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Mamadou Niang - One of the best experts on this subject based on the ideXlab platform.

  • characterisation of the lymph node immune response following mycoplasma mycoides subsp mycoides sc infection in Cattle
    Veterinary Research, 2006
    Co-Authors: Laurence Dedieu, Valerie Balcerrodrigues, Ousmane Cisse, Mahamadou Diallo, Mamadou Niang
    Abstract:

    Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides biotype Small Colony (MmmSC), is still a major Cattle Disease in Africa. Development of long-term protective vaccines, the only relevant strategy to achieve CBPP eradication, requires the characterisation of the protective immune mechanism. To this aim, the present study investigated the cellular immune response persisting in the lymph nodes of Cattle infected naturally and experimentally by contact, one year post exposure. The lymph node cell composition, MmmSC responsiveness and phenotype of the MmmSC-responding lymphocytes were compared between animals according to the different outcomes of the infection. To unravel the protective mechanism, the study focussed on the MmmSC-specific memory immune response generated in recovered Cattle, known to develop long-term immunity and to be resistant to reinfection. An MmmSC-specific immune response, mediated by IFN[gamma]-secreting CD4 T-cells, was detected in the lymph nodes of all recovered Cattle. Furthermore, the magnitude of this immune response was significantly higher in animals with complete recovery than in recovered animals presenting lung sequestra. The findings suggest that, in recovered Cattle, a subset of MmmSC-primed IFN[gamma]-secreting CD4 T-cells homed to the regional lymph nodes as MmmSC-specific memory T-cells, likely responsible for the protective anamnestic response. Induction and expansion of this subset of MmmSC-specific CD4 memory T-cells might be a major goal to develop efficient long term protective vaccines against CBPP. (Resume d'auteur)

  • Characterisation of the lymph node immune response following Mycoplasma mycoides subsp. Mycoides SC infection in Cattle
    Veterinary Research, 2006
    Co-Authors: Laurence Dedieu, Ousmane Cisse, Mahamadou Diallo, Valerie Balcer-rodrigues, Mamadou Niang
    Abstract:

    Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides biotype Small Colony (MmmSC), is still a major Cattle Disease in Africa. Development of long-term protective vaccines, the only relevant strategy to achieve CBPP eradication, requires the characterisation of the protective immune mechanism. To this aim, the present study investigated the cellular immune response persisting in the lymph nodes of Cattle infected naturally and experimentally by contact, one year post exposure. The lymph node cell composition, MmmSC responsiveness and phenotype of the MmmSC-responding lymphocytes were compared between animals according to the different outcomes of the infection. To unravel the protective mechanism, the study focussed on the MmmSC-specific memory immune response generated in recovered Cattle, known to develop long-term immunity and to be resistant to reinfection. An MmmSC-specific immune response, mediated by IFN$\gamma$-secreting CD4 T-cells, was detected in the lymph nodes of all recovered Cattle. Furthermore, the magnitude of this immune response was significantly higher in animals with complete recovery than in recovered animals presenting lung sequestra. The findings suggest that, in recovered Cattle, a subset of MmmSC-primed IFN$\gamma$-secreting CD4 T-cells homed to the regional lymph nodes as MmmSC-specific memory T-cells, likely responsible for the protective anamnestic response. Induction and expansion of this subset of MmmSC-specific CD4 memory T-cells might be a major goal to develop efficient long term protective vaccines against CBPP.

  • gamma interferon producing cd4 t cells correlate with resistance to mycoplasma mycoides subsp mycoides s c infection in Cattle
    Veterinary Immunology and Immunopathology, 2005
    Co-Authors: Laurence Dedieu, Valerie Balcerrodrigues, Ousmane Cisse, Mahamadou Diallo, Aboubakar Yaya, B Hamadou, Mamadou Niang
    Abstract:

    Abstract Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides SC ( Mmm SC ), is one of the most significant Cattle Disease in Africa. The control measures, which led to eradication from numerous countries are not feasible in Africa where the only prophylaxis relies on vaccination. However, the attenuated vaccines, used up to now in Africa, are of low efficiency. The development of an improved vaccine is, therefore, a necessity. The purpose of this study was to compare some immunological parameters in Mmm SC-infected Cattle (endobronchial versus natural in-contact infection) and assess the response in correlation with the clinical outcome (death versus recovery). Characterization of the immune parameters elicited in recovered animals, known to be refractory to new infection, will be an important step towards development of new vaccines against CBPP. A significant outcome of this study was the demonstration that all Mmm SC-infected Cattle developed a Mmm SC-specific cell-mediated immune response. A kinetic analysis of the Mmm SC responsiveness showed that the main difference between endobronchially- and in-contact infected animals was the delay before the onset of the Mmm SC-specific immune response. The first Mmm SC-responding PBMC sample was selected from each animal for cell phenotyping. The phenotypic analysis of this early Mmm SC-induced response revealed the predominant contribution of the CD4 T-cells in all animals whereas IFNγ was only constantly produced in recovered animals. Evolution of this early Mmm SC-specific immune response was then followed by a kinetic analysis of the Mmm SC-induced CD4 T-cell response and IFNγ released. The results demonstrated that in recovered animals, the Mmm SC-specific CD4 Th1-like T-cell response was maintained until slaughtering whereas in animals with acute Disease, progression of CBPP was associated with a decreased ability of the PBMC to produce IFNγ. The results led to the identification of immune parameters, which correlate with protection against CBPP and to a relevant strategy for the development of improved vaccines against this Disease.

