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Hada A, Li L, Kandel A, Jin Y, Xiao Z. Characterization of Bovine Intraepithelial T Lymphocytes in the Gut. Pathogens 2023; 12:1173. [PMID: 37764981 PMCID: PMC10535955 DOI: 10.3390/pathogens12091173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/16/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
Intraepithelial T lymphocytes (T-IELs), which constitute over 50% of the total T lymphocytes in the animal, patrol the mucosal epithelial lining to defend against pathogen invasion while maintaining gut homeostasis. In addition to expressing T cell markers such as CD4 and CD8, T-IELs display T cell receptors (TCR), including either TCRαβ or TCRγδ. Both humans and mice share similar T-IEL subsets: TCRγδ+, TCRαβ+CD8αα+, TCRαβ+CD4+, and TCRαβ+CD8αβ+. Among these subsets, human T-IELs are predominantly TCRαβ+ (over 80%), whereas those in mice are mostly TCRγδ+ (~60%). Of note, the majority of the TCRγδ+ subset expresses CD8αα in both species. Although T-IELs have been extensively studied in humans and mice, their profiles in cattle have not been well examined. Our study is the first to characterize bovine T-IELs using flow cytometry, where we identified several distinct features. The percentage of TCRγδ+ was comparable to that of TCRαβ+ T-IELs (both ~50% of CD3+), and the majority of bovine TCRγδ+ T-IELs did not express CD8 (CD8-) (above 60%). Furthermore, about 20% of TCRαβ+ T-IELs were CD4+CD8αβ+, and the remaining TCRαβ+ T-IELs were evenly distributed between CD4+ and CD8αβ+ (~40% of TCRαβ+ T-IELs each) with no TCRαβ+CD8αα+ identified. Despite these unique properties, bovine T-IELs, similar to those in humans and mice, expressed a high level of CD69, an activation and tissue-retention marker, and a low level of CD62L, a lymphoid adhesion marker. Moreover, bovine T-IELs produced low levels of inflammatory cytokines such as IFNγ and IL17A, and secreted small amounts of the immune regulatory cytokine TGFβ1. Hence, bovine T-IELs' composition largely differs from that of human and mouse, with the dominance of the CD8- population among TCRγδ+ T-IELs, the substantial presence of TCRαβ+CD4+CD8αβ+ cells, and the absence of TCRαβ+CD8αα+ T-IELs. These results provide the groundwork for conducting future studies to examine how bovine T-IELs respond to intestinal pathogens and maintain the integrity of the gut epithelial barrier in animals.
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Affiliation(s)
| | | | | | | | - Zhengguo Xiao
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA; (A.H.); (L.L.); (A.K.); (Y.J.)
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Early immune innate hallmarks and microbiome changes across the gut during Escherichia coli O157: H7 infection in cattle. Sci Rep 2020; 10:21535. [PMID: 33299023 PMCID: PMC7726576 DOI: 10.1038/s41598-020-78752-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 11/27/2020] [Indexed: 12/24/2022] Open
Abstract
The zoonotic enterohemorrhagic Escherichia coli (EHEC) O157: H7 bacterium causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS) in humans. Cattle are primary reservoirs and EHEC O157: H7; the bacteria predominately inhabit the colon and recto-anal junctions (RAJ). The early innate immune reactions in the infected gut are critical in the pathogenesis of EHEC O157: H7. In this study, calves orally inoculated with EHEC O157: H7 showed infiltration of neutrophils in the lamina propria of ileum and RAJ at 7 and 14 days post-infection. Infected calves had altered mucin layer and mast cell populations across small and large intestines. There were differential transcription expressions of key bovine β defensins, tracheal antimicrobial peptide (TAP) in the ileum, and lingual antimicrobial peptide (LAP) in RAJ. The main Gram-negative bacterial/LPS signaling Toll-Like receptor 4 (TLR4) was downregulated in RAJ. Intestinal infection with EHEC O157: H7 impacted the gut bacterial communities and influenced the relative abundance of Negativibacillus and Erysipelotrichaceae in mucosa-associated bacteria in the rectum. Thus, innate immunity in the gut of calves showed unique characteristics during infection with EHEC O157: H7, which occurred in the absence of major clinical manifestations but denoted an active immunological niche.
