BACKGROUND: Regulatory dendritic cell (DCreg) subset exhibits a unique capacity for inducing immune tolerance among the variety subsets of dendritic cells (DCs) within gut-associated lymphoid tissues (GALTs). Fms-like tyrosine kinase 3 ligand (FLT3L) is involved in the differentiation of DCregs and the subsequent expansion of regulatory T-cells (Tregs) mediated by DCregs, though the precise mechanism remains poorly understood. This study aimed to explore the expansion mechanism of Treg induced by DCreg and the role of FLT3L in this process. METHODS: DCregs were distinguished from other DC subsets isolated from GALTs of BALB/c mice through a mixed lymphocyte reaction assay. The functions and mechanisms by which FLT3L promoted Treg expansion via DCregs were investigated in vitro through co-culture experiments involving DCregs and either CD4 + CD25 - T-cells or CD4 + CD25 + T-cells. Additionally, an in vivo experiment was conducted using a dextran sulfate sodium (DSS)-induced colitis model in mice. RESULTS: CD103 + CD11b + DC exhibited DCreg-like functionality and was identified as DCreg for subsequent investigation. Analysis of Foxp3 + Treg percentages within a co-culture system of CD4 + CD25 - T-cells and DCregs, with or without FLT3L, demonstrated the involvement of the FLT3/FLT3L axis in driving the differentiation of precursor T-cells into Foxp3 + Tregs induced by DCregs. Cell migration and co-culture assays revealed that the FLT3/FLT3L axis enhanced DCreg migration toward Tregs via the Rho pathway. Additionally, it was observed that DCregs could promote Treg proliferation through the Notch pathway, as inhibition of Notch signaling by DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester) suppressed Treg expansion within the co-culture system of DCregs and CD4 + T-cells or CD4 + CD25 + T-cells. Furthermore, the FLT3/FLT3L axis influenced JAG1 expression in DCregs, indirectly modulating Treg expansion. In vivo experiments further established that FLT3L promoted DCreg expansion and restored Treg balance in DSS-induced colitis models, thereby ameliorating colitis symptoms in mice. CONCLUSION The FLT3/FLT3L axis is integral to the maintenance of DCreg function in Treg expansion.
Animals ; T-Lymphocytes, Regulatory/immunology* ; Dendritic Cells/immunology* ; Mice ; Mice, Inbred BALB C ; Membrane Proteins/metabolism* ; Receptors, Notch/metabolism* ; Lymphoid Tissue/metabolism* ; Signal Transduction/physiology* ; Coculture Techniques ; Flow Cytometry

Animals ; Antineoplastic Agents ; pharmacology ; B-Cell CLL-Lymphoma 10 Protein ; deficiency ; metabolism ; CARD Signaling Adaptor Proteins ; deficiency ; metabolism ; Cell Survival ; drug effects ; DNA Damage ; Doxorubicin ; pharmacology ; HeLa Cells ; Humans ; Mice ; Mice, Knockout ; Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein ; deficiency ; metabolism ; NF-kappa B ; metabolism

OBJECTIVETo show the involvement of lymphocyte-derived catecholamines in the pathogenesis of rheumatoid arthritis (RA), we investigated the change in expression of tyrosine hydroxylase (TH), a rate-limiting enzyme of catecholamine synthesis, by CD4+ T lymphocytes in lymphoid tissues of DBA/1 mice with collagen-induced arthritis (CIA).

METHODSCIA model was induced by chicken type II collagen in DBA/1 mice. The joints of the mice were observed for clinical score of swelling on and after the 22nd day of primary immunization. Pathological changes of ankles were examined by staining of tissue sections with hematoxylin and eosin on the 35th and 55th day following primary immunization. Immunofluorescent histochemistry was used to identify the number of TH-positive, CD4-positive, and double-labeled cells in the mesenteric lymph nodes and the spleen.

RESULTSPaw-swelling onset was on days 29 - 32 after the first immunization in DBA/1 mice. Clinical score for swelling of the paws reached peak on day 46 after the first immunization. Compared with the ankles of intact or vehicle mice, the joints of CIA mice had these characteristics: increased inflammatory cells in the synovial tissues, proliferated synoviocytes in the multilayers, narrowed articular space, and destructed articular cartilages. Simultaneously, the number of TH-positive, CD4-positive, and double-labeled cells in the mesenteric lymph nodes and the spleen was significantly increased on days 35 and 55 following the first immunization. Between day 35 and day 55 post-immunization, there was no significant difference in the number of these positive cells.

