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Huang Y, Babiuk LA, van Drunen Littel-van den Hurk S. Immunization with a bovine herpesvirus 1 glycoprotein B DNA vaccine induces cytotoxic T-lymphocyte responses in mice and cattle. J Gen Virol 2005; 86:887-898. [PMID: 15784883 DOI: 10.1099/vir.0.80533-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Virus-specific cytotoxic T lymphocytes (CTLs) are considered to be important in protection against and recovery from viral infections. In this study, several approaches to induce cytotoxicity against bovine herpesvirus 1 (BHV-1) were evaluated. Vaccination of C57BL/6 mice with BHV-1 induced a strong humoral, but no CTL, response, which may be due to downregulation of major histocompatibility complex class I molecules. In contrast, vaccinia virus expressing glycoprotein B (gB) elicited a weaker antibody response, but strong cytotoxicity, in mice. As an approach to inducing both strong humoral and cellular immune responses, a plasmid vector was then used to express gB. Both antibody and CTL responses were induced by the plasmid encoding gB in C57BL/6 and C3H mice, regardless of the type of vector backbone. This demonstrated that DNA immunization induces a broad-based immune response to BHV-1 gB. Interestingly, removal of the membrane anchor, which resulted in secretion of gB from transfected cells, did not result in reduced cytotoxicity. Here, it is shown that, compared with the cell-associated counterpart, plasmid-encoded secreted protein may induce enhanced immune responses in cattle. Therefore, calves were immunized intradermally with pMASIAtgB, a plasmid encoding the secreted form of gB (tgB), using a needle-free injection system. This demonstrated that pMASIAtgB elicited both humoral responses and activated gamma interferon-secreting CD8+ CTLs, suggesting that a DNA vaccine expressing tgB induces a CTL response in the natural host of BHV-1.
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Affiliation(s)
- Y Huang
- Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada S7N 5E3
| | - L A Babiuk
- Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada S7N 5E3
| | - S van Drunen Littel-van den Hurk
- Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada S7N 5E3
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Manoj S, Babiuk LA, van Drunen Littel-van den Hurk S. Immunization with a dicistronic plasmid expressing a truncated form of bovine herpesvirus-1 glycoprotein D and the amino-terminal subunit of glycoprotein B results in reduced gB-specific immune responses. Virology 2003; 313:296-307. [PMID: 12951041 DOI: 10.1016/s0042-6822(03)00325-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
As an approach to create a divalent DNA vaccine, a truncated secreted version of bovine herpesvirus-1 (BHV-1) glycoprotein D (tgD) and the amino-terminal subunit of glycoprotein B (gBb) were expressed from a dicistronic plasmid, designated pSLIAtgD-IRES-gBb. Intradermal immunization of mice with pSLIAtgD-IRES-gBb or a mixture of plasmids encoding tgD (pSLIAtgD) and gBb (pSLIAgBb) by needle injection or gene gun elicited strong tgD-specific immune responses. However, a significant reduction in gBb-specific immune responses was observed upon immunization of mice with pSLIAtgD-IRES-gBb or a mixture of pSLIAtgD and pSLIAgBb in comparison to immunization with pSLIAgBb alone. This reduction in gBb-specific immune responses induced by pSLIAtgD-IRES-gBb was due to production of low amounts of gBb from pSLIAtgD-IRES-gBb, inefficient processing and transport of gBb, and possibly competition for antigen-presenting cells by tgD and gBb. These results indicate that, although divalent plasmids may be used to express different antigens, the efficacy of vaccination with such plasmids may be influenced by the plasmid design and the characteristics of the expressed antigens.
