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Abstract
Objective—To assess binding of IgE to native, whole hydrolyzed, and separated hydrolyzed fractions of soy protein in serum obtained from dogs with experimentally induced soy protein hypersensitivity.
Animals—8 naïve Beagles (6 experimentally sensitized to native soy protein and 2 control dogs).
Procedures—6 dogs were sensitized against soy protein by administration of allergens during a 90-day period. After the sensitization protocol was completed, serum concentrations of soy-specific IgE were measured and intradermal skin tests were performed in all 6 dogs to confirm that the dogs were sensitized against soy protein. Serum samples from each sensitized and control dog underwent western blot analysis to assess the molecular mass band pattern of the different allergenic soy fractions and evaluate reactivities to native and hydrolyzed soy protein.
Results—In sera from sensitized dogs, a characteristic band pattern with 2 major bands (approx 75 and 50 kd) and 2 minor bands (approx 31 and 20 kd) was detected, whereas only a diffuse band pattern associated with whole hydrolyzed soy protein was detected in the most reactive dog. Reactivity was evident only for the higher molecular mass peptide fraction. In control dogs, no IgE reaction to native or hydrolyzed soy protein was detected.
Conclusions and Clinical Relevance—Data suggest that the binding of soy-specific IgE to the hydrolyzed soy protein used in the study was significantly reduced, compared with binding of soy-specific IgE to the native soy protein, in dogs with experimentally induced soy hypersensitivity.
Abstract
Objective—To determine the efficacy of a modified-live virus vaccine containing bovine herpes virus 1 (BHV-1), bovine respiratory syncytial virus (BRSV), parainfluenza virus 3, and bovine viral diarrhea virus (BVDV) types 1 and 2 to induce neutralizing antibodies and cell-mediated immunity in naïve cattle and protect against BHV-1 challenge.
Animals—17 calves.
Procedures—8 calves were mock-vaccinated with saline (0.9% NaCl) solution (control calves), and 9 calves were vaccinated at 15 to 16 weeks of age. All calves were challenged with BHV-1 25 weeks after vaccination. Neutralizing antibodies and T-cell responsiveness were tested on the day of vaccination and periodically after vaccination and BHV-1 challenge. Specific T-cell responses were evaluated by comparing CD25 upregulation and intracellular interferon-γ expression by 5-color flow cytometry. Titration of BHV-1 in nasal secretions was performed daily after challenge.
Results—Vaccinated calves seroconverted by week 4 after vaccination. Antigen-specific cell-mediated immune responses, by CD25 expression index, were significantly higher in vaccinated calves than control calves. Compared with control calves, antigen-specific interferon-γ expression was significantly higher in calves during weeks 4 to 8 after vaccination, declining by week 24. After BHV-1 challenge, both neutralizing antibodies and T-cell responses of vaccinated calves had anamnestic responses to BHV-1. Vaccinated calves shed virus in nasal secretions at significantly lower titers for a shorter period and had significantly lower rectal temperatures than control calves.
Conclusion and Clinical Relevance—A single dose of vaccine effectively induced humoral and cellular immune responses against BHV-1, BRSV, and BVDV types 1 and 2 and protected calves after BHV-1 challenge for 6 months after vaccination.
Abstract
Objective—To assess the biological response to recombinant feline interferon-omega (rFeIFN-ω) following ocular or oral administration in cats via estimation of Mx protein expression in conjunctival cells (CCs) and WBCs.
Animals—10 specific pathogen–free cats.
Procedures—In multiple single-dose drug experiments, each cat received various concentrations of rFeIFN-ω administered topically into both eyes (50 to 10,000 U/eye) and orally (200 to 20,000 units). The same cats received saline (0.9% NaCl) solution topically and orally as control treatments. The CCs and WBCs were collected prior to treatment (day 0), on day 1, and every third or seventh day thereafter until samples yielded negative results for Mx protein. Samples were examined for Mx protein expression via immunohistochemistry and immunoblotting procedures involving murine anti-Mx protein monoclonal antibody M143.
Results—After topical application of 10,000 U of rFeIFN-ω/eye, CCs stained for Mx protein for a minimum of 7 days, whereas WBCs were positive for Mx protein for a minimum of 31 days. After topical application of lower concentrations, CCs did not express Mx protein, in contrast to WBCs, which stained for Mx protein at 1,000 units for at least 1 day. Following oral administration, Mx protein was expressed in WBCs at rFeIFN-ω concentrations as low as 200 units, whereas CCs did not stain for Mx protein at any concentration.
Conclusions and Clinical Relevance—Results indicate that Mx protein expression (a marker of the biological response to rFeIFN-ω) in CCs and WBCs of rFeIFN-ω–treated cats depends on the dose of rFeIFN-ω, site of administration, and cell type.
Abstract
Objective—To determine the effect of fetal bovine serum (FBS) and heat-inactivated FBS (HI-FBS) on lipopolysaccharide (LPS)- and zymosan-induced procoagulant activity of equine and canine mononuclear cells.
Sample Population—Mononuclear cells from 18 horses and 3 dogs.
Procedures—Cells were incubated with various concentrations of FBS, HI-FBS, LPS, zymosan, polymyxin B, and anti–LPS-binding protein monoclonal antibody or combinations of these constituents. A 1stage recalcification assay was used to determine procoagulant activity.
Results—Addition of FBS to media significantly increased procoagulant activity; equine and canine cells were stimulated by 1% and 10% FBS, respectively. Coincubation of cells with FBS and polymyxin B did not reduce this effect, suggesting that the response was not attributable to LPS contamination. Addition of HI-FBS to media did not stimulate procoagulant activity of equine or canine cells, and the sensitivity of the equine cells to LPS was significantly increased by HI-FBS. This increased LPS sensitivity was reduced 40% with monoclonal antibody directed against human recombinant LPSbinding protein. Increasing concentrations of HIFBS significantly increased LPS- and zymosaninduced procoagulant activity of canine cells.
Conclusion and Clinical Relevance—Procoagulant activity production in equine and canine mononuclear cells was significantly increased by addition of FBS, whereas heat inactivation of FBS eliminated this effect. Heat inactivation did not eliminate the function of serum proteins involved in enhancement of LPSand zymosan-induced procoagulant activity. Results suggest that HI-FBS can be used as a source of serum proteins that increase the sensitivity of mononuclear cells to bacterial and yeast cell wall components.
Abstract
Objective—To assess whether dogs with experimentally induced type I hypersensitivity against soy protein would respond to soy hydrolysate and develop cutaneous or gastrointestinal tract reactions after intradermal and oral challenge exposure.
Animals—12 naïve Beagle pups (9 sensitized and 3 control dogs).
Procedure—9 dogs were sensitized against soy protein by administration of allergens during a 90-day period. After the sensitization period, serum concentrations of soy-specific IgE were determined and an intradermal test was performed to confirm the dogs were sensitized against soy protein. An intradermal challenge test and an oral challenge test with native and hydrolyzed soy protein were conducted on 6 sensitized and 2 control dogs.
Results—High serum concentrations of soy-specific IgE and positive results for the intradermal test were observed for the 9 sensitized dogs after completion of the sesitization process. Sensitized dogs challenge exposed with hydrolyzed soy protein had a reduced inflammatory response after intradermal injection and no clinical response after an oral challenge exposure, compared with responses after intradermal and oral challenge exposure with native soy protein.
Conclusions and Clinical Relevance—Soy-sensitized dogs did not respond to oral administration of hydrolyzed soy protein. Thus, hydrolyzed soy protein may be useful in diets formulated for the management of dogs with adverse reactions to food.
