A LRRK2 GTP Binding Inhibitor, 68, Reduces LPS-Induced Signaling Events and TNF-α Release in Human Lymphoblasts.

Mutations in the leucine-rich repeat kinase-2 (LRRK2) gene cause autosomal-dominant Parkinson's disease (PD) and contribute to sporadic PD. Common genetic variation in LRRK2 modifies susceptibility to immunological disorders including Crohn's disease and leprosy. Previous studies have reported that LRRK2 is expressed in B lymphocytes and macrophages, suggesting a role for LRRK2 in immunological functions. In this study, we characterized the LRRK2 protein expression and phosphorylation using human lymphoblasts. Lipopolysaccharide (LPS), a proinflammatory agent, induced the increase of LRRK2 expression and kinase activities in human lymphoblasts in a time-dependent manner. Moreover, LPS activated the Toll-like receptor (TLR) signaling pathway, increased TRAF6/LRRK2 interaction, and elevated the phosphorylation levels of MAPK (JNK1/2, p38, and ERK1/2) and IkBα. Treatment with LRRK2 inhibitor 68 reduced LPS-induced TRAF6/LRRK2 interaction and MAPK and IkBα phosphorylation, thereby reducing TNF-α secretion. These results indicate that LRRK2 is actively involved in proinflammatory responses in human lymphoblasts, and inhibition of GTP binding by 68 results in an anti-inflammation effect against proinflammatory stimuli. These findings not only provide novel insights into the mechanisms of LRRK2-linked immune and inflammatory responses in B-cell-like lymphoblasts, but also suggest that 68 may also have potential therapeutic value for LRRK2-linked immunological disorders.

Features of the biochemistry of Mycobacterium smegmatis, as a possible model for Mycobacterium tuberculosis.

An alternate host for mycobacteria is Mycobacterium smegmatis which is used frequently. It is a directly budding eco-friendly organism not emulated as human infection. It is mainly useful for the investigation of various microorganisms in the sort of Mycobacteria in cell culture laboratories. Some Mycobacterium species groups that is normal, unsafe ailments, likely to Mycobacterium leprae, Mycobacterium tuberculosis and Mycobacterium bovis. At present, various laboratories are clean and culture this type of species to make an opinion that fascinating route of harmful Mycobacteria. This publication provides aggregate data on cell shape, genome studies, ecology, pathology and utilization of M. smegmatis.

Population Pharmacokinetic Model to Assess the Impact of Disease State on Thalidomide Pharmacokinetics.

A population pharmacokinetic (PPK) model to describe the pharmacokinetics of thalidomide in different patient populations was developed using data pooled from healthy subjects and patients with Hansen's disease, human immunodeficiency virus (HIV), and multiple myeloma (MM). The analysis data set had a total of 164 evaluable subjects who received various doses (50 to 400 mg) of oral thalidomide in single- and/or multiple-dose regimens. The plasma thalidomide concentrations were adequately described by a linear 1-compartment PPK model with first-order absorption and first-order elimination. Inclusion of MM as a covariate on apparent clearance (CL/F) accounted for 4.4% of the interindividual variability (IIV) of CL/F. Body weight as a covariate on CL/F and apparent volume of distribution (V/F) also improved model fitting slightly, accounting for 7.2% and 20% of IIV, respectively. Although inclusion of body weight and MM as covariates of CL/F and body weight on V/F improved the goodness of fit of the model in a statistically significant manner, the impact of this difference in CL/F is not considered clinically relevant. Other factors such as age, sex, race, creatinine clearance, and alanine transaminase had no effect on thalidomide pharmacokinetics. MM, HIV, and Hansen's disease have no clinically relevant effect on thalidomide disposition relative to healthy volunteers.

Differential Expression of IFN-γ, IL-10, TLR1, and TLR2 and Their Potential Effects on Downgrading Leprosy Reaction and Erythema Nodosum Leprosum.

