The paracaspase MALT1 is essential for the activation of NF-κB in response to T cell receptor (TCR) stimulation. It recruits downstream TRAF6 and activates the E3 ligase activity of TRAF6 to polyubiquitinate several targets, which ultimately leads to NF-κB activation. Here we identified ubiquitin-specific protease 2a (USP2a) as a MALT1-associated protein by biochemical affinity purification. Endogenous USP2a constitutively interacted with TRAF6, but dynamically interacted with MALT1 and CARMA1 in a stimulation-dependent manner. RNA interference (RNAi)-mediated silencing of USP2a attenuated TCR-induced NF-κB activation and production of interleukin-2 (IL-2). In addition, the ubiquitination of MALT1 and TRAF6 were both suppressed by USP2a knockdown. By knockdown and reconstitution assays, we found that USP2a mediated the interaction between MALT1 and TRAF6 in a catalytic activity-dependent manner. Furthermore, USP2a deSUMOylated TRAF6. Our findings implicate that USP2a plays an important role in TCR signaling by deSUMOylating TRAF6 and mediating TRAF6-MALT1 interaction.
Caspases ; metabolism ; Endopeptidases ; deficiency ; genetics ; metabolism ; Gene Knockdown Techniques ; HEK293 Cells ; Humans ; Interleukin-2 ; biosynthesis ; Jurkat Cells ; Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein ; NF-kappa B ; metabolism ; Neoplasm Proteins ; metabolism ; Receptors, Antigen, T-Cell ; metabolism ; Signal Transduction ; Sumoylation ; TNF Receptor-Associated Factor 6 ; metabolism

The study was purposed to investigate the effects of humanized recombined CD25 monoclonal antibody (rhCD25MAb) on activation and proliferation of T lymphocytes in vitro. Peripheral blood mononuclear cells (PBMNC) were incubated with phytohemagglutinin (PHA). Before or after T cell activation, the cells were cultured with or without rhCD25MAb or cyclosporine A (CsA) in vitro. After 72 hours incubation, the proliferation of lymphocytes was analyzed by MTT assay. The expression of CD3 and CD25 antigens on T lymphocytes were detected by flow cytometry. The levels of sIL-2R in the supernatants were determined with ELISA. The results showed that both rhCD25MAb and CsA could inhibit the proliferation of T lymphocytes significantly in concentration-dependent manner and CsA was more efficient than rhCD25MAb. Both rhCD25MAb and CsA could also decrease the levels of sIL-2R in the supernatant and inhibit the expression of CD25 antigen on T lymphocytes. The level of sIL-2R and the expression of CD25 on T lymphocytes decreases more profoundly in rhCD25MAb group. It is concluded that rhCD25MAb shows strong immunosuppressive activity both before and after T cell activation, suggesting that this agent may be useful in not only prophylaxis but also the treatment of acute graft-versus-host disease.
Antibodies, Monoclonal ; pharmacology ; CD3 Complex ; biosynthesis ; genetics ; Cell Proliferation ; Cells, Cultured ; Cyclosporine ; pharmacology ; Humans ; Immunosuppressive Agents ; pharmacology ; Interleukin-2 Receptor alpha Subunit ; biosynthesis ; genetics ; immunology ; Lymphocyte Activation ; immunology ; Receptors, Interleukin-2 ; analysis ; Recombinant Proteins ; immunology ; pharmacology ; T-Lymphocytes ; immunology

OBJECTIVETo investigate the expression of interleukin-8 (IL-8) and its prognostic significance in breast cancer.

METHODSExpression of IL-8 in 113 breast cancers, 19 breast benign tumors and 20 breast normal tissues was examined by tissue microarray using immunohistochemistry, and the association of IL-8 expression with patient's clinico-pathological characteristics and prognosis was further analyzed.

RESULTSThe positive rate of IL-8 expression in breast cancer was 27.4%, which was significantly higher than that in benign tumor and normal tissue of breast (P = 0.002). IL-8 expression related to histological type (P = 0.040) and lymph node status (P = 0.021). The expression of IL-8 was observed to correlate negatively with ER and PR status (P = 0.015 and P = 0.034), and correlate positively with C-erbB-2 status (P = 0.002). In addition, Kaplan-Meier curves of disease-free survival analysis showed a significant difference between IL-8 positive groups and negative group (P = 0.031).

CONCLUSIONSIL-8 might be a poor prognostic factor for human breast cancer, and also might be a novel molecular marker to predicate the occurrence and progression of breast cancer.

