Prevention of collagen-induced arthritis by gene delivery of soluble p75 tumour necrosis factor receptor.
Collagen type II-induced arthritis (CIA) in DBA/1 mice can be passively transferred to SCID mice with spleen B- and T-lymphocytes. In the present study, we show that infection ex vivo of splenocytes from arthritic DBA/1 mice with a retroviral vector, containing cDNA for the soluble form of human p75 receptor of tumour necrosis factor (TNF-R) before transfer, prevents the development of arthritis, bone erosion and joint inflammation in the SCID recipients. Assessment of IgG subclass levels and studies of synovial histology suggest that down-regulating the effector functions of T helper-type 1 (Th1) cells may, at least in part, explain the inhibition of arthritis in the SCID recipients. In contrast, the transfer of splenocytes infected with mouse TNF-alpha gene construct resulted in exacerbated arthritis and enhancement of IgG2a antibody levels. Intriguingly, infection of splenocytes from arthritic DBA/1 mice with a construct for mouse IL-10 had no modulating effect on the transfer of arthritis. The data suggest that manipulation of the immune system with cytokines, or cytokine inhibitors using gene transfer protocols can be an effective approach to ameliorate arthritis. (+info
Enhanced Th1 activity and development of chronic enterocolitis in mice devoid of Stat3 in macrophages and neutrophils.
We have generated mice with a cell type-specific disruption of the Stat3 gene in macrophages and neutrophils. The mutant mice are highly susceptible to endotoxin shock with increased production of inflammatory cytokines such as TNF alpha, IL-1, IFN gamma, and IL-6. Endotoxin-induced production of inflammatory cytokines is augmented because the suppressive effects of IL-10 on inflammatory cytokine production from macrophages and neutrophils are completely abolished. The mice show a polarized immune response toward the Th1 type and develop chronic enterocolitis with age. Taken together, Stat3 plays a critical role in deactivation of macrophages and neutrophils mainly exerted by IL-10. (+info
Estrogen enhancement of anti-double-stranded DNA antibody and immunoglobulin G production in peripheral blood mononuclear cells from patients with systemic lupus erythematosus.
OBJECTIVE: To study the in vitro effect of estrogen on IgG anti-double-stranded DNA (anti-dsDNA) antibody and total IgG production in peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE), in order to elucidate its regulatory role in SLE. METHODS: PBMC from SLE patients and normal donors were cultured with 17beta-estradiol (E2). IgG anti-dsDNA antibodies, total IgG, and cytokine activity in the culture supernatants were measured by enzyme-linked immunosorbent assay. RESULTS: E2 enhanced production of IgG anti-dsDNA antibodies as well as total IgG in PBMC from SLE patients. Anti-dsDNA production in patients with inactive disease was less responsive to E2 than that in patients with active disease. E2 also enhanced total IgG, but not anti-dsDNA, production in the PBMC of normal donors. Antibody production was increased by E2 to a lesser extent in patients' B cells than in their PBMC. Anti-interleukin-10 (anti-IL-10) antibodies partially blocked the E2-induced increase in antibody production in patients' PBMC, but anti-IL-10 had no effect on B cells. E2 increased IL-10 production by patients' monocytes. Exogenous IL-10 acted additively with E2 in increasing antibody production in patients' B cells. CONCLUSION: These results suggest that E2 may polyclonally increase the production of IgG, including IgG anti-dsDNA, in SLE patients' PBMC by enhancing B cell activity and by promoting IL-10 production in monocytes. These findings support the involvement of E2 in the pathogenesis of SLE. (+info
CD40 signaling of monocyte inflammatory cytokine synthesis through an ERK1/2-dependent pathway. A target of interleukin (il)-4 and il-10 anti-inflammatory action.
