FcγRIIB, the only inhibitory IgG Fc receptor, functions to suppress the hyper-activation of immune cells. Numerous studies have illustrated its inhibitory function through the ITIM motif in the cytoplasmic tail of FcγRIIB. However, later studies revealed that in addition to the ITIM, the transmembrane (TM) domain of FcγRIIB is also indispensable for its inhibitory function. Indeed, recent epidemiological studies revealed that a non-synonymous single nucleotide polymorphism (rs1050501) within the TM domain of FcγRIIB, responsible for the I232T substitution, is associated with the susceptibility to systemic lupus erythematosus (SLE). In this review, we will summarize these epidemiological and functional studies of FcγRIIB-I232T in the past few years, and will further discuss the mechanisms accounting for the functional loss of FcγRIIB-I232T. Our review will help the reader gain a deeper understanding of the importance of the TM domain in mediating the inhibitory function of FcγRIIB and may provide insights to a new therapeutic target for the associated diseases.
Autoimmune Diseases ; drug therapy ; genetics ; immunology ; Humans ; Protein Domains ; Receptors, IgG ; chemistry ; immunology

Vav1, as a key downstream signaling molecule of T cell receptor, includes a catalytic core DH-PH-ZF domain with the function as guanine nucleotide exchange factor (GEF), and a SH3-SH2-SH3 domain with the function as adaptor protein. These two structures of Vav1 play different roles in the development, activation, proliferation and function of T cells, and thereby exert the different regulatory effect on the occurrence and development of autoimmune disease, graft rejection, cancer and other clinical conditions, implicating that Vav1 might be a potential therapeutic target for these diseases. This paper reviews the role of Vav1 in T cells and the occurrence of related diseases.
Adaptor Proteins, Signal Transducing ; Animals ; Autoimmune Diseases ; genetics ; physiopathology ; Humans ; Neoplasms ; genetics ; physiopathology ; Proto-Oncogene Proteins c-vav ; chemistry ; immunology ; metabolism ; T-Lymphocytes

Human genetic variation is represented by the genetic differences both within and among populations, and most genetic variants do not cause overt diseases but contribute to disease susceptibility and influence drug response. During the last century, various genetic variants, such as copy number variations (CNVs), have been associated with diverse human disorders. Here, we review studies on the associations between CNVs and autoimmune diseases to gain some insight. First, some CNV loci are commonly implicated in various autoimmune diseases, such as Fcgamma receptors in patients with systemic lupus erythemoatosus or idiopathic thrombocytopenic purpura and beta-defensin genes in patients with psoriasis or Crohn's disease. This means that when a CNV locus is associated with a particular autoimmune disease, we should examine its potential associations with other diseases. Second, interpopulation or interethnic differences in the effects of CNVs on phenotypes exist, including disease susceptibility, and evidence suggests that CNVs are important to understand susceptibility to and pathogenesis of autoimmune diseases. However, many findings need to be replicated in independent populations and different ethnic groups. The validity and reliability of detecting CNVs will improve quickly as genotyping technology advances, which will support the required replication.
Animals ; Autoimmune Diseases/ethnology/*genetics/immunology ; Autoimmunity/*genetics ; *DNA Copy Number Variations ; *Gene Dosage ; Genetic Association Studies ; Genetic Markers ; Genetic Predisposition to Disease ; Humans ; Phenotype ; Population Groups/genetics ; Risk Factors

To select candidate genes, we attempted to comparative analysis of protein levels between rheumatoid arthritis (RA) patients and healthy controls by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS). We identified 17 proteins that showed up- or down-regulated spots in RA patients. We found that coactosin-like1 (COTL1) were highly expressed in RA patients compared with healthy controls. We performed a case-control study to determine whether the COTL1 gene polymorphisms were associated with RA and systemic lupus erythematosus (SLE). The genotype frequency of c.-1124G>T and the allelic frequency of c.484G>A in RA patients, and the genotype frequency of c.484G>A in SLE patients were significantly different from healthy controls (P = 0.009, 0.027, and 0.025, respectively). We also investigated the correlation with the levels of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody in RA patients, and anti-nuclear antibodies (ANA) in SLE patients. The c.484G>A polymorphism in RA patients has significant association with the levels of anti-CCP antibody (P = 0.03). Our findings demonstrated that c.-1124G>T and c.484G>A polymorphisms of the COTL1 gene might be associated with the genetic susceptibility of autoimmune disorders.
Arthritis, Rheumatoid/*genetics/immunology/metabolism ; Autoimmune Diseases/genetics/immunology ; Case-Control Studies ; Electrophoresis, Gel, Two-Dimensional ; Genotype ; Humans ; Lupus Erythematosus, Systemic/genetics/immunology ; Microfilament Proteins/*genetics/metabolism ; Polymorphism, Genetic/*genetics ; Proteome/genetics ; Proteomics/*methods ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

