Is 14-3-3 the Combination to Unlock New Pathways to Improve Metabolic Homeostasis and ß-Cell Function?

Since their discovery nearly five decades ago, molecular scaffolds belonging to the 14-3-3 protein family have been recognized as pleiotropic regulators of diverse cellular and physiological functions. With their ability to bind to proteins harboring specific serine and threonine phosphorylation motifs, 14-3-3 proteins can interact with and influence the function of docking proteins, enzymes, transcription factors, and transporters that have essential roles in metabolism and glucose homeostasis. Here, we will discuss the regulatory functions of 14-3-3 proteins that will be of great interest to the fields of metabolism, pancreatic ß-cell biology, and diabetes. We first describe how 14-3-3 proteins play a central role in glucose and lipid homeostasis by modulating key pathways of glucose uptake, glycolysis, oxidative phosphorylation, and adipogenesis. This is followed by a discussion of the contributions of 14-3-3 proteins to calcium-dependent exocytosis and how this relates to insulin secretion from ß-cells. As 14-3-3 proteins are major modulators of apoptosis and cell cycle progression, we will explore if 14-3-3 proteins represent a viable target for promoting ß-cell regeneration and discuss the feasibility of targeting 14-3-3 proteins to treat metabolic diseases such as diabetes. ARTICLE HIGHLIGHTS: 14-3-3 proteins are ubiquitously expressed scaffolds with multiple roles in glucose homeostasis and metabolism. 14-3-3ζ regulates adipogenesis via distinct mechanisms and is required for postnatal adiposity and adipocyte function. 14-3-3ζ controls glucose-stimulated insulin secretion from pancreatic ß-cells by regulating mitochondrial function and ATP synthesis as well as facilitating cross talk between ß-cells and α-cells.

[Pediatric exposure to endocrine disruptors and carcinogenic, mutagenic or reprotoxic substances by pharmaceutical forms intended for the cutaneous route: Regulatory provisions in France, in Europe, and state of the art of scientific knowledge]. / Exposition pédiatrique aux perturbateurs endocriniens et substances cancérogènes, mutagènes ou reprotoxiques par des formes pharmaceutiques destinées à la voie cutanée : dispositions réglementaires en France, en Europe, et état de l'art des connaissances scientifiques.

OBJECTIVES: The objective is to conduct a review of pediatric exposure to substances whose endocrine disrupting (ED), carcinogenic, mutagenic, or reprotoxic (CMR) character has been confirmed or remains controversial, through their use in pharmaceutical forms intended for the cutaneous route, as well as regulatory measures diligent at the national and European levels. METHODS: A bibliographical search was carried out on the databases PubMed, Web of Science, Cochrane Library, supplemented by a search for recommendations from French and European authorities. References were selected following an assessment of their relevance to our topic. RESULTS: Seventy-one references were selected. Pediatric exposure to endocrine disruptors and CMR substances remains through products formulated for their use, but also through indirect exposure to products commonly used by adults. Exposure arises both from the choice of excipients (parabens, phenoxyethanol), packaging materials (bisphenols, phthalates) and the qualitative or quantitative nature of the active ingredients (iodine, boron, pyrethroids, organic sunscreens). CONCLUSION: The health professional must be able to develop a critical mind on such substances in order to inform and promote therapeutic adherence, guaranteeing the safety of the child's care.

Detection and characterization of Leptospira spp. in dogs diagnosed with kidney and/or liver disease in Selangor, Malaysia.

