Development of Anxiolytic and Depression-like Behavior in Mice Infected with Mycobacterium lepraemurium.

Murine leprosy is a systemic infectious disease of mice caused by Mycobacterium lepraemurium (MLM) in which the central nervous system (CNS) is not infected; nevertheless, diseased animals show measurable cognitive alterations. For this reason, in this study, we explored the neurobehavioral changes in mice chronically infected with MLM. BALB/c mice were infected with MLM, and 120 days later, the alterations in mice were evaluated based on immunologic, histologic, endocrine, neurochemical, and behavioral traits. We found increases in the levels of IL-4 and IL-10 associated with high bacillary loads. We also found increase in the serum levels of corticosterone, epinephrine, and norepinephrine in the adrenal gland, suggesting neuroendocrine deregulation. Mice exhibited depression-like behavior in the tail suspension and forced swimming tests and anxiolytic behavior in the open field and elevated plus maze tests. The neurobehavioral alterations of mice were correlated with the histologic damage in the prefrontal cortex, ventral hippocampus, and amygdala, as well as with a blood-brain barrier disruption in the hippocampus. These results reveal an interrelated response of the neuroimmune--endocrinological axis in unresolved chronic infections that result in neurocognitive deterioration.

Reverse vaccinology and subtractive genomics approaches for identifying common therapeutics against Mycobacterium leprae and Mycobacterium lepromatosis

Mycobacterium leprae and Mycobacterium lepromatosis are gram-positive bacterial pathogens and the causative agents of leprosy in humans across the world. The elimination of leprosy cannot be achieved by multidrug therapy alone, and highlights the need for new tools and drugs to prevent the emergence of new resistant strains. Methods In this study, our contribution includes the prediction of vaccine targets and new putative drugs against leprosy, using reverse vaccinology and subtractive genomics. Six strains of Mycobacterium leprae and Mycobacterium lepromatosis (4 and 2 strains, respectively) were used for comparison taking Mycobacterium leprae strain TN as the reference genome. Briefly, we used a combined reverse vaccinology and subtractive genomics approach. Results As a result, we identified 12 common putative antigenic proteins as vaccine targets and three common drug targets against Mycobacterium leprae and Mycobacterium lepromatosis. Furthermore, the docking analysis using 28 natural compounds with three drug targets was done. Conclusions The bis-naphthoquinone compound Diospyrin (CID 308140) obtained from indigenous plant Diospyros spp. showed the most favored binding affinity against predicted drug targets, which can be a candidate therapeutic target in the future against leprosy.(AU)

Functional biomarker signatures of circulating T-cells and its association with distinct clinical status of leprosy patients and their respective household contacts.

BACKGROUND: Leprosy is a chronic infectious disease classified into two subgroups for therapeutic purposes: paucibacillary (PB) and multibacillary (MB), closely related to the host immune responses. In this context it is noteworthy looking for immunological biomarkers applicable as complementary diagnostic tools as well as a laboratorial strategy to follow-up leprosy household contacts. METHODS: The cross-sectional study enrolled 49 participants, including 19 patients and 30 healthy controls. Peripheral blood mononuclear cells (PBMC) were isolated and incubated in the presence of Mycobacterium leprae bacilli. The cells were prepared for surface (CD4+ and CD8+) and intracytoplasmic cytokine staining (IFN-γ, IL-4 and IL-10). Multiple comparisons amongst groups were carried out by ANOVA, Kruskal-Wallis, Student T or Mann-Whitney test. Comparative analysis of categorical variables was performed by Chi-square. Functional biomarker signature analysis was conducted using the global median values for each biomarker index as the cut-off edge to identify the proportion of subjects with high biomarker levels. RESULTS: The cytokine signature analysis demonstrated that leprosy patients presented a polyfunctional profile of T-cells subsets, with increased frequency of IFN-γ+ T-cell subsets along with IL-10+ and IL-4+ from CD4+ T-cells, as compared to health Controls (Venn diagram report). Moreover, statistical analysis was carried out using parametric or non-parametric variance analysis followed by pairwise multiple comparisons, according to the data normality distribution. L(PB) displayed a polyfunctional profile characterized by enhanced percentage of IFN-γ+, IL-10+ and IL-4+ produced by most T-cell subsets, as compared to L(MB) that presented a more restricted cytokine functional profile mediated by IL-10+ and IL-4+ T-cells with minor contribution of IFN-γ produced by CD4+ T-cells. Noteworthy was that HHC(MB) exhibited enhanced frequency of IFN-γ+ T-cells, contrasting with HHC(PB) that presented a cytokine profile limited to IL-10 and IL-4. CONCLUSIONS: Our data demonstrated that L(PB) displayed enhanced percentage of IFN-γ+, IL-10+ and IL-4+ as compared to L(MB) that presented functional profile mediated by IL-10+ and IL-4+ T-cells and HHC(MB) exhibited enhanced frequency of IFN-γ+ T-cells, contrasting with HHC(PB). Together, our findings provide additional immunological features associated with leprosy and household contacts. These data provide evidence that biomarkers of immune response can be useful complementary diagnostic/prognostic tools as well as insights that household contacts should be monitored to access putative subclinical infection.