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Menge C. The Role of Escherichia coli Shiga Toxins in STEC Colonization of Cattle. Toxins (Basel) 2020; 12:toxins12090607. [PMID: 32967277 PMCID: PMC7551371 DOI: 10.3390/toxins12090607] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 11/20/2022] Open
Abstract
Many cattle are persistently colonized with Shiga toxin-producing Escherichia coli (STEC) and represent a major source of human infections with human-pathogenic STEC strains (syn. enterohemorrhagic E. coli (EHEC)). Intervention strategies most effectively protecting humans best aim at the limitation of bovine STEC shedding. Mechanisms enabling STEC to persist in cattle are only partialy understood. Cattle were long believed to resist the detrimental effects of Shiga toxins (Stxs), potent cytotoxins acting as principal virulence factors in the pathogenesis of human EHEC-associated diseases. However, work by different groups, summarized in this review, has provided substantial evidence that different types of target cells for Stxs exist in cattle. Peripheral and intestinal lymphocytes express the Stx receptor globotriaosylceramide (Gb3syn. CD77) in vitro and in vivo in an activation-dependent fashion with Stx-binding isoforms expressed predominantly at early stages of the activation process. Subpopulations of colonic epithelial cells and macrophage-like cells, residing in the bovine mucosa in proximity to STEC colonies, are also targeted by Stxs. STEC-inoculated calves are depressed in mounting appropriate cellular immune responses which can be overcome by vaccination of the animals against Stxs early in life before encountering STEC. Considering Stx target cells and the resulting effects of Stxs in cattle, which significantly differ from effects implicated in human disease, may open promising opportunities to improve existing yet insufficient measures to limit STEC carriage and shedding by the principal reservoir host.
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Affiliation(s)
- Christian Menge
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, D-07743 Jena, Germany
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Molecular Biology of Escherichia Coli Shiga Toxins' Effects on Mammalian Cells. Toxins (Basel) 2020; 12:toxins12050345. [PMID: 32456125 PMCID: PMC7290813 DOI: 10.3390/toxins12050345] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Shiga toxins (Stxs), syn. Vero(cyto)toxins, are potent bacterial exotoxins and the principal virulence factor of enterohemorrhagic Escherichia coli (EHEC), a subset of Shiga toxin-producing E. coli (STEC). EHEC strains, e.g., strains of serovars O157:H7 and O104:H4, may cause individual cases as well as large outbreaks of life-threatening diseases in humans. Stxs primarily exert a ribotoxic activity in the eukaryotic target cells of the mammalian host resulting in rapid protein synthesis inhibition and cell death. Damage of endothelial cells in the kidneys and the central nervous system by Stxs is central in the pathogenesis of hemolytic uremic syndrome (HUS) in humans and edema disease in pigs. Probably even more important, the toxins also are capable of modulating a plethora of essential cellular functions, which eventually disturb intercellular communication. The review aims at providing a comprehensive overview of the current knowledge of the time course and the consecutive steps of Stx/cell interactions at the molecular level. Intervention measures deduced from an in-depth understanding of this molecular interplay may foster our basic understanding of cellular biology and microbial pathogenesis and pave the way to the creation of host-directed active compounds to mitigate the pathological conditions of STEC infections in the mammalian body.
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Pro-inflammatory capacity of Escherichia coli O104:H4 outbreak strain during colonization of intestinal epithelial cells from human and cattle. Int J Med Microbiol 2018; 308:899-911. [PMID: 29937390 DOI: 10.1016/j.ijmm.2018.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/16/2018] [Indexed: 10/28/2022] Open
Abstract
In 2011, Germany was struck by the largest outbreak of hemolytic uremic syndrome. The highly virulent E. coli O104:H4 outbreak strain LB226692 possesses a blended virulence profile combining genetic patterns of human adapted enteroaggregative E. coli (EAEC), rarely detected in animal hosts before, and enterohemorrhagic E. coli (EHEC), a subpopulation of Shiga toxin (Stx)-producing E. coli (STEC) basically adapted to the ruminant host. This study aimed at appraising the relative level of adaptation of the EAEC/EHEC hybrid strain LB226692 to humans and cattle. Adherence and invasion of the hybrid strain to intestinal (jejunal and colonic) epithelial cells (IEC) of human and bovine origin was compared to that of E. coli strains representative of different pathovars and commensal E. coli by means of light and electron microscopy and culture. Strain-specific host gene transcription profiles of selected cytokines and chemokines as well as host-induced transcription of bacterial virulence genes were assessed. The release of Stx upon host cell contact was quantified. The outbreak strain's immunomodulation was assessed by cultivating primary bovine macrophages with conditioned supernatants from IEC infection studies with E. coli, serving as model for the innate immunity of the bovine gut. The outbreak strain adhered to IEC of both, human and bovine origin. Electron microscopy of infected cells revealed the strain's particular affinity to human small IEC, in contrast to few interactions with bovine small IEC. The outbreak strain possessed a high-level of adhesive power, similar to human-associated E. coli strains and in contrast to bovine-associated STEC strains. The outbreak strain displayed a non-invasive phenotype, in contrast to some bovine-associated E. coli strains, which were invasive. The outbreak strain provoked some pro-inflammatory activity in human cells, but to a lower extent as compared to other pathotypes. In contrasts to bovine-associated E. coli strains, the outbreak strain induced marked pro-inflammatory activity when interacting with bovine host cells directly (IEC) and indirectly (macrophages). Among stx2-positive strains, the human-pathogenic strains (LB226692 and EHEC strain 86-24) released higher amounts of Stx compared to bovine-associated STEC. The findings imply that the outbreak strain is rather adapted to humans than to cattle. However, the outbreak strain's potential to colonize IEC of both host species and the rather mixed reaction patterns observed for all strains under study indicate, that even STEC strains with an unusual genotype as the EHEC O104:H4 outbreak strain, i.e. with an EAEC genetic background, may be able to conquer other reservoir hosts.
