It is well established that TGF-beta1 and retinoic acid (RA) cause IgA isotype switching in mice. We recently found that lactoferrin (LF) also has an activity of IgA isotype switching in spleen B cells. The present study explored the effect of LF on the Ig production by mouse peritoneal B cells. LF, like TGF-beta1, substantially increased IgA production in peritoneal B1 cells but little in peritoneal B2 cells. In contrast, LF increased IgG2b production in peritoneal B2 cells much more strongly than in peritoneal B1 cells. LF in combination with RA further enhanced the IgA production and, interestingly, this enhancement was restricted to IgA isotype and B1 cells. Similarly, the combination of the two molecules also led to expression of gut homing molecules alpha4beta7 and CCR9 on peritoneal B1 cells, but not on peritoneal B2 cells. Thus, these results indicate that LF and RA can contribute to gut IgA response through stimulating IgA isotype switching and expression of gut-homing molecules in peritoneal B1 cells.
Animals ; B-Lymphocytes ; Immunoglobulin A* ; Immunoglobulin Class Switching ; Immunoglobulin G ; Lactoferrin* ; Mice ; Spleen ; Transforming Growth Factor beta1 ; Tretinoin*

TGF-beta induces IgA class switching by B cells. We previously reported that Smad3 and Smad4, pivotal TGF-beta signal-transducing transcription factors, mediate germline (GL) alpha transcription induced by TGF-beta1, resulting in IgA switching by mouse B cells. Post-translational sumoylation of Smad3 and Smad4 regulates TGF-beta-induced transcriptional activation in certain cell types. In the present study, we investigated the effect of sumoylation on TGF-beta1-induced, Smad3/4-mediated GLalpha transcription and IgA switching by mouse B cell line, CH12F3-2A. Overexpression of small ubiquitin-like modifier (SUMO)-1, SUMO-2 or SUMO-3 did not affect TGF-beta1-induced, Smad3/4-mediated GLalpha promoter activity, expression of endogenous GLalpha transcripts, surface IgA expression, and IgA production. Next, we tested the effect of the E3 ligase PIASy on TGF-beta1-induced, Smad3/4-mediated GLalpha promoter activity. We found that PIASy overexpression suppresses the GLalpha promoter activity in cooperation with histone deacetylase 1. Taken together, these results suggest that SUMO itself does not affect regulation of GLalpha transcription and IgA switching induced by TGF-beta1/Smad3/4, while PIASy acts as a repressor.
Animals ; B-Lymphocytes* ; Cell Line ; Histone Deacetylase 1 ; Immunoglobulin A ; Immunoglobulin Class Switching ; Mice ; Small Ubiquitin-Related Modifier Proteins* ; SUMO-1 Protein* ; Sumoylation ; Transcription Factors ; Transcriptional Activation ; Transforming Growth Factor beta ; Transforming Growth Factor beta1 ; Ubiquitin-Protein Ligases

Aluminum hydroxide (alum) is the most widely used adjuvant in human vaccines. Nevertheless, it is virtually unknown whether alum acts on B cells. In the present study, we explored the direct effect of alum on Ig expression by murine B cells in vitro. LPS-activated mouse spleen B cells were cultured with alum, and the level of isotype-specific Ig secretion, IgG1 secreting cell numbers, and Ig germ-line transcripts (GLT) were measured using ELISA, ELISPOT, and RT-PCR, respectively. Alum consistently enhanced total IgG1 production, numbers of IgG1 secreting cells, and GLTgamma1 expression. These results demonstrate that alum can directly cause IgG1 isotype switching leading to IgG1 production.
Alum Compounds ; Aluminum Hydroxide ; Animals ; B-Lymphocytes ; Cell Count ; Enzyme-Linked Immunosorbent Assay ; Enzyme-Linked Immunospot Assay ; Humans ; Hydroxides ; Immunoglobulin Class Switching ; Immunoglobulin G ; Mice ; Spleen ; Vaccines