Leptospirosis is a serious bacterial disease that affects both humans and animals. A wide range of symptoms have been described in humans; the disease in dogs is commonly associated with kidney and/or liver disease. In Malaysia, information about the common serovars infecting dogs is limited. Therefore, we investigated the occurrences of leptospirosis in 124 pet dogs diagnosed with kidney and/or liver disease. Blood, urine, abdominal effusion, and/or kidney and liver were collected from the dogs. Based on microscopic agglutination testing, 53 of 124 (42.7%) dogs were seropositive for leptospiral exposure. Sera were frequently positive to serovars Bataviae (n = 12), Javanica (n = 10), and Icterohaemorrhagiae (n = 10). Direct detection using PCR showed that 42 of 124 (33.9%) of the whole blood and 36 of 113 (31.9%) urine samples were positive for pathogenic Leptospira spp. By PCR, 2 of 23 (9.1%) kidney and 2 of 23 (9.1%) liver were positive for pathogenic Leptospira spp. Abdominal effusion from 4 dogs were PCR-positive for pathogenic Leptospira spp. The species detected were L. interrogans, L. borgpetersenii, L. kirschneri, and L. kmetyi by partial 16S rRNA sequencing. We further identified and characterized 11 Leptospira spp. isolates from 8 dogs as serovars Bataviae, Javanica, and Australis. The mortality rate of the Leptospira-infected dogs was high (18 of 53; 34%).

Detection and distribution of anti-leptospiral antibody among dogs and their handlers.

The incidence of leptospirosis seems to be on the rise and could be an alarming indirect indication of a global re-emergence. It is a potential public health threat when dogs are speculated to be involved in the transmission of leptospirosis through possible subclinical harbouring of Leptospira spp. and subsequent shedding into the environment. This study aimed to detect anti-leptospiral antibodies among dogs and their handlers using the microscopic agglutination test (MAT). Blood samples from 266 apparently healthy dogs and 194 dog handlers were collected at four working dog organisations and four dog shelters. Serum samples were tested using MAT against 20 leptospiral serovars with a cut-off titre >=1:100 (dog) and >=1:50 (dog handlers). Seventy dogs (70/266; 26.3%) were seropositive mainly against serovars Icterohaemorrhagiae, Ballum, Bataviae and Javanica (titres ranged: 1:100-1:800). Sixty-seven dog handlers (67/194; 34.5%) were seropositive mainly against serovars Grippotyphosa, Icterohaemorrhagiae and Malaysia (titres ranged: 1:50-1:200). Dogs were seropositive due to exposure, vaccination or active infection. Seropositive dog handlers could indicate exposure or active infection. This shows the potential of dogs in maintaining and spreading the infection in Malaysia. Due to the occupational risk as a result of frequent contact with dogs and exposure to contaminated environments, dog handlers should be made aware of the presence of this zoonotic disease.

Detection and distribution of anti-leptospiral antibody among dogs and their handlers

@# The incidence of leptospirosis seems to be on the rise and could be an alarming indirect indication of a global re-emergence. It is a potential public health threat when dogs are speculated to be involved in the transmission of leptospirosis through possible subclinical harbouring of Leptospira spp. and subsequent shedding into the environment. This study aimed to detect anti-leptospiral antibodies among dogs and their handlers using the microscopic agglutination test (MAT). Blood samples from 266 apparently healthy dogs and 194 dog handlers were collected at four working dog organisations and four dog shelters. Serum samples were tested using MAT against 20 leptospiral serovars with a cut-off titre >1:100 (dog) and >1:50 (dog handlers). Seventy dogs (70/266; 26.3%) were seropositive mainly against serovars Icterohaemorrhagiae, Ballum, Bataviae and Javanica (titres ranged: 1:100–1:800). Sixty-seven dog handlers (67/194; 34.5%) were seropositive mainly against serovars Grippotyphosa, Icterohaemorrhagiae and Malaysia (titres ranged: 1:50–1:200). Dogs were seropositive due to exposure, vaccination or active infection. Seropositive dog handlers could indicate exposure or active infection. This shows the potential of dogs in maintaining and spreading the infection in Malaysia. Due to the occupational risk as a result of frequent contact with dogs and exposure to contaminated environments, dog handlers should be made aware of the presence of this zoonotic disease.

