Feed costs are approximately 70% of total production cost for poultry producers. Poultry diets in the United States generally consist of 2 grains: corn and soybean meal. In recent years, the cost of these grains has dramatically increased. Due to these price increases, producers seek alternative feeds that provide adequate nutrition, and are also more affordable than "traditional" grains. Cottonseed meal is one alternative that is both affordable and an excellent source of crude protein. However, cottonseed meal contains gossypol, a pigment toxic to chickens. This study had two main objectives. The first objective was to determine if silymarin, an extract from milk thistle, could offset or prevent gossypol toxicosis. The second objective was to determine if divergent selection for humoral immune response would have an impact on the ability of the chicken to cope with gossypol toxicosis. Two preliminary studies were conducted. One determined basal activities of liver detoxification enzymes at various ages. The other determined concentrations of gossypol and silymarin that should be added to the diet to elicit a response. The information gathered from the second preliminary study was used to conduct the final experiment. In the final experiment, chickens from each of 2 lines selected for humoral immunity were exposed to diets containing gossypol, silymarin, gossypol and silymarin, and a control. Humoral immunity had no impact on the ability of the chicken to cope with gossypol toxicosis. Silymarin did not alleviate gossypol toxicosis. Future studies will focus on using a lower gossypol concentration in the diet. / Master of Science

No description available.

The drug-drug interaction involving zidovudine and sulfamethoxazole-trimethoprim was investigated using an in vitro culture system, an in vivo mouse model, and a clinical trial in HIV-infected patients. We hypothesized that combination exposure causes immune cell populations in the bone marrow to undergo apoptotic cell death, and that the toxicity would affect the host response to an infectious stimulus. Mice were dosed with zidovudine, sulfamethoxazole-trimethoprim, the combination of both drugs, or vehicle only control via oral gavage. Focusing on B-lineage cells in the bone marrow, we determined that cells of the rapidly cycling, early pre-B cell subset are targeted, as well as pro-B cells earlier in development. This toxicity was found to be cell cycle dependent, with an increase in percentage of cells in the S/G2/M phases of the cycle. In vitro experiments using the drugs in a bone marrow culture system demonstrated that the effect of cytotoxicity with combination exposure is synergistic and concentration-dependent. The mechanism of apoptosis that is induced appears to be caspase-independent. To measure host response in mice, animals treated with zidovudine plus sulfamethoxazole-trimethoprim were infected with Pneumocystis murina pneumonia, and the group that received the combination of agents had a blunted antigen-specific IgG response, possibly due to a decreased number of B cells and activated B cells in the draining lymph nodes of the lungs. A clinical trial was conducted in HIV-infected patients, dividing subjects into groups receiving zidovudine, sulfamethoxazole-trimethoprim, the combination of both, or neither agent. Upon vaccination with the influenza vaccine, the combination treatment group had a blunted humoral response, with reduced antigen-specific serum IgG titers as compared to the control group. We conclude that the drug-drug interaction involving zidovudine and sulfamethoxazole-trimethoprim is clinically-significant, and clinicians must consider this toxicity when treating patients with these agents concurrently.

The use of antibiotic growth promoters has been limited all around the world because of the concerns about antibiotic resistant bacteria and the presence of antibiotic residues in poultry products. Yeast-derived products are rich sources of ß1,3-1,6-glucan, mannan polysaccharides, and nucleotides and are considered as possible antibiotic alternatives due to their potential intestinal health benefits, growth promotion, and immune system stimulation. The objectives of the current research were: (1) to the evaluate effect of yeast products derived from yeast Saccharomyces cerevisiae on growth performance, gut histomorphology, and innate immune response of broiler chickens; (2) to investigate the effect of yeast products, including distillers dried grains with solubles (DDGS), on innate and antibody-mediated immune response following immunization with different antigens; and (3) to examine the effect of yeast-derived products and DDGS on growth performance, incidence of necrotic enteritis (NE), and local innate immunity in broiler chickens challenged with Clostridium perfringens. Overall, supplementation of diets with yeast products did not affect growth performance of broilers. However, the diets containing yeast cell walls (YCW) and nucleotides increased the villus height in the jejunum and enhanced the number of goblet cells in the ileum. Inclusion of diets with yeast products did not activate the innate immune response of birds under non-pathogen challenge conditions. However, the diet containing YCW activated Th2 cell-mediated immune response in birds immunized with sheep red blood cells and bovine serum albumin. Furthermore, supplementation of diets with YCW and DDGS in birds challenged with Escherichia coli lipopolysaccharide, activated the systemic innate immune response. Regarding antibody-mediated immune response, when compared to the control, serum antibody titer and specific antibody response against different antigens were not affected by dietary treatments. In the C. perfringens challenge study, growth performance, NE lesions and C. perfringens counts in the intestine were not affected by yeast-derived products. However, diets containing YCW and nucleotides stimulated the local innate immune response of birds by upregulation of cytokines and receptors involved in innate immunity. Such findings suggest that the immune-adjuvant like properties of YCW and nucleotides activate the innate immunity of broiler chickens following immunization or challenge with different antigens. / October 2015

No description available.

