ABSTRACT
Objective To establish a cell model expressing the Langerhans cell-specific C type lectin receptor Langerin in vitro.Methods The cDNA of Langerin was obtained by PCR and cloned into a eukauotic green fluorescent protein (EGFP) expression vector pEGFP-C 1 with EGFP located in the N terminal region of the Langerin gene.Then,the recombinant plasmid was transfected into a human embryonic kidney carcinoma cell line HEK293T.Subsequently,laser confocal microscopy was performed to observe the expression of EGFP-Langerin fusion protein,and flow cytometry to measure the expression of Langerin.Laser confocal microscopy was also conducted to visualize the recognition and endocytosis of dust mite antigen (nDer p 2) by Langerin.Results PCR and Western blot confirmed the successful transfection of HEK293T cells with the recombinant plasmid as well as the expression of Langerin in the transfected cells.As flow cytometry revealed,the expression level of Langerin in transfected HEK293T cells was increased by 43％ compared with untransfected cells.Laser confocal microscopy showed that green fluorescein-labeled Langerin was successfully expressed,and could bind to and endocytose the red fluorescein-labeled antigen nDer p 2.Conclusions The fusion protein EGFP-Langerin expressed in HEK293T cells showed the distribution characteristic of cell surface receptors,and could bind to and endocytose allergens.
ABSTRACT
Studies on human genetic variations are a useful source of knowledge about human immunodeficiency virus (HIV)-1 infection. The Langerin protein, found at the surface of Langerhans cells, has an important protective role in HIV-1 infection. Differences in Langerin function due to host genetic factors could influence susceptibility to HIV-1 infection. To verify the frequency of mutations in the Langerin gene, 118 samples from HIV-1-infected women and 99 samples from HIV-1-uninfected individuals were selected for sequencing of the promoter and carbohydrate recognition domain (CRD)-encoding regions of the Langerin gene. Langerin promoter analysis revealed two single nucleotide polymorphisms (SNPs) and one mutation in both studied groups, which created new binding sites for certain transcription factors, such as NFAT5, HOXB9.01 and STAT6.01, according to MatInspector software analysis. Three SNPs were observed in the CRD-encoding region in HIV-1-infected and uninfected individuals: p.K313I, c.941C>T and c.983C>T. This study shows that mutations in the Langerin gene are present in the analysed populations at different genotypic and allelic frequencies. Further studies should be conducted to verify the role of these mutations in HIV-1 susceptibility.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Antigens, CD/genetics , HIV Infections/genetics , HIV-1 , Lectins, C-Type/genetics , Mutation , Mannose-Binding Lectins/genetics , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , Brazil , Genotype , Gene Frequency/genetics , Genetic Predisposition to Disease/genetics , Hydrophobic and Hydrophilic Interactions , Homeodomain Proteins/genetics , Polymerase Chain Reaction , Sequence Analysis, DNA , /genetics , Transcription Factors/geneticsABSTRACT
BACKGROUND: Langerhans cell histiocytosis (LCH) is a well-known neoplastic disorder of Langerhans cells which has characteristic findings, however, LCH has not been adequately studied in Korea. METHODS: We analyzed the clinicopathologic features of 20 patients with LCH who were diagnosed between 1997 and 2006 at the Korea University Guro and Anam Hospitals. RESULTS: The M:F ratio was 3:1 and the age ranged from 2-60 years (mean, 23.8 years [4 in 1st decade, 6 in 2nd decade, 2 in 3rd decade, 5 in 4th decade and 3> or =40 years of age). The cases were classified as unifocal unisystemic in 13 patients, multifocal unisystemic in 4 patients, and multifocal multisystemic in 3 patients. The bone was the most commonly involved organ (14), followed by lymph node (5), lung (2), skin (2) and ureter (1). The Langerhans cells were immunohistochemically stained with Langerin, CD1a, S-100 protein, and CD68. Langerin and CD1a were specific for Langerhans cells. CONCLUSIONS: The distribution of the involved organs in patients with LCH was similar to the distribution in Western countries, but lymph node involvement was more frequent, whereas lung involvement was less common. Langerin is considered to be a specific marker for Langerhans cells.