Molecular detection of Leptospira sp. in cattle and goats in Kelantan, Malaysia after a massive flood using multiplex polymerase chain reaction.

Flood is a potential driver in spreading waterborne diseases including leptospirosis, which is a zoonotic disease caused by pathogenic bacteria of the genus Leptospira. In the case of leptospirosis, cattle and goats can be incidental hosts and potential carriers of leptospirosis. Traditionally, serology such as microscopic agglutination test (MAT) and isolation of the organisms have been commonly used as the diagnostic approaches in diagnosing leptospirosis. However, nowadays, various molecular techniques have been developed for specific detection of Leptospira sp. such as, polymerase chain reaction (PCR), which is sensitive, specific and rapid in detecting the species. This study detected Leptospira sp. directly from the blood and urine of the animals such as, cattle, goats and sheep in Kelantan after a massive flood by using multiplex PCR (mPCR). From the results collected in the study, four blood samples (0.63%; 4/635) were found to be positive with Leptospira sp. and one urine sample (3.23%; 1/31) was detected as positive with Leptospira sp. The blood and urine samples that were detected to be positive with Leptospira sp. were collected from cattle and goats exposed to the flood. However, no Leptospira sp. was detected from the sheep in this study. Multiplex PCR (mPCR) was successfully used to detect the presence of Leptospira sp. in animals. Apart from that, it is also suggested that flood has a significant role in transmitting the disease to animals.

Toxoplasma gondii infection in native village chickens (Gallus domesticus) in Selangor and Melaka, Malaysia.

Toxoplasmosis is a worldwide zoonosis caused by the protozoa Toxoplasma gondii which affects human and animals. Village chickens (Gallus domesticus) most commonly known as Ayam Kampung or free-range chickens, have been suggested to play a role in the epidemiology of toxoplasmosis. This study determines the presence of T. gondii in the village chicken populations in two states of Malaysia. A total of 50 serum samples from the chickens from Selangor (n=20) and Melaka (n=30) were collected and analysed using commercial serological kits. T. gondii antigen was detected in 20% (Selangor 30%; Melaka 13%) samples using ELISA test and anti-T. gondii antibody was detected in all positive ELISA samples using the indirect haemagglutination test (IHAT). Histopathological examination revealed tissue changes such as inflammation and degeneration in brain and liver of seropositive chickens. This is the first report of T. gondii infection in the village chickens in Malaysia.

Toxoplasma gondii infection in native village chickens (Gallus domesticus) in Selangor and Melaka, Malaysia

@#Toxoplasmosis is a worldwide zoonosis caused by the protozoa Toxoplasma gondii which affects human and animals. Village chickens (Gallus domesticus) most commonly known as Ayam Kampung or free-range chickens, have been suggested to play a role in the epidemiology of toxoplasmosis. This study determines the presence of T. gondii in the village chicken populations in two states of Malaysia. A total of 50 serum samples from the chickens from Selangor (n=20) and Melaka (n=30) were collected and analysed using commercial serological kits. T. gondii antigen was detected in 20% (Selangor 30%; Melaka 13%) samples using ELISA test and anti-T. gondii antibody was detected in all positive ELISA samples using the indirect haemagglutination test (IHAT). Histopathological examination revealed tissue changes such as inflammation and degeneration in brain and liver of seropositive chickens. This is the first report of T. gondii infection in the village chickens in Malaysia.

