Effect of IL-17A on the immune response to pulmonary tuberculosis induced by high- and low-virulence strains of Mycobacterium bovis.

Tuberculosis (TB) is an infectious, chronic, and progressive disease occurring globally. Human TB is caused mainly by Mycobacterium tuberculosis (M. tuberculosis), while the main causative agent of bovine TB is Mycobacterium bovis (M. bovis). The latter is one of the most important cattle pathogens and is considered the main cause of zoonotic TB worldwide. The mechanisms responsible for tissue damage (necrosis) during post-primary TB remain elusive. Recently, IL-17A was reported to be important for protection against M. tuberculosis infection, but it is also related to the production of an intense inflammatory response associated with necrosis. We used two M. bovis isolates with different levels of virulence and high IL-17A production to study this important cytokine's contrasting functions in a BALB/c mouse model of pulmonary TB. In the first part of the study, the gene expression kinetics and cellular sources of IL-17A were determined by real time PCR and immunohistochemistry respectively. Non-infected lungs showed low production of IL-17A, particularly by the bronchial epithelium, while lungs infected with the low-virulence 534 strain showed high IL-17A expression on Day 3 post-infection, followed by a decrease in expression in the early stage of the infection and another increase during late infection, on Day 60, when very low bacillary burdens were found. In contrast, infection with the highly virulent strain 04-303 induced a peak of IL-17A expression on Day 14 of infection, 1 week before extensive pulmonary necrosis was seen, being lymphocytes and macrophages the most important sources. In the second part of the study, the contribution of IL-17A to immune protection and pulmonary necrosis was evaluated by suppressing IL-17A via the administration of specific blocking antibodies. Infection with M. bovis strain 534 and treatment with IL-17A neutralizing antibodies did not affect mouse survival but produced a significant increase in bacillary load and a non-significant decrease in inflammatory infiltrate and granuloma area. In contrast, mice infected with the highly virulent 04-303 strain and treated with IL-17A blocking antibodies showed a significant decrease in survival, an increase in bacillary loads on Day 24 post-infection, and significantly more and earlier necrosis. Our results suggest that high expression of IL-17A is more related to protection than necrosis in a mouse model of pulmonary TB induced by M. bovis strains.

Necrosis plays a role in the concentration of mycobacterial antigens in granulomas from Mycobacterium bovis naturally infected cattle.

The dynamics that develop between cells and molecules in the host against infection by Mycobacterium bovis, leads to the formation of granulomas mainly present in the lungs and regional lymph nodes in cattle. Cell death is one of the main features in granuloma organization, however, it has not been characterized in granulomatous lesions caused by M. bovis. In this study we aimed to identify the profiles of cell death in the granuloma stages and its relationship with the accumulation of bacteria. We identified necrosis, activated caspase-3, LC3B/p62 using immunohistochemistry and digital pathology analysis on 484 granulomatous lesions in mediastinal lymph nodes from 23 naturally infected cattle. Conclusions: greater amounts of mycobacterial antigens were identified in granulomas from calves compared with adult cattle. The highest percentage of necrosis and quantity of mycobacterial antigens were identified in granuloma stages (III/IV) from adults. The LC3B/p62 profile was heterogeneous in granulomas between adults and calves. Our data suggest that necrosis is associated with a higher amount of mycobacterial antigens in the late stages of granuloma and the development of autophagy appears to play an heterogeneous effector response against infection in adults and calves. These results represent one of the first approaches in the identification of cell death in the four stages of granulomas in bovine tuberculosis.

Caveolin-1 affects early mycobacterial infection and apoptosis in macrophages and mice.

