B cell activating factor (BAFF) is one of the TNF family member, regulates the survival and maturation of B lymphocyte. BAFF binds to three receptors: BCMA, TACI and BAFF-R. In recent years, studies have revealed important roles of BAFF and its receptors in immune regulation of antibody isotype switching, germinal center maintenance, and T cell co-stimulation, that may provide new drugs in the future for the treatment of autoimmune disorders, lymphoma and B cell immunodeficiencies. Therefore, the structure, expression, receptors, biological function and clinical application of BAFF are briefly summarized in this review.
B-Cell Activating Factor ; immunology ; B-Cell Activation Factor Receptor ; immunology ; B-Cell Maturation Antigen ; immunology ; B-Lymphocytes ; immunology ; Humans ; Immunity ; Transmembrane Activator and CAML Interactor Protein ; immunology

This study was purposed to investigate the B cell-activating factor belonging to the TNF family (BAFF) and a proliferation-inducing ligand (APRIL) levels in bone marrow, and the BAFF receptor expression level on B cells in multiple myeloma (MM) patients, in order to explore the characteristics of B cells in bone marrow of MM patients. MM patients were studied before treatment (newly diagnosed group, 19 patients) and after treatment with improvement (stable group, 17 patients), 10 non-hematologic patients were selected as control (control group). The BAFF receptors (BAFF-R) and transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) on B cell (CD19(+)), naive B cell (CD19(+)IgD(+)) and memory B cell (CD19(+)CD27(+)) of bone marrow in all groups were detected by flow cytometry. The BAFF, APRIL level in bone marrow supernatant were tested with ELISA. The results showed that the BAFF-R expression level on CD19(+) cells in newly diagnosed group were higher than that in stable group and control group; there was no significant difference between the BAFF-R expression level on CD19(+)IgD(+) cells in newly diagnosed group and stable group, but BAFF-R expression level on CD19(+)IgD(+) cells in newly diagnosed group was higher than that in control group; the BAFF-R expression level on CD19(+)CD27(+) cells in newly group was higher than that in stable group and control group; there was no significant difference between the BAFF-R expression level on CD19(+) cells, CD19(+)IgD(+) cells or CD19(+)CD27(+) cells in stable group and control group. There was no significant difference among the TACI expression level on CD19(+) cells, CD19(+)IgD(+) cells or CD19(+)CD27(+) cells in newly diagnosed group, stable group and control group. The bone marrow supernatant BAFF level in newly diagnosed group was higher than that in stable group and control group, but there was no significant difference between stable group and control group. There was no significant difference among the bone marrow TACI levels in newly diagnosed group, stable group and control group. It is concluded that both the bone marrow BAFF level and the BAFF-R expression level on CD19(+) cell, CD19(+)IgD(+) cells and CD19(+)CD27(+) cells in MM patients increase, which may help to stimulate B cells, thereby may relate with to MM pathogenesis.
B-Cell Activating Factor ; metabolism ; B-Cell Activation Factor Receptor ; metabolism ; Bone Marrow ; metabolism ; Humans ; Middle Aged ; Multiple Myeloma ; metabolism ; pathology

B cell activation factor (BAFF) is a novel member of the TNF ligand superfamily, mainly produced by myeloid cells. BAFF has been shown to participate in B-cell survival and B- and T-cell maturation. BAFF expression in adipocytes has been recently demonstrated. In the current study, we verified that BAFF expression is increased during adipocyte differentiation. BAFF expression was augmented by TNF-alpha treatment and was decreased by rosiglitazone treatment. BAFF secretion in lean and in ob/ob mice sera were compared and smaller amount of BAFF was secreted in ob/ob mice. mRNA and protein expression were different between epididymal and visceral adipose tissue. BAFF expression was also increased in ob/ob mouse adipose tissue. We sought to identify known BAFF receptors (BAFF-R, BCMA, and TACI) in adipocytes, and determined that all three were present and upregulated during adipocyte differentiation. However, the expression of TACI was distinct from that of BAFF-R and BCMA under TNF-alpha and BAFF ligand treatment. BAFF-R and BCMA expression levels were upregulated under pro-inflammatory conditions, but TACI was reduced. Conversely, BAFF-R and BCMA expression levels were downregulated by rosiglitazone treatment, but TACI was increased. Taken together, our results suggest that BAFF may be a new adipokine, representing a link between obesity and inflammation.
Adipocytes/cytology ; Adipokines/biosynthesis/*physiology ; Animals ; B-Cell Activating Factor/biosynthesis/*physiology ; B-Cell Activation Factor Receptor/metabolism ; Cell Differentiation ; Hypoglycemic Agents/pharmacology ; Inflammation/*metabolism ; Mice ; Obesity/*metabolism ; Thiazolidinediones/pharmacology ; Tumor Necrosis Factor-alpha/pharmacology

<b>OBJECTIVEb>To investigate the expression of B lymphocyte stimulator (BlyS) and its receptors in multiple myeloma (MM) cells, and to explore the relationship between BLyS and the development of human multiple myeloma.

