The etiopathogenesis of autoimmunity

Acquisition by mammals of an adaptive immune system was an evolutionary leap, but occurred at the cost of autoimmunity. The necessity for self-recognition was appreciated in 1900, but autoimmune disease did not become a clinical reality until the 1950s-still the perimeters are indistinct. Autoimmune responses recapitulate the complex events of normal immune responses but cannot shut down. Immune tolerance is established during repertoire development centrally in thymus or bone marrow by deletion of self-reactive immunocytes, and is supplemented peripherally by regulatory T cells (Tregs). A startling discovery is the autoimmune regulator AIRE gene that enables expression of organ-specific autoantigens for intrathymic deletional tolerance of T cells. The origins, activities, and markers of Tregs are under intensive investigation. Of genes implicated in autoimmune, only few are characterized; contributions of environment are similarly uncertain. Time-latency considerations implicate stochastic factors or chance in the etiopathogenesis of autoimmunity, whether they are somatic mutations or successive random gene-environment interactions. Solutions to etiopathogenesis require novel experimental models and finely designed gene-environment studies on human populations. Perhaps immunomodulatory therapies will effect cures before causes are fully understood.     

Think autoimmunity,breath autoimmunity,and learn autoimmunity

Clinical Rheumatology -     

The role of autoimmunity in gastroenterology

Crohn's disease (CD) is an immune-mediated chronic intestinal disorder thought to be the result of an aggressive immune response to a subset of enteric bacteria in a genetically predisposed host. Numerous environmental factors are apparently involved in disease pathogenesis. Impaired ability of CD patients to control the gut microflora is associated with defects in the production of some antibacterial compounds (cryptdins) by epithelial cells. In addition, there are the defects in cytoplasmic NOD-like receptors which are sensing intracellularly localized bacteria in CD patients. These defects together with the failure to induce autophagy lead to lack of bacterial clearance and subsequently to mucosal immunopathology.     

The effects of royal jelly on autoimmunity in Graves' disease

Objective Graves' disease is an organ-specific autoimmune disease with unknown etiology. TSHR Ab plays the most important role for the pathogenesis of Graves' disease. Recently, the role of cytokines for the pathogenesis of Graves' disease has been studied extensively. Royal jelly (RJ) is a creamy product secreted by young nurse worker bees (Apis mellifera), and it is synthesized in the hypopharyngeal and mandibular glands. RJ has been reported to have such pharmacological characteristics as antitumor, antibacterial, antihypercholesterolemic, antiallergic, antiinflammatory, and immunomodulatory properties. The major aim of the present study is to evaluate the effect of RJ on autoimmunity in peripheral lymphocyte culture and to establish the therapeutic doses. Research Design and Methods In the first phase, lymphocyte cell isolation from four voluntary healthy subjects was performed to find the effective concentration of RJ on immunity. Serial dilutions of the RJ were prepared (0–5 mg/mL). All isolated lymphocyte cells were treated with the above diluted samples. MTT test was carried out after incubation of 72 h. In the second phase, six patients with Graves' disease, newly diagnosed by clinical and laboratory methods and admitted to my hospital and untreated were identified. RJ samples of 0 and 4 mg/mL were incubated in a culture medium for 72 h with isolated lymphocytes obtained from the patients. After incubation, MTT test in lymphocyte cell culture, Th1 cytokines IFN-γ, TNF-α, and Il-12, and Th2 cytokines IL-4 and Il-10 levels by the enzyme amplified sensitivity immunoassay (EASIA) method and TSHR Ab by the radioreceptor method were determined. Results The concentration causing lymphocytes to proliferate was found to be 4 mg/mL by MTT test after incubation of 72 h in cell culture medium. Of the cytokines produced and secreted from lymphocytes, IFN-γ increased, whereas, other cytokines decreased in RJ concentration of 4 mg/mL. Significant differences were found only for IFN-γ and TNF-α. IL-4 concentrations were kept near the level of significancy. Of Th1/Th2 ratios, IFN-γ/IL-4 and IFN-γ/IL-10 ratios also exhibited significant differences between 0 and 4 mg/mL. RJ treatment in lymphocytes from patients with Graves' disease shifted the Th1/Th2 cytokine ratio to the side of Th1 cytokine. Therefore, RJ using the treatment and establishing a remission of Graves' disease may be effective as an antithyroid drug treatment. TSHR Ab levels of lymphocyte cell culture supernatants treated with RJ showed significant decreases. Also, the result may suggest that RJ may exert an effect similar to an antithyroid drug for decreasing TSHR Ab levels. Conclusions RJ may be effective as an immunomodulatory agent in Graves' disease.     

