Differentiation and immunosuppressive function of CD19^(+)CD24^(hi)CD27^(+) regulatory B cells are regulated through the miR-29a-3p/NFAT5 pathway

Background: Regulatory B cells(Bregs) is an indispensable element in inducing immune tolerance after liver transplantation. As one of the microRNAs(miRNAs), mi R-29a-3p also inhibits translation by degrading the target mRNA, and yet the relationship between Bregs and mi R-29a-3p has not yet been fully explored. This study aimed to investigate the impact of miR-29a-3p on the regulation of differentiation and immunosuppressive functions of memory Bregs(m Bregs) and ultimately provide potentially effective therapies in inducing immune tolerance after liver transplantation. Methods: Flow cytometry was employed to determine the levels of Bregs in peripheral blood mononuclear cells. TaqMan low-density array miRNA assays were used to identify the expression of different miRNAs, electroporation transfection was used to induce mi R-29a-3p overexpression and knockdown, and dual luciferase reporter assay was used to verify the target gene of miR-29a-3p. Results: In patients experiencing acute rejection after liver transplantation, the proportions and immunosuppressive function of m Bregs in the circulating blood were significantly impaired. mi R-29a-3p was found to be a regulator of m Bregs differentiation. Inhibition of miR-29a-3p, which targeted nuclear factor of activated T cells 5(NFAT5), resulted in a conspicuous boost in the differentiation and immunosuppressive function of m Bregs. The inhibition of mi R-29a-3p in CD19~+ B cells was capable of raising the expression levels of NFAT5, thereby promoting B cells to differentiate into m Bregs. In addition, the observed enhancement of differentiation and immunosuppressive function of m Bregs upon mi R-29a-3p inhibition was abolished by the knockdown of NFAT5 in B cells. Conclusions: mi R-29a-3p was found to be a crucial regulator for m Bregs differentiation and immunosuppressive function. Silencing mi R-29a-3p could be a potentially effective therapeutic strategy for inducing immune tolerance after liver transplantation.

Action of circulating and infiltrating B cells in the immune microenvironment of colorectal cancer by single-cell sequencing analysis

BACKGROUND The complexity of the immune microenvironment has an impact on the treatment of colorectal cancer(CRC),one of the most prevalent malignancies worldwide.In this study,multi-omics and single-cell sequencing techniques were used to investigate the mechanism of action of circulating and infiltrating B cells in CRC.By revealing the heterogeneity and functional differences of B cells in cancer immunity,we aim to deepen our understanding of immune regulation and provide a scientific basis for the development of more effective cancer treatment strategies.AIM To explore the role of circulating and infiltrating B cell subsets in the immune microenvironment of CRC,explore the potential driving mechanism of B cell development,analyze the interaction between B cells and other immune cells in the immune microenvironment and the functions of communication molecules,and search for possible regulatory pathways to promote the anti-tumor effects of B cells.METHODS A total of 69 paracancer(normal),tumor and peripheral blood samples were collected from 23 patients with CRC from The Cancer Genome Atlas database(https://portal.gdc.cancer.gov/).After the immune cells were sorted by multicolor flow cytometry,the single cell transcriptome and B cell receptor group library were sequenced using the 10X Genomics platform,and the data were analyzed using bioinformatics tools such as Seurat.The differences in the number and function of B cell infiltration between tumor and normal tissue,the interaction between B cell subsets and T cells and myeloid cell subsets,and the transcription factor regulatory network of B cell subsets were explored and analyzed.RESULTS Compared with normal tissue,the infiltrating number of CD20+B cell subsets in tumor tissue increased significantly.Among them,germinal center B cells(GCB)played the most prominent role,with positive clone expansion and heavy chain mutation level increasing,and the trend of differentiation into memory B cells increased.However,the number of plasma cells in the tumor microenvironment decreased significantly,and the plasma cells secreting IgA antibodies decreased most obviously.In addition,compared with the immune microenvironment of normal tissues,GCB cells in tumor tissues became more closely connected with other immune cells such as T cells,and communication molecules that positively regulate immune function were significantly enriched.CONCLUSION The role of GCB in CRC tumor microenvironment is greatly enhanced,and its affinity to tumor antigen is enhanced by its significantly increased heavy chain mutation level.Meanwhile,GCB has enhanced its association with immune cells in the microenvironment,which plays a positive anti-tumor effect.