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Schmidt N, Luhmann T, Hüther L, Meyer U, Barth SA, Geue L, Menge C, Frahm J, Dänicke S. Effect of vitamin E supplementation in milk replacer and Shiga toxoid vaccination on serum α-tocopherol, performance, haematology and blood chemistry in male Holstein calves. J Anim Physiol Anim Nutr (Berl) 2018; 102:1167-1180. [DOI: 10.1111/jpn.12926] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/28/2018] [Accepted: 05/03/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Nadine Schmidt
- Institute of Molecular Pathogenesis; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Jena Germany
| | - Tim Luhmann
- Institute of Animal Nutrition; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Brunswick Germany
| | - Liane Hüther
- Institute of Animal Nutrition; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Brunswick Germany
| | - Ulrich Meyer
- Institute of Animal Nutrition; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Brunswick Germany
| | - Stefanie A. Barth
- Institute of Molecular Pathogenesis; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Jena Germany
| | - Lutz Geue
- Institute of Molecular Pathogenesis; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Jena Germany
| | - Christian Menge
- Institute of Molecular Pathogenesis; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Jena Germany
| | - Jana Frahm
- Institute of Animal Nutrition; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Brunswick Germany
| | - Sven Dänicke
- Institute of Animal Nutrition; Federal Research Institute for Animal Health; Friedrich-Loeffler-Institut; Brunswick Germany
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Martorelli L, Garimano N, Fiorentino GA, Vilte DA, Garbaccio SG, Barth SA, Menge C, Ibarra C, Palermo MS, Cataldi A. Efficacy of a recombinant Intimin, EspB and Shiga toxin 2B vaccine in calves experimentally challenged with Escherichia coli O157:H7. Vaccine 2018; 36:3949-3959. [PMID: 29807709 DOI: 10.1016/j.vaccine.2018.05.059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 05/09/2018] [Accepted: 05/11/2018] [Indexed: 11/30/2022]
Abstract
Escherichia coli O157:H7 is a zoonotic pathogen of global importance and the serotype of Shiga toxin-producing E.coli (STEC) most frequently associated with Hemolytic Uremic Syndrome (HUS) in humans. The main STEC reservoir is cattle. Vaccination of calves with the carboxy-terminal fraction of Intimin γ (IntC280) and EspB can reduce E.coli O157:H7 fecal shedding after experimental challenge. Shiga toxin (Stx) exerts local immunosuppressive effects in the bovine intestine and Stx2B fused to Brucella lumazine synthase (BLS-Stx2B) induces Stx2-neutralizing antibodies. To determine if an immune response against Stx could improve a vaccine's effect on fecal shedding, groups of calves were immunized with EspB + IntC280, with EspB + IntC280 + BLS-Stx2B, or kept as controls. At 24 days post vaccination calves were challenged with E.coli O157:H7. Shedding of E.coli O157:H7 was assessed in recto-anal mucosal swabs by direct plating and enrichment followed by immunomagnetic separation and multiplex PCR. Calves were euthanized 15 days after the challenge and intestinal segments were obtained to assess mucosal antibodies. Vaccination induced a significant increase of IntC280 and EspB specific antibodies in serum and intestinal mucosa in both vaccinated groups. Antibodies against Stx2B were detected in serum and intestinal mucosa of animals vaccinated with 3 antigens. Sera and intestinal homogenates were able to neutralize Stx2 verocytotoxicity compared to the control and the 2-antigens vaccinated group. Both vaccines reduced E.coli O157:H7 shedding compared to the control group. The addition of Stx2B to the vaccine formulation did not result in a superior level of protection compared to the one conferred by IntC280 and EspB alone. It remains to be determined if the inclusion of Stx2B in the vaccine alters E.coli O157:H7 shedding patterns in the long term and after recurrent low dose exposure as occurring in cattle herds.
