DNA gyrase could be a crucial regulatory factor for growth and survival of Mycobacterium leprae.

Leprosy, an important infectious disease in humans caused by Mycobacterium leprae (Mle), remains endemic in many countries. Notably, the pathogen cannot be cultured in vitro, except in mouse footpads in vivo. The molecular basis of these characteristics and the mechanisms remain unknown.

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.

A lipopeptide facilitate induction of Mycobacterium leprae killing in host cells.

Little is known of the direct microbicidal activity of T cells in leprosy, so a lipopeptide consisting of the N-terminal 13 amino acids lipopeptide (LipoK) of a 33-kD lipoprotein of Mycobacterium leprae, was synthesized. LipoK activated M. leprae infected human dendritic cells (DCs) to induce the production of IL-12.

Apoptosis-inducing activity of clofazimine in macrophages.

Clofazimine is a riminophenazine compound which has been used for the treatment of leprosy since the 1960s. Although the drug is effective in the management of leprosy reactions because of its anti-inflammatory activity, the mechanism leading to the cessation of inflammation is not well understood. In the present study, it was shown that clofazimine exhibits apoptosis-inducing activity in macrophages.

Analysis of drug-resistant strains of Mycobacterium leprae in an endemic area of Vietnam.

Background: Multidrug therapy has effectively reduced the number of leprosy cases in the world. However, the rate of reduction has decelerated over the years, giving early detection of Mycobacterium leprae and epidemiological study of relapse renewed relevance in attempts to eliminate the disease.

Methods: A molecular epidemiological survey for drug-resistant M.

Detection of serum antibodies to M. leprae major membrane protein-II in leprosy patients from Indonesia.

Background: Sero-diagnostic methods are the easiest way of diagnosing an infectious disease in developing countries. In leprosy, phenolic glycolipid-1 (PGL-I) based methods for the detection of leprosy are currently available, but the use of these methods has been hindered due to the inherent problems of sensitivity. We previously showed that antibodies to Major Membrane Protein-II (MMP-II) derived from Mycobacterium leprae could be used to diagnose leprosy in Japan.

[Forefront of vaccine development: tuberculosis and leprosy].

The role of vaccines to tuberculosis and leprosy is to induce a cellular immunity, and as a result to induce the differentiation of memory CD8+ cytotoxic T cells. 'Help' from CD4+ T cells is important for the differentiation of naive CD8+ T cells to effector and memory CD8+ cytotoxic T cells. However, how CD4+ T cell 'help' is involved in the steps instructing T helper (Th) polarization is not yet clear.

Temperature dependency for survival of Mycobacterium leprae in macrophages.

Hansen's disease is caused by an infection with an intracellular pathogen, Mycobacterium leprae, which mainly inhabits macrophages and Schwann cells. However, little is known about the survival or growth mechanisms of the bacilli in mouse and human macrophages. In the present study, by using radiorespirometry analysis for the evaluation of the viability of M.

Serological diagnosis of leprosy in patients in vietnam by enzyme-linked immunosorbent assay with Mycobacterium leprae-derived major membrane protein II.

A serological diagnostic test using phenolic glycolipid-I (PGL-I) developed in the 1980s is commercially available, but the method is still inefficient in detecting all forms of leprosy. Therefore, more-specific and -reliable serological methods have been sought. We have characterized major membrane protein II (MMP-II) as a candidate protein for a new serological antigen.

Evaluation of major membrane protein-II as a tool for serodiagnosis of leprosy.

As serodiagnosis is the easiest way of diagnosing a disease, the utility of Mycobacterium leprae-derived major membrane protein-II (MMP-II), one of the immuno-dominant antigens, in the serodiagnosis of leprosy was examined. The percent positivity by an enzyme-linked immunosorbent assay for anti-MMP-II antibody was 82.4% for multi-bacillary leprosy, and the specificity of the test was 90.

Contribution of GM-CSF on the enhancement of the T cell-stimulating activity of macrophages.

Mycobacterium leprae is an intracellular parasitic organism that multiplies in macrophages (MØ). It inhibits the fusion of mycobacterial phagosome with lysosome and induces interleukin (IL)-10 production from macrophages. However, macrophages are heterogenous in various aspects.

[Current advances in leprosy research activities].

Due to the advent of multi-drug therapy (MDT) recommended by the WHO, for the treatment of leprosy, presently, leprosy is regarded as a "curable disease". The number of new cases in Japan is relatively very low, due to which the disease is likely to be neglected, but on scientific grounds, there is a necessity to perform in depth studies. Leprosy caused by M.

[Functional changes of macrophages in Hansen's disease].

As an obligate intracellular pathogen, the principal host cells for Mycobacterium leprae are mononuclear phagocytes or macrophages. The macrophage is a primitive cell type being found in both early and advanced life forms, and possesses a variety of functions, such as phagocytosis of invaded bacteria, production of cytokines, antigen presentation and tumor killing. Hansen's disease is a chronic infectious disease characterized by specific host immune responses against M.

IL-10 treatment of macrophages bolsters intracellular survival of Mycobacterium leprae.

In these studies, metabolically active Mycobacterium leprae were maintained for as long as 8 weeks in monolayer cultures of mouse peritoneal macrophages (MPhi). Supplemental IL-10, but not TGF-beta, bolstered, directly or indirectly, M. leprae metabolism in mouse MPhi.

Active surveillance of leprosy contacts in country with low prevalence rate.

For advanced control of leprosy in Pakistan where the World Health Organization leprosy elimination goal was achieved in 1996, we conducted surveillance of Mycobacterium leprae-seropositive patients and their contacts and drug resistant strains of M. leprae. We measured anti-PGL-I antibody level in sera from leprosy patients and their contacts for early detection of M.