Comparison of rpoT gene of M. leprae strain from korean and foreign leprosy patients / 나학회지

The variance of tandem repeats in the rpoT gene of Mycobacterium leprae was recently demonstrated. The objects of this study was to examine the proportion and distributions of the genotypes of M. leprae in Korea and to compared it with genotypes of M. leprae form foreign leprosy patients using difference of the tandem repeats. Among 101 cases, 72 isolated from Korea and 4 cases from Japan (except Okinawa) demonstrated four copies of the 6 bp tandem repeats in the rpoT gene, and three copies were found in isolates from two korean, 2 cases of Okinawa in Japan, and those from Southeast Asian countries, Peru and Paraguay. These results reveal the genetic diversity of M. leprae and the related genotype-specific distribution in the world. In this study, a more detailed explanation can be also possible regarding the transmission route of M. leprae.

Detection of point mutation at C-terminal region of phagosomal coat protein (TACO) in patients with leprosy / 나학회지

Mycobacteria, which are highly successful pathogen, resist delivary to lysosomes and instead survive within a specialized vacuole, the mycobacterial phagosome. The bacteria survive intracellularly because they are able to actively recruit and retain TACO ( tryptophane aspartate-containing coat protein ) at the mycobacterial phagosome, where it prevents lysosomal delivary in a cholesterol-dependent manner. In this study, we investigated the difference of TACO expression is whether related to mutant in coro1a gene in patients with leprosy and normal volunteer. First, we screened for detection of a mutant in the leucine zipper motif within the exon 11, and then in the exon 9 to 10, and finally in the coiled-coil region. Interestingly, single base substitutions ( point mutation ) presents at assembly site of U1 snRNP, around of 5' splice site in the intron 9, there are a C to T and G to A transition are at 9 bp and 14 bp downstream of 5' splice site, respectively, and both of it. Among the 3 types of polymorphism, frequency of a G to A transition is markedly increased in patients of lepromatous type, which are new cases or relapsed. Both a C to T and G to A transitions are found in 1 case of tuberculoid type and 2 cases in lepromatoue type, but not found in control group. The silent mutation in leucine zipper motif within the exon 11 is located at codon at 454 ( CTG-->CTA), which is 1st leucine from C-terminal among four leucine zipper. In coiled-coil region, no mutation is found in genomic DNA of patients with leprosy. Further, we will do functional study about the identified point mutation and will screen any possible mutation in the region of promotor and WD repeat.

Mutations in folP1, rpoB, and gyrB associated with multiple drug resistance in Mycobacterium leprae isolates from South Korea / 나학회지

The emergence of multiple drug resistant Mycobacterium leprae has emphasized the need for early decision of effective antileprosy drug in the treatment for leprosy patients. Mutations in the genes associated with multiple drug resistance in Mycobacterium leprae isolates from 17 South Korean patients, who were already confirmed to have mutations in folP1 gene, were investigated using a PCR - single strand conformation polymorphism (SSCP) - DNA sequencing assay. Two strains, which has double mutations, were found in the two unrelated patients : one missense mutation in folP1 (Arg 55 for Pro) and in rpoB (Gly 522 for Ser), and in folP1 (Ala 53 for Thr) and in gyrB (Asn 426 for Asp), respectively. The patients were treated with the long monotheraphy of dapsone or with the inappropriate regimen of antileprosy drugs. These results emphasize the importance of multi-drug theraphy in order to prevent mult-idrug resistance and assist in the choice of the appropriate regimens for treating leprosy.

Doctor's Strike-One Year Later

No abstract available.

The application of TD (Touch-Down) PCR in Diagnosis of leprosy and Detection of MDT-resistant M. leprae / 나학회지

There are several methods for diagnosis of leprosy, including AFB stain, the measurement of PGL-1 (phenolic glycolipid - 1) antigen titer, and DNA-PCR. In this study, we have used the DNA-PCR amplifying the RLEP repetitive sequence. Our result showed that the RLEP primer offered the more sensitive detection and identification of M. leprae DNA in clinical specimens, compared with the other primer, for example, 18-kDa antigen gene. To screen the resistant M. leprae strain of MDT (Multi-Drug Therapy), we have used the TD (Touch-Down) PCR. We arranged and amplified sequences of the genes, folP, rpoB, gyr, 23S rRNA, in M. leprae involved in MDT-resistance, and could obtain the PCR product each gene, simultaneously. This method, based on annealing temperature, was useful to the detection for diagnosis and the screen of MDT-resistant strain of M. leprae, rapidly. Thus, we suggest that the RLEP primer and TD-PCR method are effective in assessing the diagnosis of leprosy and the identification of drug-resistant M. leprae.

Need for Tissue Banking and KMA's Stand

No abstract available.

Interferon-gamma (IFN-gamma) increases CD1 expression through inhibition of IL-10 secretion from M.leprae-infected macrophages of lepromatous leprosy / 나학회지

The CD1 system is a novel antigen-presenting system for T cell recognition of lipid and glycolipids in antimicrobial immunity. Lepromatous leprosy is characterized by lack of cell-mediated immunity against M.leprae. The lack of cell-mediated immunity in lepromatous leprosy has been suggested to be correlated with weak CD1 expression on antigen presenting cells. In order to define how CD1 is down-regulated on M. leprae-infected antigen-presenting cells, we examined effects of interferon-gamma(IFN-gamma) on interleukin-10 (IL-10) secretion and CD1 expression of M.leprae-infected macrophages from granuloma of lepromatous leprosy. Our results showed that a significant trend of increased CD1 expression in response to decresed IL-10 secretion from M.leprae-infected macrophages by IFN-gamma. These results suggest that the local cytokine milieu, especially the balance between IFN-gamma and IL-10, is an important determinant in the regulation of CD1 in lepromatous lesions.