Newton001 Leishmaniasis in the Brazilian Amazon: the role of accessory microbiota in disease progression, pathobiology and immunity.
Lead Research Organisation:
University of Warwick
Department Name: Warwick Medical School
Abstract
Leishmania spp. infection represents a serious public health burden in Brazil, with 35,000 suspected cases annually. Disfiguring and occasionally fatal cutaneous and muco-cutaneous forms of Leishmaniasis are most common in the Amazon region of Brazil. Differential clinical severity and drug-resistance profiles are widely reported between patients. There is thus an urgent need to identify what factors might be responsible for different patient outcomes. Leishmania species and genotype have a role in defining disease severity, as does the host immune response. Less commonly considered is the role that secondary bacterial infections and commensal skin microbiota have in modulating pathology and immunity. In this multidisciplinary project we propose to use state-of-the-art techniques to monitor Leishmania lesion-associated microbial diversity and host immune response to reveal the factors that underlie cutaneous Leishmaniasis severity and progression in Amazonian Brazil.
Technical Summary
Leishmania are protozoan parasites that cause a variety of debilitating, disfiguring and fatal diseases in humans. Cutaneous leishmaniasis (CL) is transmitted during vector feeding. Infection progresses over the course of a few weeks or months. Lesions are painful, debilitating and carry a high risk of secondary infections. Untreated CL metastasizes in 25% of cases to become severe and potentially fatal mucocutaneous leishmaniasis (MCL). An effective immune response to CL is associated with the Th1 cell-mediated pathway. In addition to TNF-alpha and IFN-gamma, cytokines IL10&12 are associated with healing CL. In contrast IL4 and TNF-beta are associated with non-healing disease and pathology.
There is significant potential interaction between the skin microbiome and Leishmania infection. Mouse models of L. major suggest that skin microbiota have an autonomous role in tuning resident T-lymphocyte function. More broadly, commensal microbiota have an important role in the development and regulation of the immune system. While there is some evidence for a role of the microbiome in defining immunity to Leishmania challenge, the role of endogenous microbiota associated with CL lesions has not been explored. Secondary pathogenic bacterial infections are common in CL. However, recent analysis of the micriobiota associated with chronic wounds suggests a more complex role for microbiota. As such, commensal bacteria associated with wounds may modulate local immune function, interact with opportunistic pathogens (e.g. Stapholococcus aureus), and ultimately define healing efficiency.
The aim of this project is to evaluate the CL lesion-associated microbial metacommunity in a pilot cohort of 50 Brazilian clinical cases through diagnosis, treatment and cure in terms of immunity, disease progression and severity. Our goal is to evaluate the potential of microbiota to modulate immunity and/or as act as biomarkers for disease progression.
There is significant potential interaction between the skin microbiome and Leishmania infection. Mouse models of L. major suggest that skin microbiota have an autonomous role in tuning resident T-lymphocyte function. More broadly, commensal microbiota have an important role in the development and regulation of the immune system. While there is some evidence for a role of the microbiome in defining immunity to Leishmania challenge, the role of endogenous microbiota associated with CL lesions has not been explored. Secondary pathogenic bacterial infections are common in CL. However, recent analysis of the micriobiota associated with chronic wounds suggests a more complex role for microbiota. As such, commensal bacteria associated with wounds may modulate local immune function, interact with opportunistic pathogens (e.g. Stapholococcus aureus), and ultimately define healing efficiency.
The aim of this project is to evaluate the CL lesion-associated microbial metacommunity in a pilot cohort of 50 Brazilian clinical cases through diagnosis, treatment and cure in terms of immunity, disease progression and severity. Our goal is to evaluate the potential of microbiota to modulate immunity and/or as act as biomarkers for disease progression.
