Germ-Free Life

Publication Title: 
Veterinary Immunology and Immunopathology

Despite accumulating knowledge of porcine macrophages and dendritic cells (DCs) from in vitro studies, information regarding monocytes/macrophages and DCs in lymphoid tissues of enteric pathogen-infected neonatal animals in vivo is limited. In this study we evaluated the influence of commensal bacterial [two strains of lactic acid bacteria (LAB), Lactobacillus acidophilus and L. reuteri] colonization and rotavirus infection on distribution and frequencies of monocytes/macrophages and conventional DCs (cDCs) in ileum, spleen and blood.

Author(s): 
Zhang, Wei
Wen, Ke
Azevedo, Marli S. P.
Gonzalez, Ana
Saif, Linda J.
Li, Guohua
Yousef, Ahmed E.
Yuan, Lijuan
Publication Title: 
Vaccine

We examined rotavirus-specific IFN-gamma producing CD4+, CD8+ and CD4+CD8+ T cell responses in gnotobiotic pigs infected with a virulent human rotavirus (VirHRV) or vaccinated with an attenuated (Att) HRV vaccine (AttHRV3x or AttHRV2x) or an AttHRV oral priming and 2/6-virus-like particle (VLP) intranasal boosting (AttHRV-2/6VLP) regimen. In VirHRV infected pigs, HRV-specific IFN-gamma producing T cells reside primarily in ileum. AttHRV-2/6VLP induced similar frequencies of intestinal IFN-gamma producing T cells as the VirHRV, whereas AttHRV3x or 2x vaccines were less effective.

Author(s): 
Yuan, Lijuan
Wen, Ke
Azevedo, Marli S. P.
Gonzalez, Ana M.
Zhang, Wei
Saif, Linda J.
Publication Title: 
Vaccine

We evaluated virus-specific B and T cell responses induced by the attenuated Wa (P1A[8]G1) human rotavirus (AttHRV) oral 2-dose vaccine with or without Lactobacillus acidophilus (LA) colonization in neonatal gnotobiotic (Gn) pigs. The AttHRV vaccinated and LA-fed pigs had a significantly higher magnitude of HRV-specific IFN-gamma producing CD8+ T cell responses in ileum and spleen, IgA and IgG antibody-secreting cell responses in ileum, and serum IgM, IgA and IgG antibody and virus neutralizing antibody titers compared to the AttHRV vaccinated pigs without LA colonization.

Author(s): 
Zhang, Wei
Azevedo, Marli S. P.
Wen, Ke
Gonzalez, Ana
Saif, Linda J.
Li, Guohua
Yousef, Ahmed E.
Yuan, Lijuan
Publication Title: 
Veterinary Immunology and Immunopathology

Toll-like receptors (TLR) play an important role in the recognition of microbes by host sentinel cells that leads to the subsequent innate and adaptive immune responses. In this study, we evaluated the patterns of TLR2-, TLR3- and TLR9-expressing antigen presenting cells (APCs) in spleen and blood of gnotobiotic (Gn) pigs after colonization with a mixture of two strains of lactic acid bacteria (LAB), Lactobacillus acidophilus and Lactobacillus reuteri or infection with the virulent human rotavirus (HRV) Wa strain.

Author(s): 
Wen, Ke
Azevedo, Marli S. P.
Gonzalez, Ana
Zhang, Wei
Saif, Linda J.
Li, Guohua
Yousef, Ahmed
Yuan, Lijuan
Publication Title: 
Immunology

To model inflammatory bowel disease, we assessed infection with Helicobacter hepaticus 3B1 (ATCC 51449) and a potential probiotic Lactobacillus reuteri (ATCC PTA-6475) in gnotobiotic B6.129P2-IL-10(tm1Cgn) (IL-10(-/-) ) mice. No typhlocolitis developed in germ-free controls (n=21) or in L. reuteri (n=8) or H. hepaticus (n=18) mono-associated mice for 20 weeks post-infection. As positive controls, three specific pathogen-free IL-10(-/-) mice dosed with H. hepaticus developed severe typhlocolitis within 11 weeks. Because L.