Effect of dialyzable leukocyte extract, sodium butyrate, and valproic acid in the development of anergy in murine leprosy.

Background: Murine leprosy is a chronic granulomatous disease caused by Mycobacterium lepraemurium (MLM) in mice and rats. The disease evolves with the development of cellular anergy that impedes the production of interferon gamma (IFNγ), tumor necrosis factor-alpha (TNFα), and nitric oxide (NO) required to kill the microorganism. In this study we investigated whether histone deacetylase inhibitors (HDACi) (valproic acid and sodium butyrate [NaB]) and the immunomodulator transfer factor in dialyzable leukocyte extracts (DLE) can prevent anergy in murine leprosy. Methods: Five groups of six Balb/c mice were intraperitoneally inoculated with 2 × 107 MLM. Thirty-days post inoculation, treatment was started; one group received no treatment, one was treated with rifampicin-clofazimine (R-C), one with sodium valproate (VPA), one with NaB, and one with DLE. The animals were monitored for the evidence of disease for 96 days. After euthanasia, their spleens were removed and processed for histologic, bacteriologic, and cytokine studies. Results: R-C completely controlled the ongoing disease. DLE and NaB significantly reduced the development of lesions, including granuloma size and the number of bacilli; VPA was less effective. DLE, NaB, and VPA reverted the anergic condition in diverse grades and allowed the expression of IFNγ, TNFα, and inducible NO synthase, also in diverse grades. Conclusion: Anergy in leprosy and murine leprosy allows disease progression. In this study, anergy was prevented, in significant degree, by DLE (an immunomodulator) and NaB (HDACi). VPA was less effective. These results suggest potential beneficial effects of DLE and NaB in the ancillary treatment of leprosy.

Late leprosy reaction presenting as erythema multiforme-like erythema nodosum leprosum with underlying rifampicin resistance and its potential implications.

Erythema multiforme (EM)-like erythema nodosum leprosum (ENL) is a rare atypical presentation, and its late appearance after the completion of multidrug therapy (MDT) is unusual. We describe the case of a lepromatous leprosy patient who after the completion of MDT presented to us with late EM-like ENL and was found to be resistant to rifampicin. We discuss the implications of this finding and the potential role of resistant bacilli in causing reactions with atypical presentations.

Expansion and suppressive capacity of regulatory T cells isolated from patients across the leprosy spectrum: a pilot study.

Knowledge of the role of Tregs in the immunopathogenesis of the different clinical outcomes within the leprosy spectrum remains limited due to the lack of studies directly assessing their suppression capacity. We thus tested a protocol to expand Tregs from the peripheral blood of patients across the leprosy spectrum and analyzed their suppressive capacity in autologous TCD4+ responses. Results of these pilot assays show that Tregs can be expanded and exert suppressive capacity, but also that their rate of expansion and suppressive capacity are influenced by the patient's clinical classification, suggesting that they possibly retain some in vivo characteristics.

