BAT3 interacts with transforming growth factor-beta (TGF-beta) receptors and enhances TGF-beta1-induced type I collagen expression in mesangial cells

The chromatin remodeling protein BRG1 regulates HSC-myofibroblast differentiation and liver fibrosis

Excessive fibrogenic response in the liver disrupts normal hepatic anatomy and function heralding such end-stage liver diseases as hepatocellular carcinoma and cirrhosis. Myofibroblasts, derived primarily from hepatic stellate cells (HSCs), are the effector of liver fibrosis. In the present study we investigated the mechanism by which Brahma-related gene 1 (BRG1, encoded by Smarca4) regulates HSC-myofibroblast transition and the implication in intervention against liver fibrosis. We report that BRG1 expression was elevated during HSC maturation in cell culture, in animal models, and in human cirrhotic liver biopsy specimens. HSC-specific deletion of BRG1 attenuated liver fibrosis in several different animal models. In addition, BRG1 ablation in myofibroblasts ameliorated liver fibrosis. RNA-seq identified IGFBP5 as a novel target for BRG1. Over-expression of IGFBP5 partially rescued the deficiency in myofibroblast activation when BRG1 was depleted. On the contrary, IGFBP5 knockdown suppressed HSC-myofibroblast transition in vitro and mollified liver fibrosis in mice. Mechanistically, IGFBP5 interacted with Bat3 to stabilize the Bat3-TβR complex and sustain TGF-β signaling. In conclusion, our data provide compelling evidence that BRG1 is a pivotal regulator of liver fibrosis by programming HSC-myofibroblast transition.

Introducing Molecular Chaperones into the Causality and Prospective Management of Autoimmune Hepatitis

Molecular chaperones influence the immunogenicity of peptides and the activation of effector T cells, and their pathogenic roles in autoimmune hepatitis are unclear. Heat shock proteins are pivotal in the processing and presentation of peptides that activate CD8+ T cells. They can also induce regulatory B and T cells and promote immune tolerance. Tapasin and the transporter associated with antigen processing-binding protein influence the editing and loading of high-affinity peptides for presentation by class I molecules of the major histocompatibility complex. Their over-expression could enhance the autoimmune response, and their deficiency could weaken it. The lysosome-associated membrane protein-2a isoform in conjunction with heat shock cognate 70 supports the importation of cytosolic proteins into lysosomes. Chaperone-mediated autophagy can then process the peptides for activation of CD4+ T cells. Over-expression of autophagy in T cells may also eliminate negative regulators of their activity. The human leukocyte antigen B-associated transcript three facilitates the expression of class II peptide receptors, inhibits T cell apoptosis, prevents T cell exhaustion, and sustains the immune response. Immunization with heat shock proteins has induced immune tolerance in experimental models and humans with autoimmune disease by inducing regulatory T cells. Therapeutic manipulation of other molecular chaperones may promote T cell exhaustion and induce tolerogenic dendritic cells. In conclusion, molecular chaperones constitute an under-evaluated family of ancillary proteins that could affect the occurrence, severity, and outcome of autoimmune hepatitis. Clarification of their contributions to the immune mechanisms and clinical activity of autoimmune hepatitis could have therapeutic implications.

Expression Analysis of FGF/FGFR and FOX Family Proteins in Mucosal Tissue Obtained from Orofacial Cleft-Affected Children