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Affiliation(s)
- Luisina Martorelli
- Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Argentina
| | - Nicolás Garimano
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gabriela A Fiorentino
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental, (IMEX), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Daniel A Vilte
- Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Argentina
| | - Sergio G Garbaccio
- Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Argentina
| | - Stefanie A Barth
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Christian Menge
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Cristina Ibarra
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marina S Palermo
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental, (IMEX), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Angel Cataldi
- Instituto de Biotecnología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Hurlingham, Argentina.
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Schmidt N, Barth SA, Frahm J, Meyer U, Dänicke S, Geue L, Menge C. Decreased STEC shedding by cattle following passive and active vaccination based on recombinant Escherichia coli Shiga toxoids. Vet Res 2018. [PMID: 29514704 PMCID: PMC5842637 DOI: 10.1186/s13567-018-0523-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The principal virulence factor of Shiga toxin (Stx)-producing Escherichia coli (STEC), the eponymous Stx, modulates cellular immune responses in cattle, the primary STEC reservoir. We examined whether immunization with genetically inactivated recombinant Shiga toxoids (rStx1MUT/rStx2MUT) influences STEC shedding in a calf cohort. A group of 24 calves was passively (colostrum from immunized cows) and actively (intra-muscularly at 5th and 8th week) vaccinated. Twenty-four calves served as unvaccinated controls (fed with low anti-Stx colostrum, placebo injected). Each group was divided according to the vitamin E concentration they received by milk replacer (moderate and high supplemented). The effective transfer of Stx-neutralizing antibodies from dams to calves via colostrum was confirmed by Vero cell assay. Serum antibody titers in calves differed significantly between the vaccinated and the control group until the 16th week of life. Using the expression of activation marker CD25 on CD4+CD45RO+ cells and CD8αhiCD45RO+ cells as flow cytometry based read-out, cells from vaccinated animals responded more pronounced than those of control calves to lysates of STEC and E. coli strains isolated from the farm as well as to rStx2MUT in the 16th week. Summarized for the entire observation period, less fecal samples from vaccinated calves were stx1 and/or stx2 positive than samples from control animals when calves were fed a moderate amount of vitamin E. This study provides first evidence, that transfer to and induction in young calves of Stx-neutralizing antibodies by Shiga toxoid vaccination offers the opportunity to reduce the incidence of stx-positive fecal samples in a calf cohort.
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Affiliation(s)
- Nadine Schmidt
- Friedrich-Loeffler-Institut (FLI)/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany. .,Justus Liebig Universität Giessen, Institute for Hygiene and Infectious Diseases of Animals, Giessen, Germany.
| | - Stefanie A Barth
- Friedrich-Loeffler-Institut (FLI)/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Jana Frahm
- Friedrich-Loeffler-Institut (FLI), Institute of Animal Nutrition, Brunswick, Germany
| | - Ulrich Meyer
- Friedrich-Loeffler-Institut (FLI), Institute of Animal Nutrition, Brunswick, Germany
| | - Sven Dänicke
- Friedrich-Loeffler-Institut (FLI), Institute of Animal Nutrition, Brunswick, Germany
| | - Lutz Geue
- Friedrich-Loeffler-Institut (FLI)/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Christian Menge
- Friedrich-Loeffler-Institut (FLI)/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
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Menge C, Loos D, Bridger PS, Barth S, Werling D, Baljer G. Bovine macrophages sense Escherichia coli Shiga toxin 1. Innate Immun 2015; 21:655-64. [PMID: 25907071 DOI: 10.1177/1753425915581215] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 03/10/2015] [Indexed: 11/17/2022] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) infections in cattle are asymptomatic; however, Stx impairs the initiation of an adaptive immune response by targeting bovine peripheral and intraepithelial lymphocytes. As presumptive bovine mucosal macrophages (Mø) are also sensitive to Stx, STEC may even exert immune modulatory effects by acting on steps preceding lymphocyte activation at the Mø level. We therefore studied the expression of the Stx receptor (CD77), cellular phenotype and functions after incubation of primary bovine monocyte-derived Mø with purified Stx1. A significant portion of bovine Mø expressed CD77 on their surface, with the recombinant B-subunit of Stx1 binding to >50% of the cells. Stx1 down-regulated significantly surface expression of CD14, CD172a and co-stimulatory molecules CD80 and CD86 within 4 h of incubation, while MHC-II expression remained unaffected. Furthermore, incubation of Mø with Stx1 increased significantly numbers of transcripts for IL-4, IL-6, IL-10, IFN-γ, TNF-α, IL-8 and GRO-α but not for IL-12, TGF-β, MCP-1 and RANTES. In the course of bovine STEC infections, Stx1 appears to induce in Mø a mixed response pattern reminiscent of regulatory Mø, which may amplify the direct suppressive effect of the toxin on lymphocytes.