A novel phenotype of B cells associated with enhanced phagocytic capability and chemotactic function after ischemic stroke

Accumulating evidence has demonstrated the involvement of B cells in neuroinflammation and neuroregeneration.However,the role of B cells in ischemic stroke remains unclear.In this study,we identified a novel phenotype of macrophage-like B cells in brain-infiltrating immune cells expressing a high level of CD45.Macrophage-like B cells chara cterized by co-expression of B-cell and macrophage markers,showed stronger phagocytic and chemotactic functions compared with other B cells and showed upregulated expression of phagocytosis-related genes.Gene Ontology analysis found that the expression of genes associated with phagocytosis,including phagosome-and lysosome-related genes,was upregulated in macrophage-like B cells.The phagocytic activity of macrophage-like B cells was ve rified by immunostaining and three-dimensional reconstruction,in which TREM2-labeled macrophage-like B cells enwrapped and internalized myelin debris after cerebral ischemia.Cell-cell interaction analysis revealed that macrophage-like B cells released multiple chemokines to recruit peripheral immune cells mainly via CCL pathways.Single-cell RNA sequencing showed that the transdiffe rentiation to macrophage-like B cells may be induced by specific upregulation of the transcription factor CEBP fa mily to the myeloid lineage and/or by downregulation of the transcription factor Pax5 to the lymphoid lineage.Furthermore,this distinct B cell phenotype was detected in brain tissues from mice or patients with traumatic brain injury,Alzheimer’s disease,and glioblastoma.Overall,these results provide a new perspective on the phagocytic capability and chemotactic function of B cells in the ischemic brain.These cells may serve as an immunotherapeutic target for regulating the immune response of ischemic stroke.

Dihydroartemisinin enhances cell apoptosis in diffuse large B cell lymphoma by inhibiting the STAT3 activity

Background:Dihydroartemisinin(DHA)is reported to be a potential anticancer agent,and the mechanisms underlying the effects of DHA on diffuse large B cell lymphoma however are still obscure.This study aimed to assess the antitumor effect of DHA on diffuse large B cell lymphoma cells and to determine the potential underlying mechanisms of DHA-induced cell apoptosis.Methods:Here,the Cell Counting Kit 8 assay was conducted to study cell proliferation.We performed Annexin V-FITC/propidium iodide staining,real-time polymerase chain reaction,and western blot analysis to analyze cell apoptosis and potential molecular mechanisms.Results:The results showed that DHA substantially suppressed cell proliferation and induced cell apoptosis in vitro in a time-and concentration-dependent fashion.Moreover,STAT3 activity could be inhibited after stimulation with DHA.Conclusion:These results imply that the underlying anti-tumoral effect of DHA may increase apoptosis in diffuse large B cell lymphoma cells via the STAT3 signaling pathway.In addition,DHA might be an effective drug for diffuse large B cell lymphoma therapy.

Decreased of BAFF-R expression and B cells maturation in patients with hepatitis B virus-related hepatocellular carcinoma

BACKGROUND Recent evidence has indicated the role of B cells and B cell-activating factor(BAFF)in the development of hepatocellular carcinoma(HCC).AIM To characterize circulating BAFF receptor expression and B cell subpopulations in patients with hepatitis B virus(HBV)-related HCC.METHODS Peripheral blood samples collected from 41 patients with chronic HBV infection(25 patients without HCC and 16 patients with HCC)and 9 healthy controls were assessed for BAFF receptors[BAFF-R(B cell-activating factor receptor),transmembrane activator and cyclophilin ligand interactor,B-cell maturation antigen]and B cell subpopulations by multicolor flow cytometry.RESULTS The frequency of BAFF-R expressing B cells to total B cells was significantly lower in patients with HCC(3.39%±2.12%)compared with the non-HCC group(5.37%±1.90%)and healthy controls(6.23%±2.32%),whereas there was no difference in transmembrane activator and cyclophilin ligand interactor and Bcell maturation antigen.The frequencies of CD27+Ig D+memory B cells,CD27+Ig Dclass-switched memory B cells and plasmablasts were significantly lower in the patients with HCC compared to patients without HCC(1.23±1.17 vs 3.09±1.55,P=0.001,0.60±0.44 vs 1.69±0.86,P<0.0001 and 0.16±0.12 vs 0.37±0.30,P=0.014,respectively).However,the ratio of na?ve and transitional B cell did not differ significantly between the three groups.In addition,decreased BAFF-R expression on B cells was significantly correlated with large tumor size and advanced tumor stage.CONCLUSION Our data demonstrated BAFF-R expression was reduced in B cells that involved with the frequencies of B cells maturation in patients with HCC.The depletion of BAFF-R might play an important role in the development of HCC in patients with chronic HBV infection.