Orofacial clefts affect hundreds of thousands of children worldwide annually and are usually corrected by a series of surgeries extending to childhood. The underlying mechanisms that lead to clefts are still unknown, mainly because of the multifactorial etiology and the myriad of interactions between genes and environmental factors. In the present study, we investigated the role and expression of candidate genes belonging to the FGF/FGFR signaling pathway and FOX family in tissue material obtained from 12 pediatric patients undergoing cleft correction surgery. The expression was investigated using immunohistochemistry (IHC) and chromogenic in-situ hybridization (CISH) in three cell/tissue types-epithelial cells, connective tissue, and endothelial cells. We found elevated expression of FGFR1 in epithelial cells while no expression was observed in endothelial cells. Further, our results elucidate the potential pathogenetic role of FGFR1 in cellular proliferation, local site inflammation, and fibrosis in cleft patients. Along with bFGF (also called FGF2), FGFR1 could play a pro-inflammatory role in clefts. Over-amplification of FGFR2 in some patients, along with bFGF, could potentially suggest roles for these genes in angiogenesis. Additionally, increased expression of FOXE1 (also called TTF2) contributes to local site inflammation. Finally, zero to low amplification of FOXO1 could suggest its potential role in inducing oxidative stress in the endothelium along with reduced epithelial apoptosis.

The cleft palate candidate gene BAG6 supports FoxO1 acetylation to promote FasL-mediated apoptosis during palate fusion

BACKGROUND

Cleft palate is a common craniofacial defect, which occurs when the palate fails to fuse during development. During fusion, the palatal shelves migrate towards the embryonic midline to form a seam. Apoptotic elimination of medial edge epithelium (MEE) cells along this seam is required for the completion of palate fusion.

METHODS

Whole exome sequencing (WES) of six Chinese cleft palate families was applied to identify novel cleft palate-associated gene variants. Palatal fusion and immunofluorescence studies were performed in a murine palatal shelf organ culture model. Gene and protein expression were analyzed by qPCR and immunoblotting in murine MEE cells during seam formation in vivo. Mechanistic immunoprecipitation studies were performed in murine MEE cells in vitro.

RESULTS

WES identified Bcl-2 associated anthanogene 6 (BAG6) as a novel cleft palate-associated gene. In murine MEE cells, we discovered upregulation of Bag6 and the transcription factor forkhead box protein O1 (FoxO1) during seam formation in vivo. Using a palatal shelf organ culture model, we demonstrate that nuclear-localized Bag6 enhances MEE cell apoptosis by promoting p300's acetylation of FoxO1, thereby promoting transcription of the pro-apoptotic Fas ligand (FasL). Subsequent gain- and loss-of-function studies in the organ culture model demonstrated that FasL is required for Bag6/acFoxO1-mediated activation of pro-apoptotic Bax/caspase-3 signaling, MEE apoptosis, and palate fusion. Palatal shelf contact was shown to enhance Bag6 nuclear localization and upregulate nuclear acFoxO1 in MEE cells.

CONCLUSIONS

These findings demonstrate that nuclear-localized Bag6 and p300 co-operatively enhance FoxO1 acetylation to promote FasL-mediated MEE apoptosis during palate fusion.

Signaling Receptors for TGF-β Family Members

Transforming growth factor β (TGF-β) family members signal via heterotetrameric complexes of type I and type II dual specificity kinase receptors. The activation and stability of the receptors are controlled by posttranslational modifications, such as phosphorylation, ubiquitylation, sumoylation, and neddylation, as well as by interaction with other proteins at the cell surface and in the cytoplasm. Activation of TGF-β receptors induces signaling via formation of Smad complexes that are translocated to the nucleus where they act as transcription factors, as well as via non-Smad pathways, including the Erk1/2, JNK and p38 MAP kinase pathways, and the Src tyrosine kinase, phosphatidylinositol 3'-kinase, and Rho GTPases.

Regulation of TGF-β Receptors

In cells responding to extracellular polypeptide ligands, regulatory mechanisms at the level of cell surface receptors are increasingly seen to define the nature of the ligand-induced signaling responses. Processes that govern the levels of receptors at the plasma membrane, including posttranslational modifications, are crucial to ensure receptor function and specify the downstream signals. Indeed, extracellular posttranslational modifications of the receptors help define stability and ligand binding, while intracellular modifications mediate interactions with signaling mediators and accessory proteins that help define the nature of the signaling response. The use of various molecular biology and biochemistry techniques, based on chemical crosslinking, e.g., biotin or radioactive labeling, immunofluorescence to label membrane receptors and flow cytometry, allows for quantification of changes of cell surface receptor presentation. Here, we discuss recent progress in our understanding of the regulation of TGF-β receptors, i.e., the type I (TβRI) and type II (TβRII) TGF-β receptors, and describe basic methods to identify and quantify TGF-β cell surface receptors.