Leprosy reactions are acute immunological events that occur during the evolution of chronic infectious disease causing neural damage and disabilities. A study using blood samples of 17 leprosy reaction patients and 17 reaction-free was carried out by means of associations between antigens, receptors, and expression of cytokines, using path analysis providing new insights into the immunological mechanisms involved in triggering leprosy reactions. Toll-like receptors (TLR) such as TLR1 and TLR2, presented balanced expression in the reaction-free multibacillary (MB) group (TLR1: 1.01 ± 0.23, TLR2: 1.22 ± 0.18; p = 0.267). On the other hand, downgrading type 1 reaction (T1R) (TLR1: 1.24 ± 0.17, TLR2: 2.88 ± 0.37; p = 0.002) and erythema nodosum leprosum (ENL) (TLR1: 1.93 ± 0.17, TLR2: 2.81 ± 0.15; p = 0.004) revealed an unbalance in relation to the expression of these receptors. When the path analysis was approached, it was noted that interleukin 10 (IL-10) expression showed a dependence relation with phenolic glycolipid I (PGL-I) in downgrading T1R (direct effect = 0.503 > residual effect = 0.364), whereas in ENL, such relationship occurred with lipoarabinomannan (LAM) (direct effect = 0.778 > residual effect = 0.280). On the contrary, in the reaction-free leprosy group, interferon-gamma (IFN-γ) levels were dependent on the association between TLR2 and TLR1 (0.8735). The high TLR2 expression associated with IL-10 levels, in the leprosy reaction groups, may be hypothetically related to the formation of TLR2/2 homodimers and/or TLR2/6 heterodimers linked to evasion mechanisms in downgrading reactions and pathophysiology of ENL.

Understanding "patient discharge in leprosy": a concept analysis. / Compreendendo a "alta em hanseníase": uma análise de conceito.

OBJECTIVE: To analyze the concept of patient discharge in leprosy. METHODS: Theoretical study guided in the methodological framework of concept analysis. A bibliographical survey was held from December 2015 to January 2016 using the following bases: SCOPUS, CINAHL, PubMed, LILACS, SCIELO and BDENF, by use of the descriptors "Leprosy" and "Patient Discharge", resulting in 13 studies. RESULTS: The following were identified as possible uses for the concept: discharge by cure, drug use discharge, bacteriological discharge and post-discharge. The attributes defined were completion of multidrug therapy, completion of multidrug therapy for paucibacillary leprosy, completion of multidrug therapy for multibacillary leprosy and cure from leprosy. The presence of an M. leprae infection, symptoms present in skin and peripheral nerves, diagnosis and treatment and leprosy reactions were identified as antecedents. Consequents were exclusion from the active leprosy record and continuity of health care. One case model and one opposing case were presented. CONCLUSIONS: The analysis broadened the concept "discharge in leprosy", providing other meanings than the clinical definition of multidrug therapy.

Overcoming clofazimine intrinsic toxicity: statistical modelling and characterization of solid lipid nanoparticles.

The aim of this work was to develop solid lipid nanoparticles (SLNs) loaded with clofazimine (CLZ) (SLNs-CLZ) to overcome its intrinsic toxicity and low water solubility, for oral drug delivery. A Box-Behnken design was constructed to unravel the relations between the independent variables in the selected responses. The optimized SLNs-CLZ exhibited the following properties: particle size ca 230 nm, zeta potential of -34.28 mV, association efficiency of 72% and drug loading of 2.4%, which are suitable for oral delivery. Further characterization included Fourier transformed infrared spectroscopy that confirmed the presence of the drug and the absence of chemical interactions. By differential scanning calorimetry was verified the amorphous state of CLZ. The storage stability studies ensured the stability of the systems over a period of 12 weeks at 4°C. In vitro cytotoxicity studies evidenced no effect of both drug-loaded and unloaded SLNs on MKN-28 gastric cells and on intestinal cells, namely Caco-2 and HT29-MTX cells up to 25 µg ml-1 in CLZ. Free CLZ solutions exhibited IC50 values of 16 and 20 µg ml-1 for Caco-2 and HT29-MTX cells, respectively. It can be concluded that the optimized system, designed considering important variables for the formulation of poorly soluble drugs, represents a promising platform for oral CLZ delivery.