Planned Impact
N/A
Publications
Schwabl P
(2019)
Meiotic sex in Chagas disease parasite Trypanosoma cruzi.
in Nature communications
Schwabl P
(2021)
Colonization and genetic diversification processes of Leishmania infantum in the Americas.
in Communications biology
| Description | American cutaneous leishmaniasis is endemic in eighteen countries in Latin America with 26% of cases occurring in Brazil, principally in the Amazon Region. Cutaneous leishmaniasis (CL) is caused by several species of Leishmania parasites and is characterized by a spectrum of clinical manifestation, ranging from self-healing single lesions to chronic and metastatic lesions. An exaggerated immune response leading to excessive inflammation is associated with chronic infections. Among the factors associated with the aggravation of lesion inflammation is the presence of cytoplasmatic Leishmania RNA Virus 1 (LRV1) within Leishmania spp.. Bacteria have been shown to be essential for skin health and perturbations to the skin microbial community have the potential to contribute to altered skin immune function. Indeed, dysbiosis of the skin microbiome has been linked to several inflammatory diseases. To explore the microbiota of cutaneous leishmaniasis lesion we conducted an analysis of bacterial communities in healthy skin and cutaneous lesions of 62 subjects with suspected of Leishmania spp. infections. Of these subjects 52 were confirmed by parasitological exams. Ten lesions were Leishmania negative and were treated as non-leishmaniasis patients. Considering the role of LRV1 in the inflammatory process of leishmaniasis, the presence of LRV1 was investigated and considered in the analysis. Results Microbiome profiles were obtained from healthy skin and cutaneous lesions based on sequencing the 16S rRNA. Comparing overall community structures, Leishmaniasis lesion-associated microbiota was less diverse than healthy skin, a feature not observed when non-leishmaniasis lesion were compared to healthy skin. Specific microbial community compositions were not associated with different lesion types (i.e. non-leishmaniasis / leishmaniasis). Differential abundances of specific microbial genera were observed. Pseudomonas sp. represented almost 14% of the microbial community observed in non-leishmaniasis lesions and absent from leishmaniasis lesions or in healthy skin. An increase of Staphylococcus and decrease of Streptococcus was observed in samples from leishmaniasis patients (either lesions and healthy skin) when comparing with samples from non-leishmaniasis patients. Further differences in the abundance of microbial taxa were observed accordingly to the type of sample analysed, the time of evolution of leishmaniasis lesions, the place of residence of the patients and the presence of LRV1. Conclusion This study suggests that microbial communities on leishmaniasis lesion are distinct from those observed in other types of cutaneous lesions clinically confused with leishmaniasis and reinforce the idea of a microbiome profile associated to cutaneous leishmaniasis, characterized by lower bacteria diversity in lesions than in normal skin and a skin dysbiosis linked to Staphylococcus increase in any skin [ML1] site. Contradictories results were observed in different studies evaluating skin microbiome and CL, but these are probably related to differences in the environment. Despite the severe immune response often associated with LRV1-infected Leishmania, we found no evidence the virus does not influences the skin microbiome already impacted by Leishmania infection. |
| Exploitation Route | These results may provide a basis for further research into the impact of the microbiome on Leishmania lesions potentially leading to strategies to mitigate the impact of this disease. |
| Sectors | Healthcare |
| Description | Cuntaneous Leishmanisis is a debilating, disfiguring and occasionally fatal disease. Immune response to the paarasite is criticial to defining disease progresson. The aim of this project was to explore the impact of Lesihamania infection on the associated skin microbiome as well as link between the microbiome and disease severity. Our findings clearly indicate that infection with Leshmania has an impact on the lesion microbiome, as well as a more generalised effect on the the patient's healthy skin. These data provide the basis for further study to define the downstream impact microbiome peturbation on immune function, and hence understand any link with disease progression. Our findings are of particular relevance to clinician in Leishmania endemic countries, as well as elsewhere in the world. |