Follicular helper T cells (Tfh) play a significant role in providing T cell help to B cells during the germinal center reaction, where somatic hypermutation, affinity maturation, isotype class switching, and the differentiation of memory B cells and long-lived plasma cells occur. Antigen-specific T cells with IL-6 and IL-21 upregulate CXCR5, which is required for the migration of T cells into B cell follicles, where these T cells mature into Tfh. The surface markers including PD-1, ICOS, and CD40L play a significant role in providing T cell help to B cells. The upregulation of transcription factor Bcl-6 induces the expression of CXCR5, which is an important factor for Tfh differentiation, by inhibiting the expression of other lineage-specific transcription factors such as T-bet, GATA3, and RORgammat. Surprisingly, recent evidence suggests that CD4 T cells already committed to Th1, Th2, and Th17 cells obtain flexibility in their differentiation programs by downregulating T-bet, GATA3, and RORgammat, upregulating Bcl-6 and thus convert into Tfh. Limiting the numbers of Tfh within germinal centers is important in the regulation of the autoantibody production that is central to autoimmune diseases. Recently, it was revealed that the germinal center reaction and the size of the Tfh population are also regulated by thymus-derived follicular regulatory T cells (Tfr) expressing CXCR5 and Foxp3. Dysregulation of Tfh appears to be a pathogenic cause of autoimmune disease suggesting that tight regulation of Tfh and germinal center reaction by Tfr is essential for maintaining immune tolerance. Therefore, the balance between Tfh and Tfr appears to be a critical peripheral tolerance mechanism that can inhibit autoimmune disorders.
Autoimmune Diseases ; Autoimmunity ; B-Lymphocytes ; CD40 Ligand ; Germinal Center ; Immune Tolerance ; Immunoglobulin Class Switching ; Interleukin-6 ; Interleukins ; Memory ; Nuclear Receptor Subfamily 1, Group F, Member 3 ; Peripheral Tolerance ; Plasma Cells ; Pliability ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer ; T-Lymphocytes, Regulatory ; Th17 Cells ; Transcription Factors ; Up-Regulation

Production of thymus-dependent antibodies by autoreactive B cells requires help from T cells. Follicular helper T (Tfh) cells are a unique lineage of CD4+ T subsets present in the follicles of peripheral lymphoid tissues which functions primarily to provide help to cognate B cells. Within germinal centers Tfh cells stimulate germinal center B cells to undergo affinity maturation, Ig class switching, and differentiation to memory B cells and plasma cells. Proposals that activity of Tfh cells is crucial for long-lived humoral autoimmunity are supported by the correlation of numbers and/or functions of Tfh cells with disease activity in many autoimmune disorders. In this review, we discuss recent findings regarding Tfh cell development and function. In addition, we discuss putative roles of Tfh cells in the pathogenesis and highlight the potential of Tfh cells as therapeutic targets in autoimmune diseases.
Antibodies ; Autoimmune Diseases ; Autoimmunity ; B-Lymphocytes ; Germinal Center ; Immunity, Humoral ; Immunoglobulin Class Switching ; Lymphoid Tissue ; Memory ; Plasma Cells ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer

<b>OBJECTIVEb>To study the relationship between myc gene rearrangement and myc protein expression in diffuse large B cell lymphoma (DLBCL), and their correlation with prognosis.

<b>METHODSb>One hundred and six cases of DLBCLs with follow-up data were analyzed using interphase fluorescence in situ hybridization (FISH) technique. Immunophenotyping analysis for CD20, CD3, myc, Mum-1, CD10, bcl-6 was also performed using EnVision immunohistochemistry.

<b>RESULTSb>The percentages of tumor cells expressing myc, Mum-1, CD10 and bcl-6 were 70.8%, 56.6%, 21.7% and 26.4%, respectively. Twenty six cases (24.5%) were of GCB type and the rest (75.5%) were of non-GCB (non germinal center) type. The myc rearrangement was identified in 13 (12.3%) of 106 cases. 13 cases showed to be of non-GCB type. There was no correlation between myc rearrangement and myc protein expression. DLBCLs (n = 13) with myc rearrangement showed significantly poorer overall survival (OS) and progression free survival (PFS), with a median OS and PFS time of 4.7 and 3.2 months, respectively (for OS and PFS, P < 0.001). Multivariate analysis using Cox proportional hazard model confirmed that myc rearrangement, ECOG performance status of 2-4, immunophenotyping subgroup and myc protein were independent factors affecting the prognosis and significantly associated with the survival. However, myc rearrangement was the strongest prognostic factor.

<b>CONCLUSIONSb>DLBCL with myc gene rearrangement is a subgroup of non-GCB DLBCL with poor outcome. It is an independent and useful factor for prognosis in DLBCL. Expression of myc is influenced by many factors and myc rearrangement may be one of these factors.

Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cyclophosphamide ; therapeutic use ; Disease-Free Survival ; Doxorubicin ; therapeutic use ; Female ; Follow-Up Studies ; Gene Rearrangement, B-Lymphocyte ; Genes, myc ; Humans ; In Situ Hybridization, Fluorescence ; Interferon Regulatory Factors ; metabolism ; Lymphoma, Large B-Cell, Diffuse ; drug therapy ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Neoplasm Staging ; Neprilysin ; metabolism ; Prednisone ; therapeutic use ; Proportional Hazards Models ; Proto-Oncogene Proteins c-bcl-6 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; Survival Rate ; Vincristine ; therapeutic use

Antigens, Differentiation, B-Lymphocyte ; genetics ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; metabolism ; Gene Fusion ; Gene Rearrangement ; Histocompatibility Antigens Class II ; genetics ; Humans ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; Lung Neoplasms ; drug therapy ; genetics ; metabolism ; Protein Kinase Inhibitors ; therapeutic use ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; genetics ; metabolism ; Proto-Oncogene Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Pyrazoles ; therapeutic use ; Pyridines ; therapeutic use ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Sodium-Phosphate Cotransporter Proteins, Type IIb ; genetics

<b>OBJECTIVEb>To study the clinicopathologic features and differential diagnosis of splenic B-cell marginal zone lymphoma (SMZL) involving bone marrow.

<b>METHODSb>The clinical and pathologic features of 22 patients with SMZL were retrospectively studied. Immunophenotypic analysis was carried out by flow cytometry and immunohistochemistry. Immunoglobulin heavy chain rearrangement study was performed using polymerase chain reaction-based method.

<b>RESULTSb>Villous lymphocytes were found in peripheral blood smears of 11/18 of the patients. In bone marrow aspirates, lymphocytosis (> 20%) was demonstrated in 15 cases (15/18) and villous lymphocytes in 6 cases (6/18). Flow cytometry showed CD19(+) CD20(+) FMC7(+) CD22(+) CD10(-) CD2(-) CD3(-) CD7(-) in 18 cases. Bone marrow biopsies of all the 22 patients revealed various degrees and patterns of neoplastic infiltration, as follows: mild (4 cases, 18.2%), moderate (11 cases, 50.0%) or severe (7 cases, 31.8%); intrasinusoidal (16 cases, 72.7%), interstitial (14 cases, 63.6%), nodular (11 cases, 50.0%) or diffuse (1 case, 4.5%). Reactive germinal center formation (CD23(+) bcl-2(-)) was found in 2 cases (91.0%). Immunohistochemical study showed the following results: CD20(+) PAX5(+) CD3(-) CD5(-) CD10(-) cyclin D1(-) CD23(-) CD43(-) Annexin A1(-) CD11C(-) CD25(-) in all the 22 cases, CD38(+) in 2 cases (9.1%) and CD138(+) in 2 cases (9.1%).

<b>CONCLUSIONSb>Different and overlapping patterns of bone marrow involvement are observed in SMZL. As the histologic and immunophenotypic features are not specific to SMZL, distinction from other types of mature B-cell lymphomas is necessary.

Adult ; Aged ; Aged, 80 and over ; Antigens, CD20 ; metabolism ; Bone Marrow ; pathology ; Diagnosis, Differential ; Female ; Gene Rearrangement, B-Lymphocyte, Heavy Chain ; Humans ; Leukemia, Lymphocytic, Chronic, B-Cell ; metabolism ; pathology ; Lymphoma, B-Cell, Marginal Zone ; genetics ; metabolism ; pathology ; Lymphoma, Follicular ; metabolism ; pathology ; Lymphoma, Mantle-Cell ; metabolism ; pathology ; Male ; Middle Aged ; Neoplasm Invasiveness ; Retrospective Studies ; Splenic Neoplasms ; genetics ; metabolism ; pathology ; Waldenstrom Macroglobulinemia ; metabolism ; pathology

<b>OBJECTIVEb>To study the clinicopathologic features, immunohistochemical findings, differential diagnosis and prognosis of type II enteropathy-associated T-cell lymphoma (EATL).

<b>METHODSb>Fourteen cases of type II EATL encountered in Department of Pathology, Nanjing General Hospital were retrospectively reviewed. The clinical data, histologic features, immunohistochemical findings and follow-up information were analyzed, with literature review.