Efficacy of rituximab in gastric diffuse large B cell lymphoma patients

AIM:To evaluate retrospectively the efficacy of rituximab plus chemotherapy in gastric diffuse large B cell lymphoma(DLBCL).METHODS:Sixty patients(median age:58 years)with histologically confirmed gastric DLBCL treated at four Italian institutions between 2000 and 2007,were included in this analysis.Patients were selected by stage (Ⅰ-Ⅳ,Lugano staging system),European Cooperative Oncology Group performance status(0-2)and treatment strategies.Treatment strategies were chemotherapy alone(group A,n=30)[scheduled as cyclophosphamide,doxorubicin,vincristine and prednisone (CHOP)and CHOP-like],and chemotherapy combined with rituximab(group B,n=30).The primary end point of the study was complete response(CR)rate;the secondary end points were disease-free survival (DFS)at 5 years and overall survival(OS).RESULTS:Median follow-up was 62 mo(range:31102 mo).We observed a significant difference between the two groups(A vs B)in terms of CR[76.6%(23/30) vs 100%,P=0.04)and DFS at 5 years[73.3%(22/30) vs 100%,P=0.03).To date,19 group A(63.3%) patients are alive and 11 have died,while all group B patients are alive.No significant differences in toxicity were observed between the two groups.CONCLUSION:Rituximab in combination with chemotherapy improves CR rate,DFS and OS.Further prospective trials are needed to confirm our results.

B cell receptor signaling pathway involved in benign lymphoepithelial lesions of the lacrimal gland

AIM：To detect the expression of B cell receptor signaling pathway（BCRSP） in lacrimal gland benign lymphoepithelial lesions（LGBLEL）.METHODS：Gene microarray was used to compare whole-genome expression in lacrimal gland tissues from LGBLEL patients to tissues from orbital cavernous hemangioma（control tissues）. Expression of BCRSP was confirmed by polymerase chain reaction（PCR） and immunohistochemistry. RESULTS：The expression of 22 genes of the BCRSP increased significantly in LGBLEL patients. PCR analysis showed that CD22, CR2, and BTK were all highly expressed in LGBLEL tissues. Immunohistochemical analysis showed that CR2 protein was present in LGBLEL, but CD22 and BTK proteins were negative. CR2, CD22, and BTK were not observed in the orbital cavernous hemangiomas with either PCR or immunohistochemistry. CONCLUSION：BCRSP might be involved in the pathogenesis of LGBLEL.

Prognostic potential of an immune score based on the density of CD8＋ T cells, CD20＋ B cells, and CD33＋/p-STAT1＋ double-positive cells and HMGB1 expression within cancer nests in stage ⅢA gastric cancer patients

Objoctive： There is heterogeneity in the prognosis of gastric cancers staged according to the tumornodes-metastasis （TNM） system. This study evaluated the prognostic potential of an immune score system to supplement the TNM staging system. Mothodsg An immunohistochemical analysis was conducted to assess the density of T cells, B cells, and myeloid-derived suppressor cells （MDSCs） in cancer tissues from 100 stage IIIA gastric cancer patients; the expression of the high-mobility group protein B1 （HMGB1） was also evaluated in cancer cells. The relationship between the overall survival （OS）, disease-free survival （DFS）, and immunological parameters was analyzed.Results： An immune score system was compiled based on the prognostic role of the density ofT cells, B cells, MDSCs, and the expression of HMGB1 in cancer tissues. The median 5-year survival of this group of patient was 32%. However, the 5-year survival rates of 80.0%, 51.7%, 0%, 5.8%, and 0% varied among the patients with an immune score of 4 to those with an immune score of 0 based on the immune score system, respectively. Similarly, differences in DFS rates were observed among the immune score subgroups. Concluslons： An immune score system could effectively identify the prognostic heterogeneity within stage IliA gastric cancer patients, implying that this immune score system may potentially supplement the TNM staging system, and help in identifying a more homogeneous group of patients who on the basis of prognosis can undergo adjuvant therapy.