Laurence Dedieu - One of the best experts on this subject based on the ideXlab platform.

  • characterisation of the lymph node immune response following mycoplasma mycoides subsp mycoides sc infection in Cattle
    Veterinary Research, 2006
    Co-Authors: Laurence Dedieu, Valerie Balcerrodrigues, Ousmane Cisse, Mahamadou Diallo, Mamadou Niang
    Abstract:

    Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides biotype Small Colony (MmmSC), is still a major Cattle Disease in Africa. Development of long-term protective vaccines, the only relevant strategy to achieve CBPP eradication, requires the characterisation of the protective immune mechanism. To this aim, the present study investigated the cellular immune response persisting in the lymph nodes of Cattle infected naturally and experimentally by contact, one year post exposure. The lymph node cell composition, MmmSC responsiveness and phenotype of the MmmSC-responding lymphocytes were compared between animals according to the different outcomes of the infection. To unravel the protective mechanism, the study focussed on the MmmSC-specific memory immune response generated in recovered Cattle, known to develop long-term immunity and to be resistant to reinfection. An MmmSC-specific immune response, mediated by IFN[gamma]-secreting CD4 T-cells, was detected in the lymph nodes of all recovered Cattle. Furthermore, the magnitude of this immune response was significantly higher in animals with complete recovery than in recovered animals presenting lung sequestra. The findings suggest that, in recovered Cattle, a subset of MmmSC-primed IFN[gamma]-secreting CD4 T-cells homed to the regional lymph nodes as MmmSC-specific memory T-cells, likely responsible for the protective anamnestic response. Induction and expansion of this subset of MmmSC-specific CD4 memory T-cells might be a major goal to develop efficient long term protective vaccines against CBPP. (Resume d'auteur)

  • Characterisation of the lymph node immune response following Mycoplasma mycoides subsp. Mycoides SC infection in Cattle
    Veterinary Research, 2006
    Co-Authors: Laurence Dedieu, Ousmane Cisse, Mahamadou Diallo, Valerie Balcer-rodrigues, Mamadou Niang
    Abstract:

    Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides biotype Small Colony (MmmSC), is still a major Cattle Disease in Africa. Development of long-term protective vaccines, the only relevant strategy to achieve CBPP eradication, requires the characterisation of the protective immune mechanism. To this aim, the present study investigated the cellular immune response persisting in the lymph nodes of Cattle infected naturally and experimentally by contact, one year post exposure. The lymph node cell composition, MmmSC responsiveness and phenotype of the MmmSC-responding lymphocytes were compared between animals according to the different outcomes of the infection. To unravel the protective mechanism, the study focussed on the MmmSC-specific memory immune response generated in recovered Cattle, known to develop long-term immunity and to be resistant to reinfection. An MmmSC-specific immune response, mediated by IFN$\gamma$-secreting CD4 T-cells, was detected in the lymph nodes of all recovered Cattle. Furthermore, the magnitude of this immune response was significantly higher in animals with complete recovery than in recovered animals presenting lung sequestra. The findings suggest that, in recovered Cattle, a subset of MmmSC-primed IFN$\gamma$-secreting CD4 T-cells homed to the regional lymph nodes as MmmSC-specific memory T-cells, likely responsible for the protective anamnestic response. Induction and expansion of this subset of MmmSC-specific CD4 memory T-cells might be a major goal to develop efficient long term protective vaccines against CBPP.