No description available.

No description available.

The Early Growth Response genes 2 and 3 (Egr2/3) are zinc finger transcription factors that play an important role in the immune system. These transcription factors have reported functions in T cell receptor signaling, differentiation of effector T cell subsets and the development of lupus-like autoimmune diseases. Using CD2-Egr2-/- Egr3-/- mouse model, I investigate the development of inflammation pathology, differentiation of T follicular helper (Tfh) cells and the formation of germinal centers (GC) following viral challenge within these mice. The onset of inflammation pathology in CD2-Egr2-/- Egr3-/- mice was discovered to correlate with high levels of pro-inflammatory cytokines in the serum and the development of autoimmune diseases as previously reported by Li et al, 2012. Most importantly, a novel role for the Egr2/3 genes in the differentiation of T follicular helper (Tfh) cells was identified. Tfh cells are responsible for T cell dependent antibody immune response in the GC. They support the differentiation of GC B cells into plasma cells producing long lived high-affinity isotype-switched antibodies and memory B cells. Tfh cell differentiation is regulated by Bcl6 however; the regulators of Bcl6 during Tfh differentiation remain largely unknown. We have now discovered that Egr2/3 genes are required for Bcl6 expression during Tfh cell differentiation. In the absence of the Egr2 and 3 genes, Tfh cell differentiation is severely impaired and GC formation and functions were defective in response to Vaccinia Virus Western Reserve strain (VVWR) infection. Further investigation revealed that Egr2 regulated Bcl6 expression in a Tfh-specific manner as adoptive transfer of WT CD4+ T cells into Egr2-/- Egr3-/- mice was able to rescue Bcl6 expression, Tfh differentiation and GC formation. When the molecular mechanism of how Egr2 regulated Bcl6 was investigated, it was uncovered that Egr2 directly bound to the promoter region of Bcl6 gene in CD4 T cells to regulated Bcl6 expression. Indeed constitutive expression of either Egr2 or Bcl6 in CD2-Egr2-/- Egr3-/- CD4+ T cells rescued Tfh cell differentiation and GC formation. Our results inferred that the Egr2/3 genes are essential for Tfh differentiation and GC formation by regulating Bcl6 expression in CD4 T cells under Tfh condition. Our studies thus suggest that the Egr2/3 genes are paramount for minimising immunopathology and are also critical for efficient antibody production by regulating Tfh cell differentiation.