Ligation of CD40 on monocytes through its interaction with CD40 ligand (CD154) present on activated T helper cells, results in activation of monocyte inflammatory cytokine synthesis and rescue of monocytes from apoptosis induced through serum deprivation. Both of these consequences of CD40 stimulation have been shown to be dependent on the induction of protein tyrosine kinase activity. CD40-mediated activation of protein tyrosine kinase activity and subsequent inflammatory cytokine production are abrogated by treatment of monocytes with the T helper type 2 cytokines interleukin 4 (IL-4) and interleukin 10 (IL-10). In the current study we demonstrate that stimulation of monocytes through CD40 resulted in the phosphorylation and activation of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) mitogen-activated protein kinases, whereas phosphorylation of mitogen-activated protein kinases family members p38 and c-Jun N-terminal kinase was not observed in response to this stimuli over the time course examined. PD98059, an inhibitor of the upstream activator of ERK1/2, the MAP/ERK kinase MEK1/2, suppressed IL-1beta and tumor necrosis factor-alpha production in a dose-dependent fashion. Pretreatment of monocytes with IL-4 and IL-10 inhibited CD40-mediated activation of ERK1/2 kinase activity when used individually, and are enhanced in effectiveness when used in combination. Together, the data demonstrate that CD40-mediated induction of IL-1beta and tumor necrosis factor-alpha synthesis is dependent on a MEK/ERK pathway which is obstructed by signals generated through the action of IL-4 and IL-10. (+info
Tumor-induced interleukin-10 inhibits type 1 immune responses directed at a tumor antigen as well as a non-tumor antigen present at the tumor site.
Interleukin (IL)-10 is a potent immunosuppressive cytokine that has been found to be present at the tumor site in a wide variety of human cancers, including transitional cell carcinoma of the bladder. Using a murine bladder tumor (MB49), which we show to express the male transplantation antigen (HY), we tested the hypothesis that IL-10 at the tumor site can block the generation of a tumor-specific type 1 immune response. We show that, despite its expression of HY, MB49 fails to prime for an HY-specific type 1 (IFN-gamma) response in normal female mice. Although MB49 does not constitutively produce IL-10, our data support a model whereby MB49 induces infiltrating cells to produce IL-10. This feature rendered the IL-10 knockout (KO) mouse, whose infiltrating cells are incapable of IL-10 production, a suitable model in which to study MB49 in the absence of IL-10. When injected into IL-10 KO mice, MB49 does prime for an HY-specific, type 1 immune response. Furthermore, IL-10 KO mice show prolonged survival and an increased capacity to reject tumors as compared with normal mice. We also tested the ability of tumor-induced IL-10 to inhibit immunization to a non-tumor antigen present at the tumor site. When vaccinia virus encoding beta-galactosidase (beta-gal) is injected into the tumors of normal mice, no beta-gal-specific IFN-gamma response is mounted. However, when this same viral construct is injected into the tumors of IL-10 KO mice, it produces a strong beta-gal-specific, IFN-gamma response. These studies demonstrate that tumor-induced IL-10 can block the generation of a tumor-specific type 1 immune response as well as subvert attempts to elicit a type 1 immune response to a non-tumor antigen at the tumor site. (+info
Interleukin-10 inhibits expression of both interferon alpha- and interferon gamma- induced genes by suppressing tyrosine phosphorylation of STAT1.
Interleukin-10 (IL-10) helps maintain polarized T-helper cells in a T-helper lymphocyte 2 (Th2) phenotype. Part of this process involves the prevention of the development of Th1 cells, which are a primary source of interferon gamma (IFNgamma), a potent activator of monocytes and an inhibitor of Th2 proliferation. Because monocytes and macrophages are important mediators of Th1-type responses, such as delayed-type hypersensitivity, we sought to determine if IL-10 could directly mediate inhibition of IFNgamma- and IFNalpha-induced gene expression in these cells. Highly purified monocytes were incubated with IL-10 for 60 to 90 minutes before the addition of IFNgamma or IFNalpha. IL-10 preincubation resulted in the inhibition of gene expression for several IFN-induced genes, such as IP-10, ISG54, and intercellular adhesion molecule-1. The reduction in gene expression resulted from the ability of IL-10 to suppress IFN-induced assembly of signal transducer and activator of transcription (STAT) factors to specific promoter motifs on IFNalpha- and IFNgamma-inducible genes. This was accomplished by preventing the IFN-induced tyrosine phosphorylation of STAT1, a component of both IFNalpha- and IFNgamma-induced DNA binding complexes. Therefore, IL-10 can directly inhibit STAT-dependent early response gene expression induced by both IFNalpha and IFNgamma in monocytes by suppressing the tyrosine phosphorylation of STAT1. This may occur through the ability of IL-10 to induce expression of the gene, suppressor of cytokine signaling 3 (SOCS3). (+info
Interleukin-10-treated human dendritic cells induce a melanoma-antigen-specific anergy in CD8(+) T cells resulting in a failure to lyse tumor cells.