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Affiliation(s)
- Christian Menge
- Institute of Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Gießen, Germany
| | - Daniela Loos
- Institute of Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Gießen, Germany
| | - Philip S Bridger
- Institute of Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Gießen, Germany
| | - Stefanie Barth
- Institute of Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Gießen, Germany
| | - Dirk Werling
- Royal Veterinary College, Department of Pathology and Pathogen Biology, Hatfield, UK
| | - Georg Baljer
- Institute of Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Gießen, Germany
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Kerner K, Bridger PS, Köpf G, Fröhlich J, Barth S, Willems H, Bauerfeind R, Baljer G, Menge C. Evaluation of biological safety in vitro and immunogenicity in vivo of recombinant Escherichia coli Shiga toxoids as candidate vaccines in cattle. Vet Res 2015; 46:38. [PMID: 25889651 PMCID: PMC4391668 DOI: 10.1186/s13567-015-0175-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 03/26/2015] [Indexed: 12/18/2022] Open
Abstract
Cattle are the most important reservoir for enterohemorrhagic Escherichia coli (EHEC), a subset of shigatoxigenic E. coli (STEC) capable of causing life-threatening infectious diseases in humans. In cattle, Shiga toxins (Stx) suppress the immune system thereby promoting long-term STEC shedding. First infections of animals at calves’ age coincide with the lack of Stx-specific antibodies. We hypothesize that vaccination of calves against Shiga toxins prior to STEC infection may help to prevent the establishment of a persistent type of infection. The objectives of this study were to generate recombinant Shiga toxoids (rStx1mut & rStx2mut) by site-directed mutagenesis and to assess their immunomodulatory, antigenic, and immunogenic properties. Cultures of bovine primary immune cells were used as test systems. In ileal intraepithelial lymphocytes both, recombinant wild type Stx1 (rStx1WT) and rStx2WT significantly induced transcription of IL-4 mRNA. rStx1WT and rStx2WT reduced the expression of Stx-receptor CD77 (syn. Globotriaosylceramide, Gb3) on B and T cells from peripheral blood and of CD14 on monocyte-derived macrophages. At the same concentrations, rStx1mut and rStx2mut exhibited neither of these effects. Antibodies in sera of cattle naturally infected with STEC recognized the rStxmut toxoids equally well as the recombinant wild type toxins. Immunization of calves with rStx1mut plus rStx2mut led to induction of antibodies neutralizing Stx1 and Stx2. While keeping their antigenicity and immunogenicity recombinant Shiga toxoids are devoid of the immunosuppressive properties of the corresponding wild type toxins in cattle and candidate vaccines to mitigate long-term STEC shedding by the reservoir host.
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Affiliation(s)
- Katharina Kerner
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany.
| | - Philip S Bridger
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany.
| | - Gabriele Köpf
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany.
| | - Julia Fröhlich
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany.
| | - Stefanie Barth
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany. .,Current Address: Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743, Jena, Germany.
| | - Hermann Willems
- Clinic for Ruminants and Swine (Internal Medicine & Surgery), Justus Liebig University, Giessen, Germany.
| | - Rolf Bauerfeind
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany.
| | - Georg Baljer
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany.
| | - Christian Menge
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Frankfurter Str. 85-89, 35392, Giessen, Germany. .,Current Address: Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743, Jena, Germany.
