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the ability of two different N. caninum antigen preparations, i.e., sonicated soluble antigens and intact heat-inactivated parasites, to induce proliferation and IFN-␥ production in various cell types. The heat inactivated tachyzoites induced a 3.7 times higher increase in the number of IFN-␥ producing NK cells compared to the sonicated soluble fraction. This indicates the presence of NK cell stimulating antigens in the intact tachyzoite. We also found that heat inactivated whole tachyzoites clearly inhibited ␥␦ T-cells proliferation while the soluble antigens from N. caninum did not. For the first time we demonstrate the role of bovine NK cells as primary responders in a N. caninum infection in calves, and additionally a distinct difference in the effect of heatinactivated N. caninum tachyzoites and soluble antigens on the IFN-␥ production from NK cells and proliferation of ␥␦ T-cells. doi:10.1016/j.vetimm.2008.10.176 Interleukin-4 downregulates the goat beta-defensin-2 gene in caprine intestinal epithelial cells infected with Eimeria spp.
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sion strategy of the parasite to avoid pro-inflammatory responses. doi:10.1016/j.vetimm.2008.10.177 Feeding probiotic bacteria to swine enhances immunity to Ascaris suum Gloria Solano-Aguilar 1,∗ , Terez Shea-Donohue 2 , Kathleen Madden 3 , Harry Dawson 1 , Ethiopia Beshah 1 , Yolanda Jones 1 , Marta Restrepo 1 , Joseph Urban Jr. 1 1 Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, ARS-USDA, Beltsville, MD 20705, USA 2 Mucosal Biology Research Center, University of Maryland, Baltimore, USA 3 Uniformed Services University, Bethesda, MD, USA Keywords: Probiotic; Ascaris suum; Immunity; Gastrointestinal function
E-mail address: Solano-Aguilar).
[email protected]
(G.
Froylan Ibarra-Velarde, Yazmin Alcala-Canto ∗ Departamento de Parasitología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico Keywords: Defensins; Eimeriosis; Caprine; Cytokines E-mail address:
[email protected] (Y. AlcalaCanto). Species: Ruminants Defensins are antimicrobial peptides produced by leukocytes and epithelial cells. These peptides have been shown to play an important role in innate immune responses. However, the role of defensins in goat eimeriosis remains unknown. Therefore, this study investigated the expression of the goat beta-defensin named GBD2 in caprine intestinal epithelial cells (CIEC) stimulated with recombinant bovine interferon-gamma (IFN-gamma) in the presence or absence of recombinant bovine interleukin-4 (IL-4) by a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. GBD-2 mRNA was clearly expressed in IFN-gamma-stimulated CIEC. On the other hand, the direct addition of IL-4 showed no significant effect on GBD-2 expression in CIEC. However, when supernatants from peripheral blood mononuclear cells (PBMC) cultured with IL-4 were added to CIEC, the expression of GBD-2 decreased. To elucidate if IFN-gamma functions as a signaling molecule that facilitates the generation of GBD-2 against Eimeria spp. in goats, anti- IL-4 was added to PBMC from Eimeria-infected goats and levels of IFN-gamma in culture supernatants were determined by an enzyme-linked immunosorbent assay test. Results showed that IFN-gamma secretion increased when antiIL-4 was added to PBMC. Hence it is suggested that IL-4 may be a further factor in the pathogenesis of goat coccidiosis and its induction may be part of an eva-
Species: Swine Probiotic bacterial Species are included in the diet to promote health. Probiotics purportedly protect the intestine against pathogenic microorganisms and can reduce inflammation, however, quantitative measurement of probiotic growth and related effects on intestinal function are often lacking. Ascaris suum commonly infects pigs and induces a Th2-derived response in the intestine that is associated with expulsion of the fourth-stage larvae (L4) from the jejunum. The physiological aspect of expulsion represent a “weep and sweep” response characterized by smooth muscle hyper-contractility and increased luminal fluid associated with reduced sodium-linked glucose absorption. We investigated the effect of feeding Bifidobacterium lactis subSpecies animalis (Bb12) on the immune and intestinal function of young pigs subsequently infected with A. suum. Pregnant sows were orally inoculated with a daily dose of Bb12 (3.5 × 1010 cfu) or a placebo during the last trimester of pregnancy, and to their offspring from birth until weaning. Six weeks after weaning, piglets were inoculated with A. suum and the jejunal mucosae was stripped and mounted in Ussing chambers to determine changes in permeability and glucose absorption at 21 days after infection. Pig jejunum, mesenteric lymph nodes, and proximal colon were collected and assayed for gene expression by real time PCR. Bb12 was quantitatively detected using a single copy tuf gene and found at the highest concentration in the colon of probiotic-treated piglets. Probiotic treatment did not affect intestinal permeability, but significantly attenuated the reduction in glucose absorption and the hyper-secretory response to histamine induced by A. suum infection; suggesting a selective effect of the probiotic on nutrient absorption and mast cell responses against parasite infection. Probiotic treatment of A. suum-infected pigs significantly increased mRNA expression of genes associated with enhanced protection against parasitic infection, including IL-25, RETNLB, and SOCS3, and did not interfere
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with normal expulsion of L4 from the jejunum. The results show that probiotic bacteria can selectively enhance local immunity to A. suum without affecting nutrient absorption. This experimental system could be used to evaluate the effect of feeding Bb12 and other probiotics on responses to different infectious agents to reduce antibiotic use. It also models the effect of feeding probiotics to mothers and their newborn children on reduced expression of allergic disease in human. doi:10.1016/j.vetimm.2008.10.178 Rhipicephalus sanguineus ticks fed on resistant host: Histology of lesions associated with immunity Viviane Aparecida Veronez 1 , Márcio Botelho de Castro 2 , Gervásio Henrique Bechara 1 , Matias Pablo Juan Szabó 1,3,∗ 1
Departamento de Patologia Veterinária, Universidade Estadual Paulista, Jaboticabal, SP, Brazil 2 Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília, DF, Brazil 3 Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil Keywords: Rhipicephalus sanguineus; Lesions; Immune response; Dog; Guinea pig E-mail address:
[email protected] (M.P.J. Szabó).