<b>METHODSb>Flow cytometry, RT-PCR and Western blot were used to examine the expression of BLyS and its receptors in MM (KM3 and CZ1) cells. Fluorescence immunocytochemical method and confocal laser scanning technique were applied to the localization of BLyS in KM3 cell. WST proliferation assay was used to examine the effect of BLyS on MM cells growth and survival. Linear correlation analysis was used to detect LDH and beta 2-microglobulin (beta2M) levels with BLyS protein and mRNA expressions in MM patients.

<b>RESULTSb>(1) BLyS and its receptors were expressed in MM cells. (2) BLyS protein was localized on the KM3 plasma membrane. (3) BLyS promoted survival and proliferation of MM cells. (4) MM patients had significantly higher expression levels of BLyS [77.42% (24/31)] BLyS mRNA [93.55% (29/31)], which were significantly correlated with the levels of LDH and beta 2-microglobulin (beta2M).

<b>CONCLUSIONb>BLyS and its receptors in MM cell lines and MM patient bone marrow might have a potential role in the growth and survival of malignant plasma cells.

Aged ; B-Cell Activating Factor ; genetics ; metabolism ; B-Cell Activation Factor Receptor ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Female ; Humans ; Male ; Middle Aged ; Multiple Myeloma ; metabolism ; pathology ; RNA, Messenger ; genetics ; beta 2-Microglobulin ; metabolism

B lymphocyte stimulator (BLyS), a tumor neurosis factor ligand superfamily, is an important factor of B cell survival and activation. However, BLyS also regulates T cell activation and survival, playing key roles in T cell-mediated autoimmune disorders. In the paper, we introduced the mechanisms of BLyS and a proliferation-inducing ligand (APRIL) regulating T cell responses and their roles in rheumatoid arthritis (RA).
Animals ; Antibodies, Monoclonal, Humanized ; therapeutic use ; Arthritis, Rheumatoid ; drug therapy ; metabolism ; pathology ; B-Cell Activating Factor ; metabolism ; B-Cell Activation Factor Receptor ; metabolism ; B-Cell Maturation Antigen ; metabolism ; B-Lymphocytes ; metabolism ; pathology ; Humans ; Lymphocyte Activation ; Recombinant Fusion Proteins ; therapeutic use ; T-Lymphocytes ; metabolism ; pathology ; Transmembrane Activator and CAML Interactor Protein ; metabolism ; Tumor Necrosis Factor Ligand Superfamily Member 13 ; metabolism

B cells play an important role in the pathogenesis of rheumatoid arthritis (RA). High levels of B cell activating factor (BAFF) are detected in autoimmune diseases. BAFF and BAFF receptor (BAFF-R) are expressed in B and T cells of RA synovium. The study was undertaken to identify the NF-kappaB signal pathway involved in the induction of BAFF-R in human B cells. Immunohistochemical staining of NF-kappaB p65, NF-kappaB p50, BAFF, and BAFF-R was performed on sections of synovium from severe and mild RA and osteoarthritis (OA) patients. Peripheral blood mononuclear cells (PBMCs) were isolated from control and RA patients and B cells were isolated from controls. BAFF-R was analyzed by flow cytometry, realtime PCR and confocal staining after treatment with NF-kappaB inhibitors. NF-kappaB p65, NF-kappaB p50, BAFF, and BAFF-R were highly expressed in severe RA synovium relative to mild RA synovium or OA synovium. BAFF-R expression was reduced by NF-kappaB inhibitors in PBMCs and B cells from normal controls. We also showed reduction in expression of BAFF-R via inhibition of the NF-kappaB pathway in PBMCs of RA patients. BAFF/BAFF-R signaling is an important mechanism of pathogenesis in RA and that BAFF-R reduction by NF-kappaB blocking therapy is another choice for controlling B cells in autoimmune diseases such as RA.
Arthritis, Rheumatoid/genetics/*metabolism/pathology/physiopathology ; B-Cell Activating Factor/genetics/metabolism ; B-Cell Activation Factor Receptor/genetics/*metabolism ; B-Lymphocytes/*drug effects/immunology/metabolism/pathology ; Cell Separation ; Cells, Cultured ; Disease Progression ; Enzyme Inhibitors/pharmacology ; Flow Cytometry ; Gene Expression Regulation/immunology ; Humans ; Immunohistochemistry ; NF-kappa B/*metabolism ; Signal Transduction/immunology ; Synovial Membrane/*pathology ; T-Lymphocytes/drug effects/immunology/metabolism/pathology ; Transcriptional Activation/drug effects

<b>OBJECTIVEb>To explore the expressions of B lymphocyte activating factor (BAFF) in the serum and peripheral blood B cells (PBBCs) of BXSB lupus nephritis mice, and to investigate the efficacy of Langchuangping Granule (LG).