Computational identification of potential transcriptional regulators of TGF-ß1 in human atherosclerotic arteries

TGF-ß is protective in atherosclerosis but deleterious in metastatic cancers. Our aim was to determine whether TGF-ß transcriptional regulation is tissue-specific in early atherosclerosis. The computational methods included 5 steps: (i) from microarray data of human atherosclerotic carotid tissue, to identify the 10 best co-expressed genes with TGFB1 (TGFB1 gene cluster), (ii) to choose the 11 proximal promoters, (iii) to predict the TFBS shared by the promoters, (iv) to identify the common TFs co-expressed with the TGFB1 gene cluster, and (v) to compare the common TFs in the early lesions to those identified in advanced atherosclerotic lesions and in various cancers. Our results show that EGR1, SP1 and KLF6 could be responsible for TGFB1 basal expression, KLF6 appearing specific to atherosclerotic lesions. Among the TFs co-expressed with the gene cluster, transcriptional activators (SLC2A4RG, MAZ) and repressors (ZBTB7A, PATZ1, ZNF263) could be involved in the fine-tuning of TGFB1 expression in atherosclerosis.

BAG-6, a jack of all trades in health and disease

BCL2-associated athanogene 6 (BAG-6) (also Bat-3/Scythe) was discovered as a gene product of the major histocompatibility complex class III locus. The Xenopus ortholog Scythe was first identified to act as an anti-apoptotic protein. Subsequent studies unraveled that the large BAG-6 protein contributes to a number of cellular processes, including apoptosis, gene regulation, protein synthesis, protein quality control, and protein degradation. In this context, BAG-6 acts as a multifunctional chaperone, which interacts with its target proteins for shuttling to distinct destinations. Nonetheless, as anticipated from its genomic localization, BAG-6 is involved in a variety of immunological pathways such as macrophage function and TH1 response. Most recently, BAG-6 was identified on the plasma membrane of dendritic cells and malignantly transformed cells where it serves as cellular ligand for the activating natural killer (NK) cell receptor NKp30 triggering NK cell cytotoxicity. Moreover, target cells were found to secrete soluble variants of BAG-6 and release BAG-6 on the surface of exosomes, which inhibit or activate NK cell cytotoxicity, respectively. These data suggest that the BAG-6 antigen is an important target to shape a directed immune response or to overcome tumor-immune escape strategies established by soluble BAG-6. This review summarizes the currently known functions of BAG-6, a fascinating multicompetent protein, in health and disease.

A soluble fragment of the tumor antigen BCL2-associated athanogene 6 (BAG-6) is essential and sufficient for inhibition of NKp30 receptor-dependent cytotoxicity of natural killer cells

Immunosurveillance of tumor cells depends on NKp30, a major activating receptor of human natural killer (NK) cells. The human BCL2-associated athanogene 6 (BAG-6, also known as BAT3; 1126 amino acids) is a cellular ligand of NKp30. To date, little is known about the molecular details of this receptor ligand system. Within the current study, we have located the binding site of NKp30 to a sequence stretch of 250 amino acids in the C-terminal region of BAG-6 (BAG-6(686-936)). BAG-6(686-936) forms a noncovalent dimer of 57-59 kDa, which is sufficient for high affinity interaction with NKp30 (KD < 100 nM). As our most important finding, BAG-6(686-936) inhibits NKp30-dependent signaling, interferon-γ release, and degranulation of NK cells in the presence of malignantly transformed target cells. Based on these data, we show for the first time that BAG-6(686-936) comprises a subdomain of BAG-6, which is sufficient for receptor docking and inhibition of NKp30-dependent NK cell cytotoxicity as part of a tumor immune escape mechanism. These molecular insights provide an access point to restore tumor immunosurveillance by NK cells and to increase the efficacy of cellular therapies.