Molecular detection of Leptospira sp. in cattle and goats in Kelantan, Malaysia after a massive flood using multiplex polymerase chain reaction

@#Flood is a potential driver in spreading waterborne diseases including leptospirosis, which is a zoonotic disease caused by pathogenic bacteria of the genus Leptospira. In the case of leptospirosis, cattle and goats can be incidental hosts and potential carriers of leptospirosis. Traditionally, serology such as microscopic agglutination test (MAT) and isolation of the organisms have been commonly used as the diagnostic approaches in diagnosing leptospirosis. However, nowadays, various molecular techniques have been developed for specific detection of Leptospira sp. such as, polymerase chain reaction (PCR), which is sensitive, specific and rapid in detecting the species. This study detected Leptospira sp. directly from the blood and urine of the animals such as, cattle, goats and sheep in Kelantan after a massive flood by using multiplex PCR (mPCR). From the results collected in the study, four blood samples (0.63%; 4/635) were found to be positive with Leptospira sp. and one urine sample (3.23%; 1/31) was detected as positive with Leptospira sp. The blood and urine samples that were detected to be positive with Leptospira sp. were collected from cattle and goats exposed to the flood. However, no Leptospira sp. was detected from the sheep in this study. Multiplex PCR (mPCR) was successfully used to detect the presence of Leptospira sp. in animals. Apart from that, it is also suggested that flood has a significant role in transmitting the disease to animals.

Prospective role of indigenous Exiguobacterium profundum PT2 in arsenic biotransformation and biosorption by planktonic cultures and biofilms.

AIMS: The aim of this study was to analyse arsenic (As) transformation and biosorption by indigenous As-resistant bacteria both in planktonic and biofilm modes of growth. METHODS AND RESULTS: As-resistant bacteria were isolated from industrial waste water and strain PT2, and identified as Exiguobacterium profundum through 16S rRNA gene sequencing was selected for further study. As transformation and biosorption by E. profundumPT2 was determined by HPLC-ICP-MS analysis. Planktonic cultures reduced 3·73 mmol l-1 As5+ into As3+ from artificial waste water effluent after 48-h incubation. In case of biosorption, planktonic cultures and biofilms exhibited 25·2 and 29·4 mg g-1 biomass biosorption, respectively. As biosorption kinetics followed Freundlich isotherm and pseudo second-order model. Biofilm formation peaked after 3 days of incubation, and in the presence of As stress, biofilm formation was significantly affected in contrast to control (P < 0·05). Homogeneous nature of mature biofilms with an increased demand of nutrients was revealed by minimum roughness and maximum surface to biovolume ratio measured through CLSM analysis. CONCLUSION: Indigenous As-resistant E. profundumPT2 was found capable of As transformation and biosorption both in the form of planktonic cultures and biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: Indigenous biofilm forming E. profundum PT2 revealing As biosorption and biotransformation potential is presented an eco-friendly and cost-effective source for As remediation that can be implemented for waste water treatment.

The airway in inhalational injury: diagnosis and management.

It is estimated that 13.000 to 22.000 individuals suffer from inhalational burns each year in the United States alone. Despite these high numbers, inhalational burns remain a major challenge to otolaryngologists. In this paper, a review of literature is presented in order to provide otolaryngologists with a systematic approach to patients with inhalational burns to optimize treatment, cost, morbidity and, most importantly, mortality. For this purpose, a broad PubMed search was conducted. The available literature was found to highlight the importance of airway management in terms of the timing of intubation, method of intubation, trachea-esophageal (TE) fistula formation and TE rupture. It also emphasizes the importance of carbon monoxide intoxication and prompt correction. Drugs such as heparin sulfate, N-acetylcysteine and albuterol have been proven to help in the treatment of patients with inhalational burns, and more research is currently underway with the purpose of developing chelating drugs that scavenge the toxic substances in the smoke before they can damage the airway.

On estime que 13 000 à 22 000 personnes présentent chaque année, aux États-Unis, une inhalation de fumées. Cette pathologie représente un défi majeur pour les ORL. Cette revue de littérature a pour but de proposer aux ORL une approche systématisée de la prise en charge de cette pathologie afin d'en optimiser le traitement pour diminuer mortalité, morbidité et coûts. Les articles trouvés dans PubMed insistent sur le délai d'intubation et sa technique, les intoxications au CO, les complications trachéales (ruptures) et trachéo-oesophagiennes (fistule). L'héparine, la N-acétyl cystéine et l'albutérol ont montré leur intérêt en traitement d'appoint. Les recherches sur les chélateurs permettant de diminuer la toxicité des fumées sont en cours.