Dapsone as a potential treatment option for Henoch-Schönlein Purpura (HSP).

Henoch-Schönlein Purpura (HSP, IgA vasculitis) is an immunoglobulin A (IgA) mediated disorder characterized by systemic vasculitis with variable presentation, frequently affecting the skin, mucous membrane, joints, kidneys, and rarely lungs and the central nervous system. Interestingly, enhanced production of interleukin-8 (IL-8) levels are found during active disease and increased levels have been reported in supernatants from human umbilical venous endothelial cells after stimulation with sera from patients affected by HSP. While corticosteroid therapy is currently the recommended treatment for HSP, dapsone, an anti-leprosy agent, has also recently been suggested to have therapeutic efficacy due to its ability to suppress IL-8. Moreover, in addition to IL-8 suppression, dapsone has been reported to exert various anti-inflammatory effects by inhibiting the generation of toxic free radicals, myeloperoxidase mediated halogenation that converts H2O2 to HOCl, leukocyte chemotaxis, production of tumor necrosis factor, and other anti-inflammatory molecules. This review aims to provide a solid hypothesis for the pathogenesis of vasculitis in HSP. Moreover, we highlight potential mechanistic actions of dapsone in hopes that dapsone may be considered as an alternative viable treatment for patients affected by HSP.

The Intergenic Recombinant HLA-B∗46:01 Has a Distinctive Peptidome that Includes KIR2DL3 Ligands.

HLA-B∗46:01 was formed by an intergenic mini-conversion, between HLA-B∗15:01 and HLA-C∗01:02, in Southeast Asia during the last 50,000 years, and it has since become the most common HLA-B allele in the region. A functional effect of the mini-conversion was introduction of the C1 epitope into HLA-B∗46:01, making it an exceptional HLA-B allotype that is recognized by the C1-specific natural killer (NK) cell receptor KIR2DL3. High-resolution mass spectrometry showed that HLA-B∗46:01 has a low-diversity peptidome that is distinct from those of its parents. A minority (21%) of HLA-B∗46:01 peptides, with common C-terminal characteristics, form ligands for KIR2DL3. The HLA-B∗46:01 peptidome is predicted to be enriched for peptide antigens derived from Mycobacterium leprae. Overall, the results indicate that the distinctive peptidome and functions of HLA-B∗46:01 provide carriers with resistance to leprosy, which drove its rapid rise in frequency in Southeast Asia.

Compreendendo a "alta em hanseníase": uma análise de conceito / Understanding "patient discharge in leprosy": a concept analysis

Resumo OBJETIVO Analisar o conceito de alta em hanseníase. MÉTODOS Estudo teórico pautado no referencial metodológico de análise de conceito. Realizou-se levantamento bibliográfico, de dezembro de 2015 a janeiro de 2016, nas bases SCOPUS, CINAHL, PUBMED, LILACS, SCIELO e BDENF, mediante uso dos descritores "Hanseníase" e "Alta do Paciente", obtendo-se 13 estudos. RESULTADOS Identificou-se alta por cura, alta medicamentosa, alta bacteriológica e pós-alta como possíveis usos do conceito. Os atributos definidos foram conclusão da poliquimioterapia, conclusão da poliquimioterapia para paucibacilares, conclusão da poliquimioterapia para multibacilares e cura da hanseníase. Como antecedentes, identificou-se infecção pelo M. leprae, acometimento de pele e de nervos periféricos, diagnóstico e tratamento e reações hansênicas. Saída do registro ativo de casos de hanseníase e continuidade de atenção em saúde foram os consequentes. Apresentou-se um caso modelo e um caso contrário. CONCLUSÕES A análise ampliou o conceito "alta em hanseníase", para além da clínica focada na poliquimioterapia.