To select candidate genes, we attempted to comparative analysis of protein levels between rheumatoid arthritis (RA) patients and healthy controls by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS). We identified 17 proteins that showed up- or down-regulated spots in RA patients. We found that coactosin-like1 (COTL1) were highly expressed in RA patients compared with healthy controls. We performed a case-control study to determine whether the COTL1 gene polymorphisms were associated with RA and systemic lupus erythematosus (SLE). The genotype frequency of c.-1124G>T and the allelic frequency of c.484G>A in RA patients, and the genotype frequency of c.484G>A in SLE patients were significantly different from healthy controls (P = 0.009, 0.027, and 0.025, respectively). We also investigated the correlation with the levels of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody in RA patients, and anti-nuclear antibodies (ANA) in SLE patients. The c.484G>A polymorphism in RA patients has significant association with the levels of anti-CCP antibody (P = 0.03). Our findings demonstrated that c.-1124G>T and c.484G>A polymorphisms of the COTL1 gene might be associated with the genetic susceptibility of autoimmune disorders.
Arthritis, Rheumatoid/*genetics/immunology/metabolism ; Autoimmune Diseases/genetics/immunology ; Case-Control Studies ; Electrophoresis, Gel, Two-Dimensional ; Genotype ; Humans ; Lupus Erythematosus, Systemic/genetics/immunology ; Microfilament Proteins/*genetics/metabolism ; Polymorphism, Genetic/*genetics ; Proteome/genetics ; Proteomics/*methods ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Autoimmune Diseases ; immunology ; Gene Expression Regulation ; immunology ; Humans ; Immunoglobulin G ; genetics ; immunology ; Sclerosis ; genetics ; immunology ; pathology

OBJECTIVETo explore the effects of adenovirus vector-mediated gene transfer of ICOSIg fusion protein on experimental autoimmune myocarditis (EAM) in Lewis rats.

METHODSExpression vector containing ICOSIg (p-Adeno-ICOSIg) was constructed by fusion of human ICOS and IgGFc segment. Adenovirus vector was digested by PacI enzyme and transfected into HEK 293 cells. Adenovirus expressing ICOSIg was produced. EGFP was constructed into adenovirus vector and used as control. EAM was induced in Lewis rats by injection of porcine cardiac myosin. All immunized Lewis rats were divided into 4 groups. Group A (n = 15) and B (n = 15) received adenovirus containing ICOSIg on day 0 and day 14 respectively to study the effects of costimulatory molecules gene therapy on T cell activation and inflammation; group C (n = 10) and group D (n = 10) received adenovirus containing EGFP on day 0 and day 14 respectively as controls. Group E (n = 10) was normal controls that did not receive immunization. On day 28, all rats were killed after echocardiography examination. Histopathological examination was performed to observe myocardial inflammation. Protein levels of ICOS, ICOSL, B7-1 and B7-2 were detected by Western blot. INF-gamma, IL-2 and IL-4 mRNA were determined by realtime RT-PCR.

RESULTSOn day 28, cardiac function was significantly improved and myocardial inflammation significantly attenuated in group B compared to group A, C and D (all P < 0.05). B7-1 expression at protein level was significantly lower in group B than that of group C (P < 0.05). ICOS and ICOSL expressions at protein level were significantly decreased in both group A and B compared with group C and D (P < 0.05). IFN-gamma mRNA level significantly decreased and IL-4 mRNA significantly increased in group A and B compared to group C and D (P < 0.05).

CONCLUSIONSBlockade of costimulatory pathway with gene therapy of ICOSIg alleviated autoimmune inflammatory damage and improved cardiac function in Lewis rats with EAM. Down-regulated costimulatory molecules in the myocardium and reduced inflammatory cytokine secretion might be responsible for the beneficial effects of ICOSIg in this model.

Adenoviridae ; genetics ; Animals ; Antigens, Differentiation, T-Lymphocyte ; genetics ; Autoimmune Diseases ; immunology ; pathology ; therapy ; Disease Models, Animal ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; Immunoglobulin Fc Fragments ; genetics ; Inducible T-Cell Co-Stimulator Protein ; Male ; Myocarditis ; immunology ; pathology ; therapy ; Rats ; Rats, Inbred Lew ; Recombinant Fusion Proteins ; genetics

Th17(T helper 17 cell), a newly discovered subset of T cells is associated with IL-23 and characterized by production of IL-17, the functions of which are distinct from those of Th1, Th2 and Treg subsets. The development of Th17 cells can be promoted by TGF-beta1, IL-6, and IL-23; but inhibited by IFN-gamma, IL-4 and Socs3. It is clear that Th17 cells have protective effects on body by facilitating the pro-inflammatory responses. On the other hand, the role of Th17 cells in the pathophysiology of autoimmune diseases has been described.
Autoimmune Diseases ; immunology ; physiopathology ; Interleukin-17 ; biosynthesis ; immunology ; Interleukin-23 ; biosynthesis ; genetics ; T-Lymphocyte Subsets ; immunology ; physiology ; T-Lymphocytes, Helper-Inducer ; classification ; cytology ; immunology ; Transforming Growth Factor beta1 ; biosynthesis ; genetics