  • gamma interferon producing cd4 t cells correlate with resistance to mycoplasma mycoides subsp mycoides s c infection in Cattle
    Veterinary Immunology and Immunopathology, 2005
    Co-Authors: Laurence Dedieu, Valerie Balcerrodrigues, Ousmane Cisse, Mahamadou Diallo, Aboubakar Yaya, B Hamadou, Mamadou Niang
    Abstract:

    Abstract Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides SC ( Mmm SC ), is one of the most significant Cattle Disease in Africa. The control measures, which led to eradication from numerous countries are not feasible in Africa where the only prophylaxis relies on vaccination. However, the attenuated vaccines, used up to now in Africa, are of low efficiency. The development of an improved vaccine is, therefore, a necessity. The purpose of this study was to compare some immunological parameters in Mmm SC-infected Cattle (endobronchial versus natural in-contact infection) and assess the response in correlation with the clinical outcome (death versus recovery). Characterization of the immune parameters elicited in recovered animals, known to be refractory to new infection, will be an important step towards development of new vaccines against CBPP. A significant outcome of this study was the demonstration that all Mmm SC-infected Cattle developed a Mmm SC-specific cell-mediated immune response. A kinetic analysis of the Mmm SC responsiveness showed that the main difference between endobronchially- and in-contact infected animals was the delay before the onset of the Mmm SC-specific immune response. The first Mmm SC-responding PBMC sample was selected from each animal for cell phenotyping. The phenotypic analysis of this early Mmm SC-induced response revealed the predominant contribution of the CD4 T-cells in all animals whereas IFNγ was only constantly produced in recovered animals. Evolution of this early Mmm SC-specific immune response was then followed by a kinetic analysis of the Mmm SC-induced CD4 T-cell response and IFNγ released. The results demonstrated that in recovered animals, the Mmm SC-specific CD4 Th1-like T-cell response was maintained until slaughtering whereas in animals with acute Disease, progression of CBPP was associated with a decreased ability of the PBMC to produce IFNγ. The results led to the identification of immune parameters, which correlate with protection against CBPP and to a relevant strategy for the development of improved vaccines against this Disease.

Joerg Jores - One of the best experts on this subject based on the ideXlab platform.

  • mathematical modelling of the transmission dynamics of contagious bovine pleuropneumonia reveals minimal target profiles for improved vaccines and diagnostic assays
    PLOS ONE, 2015
    Co-Authors: Amos Ssematimba, Joerg Jores, Jeffrey C Mariner
    Abstract:

    Contagious bovine pleuropneumonia (CBPP) is a Cattle Disease that has hampered the development of the livestock sector in sub-Saharan Africa. Currently, vaccination with a live vaccine strain is its recommended control measure although unofficial antimicrobial use is widely practiced. Here, modelling techniques are used to assess the potential impact of early elimination of infected Cattle via accurate diagnosis on CBPP dynamics. A herd-level stochastic epidemiological model explicitly incorporating test sensitivity and specificity is developed. Interventions by annual vaccination, annual testing and elimination and a combination of both are implemented in a stepwise manner and their effectiveness compared by running 1000 simulations per intervention over ten years. The model predicts that among the simulated interventions, the ones likely to eliminate the Disease from an isolated herd all involved annual vaccination of more than 75% of the animals with a vaccine that protects for at least 18 months combined with annual testing (and elimination of positive reactors) of 75% of the animals every six months after vaccination. The highest probability of Disease elimination was 97.5% and this could occur within a median of 2.3 years. Generally, our model predicts that regular testing and elimination of positive reactors using improved tests will play a significant role in minimizing CBPP burden especially in the current situation where improved vaccines are yet to be developed.

  • characterization of the in vitro core surface proteome of mycoplasma mycoides subsp mycoides the causative agent of contagious bovine pleuropneumonia
    Veterinary Microbiology, 2014
    Co-Authors: Ivanka Krasteva, Anne Liljander, Anne Fischer, David Smith, Neil F Inglis, Massimo Scacchia, A Pini, Joerg Jores, Flavio Sacchini
    Abstract:

    Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides (Mmm) is a severe Cattle Disease, present in many countries in sub-Saharan Africa. The development of improved diagnostic tests and vaccines for CBPP control remains a research priority. Polyacrylamide gel electrophoresis and mass spectrometry were used to characterize the Triton X-114 soluble proteome of nine Mmm strains isolated from Europe or Africa. Of a total of 250 proteins detected, 67 were present in all strains investigated. Of these, 44 were predicted to be lipoproteins or cytoplasmic membrane-associated proteins and are thus likely to be members of the core in vitro surface membrane-associated proteome of Mmm. Moreover, the presence of all identified proteins in other ruminant Mycoplasma pathogens were investigated. Two proteins of the core proteome were identified only in other Cattle pathogens of the genus Mycoplasma pointing towards a role in host–pathogen interactions. The data generated will facilitate the identification and prioritization of candidate Mycoplasma antigens for improved control measures, as it is likely that surface-exposed membrane proteins will include those that are involved in host–pathogen interactions.