Species: Dog, guinea pig Dog is the natural, non-resistant host, of the tick Rhipicephalus sanguineus whereas guinea pigs develop a strong resistance to the same tick Species following repeated infestations. In this work histological features of ticks fed on dogs and on guinea pigs were compared to evaluate caused by the immune response of the resistant host lesions in target tissues. Additionally host complement fraction C3 and IgG1 and IgG2 antibodies were searched in tick tissues by immunohistochemistry to associate effector mechanisms with lesions. Ticks from each host Species were collected during the first and the third infestation and processed according to routine histological techniques. It was observed that many ticks from guinea pigs, especially during third infestation where unattached, dehydrated and smaller when compared to those from dogs. Gut of 13.6% and 38% of the ticks fed on guinea pigs during first and third infestation, respectively, had host inflammatory cells with the features of eosinophils and basophils, whereas no inflammatory cell was seen in the gut of ticks fed on dogs. Vacuolization of gut cells were observed in all ticks except in those fed on dogs for more than 96 h. It was also observed that 85.7% of ticks fed on guinea pigs during first infestation had vacuolated tracheae and all displayed swelling of Malpighian tubules. During third infestation, all ticks from guinea pigs had vacuolated tracheae and swelling of Malpighian tubules and in 25% of these ticks vacuolization of oocytes was also observed. At the same time such alterations were lacking in ticks from dogs. Another interesting feature was the presence of an increased number of guanine granules in ticks fed on guinea pigs, especially during third infestation. No association between host complement and
antibodies with tick lesions could be done because of the diffuse staining of several tissues on ticks from both dogs and guinea pigs during the first and third infestation. Overall results show that the natural resistance of guinea pigs to R. sanguineus ticks is associated with lesions in many different tissues and dehydration of the tick. Eosinophils and basophils in the gut might be interfering with tick feeding. Finally irrespective of host resistance host complement and antibodies seem to reach several tick tissues during infestations and thus functional activities of these proteins inside the ticks should be evaluated. Financial support: FAPESP and FAPEMIG. doi:10.1016/j.vetimm.2008.10.179 Serological, histological and immunohistochemical tests for canine visceral leishmaniasis diagnosis Nina Mari G.P. de Queiroz 1,∗ , Wilma A. Starke-Buzetti 1 , Rita de Cassia S. Viveiros 1 , Silvana C. Paulan 1 , Karen I. Tasca 1 , Flávia L. Lima 1 , Michely S. Tenorio 1 , Maria Francisca Neves 1 , Rosangela Zacarias Machado 2 , Tricia Maria de Oliveira 2 , Antonio Carlos F. de Noronha 3 1
University of São Paulo State, FEIS/UNESP-Campus of Ilha Solteira, SP, Brazil 2 University of São Paulo State, FCAVJ/UNESP-Campus of Jaboticabal, SP, Brazil 3 Centre of Zoonosis Control, Ilha Solteira, SP, Brazil Keywords: Dogs; Diagnosis; Histochemical; Leishmania chagasi; Leishmaniose visceral canina Species: CanineCanine visceral leishmaniasis (CVL) is caused by a parasite of the specie Leishmania (L.) chagasi, endemic for humans and dogs in many regions of Brazil. The purpose of the present study was to evaluate the serological testes (RIFI and ELISA) in asymptomatic, oligosymptomatic and symptomatic Leishmania-infected dogs from Solteira, SP, Brazil. These methods were also compared with other methods used for diagnosis of this disease in dogs such as histological (H&E) and immunohistochemical (IMHC) methods for demonstration of Leishmania in skin. When serological tests were done, 24 (70.6%) dogs were positive by ELISA or IFAT, but the numbers of dogs positive by ELISA was slightly higher than IFAT (56% for IFAT and 65% for ELISA), and in 7 (21%) dogs there was no agreement between ELISA and IFAT. There was also no agreement between serological tests and H&E or IMHC in 32.4%, particularly in asymptomatic (8 dogs) and oligosymptomatic (17 dogs) groups. In asymptomatic group, 5 (62.5%) were negative by both serological tests, but 3 (37.5%) of these dogs were positives by the presence of the parasite in their skins confirmed by H&E and IMHC methods. On the other hand, one asymptomatic dog was positive in all tests (serological, H&E and IMHC), indicating that even dogs without any clinical signs can be infected. In symptomatic group (9 dogs), the agreement among tests was 100%, but 1 dog (11.1%) of this group was negative and 8 (88.8%) were positives. The skin biopsies from asymptomatic dogs had negligible if any lesions, and parasite direct examination showed that the most of these dogs (62.5%) were negative or suspect,
