Jayne C Hope

..The observations imply that DCs in afferent lymph are all DEC-205high, but not a uniform population of homogeneous mature DCs...

..In this review we discuss immune responses elicited by mycobacteria in cattle and the novel approaches emerging for the control of bovine TB based on our increasing knowledge of protective immune responses...

..The findings suggest that immunity to M. bovis induced by BCG vaccination in cattle may involve CD8+ memory T cells which produce IFN-gamma, as well as CD4+ memory T cells...

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..Overall, vaccination of neonatal calves with BCG induced significant protection against disease and has potential as a strategy for the reduction of the incidence of bovine tuberculosis...

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..The implication is that responses to M. avium, although providing some immunity, may mask diagnosis of M. bovis infection, even when specific antigens are employed, potentially contributing to disease transmission in the field...

..The ability to detect ruminant IL-12 by three methods: ELISA, bioassay with neutralising mAb and cytoplasmic staining, will permit studies of the role of this important cytokine in the immunology and pathogenesis of animal diseases...

..These strategies are also highly applicable to the fight against tuberculosis in humans...

..In addition, we show that measurement of antigen-specific T lymphocyte populations may provide a reliable means for identifying protective vaccine candidates...

..The presence of mycobacteria-reactive, IFN-gamma-secreting CD8(+) NK cells in neonatal calves may have important consequences for the induction of a Th1-biased immune response...

..This technique, although technically demanding, facilitates studies of DCs and other cells that traffic in the lymph in both the steady state and following antigenic exposure...

..We conclude that the failure to stimulate CD8+ T cell proliferation results from the lack of IL-1alpha synthesis by this population, which may have important consequences in vivo...

..These studies indicate that infection of bovine antigen presenting cells by mycobacterial species results in the induction of both innate and adaptive immune responses that are critical for the outcome of infection...

..The high numbers of WC1(+)gammadelta T cells in neonatal calves, and their inherent ability to respond to inflammatory cytokines, could be a key factor in the enhanced responses seen in calves to BCG vaccination...

..These interactions are likely to form a critical part of the T helper type 1-conditioning response of DCs to M. bovis...

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..However, the proportion of NKp46(+) and CD3(-)CD2(+) cells that expressed perforin was not significantly different in any age group tested...

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..The implication is that acute infections of cattle with non-cytopathic BVDV may temporarily compromise diagnostic tests for M. bovis infections and result in a failure to identify cattle with tuberculosis...

..bovis-infected animals. This assay could allow an accurate diagnosis of M. bovis and allow the discrimination of BCG-vaccinated cattle from infected cattle...

..An antibody response was not evident as a result of repeat skin testing prior to infection but was seen in both groups of calves following skin testing performed 7 weeks after infection...

..We conclude that the prevention of cell death in DCs is not associated with enhanced production of IFN-alpha/beta, as proposed for influenza virus, but is by a distinct mechanism...

..The results of this study indicate that the immunosuppression caused by ncpBVDV is not associated with low interferon responses or elevated levels of TGF-beta...

..These observations may offer the potential for further diagnostic assays that could complement the TT and IFNgamma test...

..A model is proposed that takes these observations into account in which SIRPalpha(-) DC would be expected to promote a Th1 biased response and the SIRPalpha(+) DC a more balanced one...

..By deliberately targeting functionally distinct subsets of either precursor or mature dendritic cells in vivo, it should become feasible to achieve an appropriately biased immune response...

..They suggest that M. avium infection primes the immune system of calves and that the detection of an immune response specific for M. bovis BCG is masked by reactivity to antigens also present in M. avium...

..Dendritic cells also interact with the innate immune system, inducing responses that potentially bias the subsequent adaptive response...

..These mAbs have generated the capability to study the role of TNF-alpha in host immune protection and disease pathogenesis in ruminants...

..Here the case is made for how studies in cattle have aided our understanding of immunity to several infections that can be exploited for the rational design of effective vaccination and control strategies...

..The identification of antibodies specific for bovine and ovine TLR2 will facilitate studies of the role of this important PRR in the initiation of immune responses to important pathogens...

..The pattern of recognition of epitope clusters by T cells and of HVR epitopes by B cells is consistent with the influence of protein structure on epitope recognition...

..These results demonstrate that DNA vaccines targeting key intercellular and intracellular events significantly enhance priming and expansion and support the feasibility of single-dose DNA immunization in outbred populations...

..Upon cytokine-induced maturation, splenic DCs both efficiently present antigen in the stimulation of allogeneic lymphocyte proliferation and recall antigen-specific responses...

..Collectively, our results point to profound differences in pathogen-derived signal-response coupling occurring commensurate with distinct functions carried out by Mphi or DC...

..No differences in IL-10 mRNA expression were detected among the groups. These results indicate that CpG ODN 2006 is an effective vaccine adjuvant for stimulating both antibody and IFN-gamma mediated cellular immune responses in cattle...

..marginale organisms. These results suggest that loss of memory T cell responses following A. marginale infection is due to a mechanism other than induction of T regulatory cells, such as peripheral deletion of MSP2-specific T cells...

..coli and S. aureus and suggest that the limited cytokine response to S. aureus may contribute to the well-known ability of the bacterium to establish chronic intramammary infection...

..These results support use of these growth factors in DNA vaccination and specifically indicate their applicability for vaccine testing in outbred animals...

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..Together, these data indicate that bovine NKp46 is anactivating receptor and demonstrate the existence of a subset of leukocytes in cattle that, in terms of surface markers, morphology and function, represent NK cells...

..aeruginosa that is characterized by the induction of pro-inflammatory cytokines, complement activation, and increased levels of accessory molecules involved in Gram-negative bacterial recognition...

..marcescens infection. Together, these data demonstrate the variability of the innate immune response to two distinct mastitis pathogens...