Aspectos clínicos y epidemiológicos en pacientes timorenses con enfermedad de Hansen / Clinical and epidemiological aspects in Timor patients with the Hansen disease

Se realizó un estudio observacional, descriptivo y transversal de 14 pacientes con lepra, diagnosticados y atendidos en la consulta de Dermatología del Hospital Nacional Guido Valadares, en Dili, Timor Oriental, de julio a diciembre del 2015, con vistas a caracterizarles y describir algunos aspectos clínicos y epidemiológicos de la enfermedad. En la serie se obtuvo una mayor frecuencia de pacientes en el grupo etario de 26 a 35 años y del sexo masculino, la forma clínica predominante fue la multibacilar y el tiempo de evolución de los síntomas hasta que fuera establecido el diagnóstico fue de menos de un año. Igualmente, en la mayoría existieron reacciones agudas, principalmente de tipo II o eritema nudoso leproso, y diferentes grados de discapacidad.

An observational, descriptive and cross-sectional study of 14 patients with leprosy, diagnosed and assisted in the Dermatology Service of Guido Valadares National Hospital, in Dili, Timor Lester was carried out from July to December, 2015, with the aim of characterizing them and to describe some clinical and epidemiological aspects of the disease. In the series a higher frequency of patient was obtained in the age group 26 to 35 years and of the male sex, the predominant clinical form was the multibacilar and the time of clinical course of the symptoms up to reaching the diagnosis was shorter than a year. Equally, in most of them acute reactions were presented, mainly of type II or from the erythema leprosy group, and different degrees of inability.

Aspectos clínicos y epidemiológicos en pacientes timorenses con enfermedad de Hansen / Clinical and epidemiological aspects in Timor patients with the Hansen disease

Se realizó un estudio observacional, descriptivo y transversal de 14 pacientes con lepra, diagnosticados y atendidos en la consulta de Dermatología del Hospital Nacional Guido Valadares, en Dili, Timor Oriental, de julio a diciembre del 2015, con vistas a caracterizarles y describir algunos aspectos clínicos y epidemiológicos de la enfermedad. En la serie se obtuvo una mayor frecuencia de pacientes en el grupo etario de 26 a 35 años y del sexo masculino, la forma clínica predominante fue la multibacilar y el tiempo de evolución de los síntomas hasta que fuera establecido el diagnóstico fue de menos de un año. Igualmente, en la mayoría existieron reacciones agudas, principalmente de tipo II o eritema nudoso leproso, y diferentes grados de discapacidad(AU)

An observational, descriptive and cross-sectional study of 14 patients with leprosy, diagnosed and assisted in the Dermatology Service of Guido Valadares National Hospital, in Dili, Timor Lester was carried out from July to December, 2015, with the aim of characterizing them and to describe some clinical and epidemiological aspects of the disease. In the series a higher frequency of patient was obtained in the age group 26 to 35 years and of the male sex, the predominant clinical form was the multibacilar and the time of clinical course of the symptoms up to reaching the diagnosis was shorter than a year. Equally, in most of them acute reactions were presented, mainly of type II or from the erythema leprosy group, and different degrees of inability(AU)

Human antimicrobial cytotoxic T lymphocytes, defined by NK receptors and antimicrobial proteins, kill intracellular bacteria.

Human CD8+ cytotoxic T lymphocytes (CTLs) contribute to antimicrobial defense against intracellular pathogens through secretion of cytotoxic granule proteins granzyme B, perforin, and granulysin. However, CTLs are heterogeneous in the expression of these proteins, and the subset(s) responsible for antimicrobial activity is unclear. Studying human leprosy, we found that the subset of CTLs coexpressing all three cytotoxic molecules is increased in the resistant form of the disease, can be expanded by interleukin-15 (IL-15), and is differentiated from naïve CD8+ T cells by Langerhans cells. RNA sequencing analysis identified that these CTLs express a gene signature that includes an array of surface receptors typically expressed by natural killer (NK) cells. We determined that CD8+ CTLs expressing granzyme B, perforin, and granulysin, as well as the activating NK receptor NKG2C, represent a population of "antimicrobial CTLs" (amCTLs) capable of T cell receptor (TCR)-dependent and TCR-independent release of cytotoxic granule proteins that mediate antimicrobial activity.