Resumen OBJETIVO Analizar el concepto de alta lepra. MÉTODOS Análisis de concepto, propuesto por Walker y Avant. Literatura detenido en los meses de diciembre de 2015 y enero de 2016, las bases SCOPUS, CINAHL, PUBMED, LILACS, SCIELO y BDENF mediante el uso de descriptores "alta" del paciente asociados con el operador boleano AND, dando lugar a 13 estudios "lepra". RESULTADOS Se identificaron alta curación, drogas alta, alta bacteriológico y después del alta como posibles usos del concepto. Los atributos definidos eran finalización de la poliquimioterapia, la finalización de la poliquimioterapia para paucibacilar, la finalización de la poliquimioterapia para la curación de la lepra multibacilar y. Como antecedente, se identifico la infección por M. leprae, lapiel y La participación de los nervios periféricos, diagnóstico y tratamiento de las reacciones y la lepra. Activa La producción récord de casos de lepra, La continuidad del cuidado de la salud son consecuentes. CONCLUSIONES El término "alta lepra" se agranda, además de la terapia de múltiples fármacos.

Abstract OBJECTIVE To analyze the concept of patient discharge in leprosy. METHODS Theoretical study guided in the methodological framework of concept analysis. A bibliographical survey was held from December 2015 to January 2016 using the following bases: SCOPUS, CINAHL, PubMed, LILACS, SCIELO and BDENF, by use of the descriptors "Leprosy" and "Patient Discharge", resulting in 13 studies. RESULTS The following were identified as possible uses for the concept: discharge by cure, drug use discharge, bacteriological discharge and post-discharge. The attributes defined were completion of multidrug therapy, completion of multidrug therapy for paucibacillary leprosy, completion of multidrug therapy for multibacillary leprosy and cure from leprosy. The presence of an M. leprae infection, symptoms present in skin and peripheral nerves, diagnosis and treatment and leprosy reactions were identified as antecedents. Consequents were exclusion from the active leprosy record and continuity of health care. One case model and one opposing case were presented. CONCLUSIONS The analysis broadened the concept "discharge in leprosy", providing other meanings than the clinical definition of multidrug therapy.

Proposing a Compartmental Model for Leprosy and Parameterizing Using Regional Incidence in Brazil.

Hansen's disease (HD), or leprosy, is still considered a public health risk in much of Brazil. Understanding the dynamics of the infection at a regional level can aid in identification of targets to improve control. A compartmental continuous-time model for leprosy dynamics was designed based on understanding of the biology of the infection. The transmission coefficients for the model and the rate of detection were fit for each region using Approximate Bayesian Computation applied to paucibacillary and multibacillary incidence data over the period of 2000 to 2010, and model fit was validated on incidence data from 2011 to 2012. Regional variation was noted in detection rate, with cases in the Midwest estimated to be infectious for 10 years prior to detection compared to 5 years for most other regions. Posterior predictions for the model estimated that elimination of leprosy as a public health risk would require, on average, 44-45 years in the three regions with the highest prevalence. The model is easily adaptable to other settings, and can be studied to determine the efficacy of improved case finding on leprosy control.

Evaluation of a cross contamination model describing transfer of Salmonella spp. and Listeria monocytogenes during grinding of pork and beef.