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11
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Strain-dependent cellular immune responses in cattle following Escherichia coli O157:H7 colonization. Infect Immun 2014; 82:5117-31. [PMID: 25267838 DOI: 10.1128/iai.02462-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes hemorrhagic diarrhea and potentially fatal renal failure in humans. Ruminants are considered to be the primary reservoir for human infection. Vaccines that reduce shedding in cattle are only partially protective, and their underlying protective mechanisms are unknown. Studies investigating the response of cattle to colonization generally focus on humoral immunity, leaving the role of cellular immunity unclear. To inform future vaccine development, we studied the cellular immune responses of cattle during EHEC O157:H7 colonization. Calves were challenged either with a phage type 21/28 (PT21/28) strain possessing the Shiga toxin 2a (Stx2a) and Stx2c genes or with a PT32 strain possessing the Stx2c gene only. T-helper cell-associated transcripts at the terminal rectum were analyzed by reverse transcription-quantitative PCR (RT-qPCR). Induction of gamma interferon (IFN-γ) and T-bet was observed with peak expression of both genes at 7 days in PT32-challenged calves, while upregulation was delayed, peaking at 21 days, in PT21/28-challenged calves. Cells isolated from gastrointestinal lymph nodes demonstrated antigen-specific proliferation and IFN-γ release in response to type III secreted proteins (T3SPs); however, responsiveness was suppressed in cells isolated from PT32-challenged calves. Lymph node cells showed increased expression of the proliferation marker Ki67 in CD4(+) T cells from PT21/28-challenged calves, NK cells from PT32-challenged calves, and CD8(+) and γδ T cells from both PT21/28- and PT32-challenged calves following ex vivo restimulation with T3SPs. This study demonstrates that cattle mount cellular immune responses during colonization with EHEC O157:H7, the temporality of which is strain dependent, with further evidence of strain-specific immunomodulation.
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Bridger PS, Mohr M, Stamm I, Fröhlich J, Föllmann W, Birkner S, Metcalfe H, Werling D, Baljer G, Menge C. Primary bovine colonic cells: a model to study strain-specific responses to Escherichia coli. Vet Immunol Immunopathol 2010; 137:54-63. [PMID: 20471109 DOI: 10.1016/j.vetimm.2010.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 04/15/2010] [Accepted: 04/15/2010] [Indexed: 11/27/2022]
Abstract
The parasitic or commensal lifestyle of bacteria in different hosts depends on specific molecular interactions with the respective host species. In vitro models to study intestinal bacteria-host interactions in cattle are not available. Bovine primary colonocyte (PC) cultures were generated from colon crypt explants. Up to day 4 of culture, the vast majority of cells were of epithelial phenotype (i.e., expressed cytokeratin but not vimentin). PCs harboured mRNA specific for Toll-like receptors (TLR) 1, TLR3, TLR4 and TLR6 but not for TLR2, TLR5, TLR7, TLR8, TLR9 and TLR10. Six hours after inoculation of PC cultures with Escherichia coli (E. coli) prototype strains representing different pathovars (enterohaemorrhagic E. coli [EHEC], enteropathogenic E. coli [EPEC], enterotoxic E. coli [ETEC]), bacteria were found attached to the cells. EPEC adhesion was accompanied by intracellular actin accumulation. An attenuated laboratory strain (E. coli K12 C600) and a bovine commensal E. coli strain (P391) both did not adhere. Bacterial or LPS challenge of PC cultures resulted in specific increases in mRNA transcripts for IL-8, GRO-alpha, MCP-1, RANTES, and IL-10. The level of mRNA transcripts for TGF-beta stayed constant, while IL-12 mRNA was not detectable. Short-term cultures of PCs, maintaining epithelial cell properties, interacted with commensal and pathogenic bacteria in a strain-specific manner and have proven to be a useful in vitro model to study the interaction of bacteria with the bovine intestinal mucosa.
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Affiliation(s)
- Philip Simon Bridger
- Institute for Hygiene and Infectious Diseases of Animals, Justus-Liebig-University, D-35392 Giessen, Germany
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Fonseca I, Silva PV, Lange CC, Guimarães MFM, Weller MMDCA, Sousa KRS, Lopes PS, Guimarães JD, Guimarães SEF. Expression profile of genes associated with mastitis in dairy cattle. Genet Mol Biol 2009; 32:776-81. [PMID: 21637453 PMCID: PMC3036910 DOI: 10.1590/s1415-47572009005000074] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 07/08/2009] [Indexed: 11/21/2022] Open
Abstract
In order to characterize the expression of genes associated with immune response mechanisms to mastitis, we quantified the relative expression of the IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ and TNF- α genes in milk cells of healthy cows and cows with clinical mastitis. Total RNA was extracted from milk cells of six Black and White Holstein (BW) cows and six Gyr cows, including three animals with and three without mastitis per breed. Gene expression was analyzed by real-time PCR. IL-10 gene expression was higher in the group of BW and Gyr cows with mastitis compared to animals free of infection from both breeds (p < 0.05). It was also higher in BW Holstein animals with clinical mastitis (p < 0.001), but it was not significant when Gyr cows with and without mastitis were compared (0.05 < p < 0.10). Among healthy cows, BW Holstein animals tended to present a higher expression of all genes studied, with a significant difference for the IL-2 and IFN- γ genes (p < 0.001). For animals with mastitis no significant difference in gene expression was observed between the two breeds. These findings suggest that animals with mastitis develop a preferentially cell-mediated immune response. Further studies including larger samples are necessary to better characterize the gene expression profile in cows with mastitis.