[Feline leprosy in a 5-month-old male cat in Germany]. / Feline Lepra bei einem 5 Monate alten Kater in Deutschland.

A 5-month-old, male, 4 kg European shorthair cat presented with ulcera ted cutaneous nodules in many areas over its entire body. The serological results for feline immunodeficiency virus and the feline leukaemia virus were negative. Following detection of acid-proof bacilli in histological examination of three skin biopsies, the diagnosis of mycobacteriosis of the skin was made. Polymerase chain reaction revealed the presence of Mycobacteriumlepraemurium. After surgical excision of all cutaneous nodules and a 14.5-week antibiotic therapy with Rifampicin and Clarithromycin, the cat was classified as being cured. During the observation period of 1 year after the end of the therapy, no relapse occurred.

Chronic infection with Mycobacterium lepraemurium induces alterations in the hippocampus associated with memory loss.

Murine leprosy, caused by Mycobacterium lepraemurium (MLM), is a chronic disease that closely resembles human leprosy. Even though this disease does not directly involve the nervous system, we investigated a possible effect on working memory during this chronic infection in Balb/c mice. We evaluated alterations in the dorsal region of the hippocampus and measured peripheral levels of cytokines at 40, 80, and 120 days post-infection. To evaluate working memory, we used the T-maze while a morphometric analysis was conducted in the hippocampus regions CA1, CA2, CA3, and dentate gyrus (DG) to measure morphological changes. In addition, a neurochemical analysis was performed by HPLC. Our results show that, at 40 days post-infection, there was an increase in the bacillary load in the liver and spleen associated to increased levels of IL-4, working memory deterioration, and changes in hippocampal morphology, including degeneration in the four subregions analyzed. Also, we found a decrease in neurotransmitter levels at the same time of infection. Although MLM does not directly infect the nervous system, these findings suggest a possible functional link between the immune system and the central nervous system.

Insights from the Genome Sequence of Mycobacterium lepraemurium: Massive Gene Decay and Reductive Evolution.

Mycobacterium lepraemurium is the causative agent of murine leprosy, a chronic, granulomatous disease similar to human leprosy. Due to the similar clinical manifestations of human and murine leprosy and the difficulty of growing both bacilli axenically, Mycobacterium leprae and M. lepraemurium were once thought to be closely related, although it was later suggested that M. lepraemurium might be related to Mycobacterium avium In this study, the complete genome of M. lepraemurium was sequenced using a combination of PacBio and Illumina sequencing. Phylogenomic analyses confirmed that M. lepraemurium is a distinct species within the M. avium complex (MAC). The M. lepraemurium genome is 4.05 Mb in length, which is considerably smaller than other MAC genomes, and it comprises 2,682 functional genes and 1,139 pseudogenes, which indicates that M. lepraemurium has undergone genome reduction. An error-prone repair homologue of the DNA polymerase III α-subunit was found to be nonfunctional in M. lepraemurium, which might contribute to pseudogene formation due to the accumulation of mutations in nonessential genes. M. lepraemurium has retained the functionality of several genes thought to influence virulence among members of the MAC.IMPORTANCEMycobacterium lepraemurium seems to be evolving toward a minimal set of genes required for an obligatory intracellular lifestyle within its host, a niche seldom adopted by most mycobacteria, as they are free-living. M. lepraemurium could be used as a model to elucidate functions of genes shared with other members of the MAC. Its reduced gene set can be exploited for studying the essentiality of genes in related pathogenic species, which might lead to discovery of common virulence factors or clarify host-pathogen interactions. M. lepraemurium can be cultivated in vitro only under specific conditions and even then with difficulty. Elucidating the metabolic (in)capabilities of M. lepraemurium will help develop suitable axenic media and facilitate genetic studies.

Feline leprosy due to Mycobacterium lepraemurium.

