Veterinary vaccine adjuvants

Veterinary vaccine adjuvants

248 Abstracts / Veterinary Immunology and Immunopathology 128 (2009) 211–347 IL-15-producing cells appeared to be predominantly nonT non-B lymphocyt...

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Abstracts / Veterinary Immunology and Immunopathology 128 (2009) 211–347

IL-15-producing cells appeared to be predominantly nonT non-B lymphocytes. Large granular lymphocytes (LGL), which are virus-infected cells obtained from MCF-affected tissues in culture, did not produce IL-15 but did respond to the cytokine in bioassays. Experiments to deplete IL15 in vivo with an IL-15 receptor protein gave equivocal results. This could be due to the recent discovery that such treatment can enhance IL-15 activity rather than block it. Other experiments are under way to block TNF-␣ with Etanercept® , a TNF-␣ receptor protein. We conclude that IL-15 is produced in abundance in MCF and that cytotoxic cells maintain their active phenotype in the presence of IL-15, contributing to the tissue damage seen in MCF. doi:10.1016/j.vetimm.2008.10.081 Immune responses against measles virus in cynomolgus monkeys Hiroki Sato ∗ , Fumio Kobune, Yasushi Ami, Misako Yoneda, Chieko Kai Laboratory Animal Research Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan Keywords: Measles virus; Cytokine; Immunosuppression; Cynomolgus monkey Species: Other (monkeys) Measles virus (MV) induces profound suppression of the immune response during and for weeks after acute infection. On the other hand, virus-specific immune responses that mediate viral clearance and confer long-lasting immunity are efficiently generated. To investigate this paradox we studied the immune responses in cynomolgus monkeys against MV infection. Cynomolgus monkeys experimentally infected with wild-type MV (MV-HL) showed marked leukopenia associated with a steady reduction in CD4+ T cell numbers for 18 days post-inoculation. Transient expression of interferon and interleukin (IL)-6 were observed in the serum between 4 and 6 days postinoculation, indicating that MV replication induced early antiviral response. IL-10 levels increased after 11 days post-inoculation, suggesting that the prolonged immunosuppression observed during measles infection is due to the inhibitory effects of IL-10 on type 1 CD4+ T cells. Interestingly, serum levels of IL-8 showed considerable variation that was characteristic of three peaks at day 3, 5, 6, and 11 post-inoculation. IL-8 mRNA in peripheral blood mononuclear cells peaked at day 2, 4, and 9 post-inoculation, which correlated with IL-8 serum protein levels. Although the first IL-8 serum protein peak was the highest of the three protein peaks observed, the IL8 mRNA peak was lower than estimated from the serum protein. In vitro study using a respiratory epithelial cell line revealed that MV particle induces IL-8 production via binding to and/or incorporation into cells without virus replication. These suggested that rapid IL-8 secretion at day three post-inoculation is primarily induced by a small amount of circulating MV particles that arose from respiratory epithelial cells. The cynomolgus mon-

key is valuable for the study of measles pathogenesis, the mechanism of long-term immune memory, and for the development of a new measles vaccine that would still be effective in the presence of maternal neutralizing antibodies. doi:10.1016/j.vetimm.2008.10.082 Veterinary vaccine adjuvants L. Dupuis 1 , S. Deville 1 , J. Aucouturier 1 , S. Ascarateil 1 , A. Laval 2 , V. Ganne 3 1

SEPPIC S.A., Tour Kupka C, 7 Boulevard Franck Kupka, 92039 Paris La Defense Cedex, France 2 National Veterinary School of Nantes, Atlanpole-La Chantrerie-BP 40706, Nantes Cedex 03, France 3 SEPPIC China Room 510, Jin Tai Building 58, South Moa Ming Road, Shanghai 200020, China Keywords: Vaccine; Adjuvant; Montanide Species: All species The development of efficacious and safe vaccine is more and more linked to the selection of an appropriate adjuvant. Specific adjuvants for veterinary vaccines have to be selected according to various criteria like the target species, kind of antigen, the type and duration of immune response needed for protection. There is no known universal adjuvant formula. Most commonly used adjuvants in veterinary vaccines are oil adjuvants and aluminum hydroxide. Oil adjuvants are generally water in oil formulations inducing strong and long-term immunity. Adjuvants based on mineral oils are known to be efficacious but can sometimes induce local reactions with reactive antigens. Multiphasic emulsions have also proved their efficacy in vaccine as they can induce short- and long-term immune response with various antigens. Specific range of adjuvant based on metabolisable oils can be used to reduce local and general reactions linked to reactive antigens association to mineral oil. A second generation of adjuvant suitable for veterinary vaccines is based on nanoparticles with a new immunostimulant and combined their immunostimulating properties to induce a positive synergistic effect. Different mechanisms of action can explain the efficacy of adjuvant: • The depot effect where the emulsion entraps the antigens and induce a slow release of it at the injection site. Inflammatory reaction correlated with the induction of an immune response can be also observed. • The recruitment of immuno-competent cells by micro diffusion of the droplets via the lymphatic system, or by the facilitation of the antigen uptake by antigen presenting cells. • Adjuvants can also enhance the humoral and cell mediated immune response. Therefore, the choice of the adjuvant should be done according to several criteria with the goal to obtain a good balance between safety and immunogenicity. For example, a well tolerated adjuvant should be recommended for use with a crude bacterial extract and also for use with LPS, both of which are reac-