CONCLUSIONCD4+ T lymphocytes up-regulate TH expression in the process of CIA and therefore, it is suggested that endogenous catecholamines of lymphocytes involve in the pathogenesis of RA.

Animals ; Arthritis, Experimental ; metabolism ; Arthritis, Rheumatoid ; CD4-Positive T-Lymphocytes ; metabolism ; Lymphoid Tissue ; metabolism ; Male ; Mice ; Mice, Inbred DBA ; Tyrosine 3-Monooxygenase ; metabolism

Germanium biotite (GB) is an aluminosilicate mineral containing 36 ppm germanium. The present study was conducted to better understand the effects of GB on immune responses in a mouse model, and to demonstrate the clearance effects of this mineral against Porcine reproductive and respiratory syndrome virus (PRRSV) in experimentally infected pigs as an initial step towards the development of a feed supplement that would promote immune activity and help prevent diseases. In the mouse model, dietary supplementation with GB enhanced concanavalin A (ConA)-induced lymphocyte proliferation and increased the percentage of CD3+CD8+ T lymphocytes. In pigs experimentally infected with PRRSV, viral titers in lungs and lymphoid tissues from the GB-fed group were significantly decreased compared to those of the control group 12 days post-infection. Corresponding histopathological analyses demonstrated that GB-fed pigs displayed less severe pathological changes associated with PRRSV infection compared to the control group, indicating that GB promotes PRRSV clearance. These antiviral effects in pigs may be related to the ability of GB to increase CD3+CD8+ T lymphocyte production observed in the mice. Hence, this mineral may be an effective feed supplement for increasing immune activity and preventing disease.
Aluminum Silicates/administration & dosage/*therapeutic use ; Animal Feed/analysis ; Animals ; Antigens, CD3/metabolism ; Antigens, CD8/metabolism ; Antiviral Agents/administration & dosage/*therapeutic use ; Concanavalin A/metabolism ; Dietary Supplements/analysis ; Disease Models, Animal ; Ferrous Compounds/administration & dosage/*therapeutic use ; Germanium/administration & dosage/*therapeutic use ; Lung/immunology/virology ; Lymphocyte Activation/drug effects ; Lymphocytes/cytology/drug effects ; Lymphoid Tissue/immunology/virology ; Mice ; Mitogens/metabolism ; Porcine Reproductive and Respiratory Syndrome/*drug therapy/pathology/virology ; Porcine respiratory and reproductive syndrome virus/*drug effects ; Swine

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

OBJECTIVETo study the genetic aberrations of ocular extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) type occurring in patients from southern China.

METHODSFifty seven paraffin-embedded ocular MALT lymphoma specimens from patients in southern China were studied by interphase fluorescence-in-situ hybridization (FISH) for genetic aberrations including t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/IgH-bcl-10, t(14;18) (q32;q21)/IgH-MALT1 and bcl-6/FOXP1 gene translocations.

RESULTSAmongst the 57 cases studied, 9 cases (15.8%) showed chromosome translocations, including 4 cases (7.0%) of t(11;18)(q21;q21)/API2-MALT1, 1 case (1.8%) of t(14;18) (q32;q21)/IgH-MALT1, 1 case (1.8%) of bcl-6 gene-related chromosome translocation and 3 cases (5.3%) of IgH-unknown translocation partner. FISH revealed 17 cases (29.8%) with 3 copies of bcl-6 gene, 21 cases (36.8%) with 3 copies of MALT1 gene and 12 cases (21.1%) with 3 copies of both genes.

CONCLUSIONSThe MALT lymphoma-associated chromosome translocations t(11;18)(q21;q21)/API2-MALT1 and t(14;18) (q32;q21)/IgH-MALT1 are demonstrated in ocular MALT lymphomas of southern Chinese patients. The prevalence is significantly different from that reported in northern Chinese and northern American patients, indicating a geographic heterogeneity in the MALT lymphoma-associated genetic aberrations. The presence of 3 copies of bcl-6 and MALT1 genes is the commonest genetic abnormalities observed in ocular MALT lymphomas, suggesting a possible role in MALT lymphomagenesis.