BAG6/BAT3: emerging roles in quality control for nascent polypeptides

BAG6 (also known as BAT3/Scythe) is a ubiquitin-like protein that is thought to participate in a variety of seemingly unrelated physiological and pathological processes, such as apoptosis, antigen presentation and the T-cell response. Recent studies have shown that BAG6 is essential for the quality control of aggregation-prone polypeptide biogenesis. It forms part of a complex that determines the fate of newly synthesized client proteins for membrane insertion, ubiquitin-mediated degradation and/or aggregate formation. A biologically relevant transmembrane protein family has recently been shown to be a major client of BAG6, suggesting that many of the known diverse BAG6 functions can be interpreted by BAG6-mediated control of membrane protein biogenesis. In this review, we summarize the current understanding of the physiological roles of BAG6 with a particular focus on quality control for nascent chain polypeptides.

Bat3 promotes T cell responses and autoimmunity by repressing Tim-3–mediated cell death and exhaustion

T cell immunoglobulin and mucin domain–containing 3 (Tim-3) is an inhibitory receptor that is expressed on exhausted T cells during infection with HIV-1 and hepatitis C virus. By contrast, Tim-3 expression and function are defective in multiple human autoimmune diseases. However, the molecular mechanisms modulating Tim-3 function are not well understood. Here we show that human leukocyte antigen B (HLA-B)-associated transcript 3 (Bat3) binds to, and represses the function of, Tim-3. Bat3 protects T helper type 1 (TH1) cells from galectin-9–mediated cell death and promotes both proliferation and proinflammatory cytokine production. Bat3-deficient T cells have elevated expression of exhaustion-associated molecules such as Tim-3, Lag3, Prdm1 and Pbx3, and Bat3 knockdown in myelin-antigen–specific CD4+ T cells markedly inhibits the development of experimental autoimmune encephalomyelitis while promoting the expansion of a dysfunctional Tim-3hi, interferon-γ (IFN-γ)loCD4+ cell population. Furthermore, expression of Bat3 is reduced in exhausted Tim-3+ T cells from mouse tumors and HIV-1–infected individuals. These data indicate that Bat3 acts as an inhibitor of Tim-3–dependent exhaustion and cell death. Bat3 may thus represent a viable therapeutic target in autoimmune disorders, chronic infections and cancers.

BAT3 regulates Mycobacterium tuberculosis protein ESAT-6-mediated apoptosis of macrophages

HLA-B-associated transcript 3 (BAT3), also known as Scythe or BAG6, is a nuclear protein implicated in the control of apoptosis and natural killer (NK) cell-dendritic cell (DC) interaction. We demonstrate that BAT3 modulates the immune response by regulating the function of macrophages. BAT3 is released by macrophages in vitro and it down-regulates nitric oxide and proinflammatory cytokines release in IFN-γ and LPS stimulated macrophages. Furthermore, Mycobacterium tuberculosis-derived protein ESAT-6 (Rv3875) induced transient increase in the expression and release of BAT3 in macrophages. We show that induction of apoptosis by ESAT-6 is dependent on the cleavage of BAT3 by caspase-3 and proteasomal degradation. Our results also indicate that BAT3 regulates ESAT-6-induced apoptosis by interacting with anti-apoptotic protein BCL-2. Taken together, the data suggest that BAT3 plays a role in the early immune response to M. tuberculosis infection and may be a key protein associated with the fate of antigen presenting cells during infection.