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Affiliation(s)
- Isabela Fonseca
- Departamento de Zootecnia, Universidade Federal de Viçosa, Viçosa, MG Brazil
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Monocyte- and macrophage-mediated immune reactions against Eimeria bovis. Vet Parasitol 2009; 164:141-53. [DOI: 10.1016/j.vetpar.2009.06.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 05/28/2009] [Accepted: 06/02/2009] [Indexed: 01/08/2023]
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Maternally and naturally acquired antibodies to Shiga toxins in a cohort of calves shedding Shiga-toxigenic Escherichia coli. Appl Environ Microbiol 2009; 75:3695-704. [PMID: 19363081 DOI: 10.1128/aem.02869-08] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Calves become infected with Shiga toxin-producing Escherichia coli (STEC) early in life, which frequently results in long-term shedding of the zoonotic pathogen. Little is known about the animals' immunological status at the time of infection. We assessed the quantity and dynamics of maternal and acquired antibodies to Shiga toxins (Stx1 and Stx2), the principal STEC virulence factors, in a cohort of 27 calves. Fecal and serum samples were taken repeatedly from birth until the 24th week of age. Sera, milk, and colostrums of dams were also assessed. STEC shedding was confirmed by detection of stx in fecal cultures. Stx1- and Stx2-specific antibodies were quantified by Vero cell neutralization assay and further analyzed by immunoblotting. By the eighth week of age, 13 and 15 calves had at least one stx(1)-type and at least one stx(2)-type positive culture, respectively. Eleven calves had first positive cultures only past that age. Sera and colostrums of all dams and postcolostral sera of all newborn calves contained Stx1-specific antibodies. Calf serum titers decreased rapidly within the first 6 weeks of age. Only five calves showed Stx1-specific seroconversion. Maternal and acquired Stx1-specific antibodies were mainly directed against the StxA1 subunit. Sparse Stx2-specific titers were detectable in sera and colostrums of three dams and in postcolostral sera of their calves. None of the calves developed Stx2-specific seroconversion. The results indicate that under natural conditions of exposure, first STEC infections frequently coincide with an absence of maternal and acquired Stx-specific antibodies in the animals' sera.
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Taubert A, Hermosilla C, Sühwold A, Zahner H. Antigen-induced cytokine production in lymphocytes of Eimeria bovis primary and challenge infected calves. Vet Immunol Immunopathol 2008; 126:309-20. [PMID: 18947883 DOI: 10.1016/j.vetimm.2008.09.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Revised: 08/25/2008] [Accepted: 09/12/2008] [Indexed: 01/05/2023]
Abstract
Cellular immune responses against Eimeria bovis are highly specific and a key factor for the development of protection against challenge infections. In this study we investigate the cellular immune responses of E. bovis primary and challenge infected calves stimulated in vitro by E. bovis merozoite I-antigen. Primary infection was accompanied by an increase of IFN-gamma and IL-2 gene transcription in whole blood samples, peaking during prepatency (8-12 days p.i.) and declining thereafter, whereas IL-4 gene transcription was induced predominantly in patency. IL-10 mRNA was not influenced by E. bovis infection. Both CD4+ and CD8+ T cells were identified as source of IFN-gamma gene transcripts, whilst IL-2 and IL-4 gene transcription was enhanced mainly in CD4+ T cells. Increased levels of IFN-gamma transcripts and protein were also found in lymphocytes isolated from ileocaecal lymph node biopsy 8 days p.i., and in cell culture supernatants obtained from antigen-stimulated peripheral blood mononuclear cells (PBMC) at days 8 and 12 p.i., respectively. Challenge infections of calves influenced neither IFN-gamma nor IL-2 gene transcription in peripheral blood or in lymph node-derived lymphocytes. In contrast, IL-4 gene transcription was increased in lymphocytes isolated from draining lymph nodes. Besides antigen-specific reactions we also found an infection-triggered induction of the non-specific activation state of PBMC in the course of primary infection as measured by the intracellular IFN-gamma and IL-4 content of phorbol-12-myristate-13-acetate/ionomycin-stimulated PBMC. This may represent a new mechanism of immune cells of E. bovis-infected calves contributing to ongoing immune reactions.
