COMMUNITY PARTICIPATORY SUSTAINABLE LAND MANAGEMENT BYELAW FORMULATION IN THE HIGHLANDS OF CENTRAL ETHIOPIA

Widespread adoption of sustainable land management (SLM) innovations by land users is considered key in addressing the rampant land degradation in the high rainfall and densely populated highlands of eastern and southern Africa. However, absence of enabling policy environments hamperes massive adoption of SLM innovations among rural communities. This paper presents the process and outcomes of a participatory approach for formulating and implementing SLM byelaws in the central highlands of Ethiopia. The participatory approach utilised three complementary tools, namely, stakeholder analysis, community needs assessment and policy dialogues. The stakeholder analysis revealed that several government institutions, non-government organisations (NOGs) and community groups promote SLM practices. Poor coordination among actors, top-down approach in planning and implementation, and limited capacity of communities hamperes SLM scaling up efforts. Stakeholder engagements culminates in establishing innovation platforms (IPs) at district and watershed levels tasked with coordinating SLM scaling up efforts. While the community needs assessment identified and prioritised SLM issues that needed to be resolved, the policy dialogue engaging IPs formulated three SLM byelaws and mechanisms for implementation.Une large adoption des innovations de la gestion durable des terres (SLM) est consid\ue9r\ue9e comme une cl\ue9 importante pour adresser le probl\ue8me de la d\ue9gradation accrue des terres dans les hautes terres \ue0 pluviom\ue9trie \ue9lev\ue9e et densement peupl\ue9es de l\u2019 Afrique de l\u2019Est et du Sud. Par ailleurs, l\u2019absence de politiques environnementales handicape l\u2019adoption massive des innovations de SLM parmi les communaut\ue9s rurales. Cet article pr\ue9sente le processus et les r\ue9sultats d\u2019une approche participative pour la formulation et l\u2019ex\ue9cution des lois de SLM dans les hautes terres de l\u2019Ethiopie centrale. L\u2019approche participative a utilis\ue9 trois voies compl\ue9mentaires, dont l\u2019analyse de partenaires, l\u2019\ue9valuation des besoins communautaires et le dialogue sur les politiques. L\u2019analyse de partenaires a r\ue9v\ue9l\ue9 que plusieurs institutions gouvernementales, organisations non gouvernementales (ONG) et groupes communautaires encouragent les pratiques des SLM. Une pauvre coordination parmi les acteurs, une approche de haut en bas dans la planification et l\u2019ex\ue9cution, et une capacit\ue9 limit\ue9e des communaut\ue9s handicapent les efforts fournis dans le SLM. L\u2019engagement de partenaires culmine dans l\u2019\ue9tablissement des plateformes d\u2019innovations (IPs) au niveau du district et du basin versant avec pour t\ue2che la coordination des efforts d\u2019innovation de SLM. Alors que l\u2019\ue9valuation des besoins communautaires a identifi\ue9 et prioritis\ue9 les probl\ue8mes de SLM qui ont besoin d\u2019\ueatre adress\ue9s, le dialogue sur les politiques ont formul\ue9 trois lois et m\ue9canismes pour l\u2019ex\ue9cution de SLM

Survey of Faba Bean («Vicia faba» L.) Virus Diseases in Ethiopia

Surveys conducted in 1996 and 1997 to assess the status of virus diseases affecting faba bean in the major growing areas of Ethiopia indicated that leaf yellowing, rolling, necrosis and stunting were the most common disease symptoms. The highest visually-observed disease incidence in a field was 85%, recorded in the Wello region (north-eastern Ethiopia). When 3049 symptomatic samples collected from 211 fields from all over Ethiopia were tested by the tissue blot immunoassay (TBIA) for 14 viruses, 1592 samples (52.2%) were found to be infected with at least one virus. Faba bean necrotic yellows virus (FBNYV, genus Nanovirus) was the most frequent (63.2%), followed by luteoviruses (28.5%) [such as Beet western yellows virus (BWYV, genus Polerovirus, family Luteoviridae) and Bean leaf roll virus (BLRV, family Luteoviridae)] and Chickpea chlorotic dwarf virus (CCDV, genus Mastrevirus, family Geminiviridae) (3.1%). Mosaic/mottling symptoms were observed in some fields but incidence was always very low