Adult ; Aged ; Aged, 80 and over ; Breast Neoplasms ; diagnosis ; metabolism ; pathology ; Female ; Humans ; Immunohistochemistry ; Interleukin-8 ; biosynthesis ; Lymphatic Metastasis ; Middle Aged ; Prognosis ; Receptor, ErbB-2 ; biosynthesis ; Receptors, Estrogen ; biosynthesis ; Receptors, Progesterone ; biosynthesis

Recent studies revealed that apoptotic cells are actively involved in immunosuppression and anti-inflammation. After being phagocytosed by macrophages, apoptotic cells can actively regulate cytokines secretion from lipopolysaccharide (LPS)-stimulated macrophages, in which the secretion of immunosuppressive cytokines such as interleukin-10 (IL-10) is increased while the pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFa), interleukin-1beta (IL-1b) and leukin-8 (IL-8) are suppressed. In this paper, we first present evidence that phagocytosed apoptotic cells regulate cytokine secretion of LPS-stimulated macrophages, but also inhibit the activation of T lymphocytes stimulated by ConA. These data suggest that apoptotic cells can alter the biological behavior of macrophages which gain immunosuppressive property.
Animals ; Antigens, CD ; metabolism ; Antigens, Differentiation, T-Lymphocyte ; metabolism ; Apoptosis ; immunology ; Chemokine CXCL2 ; Chemokines ; biosynthesis ; genetics ; Concanavalin A ; pharmacology ; Cytokines ; biosynthesis ; Female ; Humans ; Immune Tolerance ; In Vitro Techniques ; Jurkat Cells ; Lectins, C-Type ; Lipopolysaccharides ; pharmacology ; Lymphocyte Activation ; drug effects ; Macrophages ; drug effects ; immunology ; Mice ; Mice, Inbred ICR ; Phagocytosis ; Receptors, Interleukin-2 ; metabolism ; Signal Transduction ; immunology ; T-Lymphocytes ; drug effects ; immunology ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

OBJECTIVETo investigate the anti-HIV effects of ampelopsin and its interaction with HIV-1 coreceptor CXCR4.

METHODSThrough anti-virus experiments in vitro, the inhibitory effect of ampelopsin on HIV-1 infection was verified. Chemotaxis assay was performed to show the ability to induce PBMCs migration by ampelopsin, RANTES and SDF-1alpha. Fluorescence labelling monoclonal antibody was utilized to observe the interaction of ampelopsin and CXCR4. Mice immunosuppressant model was also established to detail the role ampelopsin played in regulating cellular immunological functions.

RESULTSAmpelopsin could protect sensitive cells against HIV-1 infection and dramatically reduce HIV-1 antigen P24 expression. HIV-1SF33 attaching to MT-4 cells was interfered by ampelopsin, and the EC50 was 0.175 mg/mL for cellular protection and 0.024 mg/mL for P24 inhibition. At co-cultivating phase, EC50 was 0.229 mg/mL and 0.197 mg/mL respectively. Furthermore, the EC50 was 0.179 mg/mL and 0.348 mg/mL in acute infection. Human PBMCs migration was induced after being challenged with ampelopsin or chemokines, and synergistic action was observed during co-treatment. Ampelopsin alone resulted in maximal chemotaxis at 1 mg/mL. HIV-1 co-receptor CXCR4 on the surface of PBMCs was decreased by internalization, which indicated the effect of ampelopsin on CXCR4. About 70% CXCR4 was reduced by ampelopsin at 1 mg/mL. Ampelopsin also augmented cellular immunological functions in immunosuppressive mice.

CONCLUSIONAmpelopsin displays a strong inhibitive role during HIV-1 absorption, incubation and acute infection. These results are coincident with its immune enhancement.

Ampelopsis ; chemistry ; Animals ; Anti-HIV Agents ; pharmacology ; Cell Line ; Chemokine CCL5 ; pharmacology ; Chemokine CXCL12 ; Chemokines, CXC ; pharmacology ; Chemotaxis, Leukocyte ; Down-Regulation ; Drugs, Chinese Herbal ; Flavonoids ; economics ; isolation & purification ; pharmacology ; HIV Infections ; virology ; HIV-1 ; drug effects ; metabolism ; pathogenicity ; Humans ; Interleukin-2 ; biosynthesis ; Leukocytes, Mononuclear ; drug effects ; Mice ; Mice, Inbred BALB C ; Models, Animal ; Plant Roots ; chemistry ; Receptors, CXCR4 ; antagonists & inhibitors ; drug effects ; Spleen ; immunology ; T-Lymphocytes ; immunology

We have investigated in vitro proliferative responses of peripheral blood mononuclear cells and productions of interferon-gamma and soluble interleukin-2 receptors by these cells from 6 patients with chronic active hepatitis B immediately before and 24 hours after a single intravenous injection of 100 mg of polyadenylic.polyuridylic acid. Cell proliferations were assessed by the technique of tritiated-thymidine incorporation and productions of interferon-gamma and soluble interleukin-2 receptors were measured by enzyme-linked immunosorbent assay. The administration of polyadenylic.polyuridylic acid to the patients has resulted in significant increases of in vitro proliferations of their peripheral blood mononuclear cells as well as productions of interferon-gamma by these cells. However, in vitro productions of soluble interleukin-2 receptors were not changed significantly. These results suggest that the enhanced cellular responses by polyadenylic.polyuridylic acid might be due to the increased sensitivity rather than the increased expression of cellular interleukin-2 receptor.
Adult ; Hepatitis B/*immunology ; Hepatitis, Chronic/*immunology ; Human ; Immunity, Cellular/drug effects ; Interferon Type II/biosynthesis ; Leukocytes, Mononuclear/*drug effects/immunology ; Male ; Middle Age ; Poly A-U/*pharmacology ; Receptors, Interleukin-2/biosynthesis ; Solubility