Author(s): 
Whary, Mark T.
Taylor, Nancy S.
Feng, Yan
Ge, Zhongming
Muthupalani, Suresh
Versalovic, James
Fox, James G.
Publication Title: 
Veterinary Immunology and Immunopathology

γδ T cell responses are induced by various viral and bacterial infections. Different γδ T cells contribute to activation and regulation of the inflammatory response and to epithelial repair. How γδ T cells respond to rotavirus infection and how the colonization of probiotics influences the γδ T cell response were unknown.

Author(s): 
Wen, Ke
Li, Guohua
Zhang, Wei
Azevedo, Marli S. P.
Saif, Linda J.
Liu, Fangning
Bui, Tammy
Yousef, Ahmed
Yuan, Lijuan
Publication Title: 
Vaccine

BACKGROUND: Strain-specific effects of probiotics in pro- or anti-inflammatory immune responses have been well recognized. Several proinflammatory Lactobacillus strains have been shown to act as adjuvants to enhance the immunogenicity of vaccines. However, dose effects of probiotics in modulating immune responses are not clearly understood. This study examined the dose effects of Lactobacillus acidophilus (LA) NCFM strain on T cell immune responses to rotavirus vaccination in a gnotobiotic (Gn) pig model.

Author(s): 
Wen, Ke
Li, Guohua
Bui, Tammy
Liu, Fangning
Li, Yanru
Kocher, Jacob
Lin, Lin
Yang, Xingdong
Yuan, Lijuan
Publication Title: 
Comparative Immunology, Microbiology and Infectious Diseases

We characterized immune modulating functions of porcine γδ T cell subsets in rotavirus infection using a gnotobiotic pig model of human rotavirus infection and sort-purified lymphocyte autologous co-cultures. We demonstrated that CD2+CD8- and CD2-CD8- γδ T cells have mainly pro-inflammatory function as evident by directly secreting IFN-γ or promoting CD4+ αβ T cell proliferation and IFN-γ production, whereas CD2+CD8+ γδ T cells mainly exert regulatory T cell function by expressing FoxP3, secreting IL-10 and TGF-β or increasing IL-10 and TGF-β production by CD4+ αβ T cells.

Author(s): 
Wen, Ke
Bui, Tammy
Li, Guohua
Liu, Fangning
Li, Yanru
Kocher, Jacob
Yuan, Lijuan
Publication Title: 
Beneficial Microbes

Probiotic lactic acid bacteria (LAB) have been shown to alleviate inflammation, enhance the immunogenicity of rotavirus vaccines, or reduce the severity of rotavirus diarrhoea. Although the mechanisms are not clear, the differential Th1/Th2/Th3-driving capacities and modulating effects on cytokine production of different LAB strains may be the key. Our goal was to delineate the influence of combining two probiotic strains of Lactobacillus acidophilus and Lactobacillus reuteri on the development of cytokine responses in neonatal gnotobiotic pigs infected with human rotavirus (HRV).

Author(s): 
Azevedo, M. S. P.
Zhang, W.
Wen, K.
Gonzalez, A. M.
Saif, L. J.
Yousef, A. E.
Yuan, L.
Publication Title: 
Vaccine

Breast milk (colostrum [col]/milk) components and gut commensals play important roles in neonatal immune maturation, establishment of gut homeostasis and immune responses to enteric pathogens and oral vaccines. We investigated the impact of colonization by probiotics, Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis Bb12 (Bb12) with/without col/milk (mimicking breast/formula fed infants) on B lymphocyte responses to an attenuated (Att) human rotavirus (HRV) Wa strain vaccine in a neonatal gnotobiotic pig model.

Author(s): 
Chattha, Kuldeep S.
Vlasova, Anastasia N.
Kandasamy, Sukumar
Esseili, Malak A.
Siegismund, Christine
Rajashekara, Gireesh
Saif, Linda J.

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