Tuberculosis, caused by Mycobacterium tuberculosis, remains one of the deadliest infections in humans. Because Mycobacterium bovis Bacillus Calmette-Guérin (BCG) share genetic similarities with Mycobacterium tuberculosis, it is often used as a model to elucidate the molecular mechanisms of more severe tuberculosis infection. Caveolin-1 has been implied in many physiological processes and diseases, but it's role in mycobacterial infections has barely been studied. We isolated macrophages from Wildtype or Caveolin-1 deficient mice and analyzed hallmarks of infection, such as internalization, induction of autophagy and apoptosis. For in vivo assays we intravenously injected mice with BCG and investigated tissues for bacterial load with colony-forming unit assays, bioactive lipids with mass spectrometry and changes of protein expressions by Western blotting. Our results revealed that Caveolin-1 was important for early killing of BCG infection in vivo and in vitro, controlled acid sphingomyelinase (Asm)-dependent ceramide formation, apoptosis and inflammatory cytokines upon infection with BCG. In accordance, Caveolin-1 deficient mice and macrophages showed higher bacterial burdens in the livers. The findings indicate that Caveolin-1 plays a role in infection of mice and murine macrophages with BCG, by controlling cellular apoptosis and inflammatory host response. These clues might be useful in the fight against tuberculosis.

Eventos adversos sistémicos post-vacuna BCG. Serie de casos pediátricos / Systemic adverse events post-BCG vaccine. Pediatric case series

La vacuna BCG es clave para el control de la tuberculosis. En ocasiones se observan eventos adversos sistémicos causados por Mycobacterium bovis BCG; usualmente asociados a inmunodeficiencia. Describimos seis casos clínicos de niños vacunados con BCG al nacer, con complicaciones sistémicas post-vacunación. M{ETODO: Revisión de historias clínicas de pacientes con infección por M. bovis BCG atendidos en un hospital pediátrico, entre 2010 y 2019. RESULTADOS: De 400 casos confirmados de infecciones por complejo Mycobacterium tuberculosis; ocho fueron identificados como M. bovis BCG; seis casos correspondieron a eventos adversos sistémicos post-vacuna BCG: dos con lesiones cutáneas a distancia, dos osteomielitis y dos infecciones generalizadas. En cinco de los seis pacientes se detectó una alteración de la respuesta inmune. Un paciente falleció por falla multiorgánica, uno se derivó y cuatro completaron 12 meses de tratamiento: dos meses de isoniacida, rifampicina, etambutol, y moxifloxacina, y 10 meses de isoniacida y rifampicina. Tuvieron buena tolerancia a los medicamentos, sin recaída a los dos años. CONCLUSIÓN: La infección grave por M. bovis BCG es una rara complicación sistémica de la vacunación. Es razonable buscar defectos inmunológicos en los niños que desarrollan este tipo de eventos adversos.

The BCG vaccine is key to tuberculosis control. Systemic adverse events caused by Mycobacterium bovis BCG are occasionally observed; usually associated with immunodeficiency. In this report we describe six cases of children vaccinated with BCG at birth, with post-vaccination systemic complications. METHOD: retrospective review of medical records of patients with M. bovis BCG infection treated in a pediatric hospital between 2010 and 2019. RESULTS: Of 400 confirmed cases of Mycobacterium tuberculosis complex infection, eight identified as M. bovis BCG, six corresponded to systemic adverse events post-BCG vaccine: two distant skin lesions, two osteomyelitis and two generalized infections. An altered immune response was detected in five of the six patients. One patient died of multiorgan failure, one was referred and four completed 12 months of treatment: two months of isoniazid, rifampin, ethambutol, and moxifloxacin, and 10 months of isoniazid and rifampin. They had good tolerance to medications, without relapse at two years. CONCLUSION Serious M. bovis BCG infection is a rare systemic complication of vaccination. It is reasonable to look for immunological defects in children who develop these types of adverse events.

Detection of Mycobacterium tuberculosis complex DNA in oronasal swabs from infected African buffaloes (Syncerus caffer).

