Ana Cristina C. S. Leandro

Bio: Ana Cristina C. S. Leandro is an academic researcher from Texas Biomedical Research Institute. The author has contributed to research in topics: Tuberculosis & SNP. The author has an hindex of 2, co-authored 2 publications receiving 25 citations.

No association of IFNG+874T/A SNP and NOS2A-954G/C SNP variants with nitric oxide radical serum levels or susceptibility to tuberculosis in a Brazilian population subset

Abstract: Tuberculosis (TB) is one of the most common infectious diseases in the world. Mycobacterium tuberculosis infection leads to pulmonary active disease in approximately 5–10% of exposed individuals. Both bacteria- and host-related characteristics influence latent infection and disease. Host genetic predisposition to develop TB may involve multiple genes and their polymorphisms. It was reported previously that interferon gamma (IFN-γ) and nitric oxide synthase 2 (NOS2) are expressed on alveolar macrophages from TB patients and are responsible for bacilli control; thus, we aimed this study at genotyping single nucleotide polymorphisms IFNG+874T/A SNP and NOS2A-954G/C SNP to estimate their role on TB susceptibility and determine whether these polymorphisms influence serum nitrite and NOx− production. This case-control study enrolled 172 TB patients and 179 healthy controls. Neither polymorphism was associated with susceptibility to TB. NOS2A-954G/C SNP was not associated with serum levels of nitrite and NOx−. These results indicate that variants of IFNG+874T/A SNP and NOS2A-954G/C SNP do not influence TB susceptibility or the secretion of nitric oxide radicals in the study population.

Monkey Models of Tuberculosis: Lessons Learned

Abstract: The use of animal models has been invaluable for studying the pathogenesis of Mycobacterium tuberculosis infection, as well as for testing the efficacy of vaccines and drug regimens for tuberculosis. Among the applied animal models, nonhuman primates, particularly macaques, share the greatest anatomical and physiological similarities with humans. As such, macaque models have been used for investigating tuberculosis pathogenesis and preclinical testing of drugs and vaccines. This review focuses on published major studies which illustrate how the rhesus and cynomolgus macaques have enriched and may continue to advance the field of global tuberculosis research.

The Role of Host Genetics (and Genomics) in Tuberculosis.

Abstract: Familial risk of tuberculosis (TB) has been recognized for centuries Largely through studies of mono- and dizygotic twin concordance rates, studies of families with Mendelian susceptibility to mycobacterial disease, and candidate gene studies performed in the 20th century, it was recognized that susceptibility to TB disease has a substantial host genetic component Limitations in candidate gene studies and early linkage studies made the robust identification of specific loci associated with disease challenging, and few loci have been convincingly associated across multiple populations Genome-wide and transcriptome-wide association studies, based on microarray (commonly known as genechip) technologies, conducted in the past decade have helped shed some light on pathogenesis but only a handful of new pathways have been identified This apparent paradox, of high heritability but few replicable associations, has spurred a new wave of collaborative global studies This review aims to comprehensively review the heritability of TB, critically review the host genetic and transcriptomic correlates of disease, and highlight current studies and future prospects in the study of host genomics in TB An implicit goal of elucidating host genetic correlates of susceptibility to Mycobacterium tuberculosis infection or TB disease is to identify pathophysiological features amenable to translation to new preventive, diagnostic, or therapeutic interventions The translation of genomic insights into new clinical tools is therefore also discussed

Non-Human Primate Models of Tuberculosis

Abstract: Among the animal models of tuberculosis (TB), the non-human primates, particularly rhesus macaques (Macaca fascicularis) and cynomolgus macaques (Macaca mulatta), share the greatest anatomical and physiological similarities with humans. Macaques are highly susceptible to Mycobacterium tuberculosis infection and manifest the complete spectrum of clinical and pathological manifestations of TB as seen in humans. Therefore, the macaque models have been used extensively for investigating the pathogenesis of M. tuberculosis infection and for preclinical testing of drugs and vaccines against TB. This review focuses on published major studies that exemplify how the rhesus and cynomolgus macaques have enhanced and may continue to advance global efforts in TB research.

