Immunopharmacology最新文献

Pharmacological control of interleukin-12 (IL-12) and interferon-gamma (IFN-γ) production may be a key therapeutic strategy for modulating immunological diseases dominated by Th1-derived cytokine responses. In this study, we investigated the effects of three different tanshinone pigments from Salvia miltiorrhiza (tanshinone I, dihydrotanshinone, and cryptotanshinone) on IL-12 production in mouse macrophages and on IFN-γ production in lymph node cells. All tested tanshinones significantly inhibited IL-12 production in lipopolysaccharide (LPS)-activated macrophages and also IFN-γ production in keyhole limpet hemocyanin (KLH)-primed lymph node cells in a dose-dependent manner. Dihydrotanshinone was more effective than tanshinone I or cryptotanshinone. Tanshinones significantly inhibited the expression of IL-12 p40 gene at the mRNA level. Furthermore, tanshinones potently inhibited the promoter activation of IL-12 p40 gene and nuclear factor (NF)-κB binding to the κB site, suggesting that tanshinones may negatively regulate IL-12 production at the transcription level. These results may explain some known biological activities of tanshinones including their anti-inflammatory effect, and suggest a possible use of tanshinones in the treatment of immunological diseases dominated by Th1-derived cytokine responses.

Fumonisins represent a family of toxic, structurally related metabolites produced by fungi that are found in corn worldwide. We investigated the effects of the mycotoxin, fumonisin B₁, on rat splenic macrophage and lymphocyte functions. Pretreatment (24 h) of resident macrophages with fumonisin B₁ (1, 10, and 100 μg/ml) significantly (p<0.01) stimulated nitric oxide production (0.48, 2.60, and 4.40 nmol nitrite/well, respectively), compared with the response of untreated macrophages (no nitrite detected), after 72 h of culture. Fumonisin B₁ (1 and 10 μg/ml) and IFN-γ acted in an additive manner to activate nitric oxide production. The response of IFN-γ (50 U/ml)-activated macrophages (1.68 nmol nitrite/well) was potentiated (3.52, 4.96, and 4.44 nmol nitrite/well) by fumonisin B₁ (1, 10, and 100 μg/ml, respectively). In addition, fumonisin B₁ significantly (p<0.05) potentiated Con A (1.25 to 5 μg/ml) (1.46- to 2.62-fold increases)- and antiTCR, IL-2 or antiTCR+IL-2 (1.72- to 2.60-fold increases)-induced proliferation of splenic cells in the presence of the nitric oxide synthase inhibitor N^G-monomethyl-l-arginine (NMA). These results show two distinct and separate effects of fumonisin B₁: it induces nitric oxide production by macrophages and it stimulates T cell proliferation.

Interleukin-18 (IL-18) is a novel proinflammatory cytokine. Most of the immune and inflammatory genes induced by IL-18 are nuclear factor-kappaB (NF-κB)- and activator protein-1 (AP-1)-regulated. Interleukin-1 receptor-associated kinase-1 (IRAK-1) has recently been shown to be involved in IL-18-stimulated activation of NF-κB and AP-1. The purpose of this study is to investigate the effects of preventing IRAK-1 expression by antisense IRAK-1 oligodeoxynucleotide (ODN) on IL-18-stimulated activation of NF-κB and AP-1. Semiquantitative reverse transcription-PCR (RT-PCR) and western blot analysis revealed that antisense IRAK-1 ODN inhibited IRAK-1 mRNA and protein expression (P<0.01). As a result, antisense IRAK-1 ODN attenuated IL-18-induced activation of NF-κB and AP-1 as measured by sandwich ELISA in a concentration (1–8 μg ml⁻¹)- and time (5–24 h)-dependent fashion. These data suggest that antisense IRAK-1 ODN may share a role in the design of antiinflammatory therapeutics.