  • development of an improved vaccine for contagious bovine pleuropneumonia an african perspective on challenges and proposed actions
    Veterinary Research, 2013
    Co-Authors: Joerg Jores, Jeffrey C Mariner, Jan Naessens
    Abstract:

    Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides (Mmm) is an economically very important Cattle Disease in sub-Saharan Africa. CBPP impacts animal health and poverty of livestock-dependent people through decreased animal productivity, reduced food supply, and the cost of control measures. CBPP is a barrier to trade in many African countries and this reduces the value of livestock and the income of many value chain stakeholders. The presence of CBPP also poses a constant threat to CBPP-free countries and creates costs in terms of the measures necessary to ensure the exclusion of Disease. This opinion focuses on the biomedical research needed to foster the development of better control measures for CBPP. We suggest that different vaccine development approaches are followed in parallel. Basic immunology studies and systematic OMICs studies will be necessary in order to identify the protective arms of immunity and to shed more light on the pathogenicity mechanisms in CBPP. Moreover a robust challenge model and a close collaboration with African research units will be crucial to foster and implement a new vaccine for the progressive control of this Cattle plague.

Frans Jongejan - One of the best experts on this subject based on the ideXlab platform.

  • loop mediated isothermal amplification lamp assays for detection of theileria parva infections targeting the pim and p150 genes
    International Journal for Parasitology, 2010
    Co-Authors: Oriel M M Thekisoe, Natasha E Rambritch, Ryo Nakao, Raoul S Bazie, Peter Mbati, Boniface Namangala, Imna Malele, Robert A Skilton, Frans Jongejan
    Abstract:

    We have developed two loop-mediated isothermal amplification (LAMP) assays for the detection of Theileria parva, the causative agent of East Coast fever (ECF), an economically important Cattle Disease in eastern, central and southern Africa. These assays target the polymorphic immunodominant molecule (PIM) and p150 LAMP genes. The primer set for each gene target consists of six primers, and each set recognises eight distinct regions on the target gene to give highly specific detection of T. parva. The detection limit of each primer set is 1 fg, which is equivalent to one copy of the PIM and p150 T. parva genes. These PIM and p150 LAMP primer sets amplify DNA of T. parva isolates from Cattle and buffalo from different countries including Kenya, South Africa, Tanzania, Rwanda, Uganda and Burundi, indicating their ability to detect T. parva from different countries. With the advantages of simplicity, rapidity and cost effectiveness, these LAMP assays are good candidates for molecular epidemiology studies and for monitoring control programs in ECF-endemic, resource poor countries.

Jeffrey C Mariner - One of the best experts on this subject based on the ideXlab platform.

  • mathematical modelling of the transmission dynamics of contagious bovine pleuropneumonia reveals minimal target profiles for improved vaccines and diagnostic assays
    PLOS ONE, 2015
    Co-Authors: Amos Ssematimba, Joerg Jores, Jeffrey C Mariner
    Abstract:

    Contagious bovine pleuropneumonia (CBPP) is a Cattle Disease that has hampered the development of the livestock sector in sub-Saharan Africa. Currently, vaccination with a live vaccine strain is its recommended control measure although unofficial antimicrobial use is widely practiced. Here, modelling techniques are used to assess the potential impact of early elimination of infected Cattle via accurate diagnosis on CBPP dynamics. A herd-level stochastic epidemiological model explicitly incorporating test sensitivity and specificity is developed. Interventions by annual vaccination, annual testing and elimination and a combination of both are implemented in a stepwise manner and their effectiveness compared by running 1000 simulations per intervention over ten years. The model predicts that among the simulated interventions, the ones likely to eliminate the Disease from an isolated herd all involved annual vaccination of more than 75% of the animals with a vaccine that protects for at least 18 months combined with annual testing (and elimination of positive reactors) of 75% of the animals every six months after vaccination. The highest probability of Disease elimination was 97.5% and this could occur within a median of 2.3 years. Generally, our model predicts that regular testing and elimination of positive reactors using improved tests will play a significant role in minimizing CBPP burden especially in the current situation where improved vaccines are yet to be developed.

  • development of an improved vaccine for contagious bovine pleuropneumonia an african perspective on challenges and proposed actions
    Veterinary Research, 2013
    Co-Authors: Joerg Jores, Jeffrey C Mariner, Jan Naessens
    Abstract:

    Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides (Mmm) is an economically very important Cattle Disease in sub-Saharan Africa. CBPP impacts animal health and poverty of livestock-dependent people through decreased animal productivity, reduced food supply, and the cost of control measures. CBPP is a barrier to trade in many African countries and this reduces the value of livestock and the income of many value chain stakeholders. The presence of CBPP also poses a constant threat to CBPP-free countries and creates costs in terms of the measures necessary to ensure the exclusion of Disease. This opinion focuses on the biomedical research needed to foster the development of better control measures for CBPP. We suggest that different vaccine development approaches are followed in parallel. Basic immunology studies and systematic OMICs studies will be necessary in order to identify the protective arms of immunity and to shed more light on the pathogenicity mechanisms in CBPP. Moreover a robust challenge model and a close collaboration with African research units will be crucial to foster and implement a new vaccine for the progressive control of this Cattle plague.