CD4^+CXCR5^+ T cells activate CD27^+IgG^+ B cells via IL-21 in patients with hepatitis C virus infection

BACKGROUND： Chronic hepatitis C virus （HCV） infection causes the skewing and activation of B cell subsets, but the characteristics of IgG＋ B cells in patients with chronic hepa- titis C （CHC） infection have not been thoroughly elucidated. CD4＋CXCR5＋ follicular helper T （Tfh） cells, via interleukin （IL）-21 secretion, activate B cells. However, the role of CD4＋CXCR5＋ T cells in the activation ofIgG＋ B cells in CHC patients is not clear. METHODS： The frequency of IgG＋ B cells, including CD27-IgG＋ B and CD27＋IgG＋ B cells, the expression of the activation markers （CD86 and CD95） in IgG＋ B cells, and the percentage of circu- lating CD4＋CXCR5＋ T cells were detected by flow cytometry in CHC patients （n=70） and healthy controls （n=25）. The con- centrations of serum IL-21 were analyzed using ELISA. The role of CD4＋CXCR5＋ T cells in the activation of IgG＋ B cells was investigated using a co-culture system. RESULTS： A significantly lower proportion of CD27＋IgG＋ B cells with increased expression of CD86 and CD95 was observed in CHC patients. The expression of CD95 was negatively correlated with the percentage of CD27＋IgG＋ B cells, and it contributed to CD27＋IgG＋ B cell apoptosis. Circulating CD4＋CXCR5＋ T cells and serum IL-21 were significantly increased in CHC patients. Moreover, circulating CD4＋CXCR5＋ T cells from CHC patients induced higher expressions of CD86 and CD95 in CD27＋IgG＋ B cells in a co-culture system; the blockade of the IL-21 decreased the expression levels of CD86 and CD95 in CD27＋IgG＋ B cells.CONCLUSIONS： HCV infection increased the frequency of CD4＋CXCR5＋ T cells and decreased the frequency of CD27＋IgG＋ B cells. CD4＋CXCR5＋ T cells activated CD27＋IgG＋ B cells via the secretion of IL-21.

Clinical and Pathological Implications of Increases in Tonsillar CD19+CD5+B Cells,CD208+Dendritic Cells,and IgA1-positive Cells of Immunoglobulin A Nephropathy

Objective:Several studies indicated that tonsillectomy can improve the prognosis of patients with immunoglobulin A nephropathy(IgAN).However,the relationship between tonsillar immunity and IgAN is still unclear.Methods:A total of 14 IgAN patients were recruited in the current study from May 2015 to April 2016 in Tongji Hospital.B cells,dendritic cells(DCs),and IgAl positive cells in human tonsils were detected using immunofluorescence and immunohistochemistry.Correlations between these cells and clinicopathologic features were evaluated.

Role of Immune Microenvironmental Factors for Improving the IPI-related Risk Stratification of Aggressive B Cell Lymphoma

Objective To investigate the risk stratification of aggressive B cell lymphoma using the immune microenvironment and clinical factors. Methods A total of 127 patients with aggressive B cell lymphoma between 2014 and 2015 were enrolled in this study. CD4, Foxp3, CDS, CD68, CD163, PD-1, and PD-L1 expression levels were evaluated in paraffin-embedded lymphoma tissues to identify their roles in the risk stratification. Eleven factors were identified for further evaluation using analysis of variance, chi-square, and multinomial logistic regression analysis. Results Significant differences in 11 factors （age, Ann Arbor stage, B symptom, ECOG performance status, infiltrating CD8＋ T cells, PD-L1 expression, absolute blood monocyte count, serum lactate dehydrogenase, serum iron, serum albumin, and serum l^2-microglobulin） were observed among patient groups stratified by at least two risk stratification methods [International Prognostic Index （IPI）, revised IPI, and NCCN-IPI models] （P 〈 0.05）. Concordance rates were high （81.4%-100.0%） when these factors were used for the risk stratification. No difference in the risk stratification results was observed with or without the Ann Arbor stage data. Conclusion We developed a convenient and inexpensive tool for use in risk stratification of aggressive B cell lymphomas, although further studies on the role of immune microenvironmental factors are needed.