Cryptosporidium Priming Is More Effective than Vaccine for Protection against Cryptosporidiosis in a Murine Protein Malnutrition Model

Cryptosporidium is a major cause of severe diarrhea, especially in malnourished children. Using a murine model of C. parvum oocyst challenge that recapitulates clinical features of severe cryptosporidiosis during malnutrition, we interrogated the effect of protein malnutrition (PM) on primary and secondary responses to C. parvum challenge, and tested the differential ability of mucosal priming strategies to overcome the PM-induced susceptibility. We determined that while PM fundamentally alters systemic and mucosal primary immune responses to Cryptosporidium, priming with C. parvum (106 oocysts) provides robust protective immunity against re-challenge despite ongoing PM. C. parvum priming restores mucosal Th1-type effectors (CD3+CD8+CD103+ T-cells) and cytokines (IFNγ, and IL12p40) that otherwise decrease with ongoing PM. Vaccination strategies with Cryptosporidium antigens expressed in the S. Typhi vector 908htr, however, do not enhance Th1-type responses to C. parvum challenge during PM, even though vaccination strongly boosts immunity in challenged fully nourished hosts. Remote non-specific exposures to the attenuated S. Typhi vector alone or the TLR9 agonist CpG ODN-1668 can partially attenuate C. parvum severity during PM, but neither as effectively as viable C. parvum priming. We conclude that although PM interferes with basal and vaccine-boosted immune responses to C. parvum, sustained reductions in disease severity are possible through mucosal activators of host defenses, and specifically C. parvum priming can elicit impressively robust Th1-type protective immunity despite ongoing protein malnutrition. These findings add insight into potential correlates of Cryptosporidium immunity and future vaccine strategies in malnourished children

Dual Role for Inflammasome Sensors NLRP1 and NLRP3 in Murine Resistance to Toxoplasma gondii

ABSTRACTInduction of immunity that limits Toxoplasma gondii infection in mice is critically dependent on the activation of the innate immune response. In this study, we investigated the role of cytoplasmic nucleotide-binding domain and leucine-rich repeat containing a pyrin domain (NLRP) inflammasome sensors during acute toxoplasmosis in mice. We show that in vitro Toxoplasma infection of murine bone marrow-derived macrophages activates the NLRP3 inflammasome, resulting in the rapid production and cleavage of interleukin-1β (IL-1β), with no measurable cleavage of IL-18 and no pyroptosis. Paradoxically, Toxoplasma-infected mice produced large quantities of IL-18 but had no measurable IL-1β in their serum. Infection of mice deficient in NLRP3, caspase-1/11, IL-1R, or the inflammasome adaptor protein ASC led to decreased levels of circulating IL-18, increased parasite replication, and death. Interestingly, mice deficient in NLRP1 also displayed increased parasite loads and acute mortality. Using mice deficient in IL-18 and IL-18R, we show that this cytokine plays an important role in limiting parasite replication to promote murine survival. Our findings reveal T.gondii as a novel activator of the NLRP1 and NLRP3 inflammasomes in vivo and establish a role for these sensors in host resistance to toxoplasmosis.IMPORTANCEInflammasomes are multiprotein complexes that are a major component of the innate immune system. They contain “sensor” proteins that are responsible for detecting various microbial and environmental danger signals and function by activating caspase-1, an enzyme that mediates cleavage and release of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18. Toxoplasma gondii is a highly successful protozoan parasite capable of infecting a wide range of host species that have variable levels of resistance. We report here that T. gondii is a novel activator of the NLRP1 and NLRP3 inflammasomes in vivo and establish a role for these sensors in host resistance to toxoplasmosis. Using mice deficient in IL-18 and IL-18R, we show that the IL-18 cytokine plays a pivotal role by limiting parasite replication to promote murine survival