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Affiliation(s)
- Sharmila Manoj
- Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E3, Canada
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Ioannou XP, Griebel P, Hecker R, Babiuk LA, van Drunen Littel-van den Hurk S. The immunogenicity and protective efficacy of bovine herpesvirus 1 glycoprotein D plus Emulsigen are increased by formulation with CpG oligodeoxynucleotides. J Virol 2002; 76:9002-10. [PMID: 12186884 PMCID: PMC136463 DOI: 10.1128/jvi.76.18.9002-9010.2002] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2002] [Accepted: 06/11/2002] [Indexed: 11/20/2022] Open
Abstract
The immunogenicity and protective efficacy of a bovine herpesvirus 1 (BHV-1) subunit vaccine formulated with Emulsigen (Em) and a synthetic oligodeoxynucleotide containing unmethylated CpG dinucleotides (CpG ODN) was determined in cattle. A truncated, secreted version of BHV-1 glycoprotein D (tgD) formulated with Em and CpG ODN at concentrations of 25, 2.5, or 0.25 mg/dose produced a more balanced immune response, higher levels of virus neutralizing antibodies, and greater protection after BHV-1 challenge compared to tgD adjuvanted with either Em or CpG ODN alone. In contrast, tgD formulated with Em and either 25 mg of a non-CpG ODN or another immunostimulatory compound, dimethyl dioctadecyl ammonium bromide, induced similar immunity and protection compared to tgD formulated with Em alone, a finding which confirms the immunostimulatory effect of ODN to be CpG motif mediated. Our results demonstrate the ability of CpG ODN to induce a strong and balanced immune response in a target species.
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Affiliation(s)
- X P Ioannou
- Veterinary Infectious Disease Organization, Saskatoon, Saskatchewan, S7N 5E3 Canada
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Loehr BI, Pontarollo R, Rankin R, Latimer L, Willson P, Babiuk LA, van Drunen Littel-van den Hurk S. Priming by DNA immunization augments T-cell responses induced by modified live bovine herpesvirus vaccine. J Gen Virol 2001; 82:3035-3043. [PMID: 11714981 DOI: 10.1099/0022-1317-82-12-3035] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA vaccines have several advantages over conventional vaccines. One of the most important characteristics is the presentation of antigen via both MHC class I and class II receptors. Although this generally results in strong T-cell responses, antibody production and protection achieved by DNA immunization are unfortunately not always adequate. In contrast, modified live virus (MLV) vaccines usually induce adequate antibody and moderate cellular responses, whereas killed vaccines tend to elicit weak immune responses in general. A DNA prime-MLV boost regimen should result in enhanced cellular immunity and possibly improved antibody production. To test this hypothesis, plasmids encoding bovine herpesvirus-1 (BHV-1) glycoproteins B and D were delivered by gene gun to the genital mucosa of cattle prior to immunization with modified live BHV-1 vaccine. The immune responses induced were compared to those of an MLV-vaccinated group and a negative control group. Although significantly enhanced T-cell responses were induced by priming with the DNA vaccine, there was no increase in antibody titres. Similar levels of protection were induced by the MLV vaccine alone and the DNA prime and MLV boost regimen, which suggests that there is no correlation between the induction of T-cell responses and protection from BHV-1 challenge.
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Affiliation(s)
- B I Loehr
- Veterinary Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd, Saskatoon, Saskatchewan, CanadaS7N 5E31
| | - R Pontarollo
- Veterinary Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd, Saskatoon, Saskatchewan, CanadaS7N 5E31
| | - R Rankin
- Veterinary Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd, Saskatoon, Saskatchewan, CanadaS7N 5E31
| | - L Latimer
- Veterinary Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd, Saskatoon, Saskatchewan, CanadaS7N 5E31
| | - P Willson
- Veterinary Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd, Saskatoon, Saskatchewan, CanadaS7N 5E31
| | - L A Babiuk
- Veterinary Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd, Saskatoon, Saskatchewan, CanadaS7N 5E31
| | - S van Drunen Littel-van den Hurk
- Veterinary Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd, Saskatoon, Saskatchewan, CanadaS7N 5E31
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Rankin R, Pontarollo R, Ioannou X, Krieg AM, Hecker R, Babiuk LA, van Drunen Littel-van den Hurk S. CpG motif identification for veterinary and laboratory species demonstrates that sequence recognition is highly conserved. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 2001; 11:333-40. [PMID: 11763350 DOI: 10.1089/108729001753231713] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Oligodinucleotides containing CpG motifs stimulate vertebrate immune cells in vitro, have proven efficacy in murine disease models and are currently being tested in human clinical trials as therapies for cancer, allergy, and infectious disease. As there are no known immunostimulatory motifs for veterinary species, the potential of CpG DNA as a veterinary pharmaceutical has not been investigated. Here, optimal CpG motifs for seven veterinary and three laboratory species are described. The preferential recognition of a GTCGTT motif was strongly conserved across two vertebrate phyla, although a GACGTT motif was optimal for inbred strains of mice and rabbits. In a subsequent adjuvanticity trial, the in vitro screening methodology was validated in sheep, representing the first demonstration of CpG DNA efficacy in a veterinary species. These results should provide candidate immunostimulant and therapeutic drugs for veterinary use and enable the testing of CpG DNA in large animal models of human disease.