<b>METHODSb>Eighteen 11-week-old male BXSB lupus mice were randomly divided into three groups, i.e., the lupus control group, the hormone treatment group, and the LG treatment group, 6 in each group. Besides, another 6 C57BL/6 male mice were recruited as the normal control group. The mice were given with normal sodium (10 mL/d), methylprednisolone (at the daily dose of 5 mg/kg), LG (at the daily dose of 4 g/kg), and the normal saline (10 mL/d) respectively by gastrogavage for 4 weeks. The urine protein, ds-DNA, and body weight were determined. The serum soluble BAFF (sBAFF), the expressions and changes of BAFF-mRNA in the PBBCs were detected using ELISA and RT-PCR respectively. The activity index (AI) and 24 h urine albumin excretion quantitation of renal pathological activities were observed. The correlation between ds-DNA and sBAFF were analyzed.

<b>RESULTSb>The level of sBAFF in serum, the BAFF mRNA level in PBBCs, 24 h urinary albumin excretion, and serum ds-DNA content increased more obviously in lupus mice than in the normal mice. After being treated by methylprednisolone or LG, the sBAFF and BAFF mRNA expressions decreased more obviously than before treatment, showing statistical difference (P<0.05). But there was no statistical difference in the sBAFF level or the BAFF mRNA expression (P>0.05). There was positive correlation between sBAFF and AI (r=0.8098, P<0.01), 24 h urinary albumin excretion (r=0.8220, P<0.01), and ds-DNA (r=0.8535, P<0.01).

<b>CONCLUSIONSb>BAFF plays an important role in the occurrence and development of lupus nephritis. It can be used in monitoring the disease progress and predicting its recurrence. It is one of ideal targets for treating lupus nephritis. LG could attenuate the renal injury via suppressing BAFF level. It is worth further clinical application.

Animals ; B-Cell Activation Factor Receptor ; metabolism ; B-Lymphocytes ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Lupus Nephritis ; immunology ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Phytotherapy ; RNA, Messenger ; genetics

We evaluated the effectiveness of rhamnogalacturonan II (RG-II)-stimulated bone marrow-derived dendritic cells (BMDCs) vaccination on the induction of antitumor immunity in a mouse lymphoma model using EG7-lymphoma cells expressing ovalbumin (OVA). BMDCs treated with RG-II had an activated phenotype. RG-II induced interleukin (IL)-12, IL-1beta, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) production during dendritic cell (DC) maturation. BMDCs stimulated with RG-II facilitate the proliferation of CD8+ T cells. Using BMDCs from the mice deficient in Toll-like receptors (TLRs), we revealed that RG-II activity is dependent on TLR4. RG-II showed a preventive effect of immunization with OVA-pulsed BMDCs against EG7 lymphoma. These results suggested that RG-II expedites the DC-based immune response through the TLR4 signaling pathway.
Acute-Phase Proteins/metabolism ; Adaptor Proteins, Vesicular Transport/metabolism ; Animals ; Antigens, CD14/metabolism ; Bone Marrow Cells/cytology/drug effects ; CD8-Positive T-Lymphocytes/*immunology ; Carrier Proteins/metabolism ; Cell Differentiation/drug effects ; Cell Nucleus/drug effects/metabolism ; Cell Proliferation/drug effects ; Cytokines/biosynthesis ; Dendritic Cells/cytology/drug effects/enzymology/*immunology ; Enzyme Activation/drug effects ; Lymphocyte Activation/*drug effects ; Membrane Glycoproteins/metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mitogen-Activated Protein Kinases/metabolism ; Myeloid Differentiation Factor 88/metabolism ; NF-kappa B/metabolism ; Neoplasms/immunology/*pathology ; Pectins/*pharmacology ; Phenotype ; Protein Transport/drug effects ; Receptors, Chemokine/metabolism ; Signal Transduction/drug effects ; T-Lymphocytes, Cytotoxic/cytology/drug effects ; Toll-Like Receptor 4/*agonists/metabolism