In a previous study, a model was developed to describe the transfer and survival of Salmonella during grinding of pork (Møller, C.O.A., Nauta, M.J., Christensen, B.B., Dalgaard, P., Hansen, T.B., 2012. Modelling transfer of Salmonella typhimurium DT104 during simulation of grinding of pork. Journal of Applied Microbiology 112 (1), 90-98). The robustness of this model is now evaluated by studying its performance for predicting the transfer and survival of Salmonella spp. and Listeria monocytogenes during grinding of different types of meat (pork and beef), using two different grinders, different sizes and different numbers of pieces of meats to be ground. A total of 19 grinding trials were collected. Acceptable Simulation Zone (ASZ), visual inspection of the data, Quantitative Microbiological Risk Assessment (QMRA), as well as the Total Transfer Potential (TTP) were used as approaches to evaluate model performance and to access the quality of the cross contamination model predictions. Using the ASZ approach and considering that 70% of the observed counts have to be inside a defined acceptable zone of ±0.5 log10CFU per portion, it was found that the cross contamination parameters suggested by Møller et al. (2012) were not able to describe all 19 trials. However, for each of the collected grinding trials, the transfer event was well described when fitted to the model structure proposed by Møller et al. (2012). Parameter estimates obtained by fitting observed trials performed at different conditions, such as size and number of pieces of meat to be ground, may not be applied to describe cross contamination of unlike processing. Nevertheless, the risk estimates, as well as the TTP, revealed that the risk of disease may be reduced when the grinding of meat is performed in a grinder made of stainless steel (for all surfaces in contact with the meat), using a well-sharpened knife and holding at room temperatures lower than 4°C.

Leprosy as a model to understand cancer immunosurveillance and T cell anergy.

Leprosy is a disease caused by Mycobacterium leprae that presents on a spectrum of both clinical manifestations and T cell response. On one end of this spectrum, tuberculoid leprosy is a well-controlled disease, characterized by a cell-mediated immunity and immunosurveillance. On the opposite end of the spectrum, lepromatous leprosy is characterized by M. leprae proliferation and T cell anergy. Similar to progressive tumor cells, M. leprae escapes immunosurveillance in more severe forms of leprosy. The mechanisms by which M. leprae is able to evade the host immune response involve many, including the alterations of lipid droplets, microRNA, and Schwann cells, and involve the regulation of immune regulators, such as the negative checkpoint regulators CTLA-4, programmed death 1, and V-domain Ig suppressor of T cell activation-important targets in today's cancer immunotherapies. The means by which tumor cells become able to escape immunosurveillance through negative checkpoint regulators are evidenced by the successes of treatments, such as nivolumab and ipilimumab. Many parallels can be drawn between the immune responses seen in leprosy and cancer. Therefore, the understanding of how M. leprae encourages immune escape during proliferative disease states has potential to add to our understanding of cancer immunotherapy.

Genome sequence and plasmid transformation of the model high-yield bacterial cellulose producer Gluconacetobacter hansenii ATCC 53582.

Bacterial cellulose is a strong, highly pure form of cellulose that is used in a range of applications in industry, consumer goods and medicine. Gluconacetobacter hansenii ATCC 53582 is one of the highest reported bacterial cellulose producing strains and has been used as a model organism in numerous studies of bacterial cellulose production and studies aiming to increased cellulose productivity. Here we present a high-quality draft genome sequence for G. hansenii ATCC 53582 and find that in addition to the previously described cellulose synthase operon, ATCC 53582 contains two additional cellulose synthase operons and several previously undescribed genes associated with cellulose production. In parallel, we also develop optimized protocols and identify plasmid backbones suitable for transformation of ATCC 53582, albeit with low efficiencies. Together, these results provide important information for further studies into cellulose synthesis and for future studies aiming to genetically engineer G. hansenii ATCC 53582 for increased cellulose productivity.

Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of ß-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC). These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of peptidoglycan in the assembly of crystalline cellulose.

Sleep, Hansen's disease and the immune system--a not so harmonic triad.

