| Rheumatoid arthritis (RA) is an inflammatory and autoimmune disease characterized bychronic synovial inflammation and articular damage in multiple joints. Recent progress in theresearch of immune cells including T、B and dendritic cells (DC) have greatly revised ourunderstanding of the immunopathology of autoimmune disease development. Activated T cellsplay a crucial role in the pathogenesis and progression of rheumatoid arthritis. Excessiveactivation of T cells are the main factors causing RA immune damage and synovialpathological histology by producing pro-inflammatory cytokines. Studies have demonstratedthe infiltration of DCs in the synovial tissue and it is thought that these DCs presentarthritogenic peptide to T cells and induce na ve T cells activation. Biological agents inhibitingT cells activation has been identified efficacy in the treatment of autoimmune disease includingRA. Recently more and more studies have demonstrated that B cells and humoral immunity areinvolved in RA pathology. B cells and their antibodies are the central elements of humoralimmunity. B-cell-mediated immune processes include autoantibody production, autoantigenpresentation, cytokine production and activation of T cells. They appear to play an importantimmunopathogenic role by providing long-lived memory B cells in autoimmune conditionsincluding RA. The importance of B cells in RA has been emphasised by the success ofanti-CD20monoclonal antibodies (mAbs) as a therapeutic approaches for RA.Compound K (CK,20-O-D-glucopyranosyl-20(S)-protopanaxadiol), a novel ginsenosidemetabolite, belongs to dammarane-type triterpene saponins according to its structure. CK is theginsenoside degradation in the intestine produced by intestinal bacteria and is the major form ofginsenoside absorbed in the body. The anti-inflammatory activities of CK have been reported in several studies though suppressing proinflammation cytokine production, but the underlingmechanism remains unclear. However, the effect of CK on RA and the underlying mechanismare remained unclear. We attempted to investigate CK’s effect on AA rats as well as its impacton immune cells function. This study elucidated the novel immunomodulatory property of CKresponsible for the therapeutic effect on autoimmune arthritis though regulating immunity inautoimmune condition.ObjectiveTo observer the therapeutic effect of CK on adjuvant-induced arthritis and investigate theanti-inflammatory and immunoregulatory effect of CK in autoimmune conditions.MethodsComplete Freund’s adjuvant was used to induce adjuvant-induced arthritis rats. After the onsetof arthritis, rats were given CK (5mg/kg,10mg/kg,20mg/kg,40mg/kg,80mg/kg,160mg/kg) orMTX (0.5mg/kg). To evaluate the severity of arthritis, arthritis index, swollen joint count,global assessment and paw swelling were evaluated every3days. Histopathology of joint andspleen were assayed. Subsets of T cells and B cells including CD4+CD62L+(na ve T cells),CD4+CD25+(activated T cells)、CD4+CD25+Foxp3+cells (Treg)、total B cells (CD45R+IgM+)and memory B cells (CD45R+CD27+) and CD25expression were assayed by flow cytometry.Proliferation of T cells and B was evaluated by3H-TdR. The levels of IL-1β、IL-4、TNF-α、IFN-γ、IL-17、IL-10、IL-2、RANKL、OPG、IgG1、IgG2a、anti-CCP antibody and anti-typeII collagen antibody in the serum of AA rats were evaluated by ELISA.(2) Collagen type Ⅱ was used to induce collagen-induced arthritis mice. After the onset ofarthritis, mice were given CK (14mg/kg,56mg/kg,224mg/kg) or MTX (2mg/kg). Subsets ofDC including monocytes-derived DC (CD11c+CD109+), plasmacytoid DC (CD11c+PDCA-1+),and na ve T cells (CD4+CD62L+) were examined by flowcytometry. Level of CCL21in lymphnodes was evaluated by ELISA. DC migration was measured by transwell experiment.Expression of CD80、CD86、MHCⅡ and CCR7on DC were determined by flowcytometry. Ability of DC in priming T cells activation was assayed by mixed lymphocytes reaction. T cellsproliferation was assayed by Cell Counting Kit assay.Results1. CK attenuated arthritis signs, alleviated the histopathological change of spleen andjoint, and inhibited fibroblast synoviocytes proliferationand secretion.CK (10mg/kg、20mg/kg、40mg/kg、80mg/kg、160mg/kg) attenuated arthritis index,swollen joint count, arthritis global assessment and paw swelling. The anti-inflammatoryeffects of CK enhanced gradually with the increasing dosage. The dosage of CK and the effecton arthritis global assessment revealed a positive correlation between the two(y=0.1606χ+0.1771，R2=0.8297，P=0.0116), and ED50of CK is102.5mg/kg. There is nostatistical difference between80mg/kg and160mg/kg, and CK (160mg/kg) has been achievedmaximum anti-inflammatory efficiency. CK (20mg/kg、40mg/kg、80mg/kg、160mg/kg)restored the histopathological change of spleen. CK attenuated hyperplasia of germinal center,periarterial lymphatic sheath, lymphoid nodule, and marginal zone in spleen. CK (40mg/kg、80mg/kg、160mg/kg) restored the histopathological change of joint. CK alleviated inflammation,synoviocytes hyperplasia, appearance of pannus and bone erosion of joint. CK (40mg/kg、80mg/kg、160mg/kg) inhibited fibroblast synoviocytes proliferation. CK (1×10-7、1×10-6、1×10-5mol/L) suppressed secretion of RANKL、OPG from fibroblast synoviocytes.2. CK suppressed T and B cells activation, and restored the cytokines balance.CK (40mg/kg、80mg/kg、160mg/kg) down-regulated the percentage of activated T cellsand memory B cells, up-regulated na ve T cells and Treg cells in spleen, and suppressed T cellsand B cells proliferation. CK (10mg/kg、20mg/kg、40mg/kg、80mg/kg、160mg/kg) decreasedanti-type II collagen antibody in serum, CK (160mg/kg) suppressed IgG2a in serum, but hadno effect on anti-CCP antibody and IgG1in serum. CK (40mg/kg、80mg/kg、160mg/kg)decreased IL-1β in serum, but had no effect on IL-4. CK (20mg/kg、40mg/kg、80mg/kg、160mg/kg) decreased IFN-γ secretion from macrophage. CK (40mg/kg、80mg/kg、160mg/kg)inhibited IL-17secretion from macrophage. CK (80mg/kg、160mg/kg) suppressed TNF-α, and increased IL-10production from macrophage. CK (10-5M，10-6M，10-7M) suppressed T cellactivation (CD25expression and IL-2production).3. CK suppressed dendritic cells maturation, migrationtion and ability to activate T cellsCK (56mg/kg、224mg/kg) decreased pDCs and mo-DCs, increased na ve T cells in CIAmice lymph nodes, and suppressed CCL21expression in lymph nodes. CK (10-7M，10-5M)suppressed DCs migration induced by CCL21and T cells-stimulatory capability of DC,down-regulated LPS-induced expression of CD80, CD86, MHCII and CCR7on DCs.Conclusions1．CK had theraputic effect on AA rats.2. CK exerted antiinflammatory and immuneregulatory effect by regulating T cells、B cellsand macrophages function and restoring the cellular and humoral immunity balance.3. Suppressing dendritic cells migration and maturation may be the potential mechanism bywhich CK contributes to anti-inflammation and immunoregulation in autoimmuneconditions. |
PDF Full Text Request