Dual Role for Inflammasome Sensors NLRP1 and NLRP3 in Murine Resistance to Toxoplasma gondii

ABSTRACTInduction of immunity that limits Toxoplasma gondii infection in mice is critically dependent on the activation of the innate immune response. In this study, we investigated the role of cytoplasmic nucleotide-binding domain and leucine-rich repeat containing a pyrin domain (NLRP) inflammasome sensors during acute toxoplasmosis in mice. We show that in vitro Toxoplasma infection of murine bone marrow-derived macrophages activates the NLRP3 inflammasome, resulting in the rapid production and cleavage of interleukin-1β (IL-1β), with no measurable cleavage of IL-18 and no pyroptosis. Paradoxically, Toxoplasma-infected mice produced large quantities of IL-18 but had no measurable IL-1β in their serum. Infection of mice deficient in NLRP3, caspase-1/11, IL-1R, or the inflammasome adaptor protein ASC led to decreased levels of circulating IL-18, increased parasite replication, and death. Interestingly, mice deficient in NLRP1 also displayed increased parasite loads and acute mortality. Using mice deficient in IL-18 and IL-18R, we show that this cytokine plays an important role in limiting parasite replication to promote murine survival. Our findings reveal T.gondii as a novel activator of the NLRP1 and NLRP3 inflammasomes in vivo and establish a role for these sensors in host resistance to toxoplasmosis.IMPORTANCEInflammasomes are multiprotein complexes that are a major component of the innate immune system. They contain “sensor” proteins that are responsible for detecting various microbial and environmental danger signals and function by activating caspase-1, an enzyme that mediates cleavage and release of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18. Toxoplasma gondii is a highly successful protozoan parasite capable of infecting a wide range of host species that have variable levels of resistance. We report here that T. gondii is a novel activator of the NLRP1 and NLRP3 inflammasomes in vivo and establish a role for these sensors in host resistance to toxoplasmosis. Using mice deficient in IL-18 and IL-18R, we show that the IL-18 cytokine plays a pivotal role by limiting parasite replication to promote murine survival

Inflammasome sensor NLRP1 controls rat macrophage susceptibility to Toxoplasma gondii

Toxoplasma gondii is an intracellular parasite that infects a wide range of warm-blooded species. Rats vary in their susceptibility to this parasite. The Toxo1 locus conferring Toxoplasma resistance in rats was previously mapped to a region of chromosome 10 containing Nlrp1. This gene encodes an inflammasome sensor controlling macrophage sensitivity to anthrax lethal toxin (LT) induced rapid cell death (pyroptosis). We show here that rat strain differences in Toxoplasma infected macrophage sensitivity to pyroptosis, IL-1β/IL-18 processing, and inhibition of parasite proliferation are perfectly correlated with NLRP1 sequence, while inversely correlated with sensitivity to anthrax LT-induced cell death. Using recombinant inbred rats, SNP analyses and whole transcriptome gene expression studies, we narrowed the candidate genes for control of Toxoplasma-mediated rat macrophage pyroptosis to four genes, one of which was Nlrp1. Knockdown of Nlrp1 in pyroptosis-sensitive macrophages resulted in higher parasite replication and protection from cell death. Reciprocally, overexpression of the NLRP1 variant from Toxoplasma-sensitive macrophages in pyroptosis-resistant cells led to sensitization of these resistant macrophages. Our findings reveal Toxoplasma as a novel activator of the NLRP1 inflammasome in rat macrophages