We investigated effects of IL-4, dexamethasone (DXM), and the combination of IL-4 and DXM, low- or high-dose, on collagen-induced arthritis (CIA) in DBA/1 mice and correlated severity of arthritis with changes in IL-10 and IFN-γ. Compared with control mice, mice treated with IL-4 had increased IL-10 with the same degree of arthritis, whereas mice treated with high-dose DXM had decreased IL-10 and increased IFN-γ production with less severe arthritis. Mice treated with low-dose DXM showed the absence of IL-10 and increased IFN-γ production with a trend toward the resolution of arthritis. Mice treated with IL-4 and low-dose DXM had neither IL-10 nor IFN-γ production but revealed less severe arthritis, compared with mice treated with low-dose DXM alone. These results suggest that the beneficial effects of high-dose DXM and the combination of IL-4 and DXM on CIA are independent of IL-10 and IFN-γ.

Sublytic complement attack can elicit protective cellular responses without precipitating cell death. Our investigation examined the effects of non-lethal complement activation in isolated hearts. New Zealand white rabbit hearts were subjected to 30 min of ischemia followed by 1 h of reperfusion. Prior to ischemia, hearts were perfused for 20 min with 0.5% normal human plasma (NHP). Hearts treated with NHP developed significantly (p<0.05) smaller infarcts compared with controls, expressed as percent of area at risk (AAR) (25.3±4.0% vs. 40.9±4.3%, respectively). Heat-inactivation, soluble complement receptor 1 (sCR1; 20 nM), and anti-C5a antibody reversed the protective effect of NHP (39.0±3.1%, 41.7±5.1% and 38.4±2.3% AAR, respectively). Hearts treated with 3 nM C5a exhibited infarct sizes similar to those exposed to NHP (27.6±5.0% AAR). sCR1 alone did not affect infarct size (37.9±4.5% AAR). The results suggest that non-lethal complement activation attenuates reperfusion injury through formation of C5a.

In our previous studies, we showed that angelan, a polysaccharide purified from Angelica gigas Nakai, is a potent LPS-mimetic in murine macrophages [Jeon, Y.J., Han, S.B., Ahn, K.S., Kim, H.M., 1999. Activation of NF-kB/Rel in angelan-stimulated macrophages. Immunopharmacology 43, 1–9]. Angelan stimulates murine macrophage to produce cytokines including iNOS and activate NF-κB/Rel. In the present study, we investigated the role of CD14 and complement receptor type 3 (CR3) in mediating NO production and NF-κB/Rel activation induced by angelan and LPS. Three major differences between angelan and LPS were observed. First, angelan does not require serum proteins for NO response and NF-κB/Rel activation, while the activation by LPS requires serum proteins. Second, blocking of either CD14 or CR3 decreased angelan-induced NO response, while LPS-mediated NO production was inhibited by anti-CD14 mAb only. Third, angelan induced strong NF-κB/Rel and slight AP-1 DNA binding, whereas LPS potently activated both NF-κB/Rel and AP-1. Both angelan and LPS degraded IκB proteins and subsequently induced the mobilization of NF-κB/Rel proteins (p65, c-rel and p50) into nucleus. This suggests that macrophages display a common signaling machinery leading to the NF-κB/Rel activation in response to different stimulants. In conclusion, angelan and LPS use the membrane receptor CD14 and CR3 differentially for signaling NF-κB/Rel activation and NO production.