<b>RESULTSb>There were altogether 12 males and 2 females. The median age of patient was 49 years. The sites of involvement included jejunum (10 cases) and ileum/colon (4 cases). The patients often presented with an abdominal mass, abdominal pain, diarrhea and constitutional symptoms such as fever, night sweating and cachexia. There was no clinical evidence of gluten-sensitive enteropathy. Histologically, the lymphoma cells showed full-thickness infiltration of the intestinal wall. They contained round hyperchromatic nuclei and pale cytoplasm. The stroma was minimally inflamed, with or without associated coagulative necrosis. A remarkable finding was the presence of villous atrophy, cryptal hyperplasia and intraepithelial lymphocytosis. Immunohistochemical study showed that the tumor cells expressed CD3, CD43 and CD8 (14/14). Some of them were also positive for CD56 (11/14) and CD30 (2/14). The staining for CD4, CD20, CD79a and myeloperoxidase was negative. A high proliferation index was demonstrated by Ki-67 immunostain. In-situ hybridization for EBER was negative. Follow-up data were available in 9 cases. The duration of follow-up ranged from 6 months to 36 months. Seven patients died within 14 months.

<b>CONCLUSIONSb>EATL is a rare type of lymphoma with intestinal involvement. Associated enteropathy is not demonstrated, in contrast to cases encountered in Nordic countries. A correct diagnosis requires evaluation of clinical manifestations, pathologic features and ancillary study results.

Adolescent ; Adult ; Aged ; CD3 Complex ; metabolism ; CD8 Antigens ; metabolism ; Diagnosis, Differential ; Enteropathy-Associated T-Cell Lymphoma ; genetics ; immunology ; pathology ; surgery ; Female ; Follow-Up Studies ; Gene Rearrangement, T-Lymphocyte ; Humans ; Ileal Neoplasms ; genetics ; immunology ; pathology ; surgery ; Jejunal Neoplasms ; genetics ; immunology ; pathology ; surgery ; Leukosialin ; metabolism ; Lymphoma, B-Cell, Marginal Zone ; metabolism ; pathology ; Lymphoma, Extranodal NK-T-Cell ; metabolism ; pathology ; Lymphoma, Large B-Cell, Diffuse ; metabolism ; pathology ; Male ; Middle Aged ; Retrospective Studies ; Young Adult

<b>OBJECTIVEb>To detect the changes of naive T cell level of thymic recent output at different stages of treatment in patients with diffuse large B-cell lymphoma (DLBCL), thereby to evaluate the relationship of thymic recent output function with prognosis and the impact of chemotherapy on the potential of immunological recovery.

<b>METHODSb>The levels of T-cell receptor rearrangement excision circles (TREC) in DNA of peripheral blood mononuclear cells (PBMNC) from 30 DLBCL patients were monitored before, during, until 3 months and 6 months after chemotherapy by real-time PCR (TaqMan), and TREC-level was detected according to the number of CD3 positive(CD3(+)) cells. Twelve normal individuals who matched in age were served as controls.

<b>RESULTSb>There was a dramatic reduction of TREC values in all DLBCL patients among which TREC values in germinal center B-cell-like-DLBCL (GCB-DLBCL) were higher than those in non-GCB-DLBCL, as compared with TREC values of normal individual in peripheral blood. The mean values of TREC were 0.91 ± 0.15/1000 PBMNCs and (1.22 ± 0.69)/1000 CD3(+) cells in GCB-DLBCL, (0.43 ± 0.29)/1000 PBMNCs and (0.64 ± 0.44)/1000 CD3(+) cells in non-GCB-DLBCL before chemotherapy. TREC values were significantly associated with lower international prognostic index (IPI) grade (r = -0.441, P = 0.015). TREC-level in DLBCL patients was further decreased after chemotherapy, and reached to the lowest level after the 6th cycle of chemotherapy, and during the corresponding period, the mean values of TREC were (0.63 ± 0.34)/1000 PBMNCs and (0.89 ± 0.65)/1000 CD3(+)cells in GCB-DLBCL, (0.19 ± 0.11)/1000 PBMNCs and (0.27 ± 0.25)/1000 CD3(+) cells in non-GCB-DLBCL. TREC-level began to rise obviously 3 months after the last cycle of chemotherapy in most of the DLBCL patients, and came close to normal level in five cases of patients 6 months after the last cycle of chemotherapy.

<b>CONCLUSIONSb>Thymic recent output function was impaired severely in DLBCL patients. There was an important relationship between thymic recent output function before chemotherapy and prognosis, and chemotherapy had influenced the potential of immunological recovery.

Adult ; Aged ; Case-Control Studies ; Female ; Gene Rearrangement, T-Lymphocyte ; Germinal Center ; immunology ; Humans ; Lymphoma, Large B-Cell, Diffuse ; drug therapy ; immunology ; pathology ; Male ; Middle Aged ; Receptors, Antigen, T-Cell ; immunology ; Thymus Gland ; immunology ; Young Adult