OBJECTIVES: This paper, the second in a series of three on 'feline leprosy', provides a detailed description of disease referable to Mycobacterium lepraemurium, the most common cause of feline leprosy worldwide. METHODS: Cases were sourced retrospectively and prospectively for this observational study, describing clinical, geographical and molecular microbiological data for cats definitively diagnosed with M lepraemurium infection. RESULTS: A total of 145 cases of feline leprosy were scrutinised; 114 'new' cases were sourced from the Victorian Infectious Diseases Reference Laboratory records, veterinary pathology laboratories or veterinarians, and 31 cases were derived from six published studies. Sixty-five cats were definitively diagnosed with M lepraemurium infection. Typically, cats were 1-3 years of age when first infected, with a male gender predilection. Affected cats were generally systemically well. All had outdoor access. Lesions tended to consist of one or more cutaneous/subcutaneous nodules, typically located on the head and/or forelimbs, possibly reflecting the most likely locations for a rodent bite as the site of inoculation for organisms. Nodules had the propensity to ulcerate at some stage in the clinical course. The cytological and histological picture varied from tuberculoid, with relatively low bacterial numbers, to lepromatous with moderate to high bacterial numbers. Treatment was varied, although most cats underwent surgical resection of lesions with adjunctive medical therapy, most often using a combination of oral clarithromycin and rifampicin. Prognosis for recovery was generally good, and in two cases there was spontaneous remission without the requirement for medical intervention. Untreated cats continued to enjoy an acceptable quality of life despite persistence of the disease, which extended locally but had no apparent tendency to disseminate to internal organs. CONCLUSIONS AND RELEVANCE: M lepraemurium causes high bacterial index (lepromatous) or low bacterial index (tuberculoid) feline leprosy. The infection typically causes nodules of the skin and/or subcutis (which tend towards ulceration) on the head and/or forelimbs. The disease usually has an indolent clinical course and infected cats have a generally favourable response to therapeutic interventions, with rare cases undergoing spontaneous resolution. Genomic analysis may yield clues as to the environmental niche and culture requirements of this elusive organism. Prospective treatment trials and/or additional drug susceptibility testing in specialised systems would further inform treatment recommendations.

Mycobacterium lepraemurium uses TLR-6 and MR, but not lipid rafts or DC-sign, to gain access into mouse macrophages.

OBJECTIVE/BACKGROUND: Mycobacterium lepraemurium (MLM), the etiologic agent of murine leprosy, is an intracellular parasite of macrophages; the mechanism used by this bacterium to enter macrophages is not known. The fate of the MLM phagosome inside macrophages is also unknown. This study was conducted to investigate how MLM enters macrophages and to define the maturation process of MLM phagosome inside macrophages. MATERIALS AND METHODS: Peritoneal macrophages were incubated in the presence of mannan-bovine serum albumin (BSA), and antibodies to known macrophage receptors, including, anti-FcγRIII/RII (anti-CD16/32), anti-CD35 (anti-CR1), anti-TLR2, anti-TLR4, anti-TLR6, anti-CD14, and anti-dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN). Then, macrophages were challenged with Iris Fuchsia-stained MLM, at a multiplicity of infection of 50:1. The blocking effect of the antibodies (and mannan-BSA) used was analyzed using direct microscopy and flow cytometry. The maturation process of MLM phagosomes was visualized by their interaction with antibodies to Rab5, Rab7, proton ATPase, and cathepsin D, by confocal microscopy. RESULTS: Only mannan-BSA and anti-TLR6 antibody significantly blocked the entry of MLM into macrophages. None of the other antibodies, including that for DC-SIGN, meaningfully inhibited the endocytic process. We also found that MLM is a fusiogenic mycobacterium. This was deduced from the orderly association of MLM phagosomes with Rab5, Rab7, Proton ATPase, and lysosomes (cathepsin D). CONCLUSION: Fusion of MLM phagosomes with lysosomes seems to be a necessary event for the intracellular multiplication of MLM; similar to Mycobacterium leprae, this microorganism hardly grows on artificial, synthetic, bacteriologic media.

Scabies Among Elderly Korean Patients with Histories of Leprosy.

A scabies epidemic, traced by the hospital-based surveillance system, was reported in a Korean leprosarium. A total of 200 symptomatic cases were found during 2012-2014 among 570 elderly former leprosy patients. Most of cases were classic type scabies (87%) and aged 75 years and older (72%). Surveillance system for early diagnosis and prompt intervention was applied and the scabies epidemic was controlled effectively in this long-term care facility.