Impact of Dietary Gluten on Regulatory T Cells and Th17 Cells in BALB/c Mice

Dietary gluten influences the development of type 1 diabetes (T1D) and a gluten-free (GF) diet has a protective effect on the development of T1D. Gluten may influence T1D due to its direct effect on intestinal immunity; however, these mechanisms have not been adequately studied. We studied the effect of a GF diet compared to a gluten-containing standard (STD) diet on selected T cell subsets, associated with regulatory functions as well as proinflammatory Th17 cells, in BALB/c mice. Furthermore, we assessed diet-induced changes in the expression of various T cell markers, and determined if changes were confined to intestinal or non-intestinal lymphoid compartments. The gluten-containing STD diet led to a significantly decreased proportion of γδ T cells in all lymphoid compartments studied, although an increase was detected in some γδ T cell subsets (CD8+, CD103+). Further, it decreased the proportion of CD4+CD62L+ T cells in Peyer's patches. Interestingly, no diet-induced changes were found among CD4+Foxp3+ T cells or CD3+CD49b+cells (NKT cells) and CD3−CD49b+ (NK) cells. Mice fed the STD diet showed increased proportions of CD4+CD45RBhigh+ and CD103+ T cells and a lower proportion of CD4+CD45RBlow+ T cells in both mucosal and non-mucosal compartments. The Th17 cell population, associated with the development of autoimmunity, was substantially increased in pancreatic lymph nodes of mice fed the STD diet. Collectively, our data indicate that dietary gluten influences multiple regulatory T cell subsets as well as Th17 cells in mucosal lymphoid tissue while fewer differences were observed in non-mucosal lymphoid compartments

COMMUNITY PARTICIPATORY SUSTAINABLE LAND MANAGEMENT BYELAW FORMULATION IN THE HIGHLANDS OF CENTRAL ETHIOPIA

Widespread adoption of sustainable land management (SLM) innovations by land users is considered key in addressing the rampant land degradation in the high rainfall and densely populated highlands of eastern and southern Africa. However, absence of enabling policy environments hamperes massive adoption of SLM innovations among rural communities. This paper presents the process and outcomes of a participatory approach for formulating and implementing SLM byelaws in the central highlands of Ethiopia. The participatory approach utilised three complementary tools, namely, stakeholder analysis, community needs assessment and policy dialogues. The stakeholder analysis revealed that several government institutions, non-government organisations (NOGs) and community groups promote SLM practices. Poor coordination among actors, top-down approach in planning and implementation, and limited capacity of communities hamperes SLM scaling up efforts. Stakeholder engagements culminates in establishing innovation platforms (IPs) at district and watershed levels tasked with coordinating SLM scaling up efforts. While the community needs assessment identified and prioritised SLM issues that needed to be resolved, the policy dialogue engaging IPs formulated three SLM byelaws and mechanisms for implementation.Une large adoption des innovations de la gestion durable des terres (SLM) est considérée comme une clé importante pour adresser le problème de la dégradation accrue des terres dans les hautes terres à pluviométrie élevée et densement peuplées de l’ Afrique de l’Est et du Sud. Par ailleurs, l’absence de politiques environnementales handicape l’adoption massive des innovations de SLM parmi les communautés rurales. Cet article présente le processus et les résultats d’une approche participative pour la formulation et l’exécution des lois de SLM dans les hautes terres de l’Ethiopie centrale. L’approche participative a utilisé trois voies complémentaires, dont l’analyse de partenaires, l’évaluation des besoins communautaires et le dialogue sur les politiques. L’analyse de partenaires a révélé que plusieurs institutions gouvernementales, organisations non gouvernementales (ONG) et groupes communautaires encouragent les pratiques des SLM. Une pauvre coordination parmi les acteurs, une approche de haut en bas dans la planification et l’exécution, et une capacité limitée des communautés handicapent les efforts fournis dans le SLM. L’engagement de partenaires culmine dans l’établissement des plateformes d’innovations (IPs) au niveau du district et du basin versant avec pour tâche la coordination des efforts d’innovation de SLM. Alors que l’évaluation des besoins communautaires a identifié et prioritisé les problèmes de SLM qui ont besoin d’être adressés, le dialogue sur les politiques ont formulé trois lois et mécanismes pour l’exécution de SLM