Mycobacterium bovis (M. bovis), a member of the Mycobacterium tuberculosis complex (MTBC), is the causative agent of bovine TB (bTB) in animals. Spread occurs through inhalation or ingestion of bacilli transmitted from infected individuals. Early and accurate detection of infected African buffaloes shedding M. bovis is essential for interrupting transmission. In this pilot study, we determined if MTBC DNA could be detected in M. bovis infected buffalo oronasal secretions using a molecular transport media (PrimeStore MTM) with oronasal swabs and a rapid qPCR assay (Xpert MTB/RIF Ultra). Bovine TB test-positive buffaloes were culled, then tissue samples and oronasal swabs collected post-mortem for mycobacterial culture and Ultra testing, respectively. The Ultra detected MTBC DNA in 5/12 swabs from M. bovis culture-confirmed buffaloes. Oronasal swabs from M. bovis negative buffaloes (n = 20) were negative on Ultra, indicating the high specificity of this test. This study showed that MTM can successfully preserve MTBC DNA in oronasal swabs. The proportion of MTBC positive oronasal swabs was higher than expected and suggests that the Ultra may be an additional method for identifying infected buffaloes. Further studies are needed to confirm the utility of the Ultra assay with oronasal swabs as an assay to evaluate possible MTBC shedding in buffaloes.

Mycobacterial infection aggravates Helicobacter pylori-induced gastric preneoplastic pathology by redirection of de novo induced Treg cells.

The two human pathogens Helicobacter pylori and Mycobacterium tuberculosis (Mtb) co-exist in many geographical areas of the world. Here, using a co-infection model of H. pylori and the Mtb relative M. bovis bacillus Calmette-Guérin (BCG), we show that both bacteria affect the colonization and immune control of the respective other pathogen. Co-occurring M. bovis boosts gastric Th1 responses and H. pylori control and aggravates gastric immunopathology. H. pylori in the stomach compromises immune control of M. bovis in the liver and spleen. Prior antibiotic H. pylori eradication or M. bovis-specific immunization reverses the effects of H. pylori. Mechanistically, the mutual effects can be attributed to the redirection of regulatory T cells (Treg cells) to sites of M. bovis infection. Reversal of Treg cell redirection by CXCR3 blockade restores M. bovis control. In conclusion, the simultaneous presence of both pathogens exacerbates the problems associated with each individual infection alone and should possibly be factored into treatment decisions.

Mycobacterium Bovis Causing Mycotic Aneurysm Secondary to Intravesical Treatment with Bacillus Calmette-Guérin: A Case Report.

BACKGROUND: Bacillus Calmette-Guerin (BCG) is a live, attenuated strain of Mycobacterium bovis that is used in the treatment of non-muscle invasive bladder cancer (NMIBC). Vascular complications, including mycotic aneurysms, after BCG therapy are exceedingly rare. In this patient population, the diagnosis of mycotic aneurysms can be delayed or missed due to their non-specific clinical and radiologic presentation. Literature review reveals management of mycotic aneurysms attributable to BCG therapy is widely varied.2,5-8,12,15 CASE REPORT: We report a patient who presented with mycotic aneurysm formation secondary to BCG treatment for bladder cancer that was repaired with in-line reconstruction utilizing cryoartery and buttressed with omental flap. We suggest this as an alternative treatment to in-line prosthetic graft or extra-anatomic reconstruction.

PM2.5 mediated alterations in the in vitro human granuloma and its effect on reactivation of mycobacteria.

Exposure to particulate matter pollutant PM2.5 diminishes the immune response to mycobacterial antigens relevant to contain the infection in the granuloma, thus leading to reactivation of latent bacilli. The present study was therefore designed based on the hypothesis that exposure to PM2.5 affects the granuloma formation and reactivation of latent mycobacterial bacilli contained in the granuloma. For the sampling of PM2.5, based on initial standardisations, Teflon filter was selected over the quartz filter. Two different approaches were used to study the effect of PM2.5 on the human PBMC granuloma formed by Mycobacterium bovis BCG at multiplicity of infection (MOI) 0.1. In the first approach, granuloma formed in the presence of PM2.5 was loosely packed and ill-defined with significant downregulation of dormancy-associated mycobacterial genes, upregulation of reactivation-associated rpfB gene along with a significant increase in TNFα level without any change in the bacterial load in terms of CFUs. In the second approach, preformed human PBMC granuloma using M. bovis BCG was treated with PM2.5 that resulted in the disruption of granuloma architecture along with downregulation of not only dormancy-associated genes but also reactivation-associated rpfB gene of mycobacterial bacilli recovered from granuloma. However, there was no significant change in the host cytokine levels. Therefore, it can be inferred that PM2.5 can modulate the granuloma formation in vitro as well as mycobacterial gene expression in the granuloma with a possible role in the reactivation of latent bacilli.

