Effects of dietary n-6 and n-3 fatty acids and vitamin E on the immune response of healthy geriatric dogs

Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802, USA.
American Journal of Veterinary Research (Impact Factor: 1.34). 07/2003; 64(6):762-72. DOI: 10.2460/ajvr.2003.64.762
Source: PubMed


To determine the effect of dietary n-6 to n-3 fatty acid ratios and alpha-tocopheryl acetate concentration on immune functions andT cell subpopulations in healthy dogs.
Thirty-two 7- to 10-year old female Beagles.
For 17 weeks, dogs were fed food that contained low (1.4:1) or high (40:1) ratios of n-6 to n-3 fatty acids in combination with 3 concentrations of all rac-alpha-tocopheryl acetate (low, 17 mg/kg of food; medium, 101 mg/kg; high, 447 mg/kg). Dogs were inoculated twice with a keyhole limpet hemocyanin suspension at 13 and 15 weeks.
After 12 weeks, dogs consuming low concentrations of alpha-tocopheryl acetate had lower percentages of CD8+ T cells, compared with dogs consuming medium or high alpha-tocopheryl acetate concentrations. Also, dogs consuming low alpha-tocopheryl acetate concentrations had higher CD4+ to CD8+ T cell ratios. On day 4 of week 15, the percentage of CD8+ T cells was highest in dogs fed medium concentrations of alpha-tocopheryl acetate, compared with other dogs; however, the CD4+ to CD8+ T cell ratio was higher only in dogs fed low concentrations of alpha-tocopheryl acetate with high concentrations of n-3 fatty acids. Dogs consuming low concentrations of n-3 fatty acids with medium concentrations of alpha-tocopheryl acetate had the largest delayed-type hypersensitivity (DTH) skin test response.
An optimum amount of dietary alpha-tocopheryl acetate concentration, regardless of the dietary n-6 to n-3 fatty acid ratio, stimulates the CD8+ T cell population. Effects of an optimum amount of dietary alpha-tocopheryl acetate concentration on the DTH response are blunted by dietary n-3 fatty acids.