Abstracts / Veterinary Immunology and Immunopathology 128 (2009) 211–347

tive. Conversely, a recombinant viral protein can be a weak immunogen thus requiring a strong adjuvant. doi:10.1016/j.vetimm.2008.10.083 3. Immunoendocrinology, and stress, immunology of reproduction and neonates, microbial flora, nutrients and the immune response Effects of bovine recombinant leptin on proliferation of heat shocked lymphocytes in dairy cows Nicola Lacetera ∗ , Giorgina Kuzminsky, Umberto Bernabucci, Patrizia Morera, Loredana Basiricò, Alessandro Nardone Dipartimento di Produzioni Animali, Università della Tuscia, Viterbo, Italy Keywords: Leptin; Bovine; Heat shock; Lymphocyte proliferation E-mail address: [email protected] (N. Lacetera). Species: Ruminants We have previously reported that heat shock alters mitogen driven proliferation and gene expression of leptin and leptin receptors in peripheral blood mononuclear cells (PBMC) of dairy cows, and that under conditions of elevated temperatures PBMC proliferation in response to mitogens is positively correlated with leptin mRNA. Present study was carried out to establish whether addition of bovine recombinant leptin to bovine PBMC cultured under elevated temperatures may counteract the impairment of the proliferative response of these cells to concanavalin A (ConA). Six Holstein early pregnant heifers were utilised as blood donors. PBMC were cultured under 39 or 42 ◦ C for 65 h, in the presence of the following concentrations of bovine recombinant leptin: 0, 9, 18, 27, or 150 ng/ml. ConA was added to PBMC cultures at concentrations of 2.5 or 0.25 ␮g/ml. Additional wells were also arranged to contain the five concentrations of leptin without ConA. Cultivation of PBMC at 39 ◦ C was intended to mimic conditions of normothermia, whereas cultivation at 42 ◦ C was realised to simulate conditions of hyperthermia. Addition of leptin in absence of ConA did not affect proliferation of PBMC. Proliferation of PBMC under 39 ◦ C was positively affected by the highest concentration of leptin (150 ng/ml) only when a suboptimal concentration of ConA was utilized (0.25 ␮g/ml). These results are in line with those already reported for other Species. Exposure of PBMC to 42 ◦ C was responsible for decreased proliferation only when the suboptimal concentration of ConA was added to culture media, and under these conditions, addition of leptin did not interfere with the negative effects of elevated temperature on PBMC proliferation. Verification of the hypothesis that addition of leptin may counteract the negative effects of elevated temperatures on PBMC proliferation provided negative results. Reduced expression of leptin receptors due to heat shock is likely to explain present findings. doi:10.1016/j.vetimm.2008.10.084

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Colostral CD8 positive cell is a potent producing cell for IFN-␥ Katsuro Hagiwara ∗ , Mayumi Domi, Junichi Ando Rakuno Gakuen University, Japan Keywords: IFN-␥; ␥␦-T cell; CD8+ T cell; Colostrum E-mail address: [email protected] (K. Hagiwara). Species: Ruminants IFN-␥ plays an important role in cellular immunity leading to microorganism elimination. We have reported that bovine colostrum contains high levels of IFN-␥ as well as immunoglobulin (Hagiwara et al., 2000). Lymphocytes are potent cells for IFN-␥ production, therefore, clarification of the lymphocyte population in the colostrum would help to clarify the source of colostral cytokines. In this study, we clarified the population of lymphocyte subsets in colostrum-namely, CD4 (Th) cells, CD8 (cytotoxic T) cells and ␥␦-T cells by flow cytometric analysis (EPICS XL, Beckman Coulter), and quantified the concentration of colostral IFN-␥ by ELISA. IFN-␥ was detected in the colostrum from all the 96 healthy Holstein cows, the levels tended to decrease on the day subsequent to parturition. Flow cytometric analysis showed that many ␥␦-T and CD8 positive cells were contained in the colostrum, and CD4/CD8 ratio was a low. The ratio of CD8 and ␥␦-T positive cells decreased during the 5 days after parturition, but the CD4 positive cells showed no change during the observation period. To clarify the IFN-␥ expressing colostral lymphocytes, magnetic separation technology (Dynabeads, DYNAL) was employed to sort the lymphocytes (CD4, CD8 and ␥␦-T) from the colostral cells. These positively selected lymphocytes have been examined for IFN-␥ mRNA expression by RT-real time PCR (RtPCR). RtPCR analysis showed a potent expression of IFN-␥ gene in CD8 positive cells and the gene expression was higher than CD4 or ␥␦-T positive cells. These results suggest that CD8 positive T cells in colostrum play a role in IFN-␥ producing cells. Reference Hagiwara, K., Kataoka, S., Yamanaka, H., Kirisawa, K.R., Iwai, H., 2000. Detection of cytokines in bovine colostrum. Vet. Immunol. Immunopathol. 76, 183–190.

doi:10.1016/j.vetimm.2008.10.085