100 years of Mycobacterium bovis bacille Calmette-Guérin.

Mycobacterium bovis bacille Calmette-Guérin (BCG), an experimental vaccine designed to protect cattle from bovine tuberculosis, was administered for the first time to a newborn baby in Paris in 1921. Over the past century, BCG has saved tens of millions of lives and has been given to more humans than any other vaccine. It remains the sole tuberculosis vaccine licensed for use in humans. BCG provides long-lasting strong protection against miliary and meningeal tuberculosis in children, but it is less effective for the prevention of pulmonary tuberculosis, especially in adults. Evidence mainly from the past two decades suggests that BCG has non-specific benefits against non-tuberculous infections in newborn babies and in older adults, and offers immunotherapeutic benefit in certain malignancies such as non-muscle invasive bladder cancer. However, as a live attenuated vaccine, BCG can cause localised or disseminated infections in immunocompromised hosts, which can also occur following intravesical installation of BCG for the treatment of bladder cancer. The legacy of BCG includes fundamental discoveries about tuberculosis-specific and non-specific immunity and the demonstration that tuberculosis is a vaccine-preventable disease, providing a foundation for new vaccines to hasten tuberculosis elimination.

A Bumpy Ride of Mycobacterial Phagosome Maturation: Roleplay of Coronin1 Through Cofilin1 and cAMP.

Phagosome-lysosome fusion in innate immune cells like macrophages and neutrophils marshal an essential role in eliminating intracellular microorganisms. In microbe-challenged macrophages, phagosome-lysosome fusion occurs 4 to 6 h after the phagocytic uptake of the microbe. However, live pathogenic mycobacteria hinder the transfer of phagosomes to lysosomes, up to 20 h post-phagocytic uptake. This period is required to evade pro-inflammatory response and upregulate the acid-stress tolerant proteins. The exact sequence of events through which mycobacteria retards phagolysosome formation remains an enigma. The macrophage coat protein Coronin1(Cor1) is recruited and retained by mycobacteria on the phagosome membrane to retard its maturation by hindering the access of phagosome maturation factors. Mycobacteria-infected macrophages exhibit an increased cAMP level, and based on receptor stimulus, Cor1 expressing cells show a higher level of cAMP than non-Cor1 expressing cells. Here we have shown that infection of bone marrow-derived macrophages with H37Rv causes a Cor1 dependent rise of intracellular cAMP levels at the vicinity of the phagosomes. This increased cAMP fuels cytoskeletal protein Cofilin1 to depolymerize F-actin around the mycobacteria-containing phagosome. Owing to reduced F-actin levels, the movement of the phagosome toward the lysosomes is hindered, thus contributing to the retarded phagosome maturation process. Additionally, Cor1 mediated upregulation of Cofilin1 also contributes to the prevention of phagosomal acidification, which further aids in the retardation of phagosome maturation. Overall, our study provides first-hand information on Cor1 mediated retardation of phagosome maturation, which can be utilized in developing novel peptidomimetics as part of host-directed therapeutics against tuberculosis.

Serological detection of Mycobacterium Tuberculosis complex infection in multiple hosts by One Universal ELISA.