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Available from: Jean Hall, May 14, 2015
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    • "In another study we looked at the effects of both dietary antioxidants and fish oil. In this healthy-geriatric dog study, we showed that the effects of an optimum dietary vitamin E concentration on the DTH response were blunted by dietary (n-3) fatty acids (Hall et al., 2003). "
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    ABSTRACT: Dietary (n-3) fatty acids from fish oil have been used to modulate immune function in many mammalian species. Together, dietary antioxidants and behavioral enrichment have been shown to enhance neutrophil phagocytosis in geriatric Beagle dogs. The purpose of this study was to further investigate the effects of vitamins E and C, in combination with dietary fish oil, on neutrophil mediated bacterial killing, and on transcript levels of selected neutrophil mRNA. Fifty adult Beagle dogs were randomized into five dietary treatment groups for 60 days. All foods were complete and balanced and met the nutrient profiles of AAFCO for adult dogs. For 60 days before study initiation, dogs consumed a pretrial food that contained 74 IU/kg vitamin E and 0 mg/kg vitamin C. The five experimental foods were confirmed by analytical methods to contain ≥640 IU/kg vitamin E and 130 mg/kg vitamin C (as fed). Experimental foods ranged from low levels of EPA and DHA (pretrial food and lowest experimental food had 0.01% EPA and no detectable DHA) to the highest experimental food with 0.25% EPA and 0.17% DHA. Ex vivo bactericidal activity of activated, peripheral-blood neutrophils against Lactococcus lactis was determined after 1 h incubation. Bactericidal activity was calculated as a percentage of control values (bacteria incubated in media without neutrophils). Transcript levels of genes involved in neutrophil-mediated immune functions were determined by real-time qPCR. Dogs in all treatment groups had increased serum vitamin E concentration (P<0.01). After consuming experimental food for 60 days, neutrophils from dogs in all 5 treatment groups also had increased bactericidal activity (P<0.01). Dietary fish oil however, had no effect on bactericidal activity. Stepwise multiple regression analysis demonstrated that the change in neutrophil mediated bacterial killing was significantly correlated to changes in gene expression of interleukin-8 receptor (IL-8R), interleukin converting enzyme (ICE), and myeloperoxidase (MPO; r(2)=0.33; P=0.003). When stepwise multiple regression analysis was performed considering each mRNA as a dependent variable and change in selected individual and summed fatty acid concentrations as independent variables, change in the ratio of saturated fatty acids (SFA) to polyunsaturated fatty acids (PUFA) was significant (P≤0.05) in the mRNA regression analyses for IL-8R, ICE, MPO, and cyclooxygenase-2. In summary, circulating neutrophils from dogs fed diets enriched in vitamins E and C had significantly increased bactericidal activity as well as altered gene expression. Change in SFA to PUFA ratio also altered neutrophil gene expression.
    Full-text · Article · Feb 2011 · Veterinary Immunology and Immunopathology
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    • "There were no differences due to maternal vitamin E supplementation at 48 h postchallenge ; however, 48 h postchallenge may not have offered enough time for an adequate response. Geriatric dogs receiving vitamin E supplementation with dietary n-6 and n-3 fatty acids exhibited a greater nodule-size response between 72 and 96 h postchallenge compared with 24 h postchallenge, and vitamin E increased the immune response in dogs receiving treatments of less and more α-tocopherol and less n-3 fatty acids (Hall et al., 2003). In conclusion, calves suckling cows supplemented with natural-and synthetic-source vitamin E had increased circulating concentrations of α-tocopherol at 24 h and appeared to continue throughout maternal supplementation regardless of source of vitamin E. "
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    ABSTRACT: The objective of this study was to determine the effects of maternally supplemented natural- or synthetic-source vitamin E on suckling calf performance and immune response. In a 2-yr study, one hundred fifty-two 2- and 3-yr-old, spring-calving, Angus-cross beef cows were blocked by age, BW, and BCS into 1 of 3 isocaloric, corn-based dietary supplements containing 1) no additional vitamin E (CON), 2) 1,000 IU/d of synthetic-source vitamin E (SYN), or 3) 1,000 IU/d of natural-source vitamin E (NAT). Maternal supplementation began approximately 6 wk prepartum and continued until the breeding season. Colostrum from cows and blood from calves was collected 24 h postpartum for analysis of IgG concentration as an indicator of passive transfer and circulating alpha-tocopherol concentration. At 19 d of age, blood was collected from calves to determine the expression of CD14 and CD18 molecules on leukocytes. At 21 and 35 d of age, humoral immune response was measured by a subcutaneous injection, in the neck, with ovalbumin (20 mg; OVA) and blood samples collected weekly until d 63 of age to determine antibodies produced against OVA. At d 63 of age, calves were administered an intradermal injection of OVA (1 mg) in the neck to assess cell-mediated immunity, which was determined on d 65 of age by measuring nodule size with calipers. Circulating alpha-tocopherol concentrations were increased at both 24 h (P = 0.001) and at the day of initial OVA challenge (P < 0.001) in SYN and NAT compared with CON calves. No differences were detected (P > 0.05) for calf birth BW, ADG, or weaning BW. There were no differences (P > 0.05) in calf serum total IgG or cow colostrum total IgG at 24 h or presence of CD14 and CD18 receptors at d 19 of age. The NAT calves had a greater antigen response to OVA at d 63 than SYN calves (P = 0.01; treatment x day interaction). As an indicator of cell-mediated immunity to OVA, nodule size at 65 d of age was not affected (P = 0.92) by maternal dietary supplementation. In conclusion, calves suckling cows supplemented with natural- and synthetic-source vitamin E had increased circulating concentrations of alpha-tocopherol at 24 h, which appeared to continue throughout maternal supplementation; however, calf immune function and performance were not affected.
    Full-text · Article · Sep 2010 · Journal of Animal Science
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    • "Altering the ratio of (n-6)–(n-3) FAs also affected T-cell subpopulations in aged dogs, in that after immunization with a novel protein these dogs had decreased numbers of CD4 + lymphocytes and decreased CD4 + -to-CD8 + ratios [6]. Furthermore, we have shown that there is an interaction between dietary vitamin E and (n-3) FAs such that the effects of an optimum amount of dietary vitamin E concentration on the DTH response are blunted by dietary (n-3) FAs [7]. This study is a continuation of these investigations in aged Beagles, whereby we report the effect of consumption of a diet enriched in (n-3) FAs for 36 weeks on plasma FA profiles and on leukotriene (LT) B4 and LTB5 production by peripheral blood neutrophils. "
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    ABSTRACT: The study objective was to determine the effect of feeding food enriched in (n-3) fatty acids (FA) on plasma FA profiles and leukotriene B (LTB) synthesis by stimulated peripheral blood neutrophils from dogs. For 36 weeks, two groups of dogs (n = 5) were fed food that contained either a low ratio of (n-6)-(n-3) FA (1.31:1; fish oil-enriched food) or a high ratio of (n - 6)-(n-3) FA (40.6:1; corn oil-enriched food). Consumption of food enriched in fish oil resulted in higher plasma concentrations of eicosapentaenoic acid and docosahexaenoic acid and lower concentrations of arachidonic acid. Neutrophils from dogs fed fish oil-enriched food produced 7.6-fold more LTB(5)(P = 0.002), and the ratio of LTB(5)-LTB(4) concentrations was 8.3-fold higher (P < 0.001) compared with dogs fed corn oil-enriched food. Dietary FA can modulate leukotriene production by neutrophils in dogs, and suggests that foods enriched in (n-3) FA from fish oil may have value in the treatment of canine inflammatory diseases.
    Full-text · Article · Dec 2005 · Prostaglandins Leukotrienes and Essential Fatty Acids
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