Phosphoproteomic Profiling Reveals ALK and MET as Novel Actionable Targets across Synovial Sarcoma Subtypes.

Despite intensive multimodal treatment of sarcomas, a heterogeneous group of malignant tumors arising from connective tissue, survival remains poor. Candidate-based targeted treatments have demonstrated limited clinical success, urging an unbiased and comprehensive analysis of oncogenic signaling networks to reveal therapeutic targets and personalized treatment strategies. Here we applied mass spectrometry-based phosphoproteomic profiling to the largest and most heterogeneous set of sarcoma cell lines characterized to date and identified novel tyrosine phosphorylation patterns, enhanced tyrosine kinases in specific subtypes, and potential driver kinases. ALK was identified as a novel driver in the Aska-SS synovial sarcoma (SS) cell line via expression of an ALK variant with a large extracellular domain deletion (ALKΔ2-17). Functional ALK dependency was confirmed in vitro and in vivo with selective inhibitors. Importantly, ALK immunopositivity was detected in 6 of 43 (14%) of SS patient specimens, one of which exhibited an ALK rearrangement. High PDGFRα phosphorylation also characterized SS cell lines, which was accompanied by enhanced MET activation in Yamato-SS cells. Although Yamato-SS cells were sensitive to crizotinib (ALK/MET-inhibitor) but not pazopanib (VEGFR/PDGFR-inhibitor) monotherapy in vitro, synergistic effects were observed upon drug combination. In vivo, both drugs were individually effective, with pazopanib efficacy likely attributable to reduced angiogenesis. MET or PDGFRα expression was detected in 58% and 84% of SS patients, respectively, with coexpression in 56%. Consequently, our integrated approach has led to the identification of ALK and MET as promising therapeutic targets in SS. Cancer Res; 77(16); 4279-92. ©2017 AACR.

The value of close monitoring in vestibular rehabilitation therapy.

BACKGROUND: Vestibular rehabilitation therapy is a well-established treatment modality for patients with vestibular problems. HYPOTHESIS: Performing vestibular rehabilitation therapy in a closely monitored setting may result in a better outcome than a home exercise programme. METHODS: A retrospective study was conducted of patients undergoing vestibular rehabilitation therapy between June 2005 and November 2012 in a tertiary university hospital. The Dynamic Gait Index, the main outcome measure, was utilised before and after the rehabilitation programme. The magnitude of improvement for all patients was analysed, mainly to compare the home exercise group with the closely monitored therapy group. RESULTS: Only 32 patients underwent the vestibular rehabilitation therapy programme. In all patients, there was significant improvement in the mean Dynamic Gait Index score (from 11.75 to 17.38; p < 0.01). Dynamic Gait Index improvement was significantly higher with closely monitored therapy (mean improvement of 7.83 vs 2.79; p < 0.01). CONCLUSION: The small sample size is a major limitation; nevertheless, closely monitored vestibular rehabilitation therapy resulted in improved performance status. More studies are needed to establish the efficiency of vestibular rehabilitation therapy and compare closely monitored therapy with tailored home exercise rehabilitation.

Utility of the QuantiFERON-TB Gold In-Tube assay for the diagnosis of tuberculosis in Moroccan children.