Tuberculosis (TB), a contagious disease mainly caused by Mycobacterium tuberculosis (M. tb), Mycobacterium bovis (M. bovis), and Mycobacterium caprae (M. caprae), poses a major global threat to the health of humans and many species of animals. Developing an ante-mortem detection technique for different species would be of significance in improving the surveillance employing a One Health strategy. To achieve this goal, a universal indirect ELISA was established for serologically detecting Mycobacterium tuberculosis complex infection for multiple live hosts by using a fusion protein of MPB70, MPB83, ESAT6, and CFP10 common in M. tb, M. bovis, and M. caprae as the coating antigen (MMEC) and HRP-labeled fusion protein A and G as a secondary antibody. After testing the known positive and negative sera, the receiver operating characteristic curves were constructed to decide the cut-off values. Then, the diagnostic sensitivity and specificity of MMEC/AG-iELISA were determined as 100.00% (95% CI: 96.90%, 100.00%) and 100.00% (95% CI: 98.44%, 100.00%) for M. bovis infection of cattle, 100.00% (95% CI: 95.00%, 100.00%) and 100.0% (95% CI: 96.80%, 100.00%) for M. bovis infection of sheep, 90.74% (95% CI: 80.09%, 95.98%) and 98.63% (95% CI: 95.14%, 99.76%) for M. bovis infection of cervids, 100.00% (95% CI: 15.81%, 100.00%) and 98.81% (95% CI: 93.54%, 99.97%) for M. bovis infection of monkeys, 100.00% (95% CI: 86.82%, 100.00%) and 94.85% (95% CI: 91.22%, 97.03%) for M. tb infection of humans. Furthermore, this MMEC/AG-iELISA likely detects M. caprae infection in roe deer. Thus this method has a promising application in serological TB surveillance for multiple animal species thereby providing evidence for taking further action in TB control.

Case Report: Acquired Disseminated BCG in the Context of a Delayed Immune Reconstitution After Hematological Malignancy.

Context: Disseminated infections due to Mycobacterium bovis Bacillus Calmette-Guérin (BCG) are unusual and occur mostly in patients with inborn error of immunity (IEI) or acquired immunodeficiency. However, cases of secondary BCGosis due to intravesical BCG instillation have been described. Herein, we present a case of severe BCGosis occurring in an unusual situation. Case Description: We report one case of severe disseminated BCG disease occurring after hematological malignancy in a 48-year-old man without BCG instillation and previously vaccinated in infancy with no complication. Laboratory investigations demonstrated that he was not affected by any known or candidate gene of IEI or intrinsic cellular defect involving IFNγ pathway. Whole genome sequencing of the BCG strain showed that it was most closely related to the M. bovis BCG Tice strain, suggesting an unexpected relationship between the secondary immunodeficiency of the patient and the acquired BCG infection. Conclusion: This case highlights the fact that, in addition to the IEI, physicians, as well as microbiologists and pharmacists should be aware of possible acquired disseminated BCG disease in secondary immunocompromised patients treated in centers that administrate BCG for bladder cancers.

Spoligotype-specific risk of finding lesions in tissues from cattle infected by Mycobacterium bovis.

BACKGROUND: Although the pathogenic effect of members of the Mycobacterium tuberculosis complex in susceptible hosts is well known, differences in clinical signs and pathological findings observed in infected animals have been reported, likely due to a combination of host and pathogen-related factors. Here, we investigated whether Mycobacterium bovis strains belonging to different spoligotypes were associated with a higher risk of occurrence of visible/more severe lesions in target organs (lungs and/or lymph nodes) from infected animals. A large collection of 8889 samples belonging to cattle were classified depending on the presence/absence of tuberculosis-like lesions and its degree of severity. All samples were subjected to culture irrespective of the presence of lesions, and isolates retrieved were identified and subjected to spoligotyping. The association between the presence/severity of the lesions and the isolation of strains from a given spoligotype was assessed using non-parametric tests and Bayesian mixed multivariable logistic regression models that accounted for origin (region and herd) effects. RESULTS: Results suggested a difference in severity in lesioned samples depending on the strain's spoligotype. An association between specific spoligotypes and presence of lesions was observed, with a higher risk of finding lesions in animals infected with strains with spoligotypes SB0120, SB0295 and SB1142 compared with SB0121, and in those coming from certain regions in Spain. CONCLUSIONS: Our results suggest that strains belonging to certain spoligotypes may be associated with a higher probability in the occurrence of gross/macroscopic lesions in infected cattle, although these observational findings should be confirmed in further studies that allow accounting for the effect of other possible confounders not considered here, and ultimately through experimental studies.