A single nucleotide polymorphism in the interferon-γ gene ( IFNG +874 T/A) is associated with susceptibility to tuberculosis

Abstract: // Zhang Wei 1,* , Shen Wenhao 2,* , Mi Yuanyuan 3 , Li Yang 1 , Zhou Daming 1 , Xian Jiangchun 1 and Jiang Jijun 1 1 Department of Infectious Disease, Taizhou People’s Hospital, Taizhou, China 2 Department of Oncology, Taizhou People’s Hospital, Taizhou, China 3 Department of Urology, Third Affiliated Hospital of Nantong University, Wuxi, China * These authors have contributed equally to this work Correspondence to: Zhang Wei, email: // Keywords : Interferon-γ; pulmonary tuberculosis; extra-pulmonary tuberculosis; polymorphism; meta-analysis; Immunology and Microbiology Section; Immune response; Immunity Received : January 07, 2017 Accepted : March 30, 2017 Published : April 20, 2017 Abstract Interferon-γ (Interferon gamma, IFNG) is an important cytokine involved in providing resistance to mycobacterial diseases. Common variants of IFNG , such as IFNG +874 T/A(rs2430561), may be related to tuberculosis susceptibility, but this association has not been consistently observed. We performed an updated meta-analysis to evaluate the association between the IFNG +874 T/A (rs2430561) polymorphism and tuberculosis susceptibility. PubMed and SinoMed databases were searched up to October 2016, and odds ratios (OR) and 95% confidence intervals (CI) were used to assess the association strength. Based on search criteria for manuscripts reporting tuberculosis susceptibility and its relationship with the IFNG +874 T/A(rs2430561)polymorphism, 42 case-control studies from 39 different articles were retrieved. Significantly positive, decreased, and protective associations were found between the IFNG +874 T/A(rs2430561)polymorphism and tuberculosis risk in five genetic models. Moreover, in the stratified subgroup analysis, a protective relationship was detected in four different ethnicities and sources of the control groups. Furthermore, the IFNG +874 T/A(rs2430561)polymorphism played an important role in protecting individuals from both pulmonary tuberculosis and extra-pulmonary tuberculosis. Our meta-analysis suggests that the IFNG +874 T/A(rs2430561)polymorphism is potentially associated with tuberculosis susceptibility and may be used as a predictive biomarker. Further studies with larger sample sizes and consideration of gene-environment interactions should be conducted to elucidate the role of IFNG +874 T/A(rs2430561) polymorphism in tuberculosis susceptibility.

TNF-α blockade impairs in vitro tuberculous granuloma formation and down modulate Th1, Th17 and Treg cytokines.

Abstract: Tuberculosis (TB) is a granulomatous disease that has affected humanity for thousands of years. The production of cytokines, such as IFN-γ and TNF-α, is fundamental in the formation and maintenance of granulomas and in the control of the disease. Recently, the introduction of TNF-α-blocking monoclonal antibodies, such as Infliximab, has brought improvements in the treatment of patients with chronic inflammatory diseases, but this treatment also increases the risk of reactivation of latent tuberculosis. Our objective was to analyze, in an in vitro model, the influence of Infliximab on the granulomatous reactions and on the production of antigen-specific cytokines (TNF-α, IFN-γ, IL-12p40, IL-10 and IL-17) from beads sensitized with soluble Bacillus Calmette-Guerin (BCG) antigens cultured in the presence of peripheral blood mononuclear cells (PBMC) from TB patients. We evaluated 76 individuals, with tuberculosis active, treated and subjects with positive PPD. Granuloma formation was induced in the presence or absence of Infliximab for up to 10 days. The use of Infliximab in cultures significantly blocked TNF-α production (p <0.05), and led to significant changes in granuloma structure, in vitro, only in the treated TB group. On the other hand, there was a significant reduction in the levels of IFN-γ, IL-12p40, IL-10 and IL-17 after TNF-α blockade in the three experimental groups (p <0.05). Taken together, our results demonstrate that TNF-α blockade by Infliximab directly influenced the structure of granuloma only in the treated TB group, but negatively modulated the production of Th1, Th17 and regulatory T cytokines in the three groups analyzed.