| Sector | Healthcare |
| Impact Types | Societal |
| Description | Wellcome Trust Institutional Strategic Support Fund (ISSF) Consolidator Funding |
| Amount | £7,000 (GBP) |
| Organisation | Wellcome Trust |
| Department | Wellcome Trust Bloomsbury Centre |
| Sector | Charity/Non Profit |
| Country | United Kingdom |
| Start | 03/2016 |
| End | 08/2016 |
| Title | Leishmania braziliensis lesion tissue collection |
| Description | We have collected a unique collection of Leishmania lesion tissue samples including multiple skin and lesion (cutaneous and muco-cutaneous) swabs from the same patient. |
| Type Of Material | Biological samples |
| Provided To Others? | No |
| Impact | The dataset is currently forming the basis of our study |
| Title | Panel of qPCR gene expression markers for Leishmania and human patients. |
| Description | To establish gene expression patterns of both parasite and patient withing the cutaneous and mucocutaneous lesion we have developed a panel of 96 qPCR targets with the aim of assessing expression profiles associated with disease progression. |
| Type Of Material | Technology assay or reagent |
| Provided To Others? | No |
| Impact | We are in the process of applying this panel of markers to our data |
| Description | FIOCRUZ, Brazil, Universities of Warwick and Glasgow |
| Organisation | Oswaldo Cruz Foundation (Fiocruz) |
| Country | Brazil |
| Sector | Public |
| PI Contribution | The project involves a new and close collaboration between two UK research institutions and two branches of FIOCRUZ in Brazil (Rio and Rhondonia). The UK research partners have made two collaborative visits to establish and monitor the progress of the project . |
| Collaborator Contribution | Two Brazilian research degree students have visited the UK partners. First to take part in a microbial metasequencing workshop. Subsequently one research students has made two extended visits (3 months) to the UK to undertake research and undergo training is aspects of the project. |
| Impact | Research and training outputs include: 1) Training in microbial metasequencing and host transcriptional profiling. 2) A panel of 100 microbiome and tissue samples from a cohort of Leishmania patients in Norther Brazil 3) Microbial metasequence data from the above cohort of patients 4) Patient lesion gene expression profile data from the above cohort |
| Start Year | 2015 |
| Description | FIOCRUZ, Brazil, Universities of Warwick and Glasgow |
| Organisation | University of Glasgow |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | The project involves a new and close collaboration between two UK research institutions and two branches of FIOCRUZ in Brazil (Rio and Rhondonia). The UK research partners have made two collaborative visits to establish and monitor the progress of the project . |
| Collaborator Contribution | Two Brazilian research degree students have visited the UK partners. First to take part in a microbial metasequencing workshop. Subsequently one research students has made two extended visits (3 months) to the UK to undertake research and undergo training is aspects of the project. |
| Impact | Research and training outputs include: 1) Training in microbial metasequencing and host transcriptional profiling. 2) A panel of 100 microbiome and tissue samples from a cohort of Leishmania patients in Norther Brazil 3) Microbial metasequence data from the above cohort of patients 4) Patient lesion gene expression profile data from the above cohort |
| Start Year | 2015 |
| Description | FIOCRUZ, Brazil, Universities of Warwick and Glasgow |
| Organisation | University of Warwick |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | The project involves a new and close collaboration between two UK research institutions and two branches of FIOCRUZ in Brazil (Rio and Rhondonia). The UK research partners have made two collaborative visits to establish and monitor the progress of the project . |
| Collaborator Contribution | Two Brazilian research degree students have visited the UK partners. First to take part in a microbial metasequencing workshop. Subsequently one research students has made two extended visits (3 months) to the UK to undertake research and undergo training is aspects of the project. |
| Impact | Research and training outputs include: 1) Training in microbial metasequencing and host transcriptional profiling. 2) A panel of 100 microbiome and tissue samples from a cohort of Leishmania patients in Norther Brazil 3) Microbial metasequence data from the above cohort of patients 4) Patient lesion gene expression profile data from the above cohort |
| Start Year | 2015 |