Simulating the next steps in badger control for bovine tuberculosis in England.

Industry-led culling of badgers has occurred in England to reduce the incidence of bovine tuberculosis in cattle for a number of years. Badger vaccination is also possible, and a move away from culling was "highly desirable" in a recent report to the UK government. Here we used an established simulation model to examine badger control option in a post-cull environment in England. These options included no control, various intermittent culling, badger vaccination and use of a vaccine combined with fertility control. The initial simulated cull led to a dramatic reduction in the number of infected badgers present, which increased slowly if there was no further badger management. All three approaches led to a further reduction in the number of infected badgers, with little to choose between the strategies. We do note that of the management strategies only vaccination on its own leads to a recovery of the badger population, but also an increase in the number of badgers that need to be vaccinated. We conclude that vaccination post-cull, appears to be particularly effective, compared to vaccination when the host population is at carrying capacity.

Recombinant ArgF PLGA nanoparticles enhances BCG induced immune responses against Mycobacterium bovis infection.

Mycobacterium bovis (M. bovis) is a member of mycobacterium tuberculosis complex (MTBC), and a causative agent of chronic respiratory disease in a wide range of hosts. Bacillus Calmette-Guerin (BCG) vaccine is mostly used for the prevention of childhood tuberculosis. Further substantial implications are required for the development and evaluation of new tuberculosis (TB) vaccines as well as improving the role of BCG in TB control strategies. In this study, we prepared PLGA nanoparticles encapsulated with argF antigen (argF-NPs). We hypothesized, that argF nanoparticles mediate immune responses of BCG vaccine in mice models of M. bovis infection. We observed that mice vaccinated with argF-NPs exhibited a significant increase in secretory IFN-γ, CD4+ T cells response and mucosal secretory IgA against M. bovis infection. In addition, a marked increase was observed in the level of secretory IL-1ß, TNF-α and IL-10 both in vitro and in vivo upon argF-NPs vaccination. Furthermore, argF-NPs vaccination resulted in a significant reduction in the inflammatory lesions in the lung's tissues, minimized the losses in total body weight and reduced M. bovis burden in infected mice. Our results indicate that BCG prime-boost strategy might be a promising measure for the prevention against M. bovis infection by induction of CD4+ T cells responses and mucosal antibodies.

Natural resistance to worms exacerbates bovine tuberculosis severity independently of worm coinfection.

Pathogen interactions arising during coinfection can exacerbate disease severity, for example when the immune response mounted against one pathogen negatively affects defense of another. It is also possible that host immune responses to a pathogen, shaped by historical evolutionary interactions between host and pathogen, may modify host immune defenses in ways that have repercussions for other pathogens. In this case, negative interactions between two pathogens could emerge even in the absence of concurrent infection. Parasitic worms and tuberculosis (TB) are involved in one of the most geographically extensive of pathogen interactions, and during coinfection worms can exacerbate TB disease outcomes. Here, we show that in a wild mammal natural resistance to worms affects bovine tuberculosis (BTB) severity independently of active worm infection. We found that worm-resistant individuals were more likely to die of BTB than were nonresistant individuals, and their disease progressed more quickly. Anthelmintic treatment moderated, but did not eliminate, the resistance effect, and the effects of resistance and treatment were opposite and additive, with untreated, resistant individuals experiencing the highest mortality. Furthermore, resistance and anthelmintic treatment had nonoverlapping effects on BTB pathology. The effects of resistance manifested in the lungs (the primary site of BTB infection), while the effects of treatment manifested almost entirely in the lymph nodes (the site of disseminated disease), suggesting that resistance and active worm infection affect BTB progression via distinct mechanisms. Our findings reveal that interactions between pathogens can occur as a consequence of processes arising on very different timescales.