Integrative analyses of leprosy susceptibility genes indicate a common autoimmune profile.

BACKGROUND: Leprosy is an ancient chronic infection in the skin and peripheral nerves caused by Mycobacterium leprae. The development of leprosy depends on genetic background and the immune status of the host. However, there is no systematic view focusing on the biological pathways, interaction networks and overall expression pattern of leprosy-related immune and genetic factors. OBJECTIVES: To identify the hub genes in the center of leprosy genetic network and to provide an insight into immune and genetic factors contributing to leprosy. METHODS: We retrieved all reported leprosy-related genes and performed integrative analyses covering gene expression profiling, pathway analysis, protein-protein interaction network, and evolutionary analyses. RESULTS: A list of 123 differentially expressed leprosy related genes, which were enriched in activation and regulation of immune response, was obtained in our analyses. Cross-disorder analysis showed that the list of leprosy susceptibility genes was largely shared by typical autoimmune diseases such as lupus erythematosus and arthritis, suggesting that similar pathways might be affected in leprosy and autoimmune diseases. Protein-protein interaction (PPI) and positive selection analyses revealed a co-evolution network of leprosy risk genes. CONCLUSIONS: Our analyses showed that leprosy associated genes constituted a co-evolution network and might undergo positive selection driven by M. leprae. We suggested that leprosy may be a kind of autoimmune disease and the development of leprosy is a matter of defect or over-activation of body immunity.

Successive Intramuscular Boosting with IFN-Alpha Protects Mycobacterium bovis BCG-Vaccinated Mice against M. lepraemurium Infection.

Leprosy caused by Mycobacterium leprae primarily affects the skin and peripheral nerves. As a human infectious disease, it is still a significant health and economic burden on developing countries. Although multidrug therapy is reducing the number of active cases to approximately 0.5 million, the number of cases per year is not declining. Therefore, alternative host-directed strategies should be addressed to improve treatment efficacy and outcome. In this work, using murine leprosy as a model, a very similar granulomatous skin lesion to human leprosy, we have found that successive IFN-alpha boosting protects BCG-vaccinated mice against M. lepraemurium infection. No difference in the seric isotype and all IgG subclasses measured, neither in the TH1 nor in the TH2 type cytokine production, was seen. However, an enhanced iNOS/NO production in BCG-vaccinated/i.m. IFN-alpha boosted mice was observed. The data provided in this study suggest a promising use for IFN-alpha boosting as a new prophylactic alternative to be explored in human leprosy by targeting host innate cell response.

Induction and treatment of anergy in murine leprosy.

Leprosy is a disease consisting of a spectrum of clinical, bacteriological, histopathological and immunological manifestations. Tuberculoid leprosy is frequently recognized as the benign polar form of the disease, while lepromatous leprosy is regarded as the malignant form. The different forms of leprosy depend on the genetic and immunological characteristics of the patient and on the characteristics of the leprosy bacillus. The malignant manifestations of lepromatous leprosy result from the mycobacterial-specific anergy that develops in this form of the disease. Using murine leprosy as a model of anergy in this study, we first induced the development of anergy to Mycobacterium lepraemurium (MLM) in mice and then attempted to reverse it by the administration of dialysable leucocyte extracts (DLE) prepared from healthy (HLT), BCG-inoculated and MLM-inoculated mice. Mice inoculated with either MLM or BCG developed a robust cell-mediated immune response (CMI) that was temporary in the MLM-inoculated group and long-lasting in the BCG-inoculated group. DLE were prepared from the spleens of MLM- and BCG-inoculated mice at the peak of CMI. Independent MLM intradermally-inoculated groups were treated every other day with HLT-DLE, BCG-DLE or MLM-DLE, and the effect was documented for 98 days. DLE administered at a dose of 1.0 U (1 × 10(6) splenocytes) did not affect the evolution of leprosy, while DLE given at a dose of 0.1 U showed beneficial effects regardless of the DLE source. The dose but not the specificity of DLE was the determining factor for reversing anergy.