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Affiliation(s)
- Anja Taubert
- Institute of Parasitology, Justus Liebig University Giessen, Rudolf-Buchheim-Str. 2, D-35392 Giessen, Germany.
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Epithelial and mesenchymal cells in the bovine colonic mucosa differ in their responsiveness to Escherichia coli Shiga toxin 1. Infect Immun 2008; 76:5381-91. [PMID: 18765725 DOI: 10.1128/iai.00553-08] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Bovine colonic crypt cells express CD77 molecules that potentially act as receptors for Shiga toxins (Stx). The implication of this finding for the intestinal colonization of cattle by human pathogenic Stx-producing Escherichia coli (STEC) remains undefined. We used flow cytometric and real-time PCR analyses of primary cultures of colonic crypt cells to evaluate cell viability, CD77 expression, and gene transcription in the presence and absence of purified Stx1. A subset of cultured epithelial cells had Stx receptors which were located mainly intracellularly, with a perinuclear distribution, and were resistant to Stx1-induced apoptosis and Stx1 effects on chemokine expression patterns. In contrast, a population of vimentin-positive cells, i.e., mesenchymal/nonepithelial cells that had high numbers of Stx receptors on their surface, was depleted from the cultures by Stx1. In situ, CD77(+) cells were located in the lamina propria of the bovine colon by using immunofluorescence staining. A newly established vimentin-positive crypt cell line with high CD77 expression resisted the cytolethal effect of Stx1 but responded to Stx1 with a significant increase in interleukin-8 (IL-8), GRO-alpha, MCP-1, and RANTES mRNA. Combined stimulation with lipopolysaccharide and Stx1 increased IL-10 mRNA. Our results show that bovine colonic crypt cells of epithelial origin are resistant to both the cytotoxic and modulatory effects of Stx1. In contrast, some mucosal mesenchymal cells, preliminarily characterized as mucosal macrophages, are Stx1-responsive cells that may participate in the interaction of STEC with the bovine intestinal mucosa.
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Menge C, Dean-Nystrom E. Dexamethasone Depletes γδT Cells and Alters the Activation State and Responsiveness of Bovine Peripheral Blood Lymphocyte Subpopulations. J Dairy Sci 2008; 91:2284-98. [DOI: 10.3168/jds.2007-0937] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Behrendt JH, Hermosilla C, Hardt M, Failing K, Zahner H, Taubert A. PMN-mediated immune reactions against Eimeria bovis. Vet Parasitol 2007; 151:97-109. [PMID: 18155359 DOI: 10.1016/j.vetpar.2007.11.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/06/2007] [Accepted: 11/09/2007] [Indexed: 01/17/2023]
Abstract
For successful in vivo infection, Eimeria bovis sporozoites have to traverse the mucosal layer of the ileum to infect lymphatic endothelial cells and may, thereby, be exposed to the interstitial fluid and to the lymph representing potential targets for leukocytes. To mimic this situation in vitro, we exposed E. bovis sporozoites to bovine PMN and found enhanced elimination of the parasites. Addition of immune serum clearly increased these reactions, whereas neonatal calf serum had no effect, thus proposing a PMN-derived antibody-dependent cytotoxicity. Scanning and transmission electron microscopy showed PMN engulfing sporozoites or extending filopodia towards them and occasionally incorporating the parasites. PMN reacted with enhanced transcription of IL-6, MCP-1, GROalpha, TNF-alpha, and iNOS genes after exposure to sporozoites while stimulation with merozoite-antigen, in addition, upregulated IL-8, IP-10 and IL-12 gene transcription. Furthermore, enhanced in vitro oxidative burst and phagocytic activities were observed after contact of PMN with viable sporozoites. To verify the potential role of PMN in the in vivo situation, we analysed the general phagocytic and oxidative burst activities of PMN obtained ex vivo from E. bovis experimentally infected calves. Enhanced levels of both activities were found early p.i. (1-5 days) and towards the end of the first schizogony (days 13-22 p.i.) underlining the in vitro data. Our results suggest that PMN-mediated, innate immune reactions play an important role in the early immune response to E. bovis infections in calves.
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