T614 (3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one) is a member of the family of methanesulfonanilide non-steroidal anti-inflammatory drugs (mNSAIDs), most of which act as cyclooxygenase (COX)-2 inhibitors. l-leucine methyl ester (Leu-OME) is a reagent which has been shown to kill phagocytes following interaction with intracellular proteases. There are two pathways whereby Leu-OME becomes cytotoxic to phagocytes. Within lysososmes, Leu-OME is converted into free Leu, which causes disruption of the lysosomes and subsequent cell necrosis. The other is the conversion of Leu-OME into (Leu-Leu)_n-OME, which is associated with the induction of apoptosis. In the present study, we examined the action of T614 on Leu-OME mediated killing of THP-1, a human monocytic cell line. We revealed that T614 and phenylmethyl sulfonyl fluoride (PMSF), a serine protease inhibitor, inhibited Leu-OME mediated killing of THP-1 cells. All the other mNSAIDs, including nimesulide (NIM-03), fluosulide (CGP28238), FK3311 and NS398, also rescued THP-1 from Leu-OME mediated killing, although to a lesser degree. Of the classical NSAIDs tested, a protective effect was observed with diclofenac at high concentration, but not with naproxen or indomethacin. Unlike conventional lysosomal inhibitors, such as chloroquine and ammonium chloride (NH₄Cl), T614 and PMSF did not raise lysosomal pH, as measured by flow cytometry using fluorescein isothiocyanate dextran (FITC-dextran). Therefore, the mechanism whereby T614 and PMSF inhibit Leu-OME killing is distinct from that of chloroquine or NH₄Cl. Based on the similarity of T614 and PMSF, we suggest that, besides their roles as COX-2 inhibitors, T614 and other mNSAIDs may act as lysosomal protease inhibitors.

We have isolated the lipoteichoic acid (LTA)-related molecule (OK-PSA) from OK-432, a streptococcal preparation, by an affinity chromatography on CNBr-activated Sepharose 4B-bound TS-2 monoclonal antibody (mAb) that neutralizes interferon (IFN)-γ-inducing activity of OK-432. In in vitro experiments using human peripheral blood mononuclear cells (PBMC), OK-PSA induced IFN-γ, interleukin (IL)-2, IL-12, IL-18, tumor necrosis factor (TNF)-α and TNF-β that are generally called “Th1-type cytokines” both in protein and in mRNA levels. Furthermore, the neutralizing test using cytokine-specific antibodies demonstrated that IL-18 plays a most significant role for IFN-γ- and killer cell-inducing ability of OK-PSA among the other cytokines tested. These findings clearly indicated that OK-PSA, an LTA-related molecule, is a main effective component of OK-432, and is a potent inducer of Th1-type cytokines by T cell and natural killer (NK) cell activation mediated by monocytes-derived IL-18, and that it may be a useful immunotherapeutic agent for the patients with malignancies better than original OK-432.

We have isolated 55 kDa protein from the seed extract of Aeginetia indica L. (AIL), a parasitic plant, by an affinity chromatography on N-hydroxysuccinimide (NHS)-activated Sepharose High Performance column bound F3 monoclonal antibody which neutralizes cytokine-inducing and antitumor effect of AIL. In in vitro model using human peripheral blood mononuclear cells (PBMC), the 55 kDa protein (AILb-A) induced multiple cytokines, such as IFN-γ, tumor necrosis factor (TNF)-α, granulocyte macrophage-colony stimulating factor (GM-CSF), IL-2, IL-6, IL-10, IL-12 and IL-18, and also accelerated killer cell activities of PBMC. When compared with a commonly used immunotherapeutic agent OK-432, AILb-A induced Th1 cytokines are greater than OK-432. Of the Th2 cytokines, the amounts of IL-6 and IL-10 induced by AILb-A were lower than those by OK-432. No significant induction of IL-4 and IL-13 was observed in AILb-A-stimulated PBMC. TNF family including TNF-α, TNF-β, Fas ligand (FasL) and TNF-related apoptosis-inducing ligand (TRAIL) were suggested to be important for AILb-A-induced killing activity of PBMC by reverse transcription-polymerase chain reaction (RT-PCR) analysis. Furthermore, the neutralizing test using cytokine-specific antibodies demonstrated that IL-18 plays a most significant role for IFN-γ- and killer cell-inducing ability of AILb-A among the cytokines tested. These findings clearly indicated that AILb-A, a 55 kDa protein of AIL, is a potent Th1 cytokine inducer and may be a useful immunotherapeutic agent for the patients with malignancies.