Hansen's disease is one of the oldest skin diseases in the world characterized by a spectrum of clinical manifestations that are associated with stigmatization and poor quality of life. It is also considered a model disease for investigating the human immune system because of its association with immune reactions, which are thought to be a reflection of the host's immunological response, promoting intense cellular activity or humoral secretion. This relationship between the cellular and microbial components of skin and their regulation by local immune responses may be modulated by a currently neglected behavior: sleep. Recent studies have demonstrated that sleep deprivation may aggravate the progression of chronic dermatological diseases, which in turn can lead to a non-restorative sleep pattern. Indeed, sleep is essential for immune and skin integrity. Thus, we propose here a hypothesis linking Hansen's disease, sleep and immunity in a bidirectional relationship. Hansen's disease patients may demonstrate a worse sleep quality than the general population through the modulation of immunological environment; and sleep restriction, a hallmark of modern society, being a possible predictor of the disease progression.

Competition between phytoplankton and bacteria: exclusion and coexistence.

Resource-based competition between microorganisms species in continuous culture has been studied extensively both experimentally and theoretically, mostly for bacteria through Monod and Contois "constant yield" models, or for phytoplankton through the Droop "variable yield" models. For homogeneous populations of N bacterial species (Monod) or N phytoplanktonic species (Droop), with one limiting substrate and under constant controls, the theoretical studies indicated that competitive exclusion occurs: only one species wins the competition and displaces all the others (Armstrong and McGehee in Am Nat 115:151, 1980; Hsu and Hsu in SIAM J Appl Math 68:1600-1617, 2008). The winning species expected from theory is the one with the lowest "substrate subsistence concentration" s([star]), such that its corresponding equilibrium growth rate is equal to the dilution rate D. This theoretical result was validated experimentally with phytoplankton (Tilman and Sterner in Oecologia 61(2):197-200, 1984) and bacteria (Hansen and Hubell in Science 207(4438):1491-1493, 1980), and observed in a lake with microalgae (Tilman in Ecology 58(22):338-348, 1977). On the contrary for aggregating bacterial species described by a Contois model, theory predicts coexistence between several species (Grognard et al. in Discrete Contin Dyn Syst Ser B 8(1):73-93, 2007). In this paper we present a generalization of these results by studying a competition between three different types of microorganisms: planktonic (or free) bacteria (represented by a generalized Monod model), aggregating bacteria (represented by a Contois model) and free phytoplankton (represented by a Droop model). We prove that the outcome of the competition is a coexistence between several aggregating bacterial species with a free species of bacteria or phytoplankton, all the other free species being washed out. This demonstration is based mainly on the study of the substrate concentration's evolution caused by competition; it converges towards the lowest subsistence concentration s([star]), leading to three different types of competition outcomes: (1) the best free bacteria or phytoplankton competitor excludes all other species; (2) only some aggregating bacterial species coexist in the chemostat; (3) A coexistence between the single best free species, with one or several aggregating species.

A simple mathematical model that describes the growth of the area and the number of total and viable cells in yeast colonies.

UNLABELLED: We propose a model, based on the Gompertz equation, to describe the growth of yeasts colonies on agar medium. This model presents several advantages: (i) one equation describes the colony growth, which previously needed two separate ones (linear increase of radius and of the squared radius); (ii) a similar equation can be applied to total and viable cells, colony area or colony radius, because the number of total cells in mature colonies is proportional to their area; and (iii) its parameters estimate the cell yield, the cell concentration that triggers growth limitation and the effect of this limitation on the specific growth rate. To elaborate the model, area, total and viable cells of 600 colonies of Saccharomyces cerevisiae, Debaryomyces fabryi, Zygosaccharomyces rouxii and Rhodotorula glutinis have been measured. With low inocula, viable cells showed an initial short exponential phase when colonies were not visible. This phase was shortened with higher inocula. In visible or mature colonies, cell growth displayed Gompertz-type kinetics. It was concluded that the cells growth in colonies is similar to liquid cultures only during the first hours, the rest of the time they grow, with near-zero specific growth rates, at least for 3 weeks. SIGNIFICANCE AND IMPACT OF THE STUDY: Mathematical models used to predict microbial growth are based on liquid cultures data. Models describing growth on solid surfaces, highlighting the differences with liquids cultures, are scarce. In this work, we have demonstrated that a single Gompertz equation describes accurately the increase of the yeast colonies, up to the point where they reach their maximum size. The model can be used to quantify the differences in growth kinetics between solid and liquid media. Moreover, as all its parameters have biological meaning, it could be used to build secondary models predicting yeast growth on solid surfaces under several environmental conditions.