B and T lymphocyte attenuator regulates autophagy in mycobacterial infection via the AKT/mTOR signal pathway.

The survivability of Mycobacterium tuberculosis (M.tb) in macrophages in granuloma is a predominant cause for tuberculosis (TB) infection and recurrence. However, the mechanism of mycobacterial clearance in macrophages still needs further study. Here, we explored a novel role of B and T lymphocyte Attenuator (BTLA) in macrophage-mediated host defense against mycobacterial infection. We found that the surface expression of BTLA was increased in CD14+ monocytes from active TB patients. The mRNA levels of BTLA were induced in human and mice monocytes/macrophages during Mycobacterium bovis BCG or M.tb H37Rv infection, as well as spleen and lung of H37Rv-infected mice. Furthermore, silencing of BTLA promoted the intracellular survival of BCG and H37Rv by suppressing the autophagy in macrophages but not effecting phagocytosis, reactive oxygen species (ROS) and apoptosis. Silence of BTLA reduced bacterial-autophagosome and bacterial-lysosome colocalization. Moreover, BTLA inhibited AKT and mTOR signaling substrates S6K and 4EBP1 phosphorylation in BCG and H37Rv infected macrophages, and BTLA-mediated AKT-mTOR signaling and intracellular BCG survival were reversed by PI3K inhibitors in macrophages. Finally, treatment with BTLA agonist ameliorated lung pathology and promoted autophagy and mycobacterial clearance during mycobacterial infection in vivo. These results demonstrate that BTLA promotes host defense against mycobacteria by enhancing autophagy, which may provide potential therapeutic interventions against tuberculosis.

Harmful Effects of Granulocytic Myeloid-Derived Suppressor Cells on Tuberculosis Caused by Hypervirulent Mycobacteria.

BACKGROUND: The role of myeloid-derived suppressor cells (MDSCs) in patients with severe tuberculosis who suffer from uncontrolled pulmonary inflammation caused by hypervirulent mycobacterial infection remains unclear. METHODS: This issue was addressed using C57BL/6 mice infected with highly virulent Mycobacterium bovis strain MP287/03. RESULTS: CD11b+GR1int population increased in the bone marrow, blood and lungs during advanced disease. Pulmonary CD11b+GR1int (Ly6GintLy6Cint) cells showed granularity similar to neutrophils and expressed immature myeloid cell markers. These immature neutrophils harbored intracellular bacilli and were preferentially located in the alveoli. T-cell suppression occurred concomitantly with CD11b+GR1int cell accumulation in the lungs. Furthermore, lung and bone marrow GR1+ cells suppressed both T-cell proliferation and interferon γ production in vitro. Anti-GR1 therapy given when MDSCs infiltrated the lungs prevented expansion and fusion of primary pulmonary lesions and the development of intragranulomatous caseous necrosis, along with increased mouse survival and partial recovery of T-cell function. Lung bacterial load was reduced by anti-GR1 treatment, but mycobacteria released from the depleted cells proliferated extracellularly in the alveoli, forming cords and clumps. CONCLUSIONS: Granulocytic MDSCs massively infiltrate the lungs during infection with hypervirulent mycobacteria, promoting bacterial growth and the development of inflammatory and necrotic lesions, and are promising targets for host-directed therapies.

Spatial and temporal analyses of culls due to bovine tuberculosis in slaughterhouses of Minas Gerais state, Brazil, 2008 to 2012 / Análise espacial e temporal das condenações por tuberculose bovina em frigoríficos do estado de Minas Gerais, Brasil, 2008 a 2012