BACKGROUNDExperimental autoimmune myocarditis (EAM) in rats is a T-cell-mediated disorder. The initiation and maintenance of autoimmune responses in EAM depend on the maturation state of dendritic cells. IL-10 is a pleiotrophic immunomodulatory cytokine that functions at different levels of the immune response, so it has emerged as a promising therapeutic factor for the treatment of autoimmune/inflammatory diseases. This study was designed to test the hypothesis that IL-10 gene modified bone marrow-derived immature dendritic cells (iDCs) ameliorate EAM and to explore the underlying mechanisms.

METHODSEAM was induced using the methods of cardiac myosin immunization on day 0 and day 7. Immature and mature bone marrow-derived dendritic cells (BMDCs) were generated without or with the stimulation by lipopolysaccharide (LPS) and the phenotype was analyzed by flow cytometry. Some of the iDCs were transfected by pcDNA3-IL-10 plasmid. 2 x 10(6)/per rat mature DC (mDC), immature DC (iDC), pcDNA3 transfected iDC, pcDNA3-IL-10 transfected iDC or phosphate buffered saline (PBS) were injected intravenously for treatment 5 days after the first immunization. On day 21, HE staining was performed to detect the myocardial inflammation and T lymphocyte proliferation assay was used to determine the effects of IL-10 gene transfected iDC on autoreactive T cell proliferation. Expression of IkappaB, the inhibitor of NF-kappaB pathway, was determined by Western blot.

RESULTSBMDCs generated in a medium supplemented with granulocyte-macrophage-colony-stimulating factor (GM-CSF) were relatively immature, as determined by flow cytometry. However, stimulation with LPS induced these cells to become mature (m) DCs with higher levels of surface major histocompatibility complex (MHC)-II and costimulatory molecules. Intravenous administration of iDCs, especially pcDNA3-IL-10 transfected iDC, ameliorated the histopathological severity of the myosin induced-EAM, and the effect was lost after the DCs underwent maturation induced by in vitro exposure to LPS. IL-10 gene modified iDC inhibited the antigen specific T cell responses towards cardiac myosin. IkappaB protein was up-regulated significantly in the IL-10 gene modified iDC group.

CONCLUSIONSIL-10 gene modified iDC induced antigen-specific tolerance in EAM. The underlying mechanisms may be related to costimulatory molecules down-regulation and NF-kappaB pathway inhibition.

Animals ; Autoimmune Diseases ; immunology ; Dendritic Cells ; physiology ; Immune Tolerance ; Interleukin-10 ; genetics ; Lymphocyte Activation ; Male ; Myocarditis ; immunology ; Myosins ; immunology ; NF-kappa B ; physiology ; Rats ; Rats, Inbred Lew ; Signal Transduction ; Transfection

OBJECTIVETo investigate whether IL-10 gene modification on immature dendritic cells (iDC) could induce autoimmune tolerance in rat experimental autoimmune myocarditis (EAM).

METHODSEAM was induced by cardiac myosin immunization on day 0 and day 7 in rats. A total of 2 x 10(6) mature DC (mDC), iDC, pcDNA3 transfected iDC, pcDNA3-IL-10 transfected iDC or PBS were injected intravenously at 5th immunization day. Three weeks later, echocardiography and HE staining were performed to observe the cardiac function and myocardial inflammation. Th1/Th2 cytokines were detected by ELISA and MHC-II molecules, costimulatory molecules were identified by flow cytometry. In vitro T lymphocyte proliferation assay and adoptive transfer of DCs were performed to determine the antigen specific tolerance induced by IL-10 gene modification on iDCs.

RESULTSEAM rats treated with pcDNA3-IL-10 transfected iDC showed improved cardiac function and reduced inflammatory cells infiltration into myocardium. Moreover, lower Th1 and higher Th2-type response was induced, MHC-II and costimulatory molecules down-regulated and antigen specific immunological responses towards cardiac myosin inhibited in pcDNA3-IL-10-iDC treated EAM rats.

CONCLUSIONTreatment with IL-10 gene modified iDCs could ameliorates EAM by inducing Th2 polarization and down-regulation of MHC-II molecules and costimulatory molecule expressions.

Animals ; Animals, Genetically Modified ; Autoimmune Diseases ; immunology ; Bone Marrow Cells ; Cell Line ; Dendritic Cells ; immunology ; Genetic Therapy ; Immune Tolerance ; Interleukin-10 ; genetics ; immunology ; Myocarditis ; immunology ; Rats ; Rats, Inbred Lew