Three-dimensional in vitro models of granuloma to study bacteria-host interactions, drug-susceptibility, and resuscitation of dormant mycobacteria.

Mycobacterium tuberculosis, Mycobacterium leprae, Mycobacterium bovis, and Mycobacterium avium subsp. paratuberculosis can survive within host macrophages in a dormant state, encased within an organized aggregate of immune host cells called granuloma. Granulomas consist of uninfected macrophages, foamy macrophages, epithelioid cells, and T lymphocytes accumulated around infected macrophages. Within granulomas, activated macrophages can fuse to form multinucleated giant cells, also called giant Langhans cells. A rim of T lymphocytes surrounds the core, and a tight coat of fibroblast closes the structure. Several in vivo models have been used to study granuloma's structure and function, but recently developed in vitro models of granuloma show potential for closer observation of the early stages of host's responses to live mycobacteria. This paper reviews culture conditions that resulted in three-dimensional granulomas, formed by the adhesion of cell populations in peripheral blood mononuclear cells infected with mycobacteria. The similarities of these models to granulomas encountered in clinical specimens include cellular composition, granulomas' cytokine production, and cell surface antigens. A reliable in vitro dormancy model may serve as a useful platform to test whether drug candidates can kill dormant mycobacteria. Novel drugs that target dormancy-specific pathways may shorten the current long, difficult treatments necessary to cure mycobacterial diseases.

Tuberculosis and leprosy in Italy: new skeletal evidence.

Tuberculosis (TB) and leprosy are infections caused by Mycobacteria. This paper documents new skeletal evidence in Italy from the Iron Age site of Corvaro (Central Italy; 5th century BCE) and the Roman site of Palombara (Central Italy; 4th-5th century CE), and briefly reviews the extant evidence for these infections in Italy. The skeletal evidence for TB in Italy is more ancient than for leprosy, and is more common. The oldest evidence for both mycobacterial diseases is in the North of Italy, but this could be by chance, even if biomolecular models suggest a land route from the East to central Europe, especially for leprosy.

An in vitro model of Mycobacterium leprae induced granuloma formation.

BACKGROUND: Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae. In the pathogenesis of leprosy, granulomas play a key role, however, the mechanisms of the formation and maintenance of M. leprae granulomas are still not clearly understood. METHODS: To better understand the molecular physiology of M. leprae granulomas and the interaction between the bacilli and human host cells, we developed an in vitro model of human granulomas, which mimicked the in vivo granulomas of leprosy. Macrophages were differentiated from human monocytes, and infected with M. leprae, and then cultured with autologous human peripheral blood mononuclear cells (PBMCs). RESULTS: Robust granuloma-like aggregates were obtained only when the M. leprae infected macrophages were co-cultured with PBMCs. Histological examination showed M. leprae within the cytoplasmic center of the multinucleated giant cells, and these bacilli were metabolically active. Macrophages of both M1 and M2 types co-existed in the granuloma like aggregates. There was a strong relationship between the formation of granulomas and changes in the expression levels of cell surface antigens on macrophages, cytokine production and the macrophage polarization. The viability of M. leprae isolated from granulomas indicated that the formation of host cell aggregates benefited the host, but the bacilli also remained metabolically active. CONCLUSIONS: A simple in vitro model of human M. leprae granulomas was established using human monocyte-derived macrophages and PBMCs. This system may be useful to unravel the mechanisms of disease progression, and subsequently develop methods to control leprosy.