Caspases ; genetics ; metabolism ; China ; Chromosome Aberrations ; Chromosomes, Human, Pair 11 ; genetics ; Chromosomes, Human, Pair 14 ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; Chromosomes, Human, Pair 3 ; genetics ; DNA-Binding Proteins ; genetics ; metabolism ; Eye Neoplasms ; genetics ; metabolism ; Humans ; In Situ Hybridization, Fluorescence ; Lymphoma, B-Cell, Marginal Zone ; genetics ; metabolism ; Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein ; Neoplasm Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-6 ; Translocation, Genetic ; Trisomy

AIMTo determine how SDF-1 alpha/CXCR4 activates nuclear factor-kappa B (NF-kappaB) and promotes oral squamous cell carcinoma (OSCC) invasion.

METHODOLOGYA lentivirus-based knockdown approach was utilized to deplete gene expression. NF-kappaB activation was evaluated by Western blot analysis and electrophoretic mobility shift (EMSA).

RESULTSWe show that the activation of NF-kappaB by CXCR4 occurs through the Carma3/Bcl10/Malt1 (CBM) complex in OSCC. We found that loss of components of the CBM complex in HNSCC can inhibit SDF-1 alpha induced phosphorylation and degradation of IkappaBalpha, while TNF alpha induced IKK activation remains unchanged. Further, we identified a role for novel and atypical, but not classical, PKCs in activating IKK through CXCR4. Importantly, inhibition of the CBM complex leads to a significant decrease in SDF-1 alpha mediated invasion of OSCC.

CONCLUSIONThe CBM complex plays a critical role in CXCR4-induced NF-kappaB activation in OSCC. Targeting molecular components of the NF-kappaB signaling pathway may provide an important therapeutic opportunity in controlling the progression and metastasis of OSCC mediated by SDF-1 alpha.

Adaptor Proteins, Signal Transducing ; antagonists & inhibitors ; physiology ; B-Cell CLL-Lymphoma 10 Protein ; CARD Signaling Adaptor Proteins ; antagonists & inhibitors ; physiology ; Carcinoma, Squamous Cell ; pathology ; Caspase Inhibitors ; Caspases ; physiology ; Cell Line, Tumor ; Chemokine CXCL12 ; antagonists & inhibitors ; physiology ; Enzyme Activation ; drug effects ; Gene Silencing ; Genetic Vectors ; genetics ; Humans ; I-kappa B Kinase ; drug effects ; I-kappa B Proteins ; metabolism ; Isoenzymes ; antagonists & inhibitors ; Lentivirus ; genetics ; Membrane Proteins ; antagonists & inhibitors ; physiology ; Mouth Neoplasms ; pathology ; Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein ; NF-KappaB Inhibitor alpha ; NF-kappa B ; antagonists & inhibitors ; physiology ; Neoplasm Invasiveness ; Neoplasm Proteins ; antagonists & inhibitors ; physiology ; Phosphorylation ; Plasmids ; genetics ; Protein Kinase C ; antagonists & inhibitors ; Receptors, CXCR4 ; physiology ; Tumor Necrosis Factor-alpha ; pharmacology

The nomenclature "embryonic lymphoid tissue inducer (LTi) cell" reflects the fundamental role of the cell in secondary lymphoid tissue organization. In addition, it is equally important in primary lymphoid tissue development as it regulates central tolerance to self-antigens in the thymus. An adult LTi cell constitutively expresses two sets of tumor necrosis factor (TNF) family members, whereas its embryonic counterpart expresses only one. The first set is lymphotoxin (LT)alpha, LTbeta, and TNFalpha, which are essential for the secondary lymphoid organogenesis during embryogenesis and for maintaining an organized secondary lymphoid structure during adulthood. The second set is OX40- and CD30-ligands, which are critical for memory T cell generation. Adult LTi cells regulate adaptive immune responses by providing LTbetaR signals to stromal cells to maintain secondary lymphoid tissue structure, and determine adaptive immune responses by providing OX40 and CD30 survival signals to activated T cells in memory T cell generation. Along with the consideration of the roles of embryonic LTi cells in primary and secondary lymphoid tissues, this review highlights the roles of adult LTi cells in secondary lymphoid tissue function.
Adult ; Animals ; Humans ; Lymphoid Tissue/cytology/embryology/*immunology ; Lymphokines/immunology/metabolism ; T-Lymphocytes, Helper-Inducer/cytology/*immunology/metabolism ; Thymus Gland/cytology/embryology/*immunology