Dendritic cells (DC) are critically involved in the initiation of primary immune processes, including tumor rejection. In our study, we investigated the effect of interleukin-10 (IL-10)-treated human DC on the properties of CD8(+) T cells that are known to be essential for the destruction of tumor cells. We show that IL-10-pretreatment of DC not only reduces their allostimulatory capacity, but also induces a state of alloantigen-specific anergy in both primed and naive (CD45RA+) CD8(+) T cells. To investigate the influence of IL-10-treated DC on melanoma-associated antigen-specific T cells, we generated a tyrosinase-specific CD8(+) T-cell line by several rounds of stimulation with the specific antigen. After coculture with IL-10-treated DC, restimulation of the T-cell line with untreated, antigen-pulsed DC demonstrated peptide-specific anergy in the tyrosinase-specific T cells. Addition of IL-2 to the anergic T cells reversed the state of both alloantigen- or peptide-specific anergy. In contrast to optimally stimulated CD8(+) T cells, anergic tyrosinase-specific CD8(+) T cells, after coculture with peptide-pulsed IL-10-treated DC, failed to lyse an HLA-A2-positive and tyrosinase-expressing melanoma cell line. Thus, our data demonstrate that IL-10-treated DC induce an antigen-specific anergy in cytotoxic CD8(+) T cells, a process that might be a mechanism of tumors to inhibit immune surveillance by converting DC into tolerogenic antigen-presenting cells. (+info
Effects of the Chinese traditional medicine mao-bushi-saishin-to on therapeutic efficacy of a new benzoxazinorifamycin, KRM-1648, against Mycobacterium avium infection in mice.
The Chinese traditional medicine mao-bushi-saishin-to (MBST), which has anti-inflammatory effects and has been used to treat the common cold and nasal allergy in Japan, was examined for its effects on the therapeutic activity of a new benzoxazinorifamycin, KRM-1648 (KRM), against Mycobacterium avium complex (MAC) infection in mice. In addition, we examined the effects of MBST on the anti-MAC activity of murine peritoneal macrophages (M phi s). First, MBST significantly increased the anti-MAC therapeutic activity of KRM when given to mice in combination with KRM, although MBST alone did not exhibit such effects. Second, MBST treatment of M phi s significantly enhanced the KRM-mediated killing of MAC bacteria residing in M phi s, although MBST alone did not potentiate the M phi anti-MAC activity. MBST-treated M phi s showed decreased levels of reactive nitrogen intermediate (RNI) release, suggesting that RNIs are not decisive in the expression of the anti-MAC activity of such M phi populations. MBST partially blocked the interleukin-10 (IL-10) production of MAC-infected M phi s without affecting their transforming growth factor beta (TGF-beta)-producing activity. Reverse transcription-PCR analysis of the lung tissues of MAC-infected mice at weeks 4 and 8 after infection revealed a marked increase in the levels of tumor necrosis factor alpha, gamma interferon (IFN-gamma), IL-10, and TGF-beta mRNAs. KRM treatment of infected mice tended to decrease the levels of the test cytokine mRNAs, except that it increased TGF-beta mRNA expression at week 4. MBST treatment did not affect the levels of any cytokine mRNAs at week 8, while it down-regulated cytokine mRNA expression at week 4. At week 8, treatment of mice with a combination of KRM and MBST caused a marked decrease in the levels of the test cytokines mRNAs, especially IL-10 and IFN-gamma mRNAs, although such effects were obscure at week 4. These findings suggest that down-regulation of the expression of IL-10 and TGF-beta is related to the combined therapeutic effects of KRM and MBST against MAC infection. (+info