Biological impact of hepatitis B virus X-hepatitis C virus core fusion gene on human hepatocytes

AIM： To investigate the biological impact of hepatitis B virus X- hepatitis C virus core （HBV X-HCV C） fusion gene on hepatoma cells.
METHODS： The recombinant adenoviruses Ad- XC, Ad-X and Ad-C expressing HBV X-HCV C fusion gene, HBVX gene and HCV C gene were constructed, respectively. Hepatoma cells were infected with different recombinant adenoviruses. MTT, colony- forming experiment, FCM, TUNEL assay were performed to observe the biological impact of the HBV X-HCV C fusion aene on liver cells.
RESULTS： MTT showed that the Ad-XC group cells grew faster than the other group cells. Colony-forming experiment showed that the colony-forming rate for the Ad-XC group cells was significantly higher than that for the other group cells. FCM analysis showed that Ad-XC/Ad-X/Ad-C infection enhanced the progression of G1→S phase in the HepG2 cell cycle. The apoptosis index of the Ad-XC, Ad-X, Ad-C group cells was significantly lower than that of the AdO and control group cells. Semi-quantitative RT-PCR showed that the expression level of c-myc was the highest in Ad- XC infected cells. Tumor formation was found at the injected site of mice inoculated with Ad-XC-infected LO2 cells, but not in control mice.
CONCLUSION： Ad-XC, Ad-X and Ad-C facilitate the proliferation activity of HepG2 cells and inhibit their apoptosis in vitro. The effect of Ad-XC is significantly stronger than that of Ad-X and Ad-C. Up-regulation of c-myc may be one of the mechanisms underlying the synergism of HBVX and HCV C genes on hepatocarcinogenesis in athymic nude mice.     

The incidence and prevalence of thyroid autoimmunity

The thyroid gland is the most common organ affected by autoimmune disease. Other autoimmune diseases, most notably type 1 diabetes mellitus, are increasing in incidence. It is unknown whether autoimmune thyroid diseases are following the same pattern. This review summarizes studies of autoimmune thyroid disease incidence and prevalence since 1950, not only for these measures of occurrences, but also for commenting on identified risk factors for thyroid autoimmunity. We find that incidence of autoimmune thyroid disease is currently higher than in historic series although the studies are so variable in design, patient population, disease definition, and laboratory methods that it is impossible to tell whether this difference is real. Further research is required to assess the possibility of changing disease patterns of autoimmune thyroid disease as opposed to simple changes in diagnostic thresholds.     

The genetic basis of thyroid autoimmunity.

Autoimmune thyroid diseases (AITDs), including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are prevalent autoimmune diseases, affecting up to 5% of the general population. AITDs arise due to interplay between environmental and genetic factors. In the past decade, significant progress has been made in our understanding of the genetic contribution to the etiology of AITDs. Excitingly, several AITD susceptibility genes have been identified and characterized. Some of these susceptibility genes are specific to either GD or HT, while others confer susceptibility to both conditions. The first AITD susceptibility gene locus identified was the Human-Leukocyte-Antigen DR (HLA-DR) gene locus. Subsequently, a quintet of non-HLA genes, including the cytotoxic T lymphocyte antigen (CTLA-4), CD40, protein tyrosine phosphatase-22 (PTPN22), thyroglobulin, and thyroid-stimulating hormone receptor (TSHR) gene, has been shown to contribute to the susceptibility to AITDs. Recently, the mechanisms by which these new AITD genes predispose to AITDs have been dissected. In this review, we overview and highlight the recent data on the genes predisposing to AITDs and the putative mechanisms by which they confer susceptibility to disease.