The application of spatial and temporal analysis in epidemiology aims to understand the causes and consequences of spatial and temporal heterogeneity in studies of infectious diseases. Bovine tuberculosis (bTB) is a chronic and progressive infectious disease caused by Mycobacterium bovis and is an important zoonosis worldwide. The aim of this study was to conduct spatial and temporal analyses of a secondary database of bTB-positive cases registered by the Federal Inspection Service in two slaughterhouses from the West of Minas mesoregion of Minas Gerais state, Brazil, from 2008 to 2012 and to suggest its use in epidemiological surveillance. The culled cattle with bTB macroscopic lesions during post mortem inspection were considered positive in this study. The data used were the positive cases registered on the "Sistema de Informações Gerenciais do Serviço de Inspeção Federal" (SIG/SIF - Management Information System of the Federal Inspection Service) of the "Ministério da Agricultura, Pecuária e Abastecimento" (MAPA - Ministry of Agriculture, Livestock and Supplies), the number of animals slaughtered monthly and their municipalities of origin, per slaughterhouse. The prevalence (%) of cases per cattle slaughtered was calculated, and the relationship between these cases of bTB and cases of human tuberculosis (hTB) and the GDP per capita of the mesoregions comprising the municipalities surveyed was evaluated. The prevalence was 1,030 cases of bTB (0.28%). The lowest case numbers and prevalence rates were obtained in 2010, while the highest rates were observed in 2011. Slaughterhouse 1 showed stationarity, while Slaughterhouse 2 showed an increasing annual trend for data since October 2009. A statistical correlation between the numbers of cases of bovine and human TB (p=0.006, r=0.148) was observed. The prevalence for Slaughterhouses 1 and 2 were not correlated (p>0.05). The municipalities of origin demonstrated randomness in their spatial distribution. SIG/SIF-MAPA may be used for the analysis of spatial and temporal distribution to contribute to the monitoring of animal health services with information on the prevalence of culling for bTB in the West of Minas, South/Southwest of Minas, Campo das Vertentes and Zona da Mata mesoregions of Minas Gerais, Brazil.(AU)

A aplicação de análises espacial e temporal em epidemiologia visa compreender as causas e consequências da heterogeneidade espacial e temporal nos estudos de doenças infecciosas. A tuberculose bovina (TBb) é uma doença infecciosa crônica e progressiva causada pelo Mycobacterium bovis e uma importante zoonose em todo o mundo. O objetivo deste estudo foi realizar análises espaciais e temporais em um banco de dados secundário de casos positivos de TBb registrados pelo Serviço de Inspeção Federal em dois frigoríficos da mesorregião Oeste de Minas, estado de Minas Gerais, Brasil, de 2008 a 2012 e sugerir sua utilização na vigilância epidemiológica. Os bovinos abatidos com lesões macroscópicas de TBb durante a inspeção post mortem foram considerados positivos neste estudo. Os dados utilizados foram os casos positivos cadastrados no Sistema de Informações Gerenciais do Serviço de Inspeção Federal do Ministério da Agricultura, Pecuária e Abastecimento (SIGSIF/MAPA), o número de animais abatidos mensalmente e seus municípios de origem, por frigorífico. Foi calculada a prevalência (%) de casos por bovinos abatidos e avaliada a relação entre esses casos de TBb e os casos de tuberculose humana (TBh) e o PIB per capita das mesorregiões que compõem os municípios pesquisados. A prevalência foi de 1.030 casos de TBb (0,28%). Os menores números de casos e prevalências foram obtidos em 2010, enquanto as maiores prevalências foram observadas em 2011. O Frigorífico 1 apresentou estacionariedade, enquanto o Frigorífico 2 apresentou tendência anual crescente para os dados desde outubro de 2009. Correlação estatística entre o número de casos de TBb e TBh (p=0,006, r=0,148) foi observada. As prevalências nos Frigoríficos 1 e 2 não se correlacionaram (p>0,05). Os municípios de origem demonstraram aleatoriedade em sua distribuição espacial. O SIGSIF/MAPA pode ser utilizado para a análise da distribuição espacial e temporal a fim de contribuir com o monitoramento dos serviços de saúde animal com informações sobre a prevalência de condenações por TBb nas mesorregiões Oeste de Minas, Sul/Sudoeste de Minas, Campo das Vertentes e Zona da Mata de Minas Gerais, Brasil.(AU)