhea in gnotobiotic pigs. Vaccine 26:3322-31
Nguyen, Trang V; Yuan, Lijuan; P Azevedo, Marli S et al. (2006) Low titer maternal antibodies can both enhance and suppress B cell responses to a combined live attenuated human rotavirus and VLP-ISCOM vaccine. Vaccine 24:2302-16
Nguyen, Trang V; Yuan, Lijuan; Azevedo, Marli S P et al. (2006) High titers of circulating maternal antibodies suppress effector and memory B-cell responses induced by an attenuated rotavirus priming and rotavirus-like particle-immunostimulating complex boosting vaccine regimen. Clin Vaccine Immunol 13:475-85

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