SETTING: The utility of interferon-gamma release assays (IGRAs), such as the QuantiFERON-TB Gold In-Tube (QFT-GIT) test, in diagnosing active tuberculosis (TB) in children is unclear and depends on the epidemiological setting. OBJECTIVE: To evaluate the performance of QFT-GIT for TB diagnosis in children living in Morocco, an intermediate TB incidence country with high bacille Calmette-Gurin vaccination coverage. DESIGN: We prospectively recruited 109 Moroccan children hospitalised for clinically suspected TB, all of whom were tested using QFT-GIT. RESULTS: For 81 of the 109 children, the final diagnosis was TB. The remaining 28 children did not have TB. QFT-GIT had a sensitivity of 66% (95%CI 5277) for the diagnosis of TB, and a specificity of 100% (95%CI 88100). The tuberculin skin test (TST) had lower sensitivity, at 46% (95%CI 3360), and its concordance with QFT-GIT was limited (69%). Combining QFT-GIT and TST results increased sensitivity to 83% (95%CI 6992). CONCLUSION: In epidemiological settings such as those found in Morocco, QFT-GIT is more sensitive than the TST for active TB diagnosis in children. Combining the TST and QFT-GIT would be useful for the diagnosis of active TB in children, in combination with clinical, radiological and laboratory data.

CIT, a gene involved in neurogenic cytokinesis, is mutated in human primary microcephaly.

Autosomal recessive primary microcephaly (MCPH) is a static neurodevelopmental disorder characterized by congenital small head circumference and non-progressive intellectual disability without additional severe brain malformations. MCPH is a genetically heterogeneous disorder. Sixteen genes (MCPH1-MCPH16) have been discovered so far, mutations thereof lead to autosomal recessive primary microcephaly. In a family, segregating MCPH in an autosomal recessive manner, genome-wide homozygosity mapping mapped a disease locus to 16.9-Mb region on chromosome 12q24.11-q24.32. Following this, exome sequencing in three affected individuals of the family discovered a splice site variant (c.753+3A>T) in citron kinase (CIT) gene, segregating with the disorder in the family. CIT co-localizes to the midbody ring during cytokinesis, and its loss of expression results in defects in neurogenic cytokinesis in both humans and mice. Splice site variant in CIT, identified in this study, is predicted to abolish splice donor site. cDNA sequence of an affected individual showed retention of an intron next to the splice donor site. The study, presented here, revealed the first variant in the CIT causing MCPH in the family.

A genome-wide association study of pulmonary tuberculosis in Morocco.

Although epidemiological evidence suggests a human genetic basis of pulmonary tuberculosis (PTB) susceptibility, the identification of specific genes and alleles influencing PTB risk has proven to be difficult. Previous genome-wide association (GWA) studies have identified only three novel loci with modest effect sizes in sub-Saharan African and Russian populations. We performed a GWA study of 550,352 autosomal SNPs in a family-based discovery Moroccan sample (on the full population and on the subset with PTB diagnosis at <25 years), which identified 143 SNPs with p < 1 × 10(-4). The replication study in an independent case/control sample identified four SNPs displaying a p < 0.01 implicating the same risk allele. In the combined sample including 556 PTB subjects and 650 controls these four SNPs showed suggestive association (2 × 10(-6) < p < 4 × 10(-5)): rs358793 and rs17590261 were intergenic, while rs6786408 and rs916943 were located in introns of FOXP1 and AGMO, respectively. Both genes are involved in the function of macrophages, which are the site of latency and reactivation of Mycobacterium tuberculosis. The most significant finding (p = 2 × 10(-6)) was obtained for the AGMO SNP in an early (<25 years) age-at-onset subset, confirming the importance of considering age-at-onset to decipher the genetic basis of PTB. Although only suggestive, these findings highlight several avenues for future research in the human genetics of PTB.

Pott's disease in Moroccan children: clinical features and investigation of the interleukin-12/interferon-γ pathway.