The aim of this study was to investigate the clinical feature of mucosa-associated lymphoid tissue lymphoma and clarify the relationship between the pathological, clinical features, the expression of API2-MALT1 and the prognosis. A number of factors including pathological characters, grade, stage, prognosis and treatment of 49 cases of MALT lymphoma were analyzed, and the API2-MALT1 rearrangement was detected by RT-PCR. The results showed that 49 patients were diagnosed as MALT lymphoma, in which median age was 52.4 years. The percentage of patients older than 50 years was 67.3%. The majority of tumors were found in stomach (22 cases), intestine (13 cases), thyroid (6 cases) and so on. Among 49 patients, stage I, II was 77. 6%, stage III, IV was 22.4%. API2-MALT1 rearrangement were found 38.1% in low grade, and 12.5% in transform type. Among 18 patients with gastric MALT lymphoma, 9 cases (50.0%) were helicobacter pylori (HP) positive and received antibiotic treatment. The 3 years overall survival was 93.8%. It is concluded that MALT lymphoma is often seen in older patients, most of them were in low grade with slow progression. The site, grade, stage and molecular genetic changes are important prognostic factors, which can contribute to choosing suitable treatment for patients with MALT lymphoma. The antibiotic treatment is effective for patients with positive HP.
Adult ; Aged ; Caspases ; genetics ; metabolism ; Female ; Gene Rearrangement ; Humans ; Lymphoma, B-Cell, Marginal Zone ; diagnosis ; genetics ; Male ; Middle Aged ; Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein ; Neoplasm Proteins ; genetics ; metabolism ; Neoplasm Staging ; Oncogene Proteins, Fusion ; genetics ; Prognosis ; Young Adult

OBJECTIVETo evaluate the effect of the small intestinal mesenteric lymphoid tissues stimulating mixed lymphocyte reaction with dendritic cells (DC) and peripheral blood monocyte cells (PBMC), and observe the changes of the MHC molecular expression on DC.

METHODSDC, PBMC and mixed lymphocyte were separated to culture from SD rats. Lymphoid tissue suspension was adopted from small intestinal mesentery of Wistar rats. In the mixed lymphocyte reaction (MLR), the cellular proliferation of small intestinal mesenteric lymphoid tissue antigen act on DC and PBMC was detected with cell counting of CCK-8 assay, the same assay used in small intestinal mesenteric lymphoid tissue antigen and ovalbumin (OVA) acting on DC. FACS analysis was performed after lymphoid tissue suspension stimulating DC to observe the MHC molecular expression.

RESULTSIn the lymphoid tissue suspension, 91% of the cells was lymphocyte, others including granulocyte, plasmocyte, epithelium. The effect of stimulating mixed lymphocyte proliferation were higher in DC groups than in PBMC groups with the small intestinal mesenteric lymphoid tissue (P < 0.05). In the proportion of DC and mixed lymphocyte >or= 1:100 groups, the mixed lymphocyte proliferation were higher in the small intestinal mesenteric lymphoid tissues groups than in the OVA groups (P < 0.05). After stimulated by the small intestinal mesenteric lymphoid tissue, DC expressed higher MHC-I and -II molecules than control groups.

CONCLUSIONSThe small intestinal mesenteric lymphoid tissue has high antigenicity; the antigen presenting ability of DC was much stronger than granulocytes; DC expresses high MHC-I and MHC-II molecules after stimulated by mixed lymphoid tissue suspension.

Animals ; Cell Proliferation ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; metabolism ; Flow Cytometry ; Intestine, Small ; immunology ; Lymphocyte Activation ; Lymphocyte Culture Test, Mixed ; Lymphoid Tissue ; cytology ; immunology ; Mesentery ; immunology ; Monocytes ; cytology ; immunology ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Sincalide ; analysis