A tumorigênese cutânea é determinada pela combinação de diversos fatores genéticos e ambientais, que envolvem múltiplos eventos onde as células epiteliais podem progredir e se desenvolverem. Todo esse processo é associado com alterações da imunidade celular e humoral. Muitos fatores físicos e químicos podem predispor ao câncer de pele, como o carcinógeno DMBA, com ação iniciadora e promotora. Camundongos geneticamente selecionados para a alta (High) ou baixa (Low) produção de anticorpos constituem uma excelente ferramenta para o estudo da influência da imunidade humoral no desenvolvimento de tumores. Foram avaliados camundongos das linhagens High e Low submetidos ao tratamento com o DMBA na pele após 48 horas, 120 e 240 dias. Mostramos que a linhagem selecionada para a maior produção de anticorpos (High) é a mais sensível ao tratamento com formação de lesões que progrediram para o desenvolvimento de papilomas, apresentando maior incidência e multiplicidade tumoral que os animais Low. Os machos da linhagem High também desenvolveram tumores nos pulmões em decorrência do tratamento com o DMBA na pele. O perfil de citocinas avaliado mostrou que os animais Low tem maior expressão gênica de IFN-g e IL-6 do que os animais High, e estes maior expressão de IL-1b e Cxcl2 que os animais Low após 48 horas do tratamento. A secreção de IL-6 também foi maior nos animais Low com 48 horas, sendo que a produção de TGF-b foi maior nos animais High aos 120 dias. Estes resultados sugerem que na linhagem High o perfil de resposta celular seja do tipo Th2 com produção de IL-10 e TGF-b, o que favorece o surgimento de tumores, e na linhagem Low, a resposta celular seja do tipo Th1, pela presença de IFN-g e TNF-α, favorecendo o reparo tecidual. Como não foram encontradas diferenças na via de metabolização pelas enzimas do citocromo P450 e no polimorfismo do receptor Ahr, outros fatores podem estar relacionados aos fenótipos observados. Assim, estas linhagens geneticamente selecionadas que diferem quanto à capacidade de secreção de anticorpos, representam uma nova ferramenta para o estudo de fatores genéticos que influenciam o microambiente na predisposição ao câncer. / The skin tumorigenesis is determined by the combination of various genetic and environmental factors, involving multiple events, where epithelial cells can progress and develop. This entire process is associated with changes in cellular and humoral immunity. Many physical and chemical factors may predispose to skin cancer, such as DMBA carcinogen with initiating and promoting action. Mice genetically selected for high (High) or low (Low) antibody production are an excellent tool for studying the influence of humoral immunity in the development of tumors. High and Low mice were treated with DMBA on the skin and, after 48 hours, 120 and 240 days, they were evaluated. We showed that High mice are more sensitive to DMBA treatment, presenting lesions that progressed to the development of papillomas and showing higher incidence and tumor multiplicity than Low ones. Males of High strain have also developed lung tumors as a result of treatment with DMBA on the skin. The profile of cytokines evaluated of Low animals showed that gene expression of IFN-g and IL-6 is more elevated than the one observed in High mice; on the other hand, IL- 1b and CXCL2 are increased in High animals, 48 hours after treatment. The secretion of IL-6 was also greater in Low animals, and TGF-b was higher in High animals, after 120 days of treatment. These results suggest that the High mice response has a Th2 profile with secretion of IL- 10 and TGF-b, which favors the growth of tumors; on the other hand, Low mice have a Th1 response, due to the presence of IFNg and TNFα, favoring tissue repair. As no differences were found in the enzymes of cytochrome P450 and in the polymorphism of Ahr receptor, other factors may be related to the observed phenotypes. Thus, these genetically selected mice which differ in the ability to secrete antibodies represent a new tool for the study of genetic factors influencing the microenvironment in its predisposition to cancer.

Antibodies neutralize and eliminate pathogens, malignancies, and toxins by acting either alone or in association with Fc receptors which, once engaged, activate the elimination mechanisms of phagocytic cells. Based on structural differences, antibodies are divided into functionally distinct classes (IgM, IgD, IgG, IgE and IgA). Structure-function relationships within these classes are not well characterized. In addition, animal models for the assessment of potential therapeutic strategies for the modulation of the interaction between antibodies and Fc receptors are not established. Nonhuman primates are widely used to model human diseases and, represent excellent in vivo systems for this assessment. Therefore, we have studied nonhuman primate IgD as well as IgG and IgA specific Fc receptors in rhesus macaques, cynomolgus macaques, baboons and sooty mangabeys. IgD genes had not been identified in nonhuman primates nor the IgD receptors characterized in any species. We characterized IgD genes of the four monkey species, as well as chimpanzees and dogs. In contrast to other antibody classes, the IgD hinge regions are highly conserved between human and nonhuman primates, thus indicating a role in Fc receptor binding. In humans, Fc receptors CD16a (natural killer cells) and CD16b (neutrophils) bind IgG1 and IgG3, and CD89 (myeloid cells) binds IgA. To assess ligand binding and glycosylation properties of nonhuman primate CD16a, CD16b, and CD89, we sequenced, cloned, and generated recombinant molecules in a mammalian expression system. Our results verify the presence of CD16a, but not CD16b in nonhuman primates. CD16a is expressed on monocytes and a subpopulation of lymphocytes. In sooty mangabeys, CD16 is also expressed on neutrophils. Recombinant sooty mangabey/baboon CD16a binds to human IgG1 and IgG2, but not IgG3 and IgG4. Monkey CD89 has the same peripheral blood leukocyte expression profiles as humans, and binds human and recombinant macaque IgA. Blocking of N-glycans inhibited expression of CD89, but only marginally CD16a expression. Although extensive similarities of antibody/Fc receptor interactions exist between human and nonhuman primates, several differences must be considered when evaluating therapeutic strategies. However, these differences can be exploited to further characterize the structure-function relationships existing within antibody molecules and respective receptors.