SETTING: Tuberculosis spondylodiscitis (TS), or Pott's disease, an extra-pulmonary form of tuberculosis (TB), is rare and difficult to diagnose in children. Some cases of severe TB in children were recently explained by inborn errors of immunity affecting the interleukin-12/interferon-gamma (IL-12/IFN-γ) axis. OBJECTIVE: To analyse clinical data on Moroccan children with TS, and to perform immunological and genetic explorations of the IL-12/IFN-γ axis. DESIGN: We studied nine children with TS diagnosed between 2012 and 2014. We investigated the IL-12/IFN-γ circuit by both whole-blood assays and sequencing of the coding regions of 14 core genes of this pathway. RESULTS: A diagnosis of TS was based on a combination of clinical, biological, histological and radiological data. QuantiFERON(®)-TB Gold In-Tube results were positive in 75% of patients. Whole-blood assays showed normal IL-12 and IFN-γ production in all but one patient, who displayed impaired decreased response to IL-12. No candidate disease-causing mutations were detected in the exonic regions of the 14 genes. CONCLUSIONS: TS diagnosis in children remains challenging, and is based largely on imaging. Further investigations of TS in children are required to determine the role of genetic defects in pathways that may or may not be related to the IL-12/IFN-γ axis.

Evaluation and correlation of mammographically suspicious lesions with histopathology at Addington Hospital, Durban.

BACKGROUND: Stereotactic core-needle biopsies (SCNBs) are a reliable alternative to surgical biopsy for microcalcifications. The positive predictive value (PPV) of SCNB has been shown to be reproducible in several studies using the Breast Imaging Reporting and Data System (BIRADS) classification, which is the current gold standard in mammographic reporting. At this stage, no study has been done in KwaZulu-Natal to assess local outcomes against BIRADS. The current standard of care utilises vacuum-assisted breast biopsy, but is not available in a resource-constrained environment such as ours. The need, therefore, is for constant evaluation of existing practice to ensure that it is optimised for the challenges and limitations facing local radiologists. OBJECTIVE: To assess the PPV of SCNB in Addington Hospital, and to compare it with that of BIRADS. Material and methods. Mammographically detected lesions were assigned to 3 categories: benign, indeterminate and suspicious. A retrospective review of 67 SCNBs was performed for lesions falling within the suspicious category, and the PPV and rates of ductal carcinoma in situ (DCIS) were determined. RESULTS: Our study demonstrated a PPV of 20.9%. This correlated well with international studies for BIRADS 4 and 5 lesions. DCIS accounted for 21.4% of detected malignancies, which is in keeping with current literature. CONCLUSION: Despite resource limitations, local outcomes were comparable to those of BIRADS. Given our fairly general categorisation of lesions, however, it should be emphasised that BIRADS allows better organisation, consistency and clarity in breast imaging reporting, as well as accurate data comparison between centres facing limitations similar to our own.

[Human genetics of tuberculosis]. / Génétique humaine de la tuberculose.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a major public health problem worldwide, resulting in 8.7 million new cases and 1.4 million deaths each year. One third of the world's population is exposed to M. tuberculosis and, after exposure, most, but not all, individuals become infected. Among infected subjects, only a minority (∼10%) will eventually develop clinical disease, which is typically either a primary, often extra-pulmonary, TB in children, or a reactivation, pulmonary TB in adults. Considerable genetic epidemiological evidence has accumulated to support a major role for human genetic factors in the development of TB. Numerous association studies with various candidate genes have been conducted in pulmonary TB, with very few consistent results. Recent genome-wide association studies revealed only a modest role for two inter-genic polymorphisms. However, a first major locus for pulmonary TB was mapped to chromosome 8q12-q13 in a Moroccan population after a genome-wide linkage screen. Using a similar strategy, two other major loci controlling TB infection were recently identified. While the precise identification of these major genes is ongoing, the other fascinating observation of these last years was the demonstration that TB can also reflect a Mendelian predisposition. Following the findings obtained in the syndrome of Mendelian susceptibility to mycobacterial diseases, several children with complete IL-12Rß1 deficiency, were found to have severe TB as their sole phenotype. Overall, these recent findings provide the proof of concept that the human genetics of TB involves a continuous spectrum from Mendelian to complex predisposition with intermediate major gene involvement. The understanding of the molecular genetic basis of TB will have fundamental immunological and medical implications, in particular for the development of new vaccines and treatments.