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Affiliation(s)
- R Rankin
- Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada
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Loehr BI, Willson P, Babiuk LA. Gene gun-mediated DNA immunization primes development of mucosal immunity against bovine herpesvirus 1 in cattle. J Virol 2000; 74:6077-86. [PMID: 10846091 PMCID: PMC112106 DOI: 10.1128/jvi.74.13.6077-6086.2000] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vaccination by a mucosal route is an excellent approach to the control of mucosally acquired infections. Several reports on rodents suggest that DNA vaccines can be used to achieve mucosal immunity when applied to mucosal tissues. However, with the exception of one study with pigs and another with horses, there is no information on mucosal DNA immunization of the natural host. In this study, the potential of inducing mucosal immunity in cattle by immunization with a DNA vaccine was demonstrated. Cattle were immunized with a plasmid encoding bovine herpesvirus 1 (BHV-1) glycoprotein B, which was delivered with a gene gun either intradermally or intravulvomucosally. Intravulvomucosal DNA immunization induced strong cellular immune responses and primed humoral immune responses. This was evident after BHV-1 challenge when high levels of both immunoglobulin G (IgG) and IgA were detected. Intradermal delivery resulted in lower levels of immunity than mucosal immunization. To determine whether the differences between the immune responses induced by intravulvomucosal and intradermal immunizations might be due to the efficacy of antigen presentation, the distributions of antigen and Langerhans cells in the skin and mucosa were compared. After intravulvomucosal delivery, antigen was expressed early and throughout the mucosa, but after intradermal administration, antigen expression occurred later and superficially in the skin. Furthermore, Langerhans cells were widely distributed in the mucosal epithelium but found primarily in the basal layers of the epidermis of the skin. Collectively, these observations may account for the stronger immune response induced by mucosal administration.
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Affiliation(s)
- B I Loehr
- Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada
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Li Y, van Drunen Littel-van den Hurk S, Liang X, Babiuk LA. Functional analysis of the transmembrane anchor region of bovine herpesvirus 1 glycoprotein gB. Virology 1997; 228:39-54. [PMID: 9024808 DOI: 10.1006/viro.1996.8372] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In herpesviruses, homologues of glycoprotein B (gB) are essential membrane proteins which are involved in fusion. However, there is no clear evidence regarding the location of the fusogenic domain on gB. By using bovine herpesvirus 1 (BHV-1) as a model, we studied the relationship between the structure and the fusogenic activity of gB. This was achieved by expressing genes of different gB derivatives containing specific truncations at the end of segments 2 or 3 of the transmembrane region in Madin-Darby bovine kidney cells under the control of the bovine heat-shock protein hsp70A gene promoter. All expressed gB products were structurally similar to authentic gB. One truncated form of gB, gBt, which contains residues 1-763, was efficiently secreted. However, gBtM (residues 1-807), which includes the first two segments at the carboxyl terminus, showed unstable retention on the cell surface, whereas gBtMA (residues 1 829), which contains all three membrane-spanning segments, was mostly intracellularly retained with some unstable surface anchorage. Another truncated gB, gBtDAF, which has gB residues 1-763 (gBt) and a human decay-accelerating factor (DAF) carboxyl tail, was also expressed. The DAF fragment provided a signal for the addition of a glycosyl phosphatidylinositol-based membrane anchor, which could target the gBt chimeric protein on the cell membrane. Immunofluorescence staining and pulse-chase kinetic studies support the theory that gBtM, gBtMA, and gBtDAF are retained on nuclear and cellular membranes via different segments of the transmembrane region or the DAF fragment, respectively. For the cells expressing gBt or gBtM, no cell fusion was observed, whereas cells expressing gBtMA clearly showed fusion. However, in gBtDAF cells, the overexpression and cellular accumulation of recombinant gB products did not cause fusion either, which supports our contention that the fusion phenomenon in gBtMA cells is caused by the fusogenic activity of the expressed gBtMA. With the help of sequence analysis, our results indicate that segment 2 of the transmembrane anchor region might be a fusogenic domain, whereas the real anchor is segment 3.
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Affiliation(s)
- Y Li
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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