Post-translational regulation of TGF-β receptor and Smad signaling

TGF-β family signaling through Smads is conceptually a simple and linear signaling pathway, driven by sequential phosphorylation, with type II receptors activating type I receptors, which in turn activate R-Smads. Nevertheless, TGF-β family proteins induce highly complex programs of gene expression responses that are extensively regulated, and depend on the physiological context of the cells. Regulation of TGF-β signaling occurs at multiple levels, including TGF-β activation, formation, activation and destruction of functional TGF-β receptor complexes, activation and degradation of Smads, and formation of Smad transcription complexes at regulatory gene sequences that cooperate with a diverse set of DNA binding transcription factors and coregulators. Here we discuss recent insights into the roles of post-translational modifications and molecular interaction networks in the functions of receptors and Smads in TGF-β signal responses. These layers of regulation demonstrate how a simple signaling system can be coopted to exert exquisitely regulated, complex responses.

Bat3 facilitates H3K79 dimethylation by DOT1L and promotes DNA damage-induced 53BP1 foci at G1/G2 cell-cycle phases

The methyltransferase DOT1L methylates histone H3 at K79 to facilitate specific biological events. H3K79 dimethylation (H3K79-2Me) by DOT1L influences the DNA damage response by promoting 53BP1 recruitment to DNA damage sites; however, it is unclear if this methylation is required as 53BP1 interacts with dimethylated H4 (H4K20-2Me) with a much higher affinity. We demonstrate that H3K79-2Me, while negligible during S-phase, is required for ionizing radiation (IR)-induced 53BP1 foci formation during G1/G2-phases when H4K20-2Me levels are low. Further, we describe an essential role for HLA-B-associated transcript 3 (Bat3) in regulating this process in U2OS cells. Bat3 co-localizes with DOT1L at histone H3, and Bat3 knockdown results in decreased DOT1L-H3 interaction and H3K79-2Me, leading to a reduction in IR-induced 53BP1 foci formation, defects in DNA repair and increased sensitivity to IR. We demonstrate that a conserved Bat3 ubiquitin-like motif and a conserved DOT1L ubiquitin-interacting motif promote DOT1L-Bat3 interaction to facilitate efficient H3K79-2Me and IR-induced 53BP1 foci formation during G1/G2-phases. Taken together, our findings identify a novel role for Bat3 in regulating DOT1L function, which plays a critical role in DNA damage response.

HLA-B-associated transcript 3 (Bat3/Scythe) negatively regulates Smad phosphorylation in BMP signaling

Members of the transforming growth factor-β (TGF-β) superfamily participate in numerous biological phenomena in multiple tissues, including in cell proliferation, differentiation, and migration. TGF-β superfamily proteins therefore have prominent roles in wound healing, fibrosis, bone formation, and carcinogenesis. However, the molecular mechanisms regulating these signaling pathways are not fully understood. Here, we describe the regulation of bone morphogenic protein (BMP) signaling by Bat3 (also known as Scythe or BAG6). Bat3 overexpression in murine cell lines suppresses the activity of the Id1 promoter normally induced by BMP signaling. Conversely, Bat3 inactivation enhances the induction of direct BMP target genes, such as Id1, Smad6, and Smad7. Consequently, Bat3 deficiency accelerates the differentiation of primary osteoblasts into bone, with a concomitant increase in the bone differentiation markers Runx2, Osterix, and alkaline phosphatase. Using biochemical and cell biological analyses, we show that Bat3 inactivation sustains the C-terminal phosphorylation and nuclear localization of Smad1, 5, and 8 (Smad1/5/8), thereby enhancing biological responses to BMP treatment. At the mechanistic level, we show that Bat3 interacts with the nuclear phosphatase small C-terminal domain phosphatase (SCP) 2, which terminates BMP signaling by dephosphorylating Smad1/5/8. Notably, Bat3 enhances SCP2–Smad1 interaction only when the BMP signaling pathway is activated. Our results demonstrate that Bat3 is an important regulator of BMP signaling that functions by modulating SCP2–Smad interaction.

Major histocompatibility complex class I chain-related gene polymorphisms: associated with susceptibility to Kawasaki disease and coronary artery aneurysms

BACKGROUND

Kawasaki disease (KD) involves a complex interaction of immunoinflammatory process, cytokine activation, and genetic factors. We aimed to investigate whether genetic variations in a major histocompatibility complex (MHC) class could be used as markers of susceptibility in KD and coronary artery aneurysm lesions (CALs).

METHODS

Individuals were divided into following groups: (1) normal controls; (2) KD with CAL; (3) KD without CAL. Polymorphisms for MHC class I chain-related genes A (MICA) (rs2301747, rs2256184, rs2848716), MICB (rs2855804, rs3132464, rs2516400), BAT3 (rs750332), MSH5 (rs1150793), and chromosome 6 open reading frame 27 (C6orf27, rs707928) were genotyped with polymerase chain reaction and the TaqMan(®) allelic discrimination assay. Genotypes, alleles, and haplotype in each group were compared.

RESULTS

Genotype and allele frequency of MICB*rs2516400 polymorphisms in each group were significantly different. MICB (rs2516400)*C-related genotypes/alleles are correlated with development of KD and CAL. Proportions of rs2516400*TT/TC/CC were (1) 1/39/60%, (2) 0/0/100%, and (3) 0/0/100%. Other single-nucleotide polymorphisms were not associated with KD susceptibilities. Haplotypes (rs2301747-rs2256184-rs2848716-rs2855804-rs3132464-rs2516400-rs750332-rs1150793-rs707928) G-G-G-C-T-C-T-A-A, C-A-G-T-T-C-T-A-A, and G-G-G-C-C-C-T-A-A were associated with higher susceptibilities for KD. The G-G-G-T-T-T-T-G-G and C-G-G-T-T-T-T-A-A haplotypes were associated with lower susceptibilities.

CONCLUSION

MICB*rs2516400 polymorphisms and some MHC class I-related haplotypes are associated with KD susceptibility. MICB and MHC class I genetic variations might contribute to the pathogenesis of KD and CAL.

Human lymphocyte antigen B-associated transcript 2, 3, and 5 polymorphisms and haplotypes are associated with susceptibility of Kawasaki disease and coronary artery aneurysm

CAPSULE

HLA-B associated transcript (BAT) 2, 3, and 5 polymorphisms and haplotypes are associated with Kawasaki disease (KD) and coronary artery aneurysm (CAA) formations.

OBJECTIVE

KD, an acute vasculitis with unknown etiology, involves a complex interaction of immuno-inflammatory process, cytokines activation, and genetic factors. We aimed to investigate if genetic variants of human lymphocyte antigen (HLA)-BAT2, 3, and 5 (BAT2, 3, and 5) could be used as markers of susceptibility in KD and CAA.

METHODS

Individuals were divided into three groups: (1) normal controls; (2) KD with CAA; and (3) KD without CAA. Polymorphisms for BAT2 (-8671, 16483), BAT3 (8854, 2-24), and BAT5 (22655, 9569) were genotyped by PCR system with TaqMan allelic discrimination assay. Genotype/allelic frequencies and haplotypes (BAT2(-8671)-BAT2(16483)-BAT3(8854)-BAT3(2-24)-BAT5(22655)-BAT5(9569)) in each group were compared.

RESULTS

Genotype distribution and allele frequency of BAT2 -8671, BAT3 8854, and BAT5 22655, 9569 polymorphisms in each group were significantly different. BAT2 -8671*G, BAT3 8854*C, BAT5 22655*C, and 9569*A-related genotypes and alleles are correlated with the developments of KD and CAA. BAT haplotypes of ATTGTG and ATCATG are associated with higher susceptibilities of KD with CAA susceptibility.

CONCLUSION

BAT2 -8671, BAT3 8854, and BAT5 22655, 9569 polymorphisms as well as BAT haplotypes (ATTGTG and ATCATG) might be associated with higher KD susceptibility and CAA formation. HLA-B region polymorphisms might contribute to the pathogenesis of KD and CAA.

Human lymphocyte antigen B-associated transcript 2, 3, and 5 polymorphisms and haplotypes are associated with susceptibility of Kawasaki disease and coronary artery aneurysm

CAPSULE

HLA-B associated transcript (BAT) 2, 3, and 5 polymorphisms and haplotypes are associated with Kawasaki disease (KD) and coronary artery aneurysm (CAA) formations.

OBJECTIVE

KD, an acute vasculitis with unknown etiology, involves a complex interaction of immuno-inflammatory process, cytokines activation, and genetic factors. We aimed to investigate if genetic variants of human lymphocyte antigen (HLA)-BAT2, 3, and 5 (BAT2, 3, and 5) could be used as markers of susceptibility in KD and CAA.

METHODS

Individuals were divided into three groups: (1) normal controls; (2) KD with CAA; and (3) KD without CAA. Polymorphisms for BAT2 (-8671, 16483), BAT3 (8854, 2-24), and BAT5 (22655, 9569) were genotyped by PCR system with TaqMan allelic discrimination assay. Genotype/allelic frequencies and haplotypes (BAT2(-8671)-BAT2(16483)-BAT3(8854)-BAT3(2-24)-BAT5(22655)-BAT5(9569)) in each group were compared.

RESULTS

Genotype distribution and allele frequency of BAT2 -8671, BAT3 8854, and BAT5 22655, 9569 polymorphisms in each group were significantly different. BAT2 -8671*G, BAT3 8854*C, BAT5 22655*C, and 9569*A-related genotypes and alleles are correlated with the developments of KD and CAA. BAT haplotypes of ATTGTG and ATCATG are associated with higher susceptibilities of KD with CAA susceptibility.

CONCLUSION

BAT2 -8671, BAT3 8854, and BAT5 22655, 9569 polymorphisms as well as BAT haplotypes (ATTGTG and ATCATG) might be associated with higher KD susceptibility and CAA formation. HLA-B region polymorphisms might contribute to the pathogenesis of KD and CAA.

Human lymphocyte antigen B-associated transcript 2, 3, and 5 polymorphisms and haplotypes are associated with susceptibility of Kawasaki disease and coronary artery aneurysm

CAPSULE

HLA-B associated transcript (BAT) 2, 3, and 5 polymorphisms and haplotypes are associated with Kawasaki disease (KD) and coronary artery aneurysm (CAA) formations.

OBJECTIVE

KD, an acute vasculitis with unknown etiology, involves a complex interaction of immuno-inflammatory process, cytokines activation, and genetic factors. We aimed to investigate if genetic variants of human lymphocyte antigen (HLA)-BAT2, 3, and 5 (BAT2, 3, and 5) could be used as markers of susceptibility in KD and CAA.

METHODS

Individuals were divided into three groups: (1) normal controls; (2) KD with CAA; and (3) KD without CAA. Polymorphisms for BAT2 (-8671, 16483), BAT3 (8854, 2-24), and BAT5 (22655, 9569) were genotyped by PCR system with TaqMan allelic discrimination assay. Genotype/allelic frequencies and haplotypes (BAT2(-8671)-BAT2(16483)-BAT3(8854)-BAT3(2-24)-BAT5(22655)-BAT5(9569)) in each group were compared.

RESULTS

Genotype distribution and allele frequency of BAT2 -8671, BAT3 8854, and BAT5 22655, 9569 polymorphisms in each group were significantly different. BAT2 -8671*G, BAT3 8854*C, BAT5 22655*C, and 9569*A-related genotypes and alleles are correlated with the developments of KD and CAA. BAT haplotypes of ATTGTG and ATCATG are associated with higher susceptibilities of KD with CAA susceptibility.

CONCLUSION

BAT2 -8671, BAT3 8854, and BAT5 22655, 9569 polymorphisms as well as BAT haplotypes (ATTGTG and ATCATG) might be associated with higher KD susceptibility and CAA formation. HLA-B region polymorphisms might contribute to the pathogenesis of KD and CAA.