Frequency of IL-10-producing regulatory B cells associated with disease activity in thyroid-associated orbitopathy

AIM： To investigate the association between IL-10-producing regulatory B（B10） cells and the clinical features of thyroid-associated orbitopathy（TAO）. METHODS： A total of 30 patients with TAO were recruited at Zhongshan Ophthalmic Center from May 2015 to December 2015. Peripheral blood mononuclear cells（PBMCs） were separated from blood samples of 30 TAO patients and 16 healthy controls and stimulated with CD40 ligand and CpG for 48h. The frequency of IL-10＋ B cells was examined by flow cytometry and the correlation between the frequency of IL-10＋ B cells and clinical features of TAO was analyzed by SPSS. RESULTS： The frequency of IL-10＋ B cells among CD19＋ B cells in TAO patients was significantly lower than in healthy controls（TAO： 4.66%±1.88% vs healthy control： 6.82%±2.40%, P〈0.01）. The frequency of IL-10＋ B cells showed a positive correlation with disease activity of TAO measured by Clinical Activity Score（CAS）（r=0.50, P〈0.01）, and became higher in TAO patients with family history of Graves＇ disease（GD）（P=0.04）. CONCLUSION： The decrease of the frequency of IL-10＋ B cells in TAO patients indicates the deficiency of B10 cells in TAO, and the positive association with disease activity suggests its important role in TAO inflammation regulation.

Curcumin alleviates experimental colitis via a potential mechanism involving memory B cells and Bcl-6-Syk-BLNK signaling

BACKGROUND Immune dysfunction is the crucial cause in the pathogenesis of inflammatory bowel disease(IBD),which is mainly related to lymphocytes(T or B cells,including memory B cells),mast cells,activated neutrophils,and macrophages.As the precursor of B cells,the activation of memory B cells can trigger and differentiate B cells to produce a giant variety of inducible B cells and tolerant B cells,whose dysfunction can easily lead to autoimmune diseases,including IBD.AIM To investigate whether or not curcumin(Cur)can alleviate experimental colitis by regulating memory B cells and Bcl-6-Syk-BLNK signaling.METHODS Colitis was induced in mice with a dextran sulphate sodium(DSS)solution in drinking water.Colitis mice were given Cur(100 mg/kg/d)orally for 14 consecutive days.The colonic weight,colonic length,intestinal weight index,occult blood scores,and histological scores of mice were examined to evaluate the curative effect.The levels of memory B cells in peripheral blood of mice were measured by flow cytometry,and IL-1β,IL-6,IL-10,IL-7A,and TNF-αexpression in colonic tissue homogenates were analyzed by enzyme-linked immunosorbent assay.Western blot was used to measure the expression of Bcl-6,BLNK,Syk,and other signaling pathway related proteins.RESULTS After Cur treatment for 14 d,the body weight,colonic weight,colonic length,colonic weight index,and colonic pathological injury of mice with colitis were ameliorated.The secretion of IL-1β,IL-6,TNF-α,and IL-7A was statistically decreased,while the IL-35 and IL-10 levels were considerably increased.Activation of memory B cell subsets in colitis mice was confirmed by a remarkable reduction in the expression of IgM,IgG,IgA,FCRL5,CD103,FasL,PD-1,CD38,and CXCR3 on the surface of CD19^(+)CD27^(+)B cells,while the number of CD19^(+)CD27^(+)IL-10^(+)and CD19^(+)CD27^(+)Tim-3^(+)B cells increased significantly.In addition,Cur significantly inhibited the protein levels of Syk,p-Syk,Bcl-6,and CIN85,and increased BLNK and p-BLNK expression in colitis mice.CONCLUSION Cur could effectively alleviate DSS-induced colitis in mice by regulating memory B cells and the Bcl-6-Syk-BLNK signaling pathway.

Immunotherapeutic strategies targeting B cell maturation antigen in multiple myeloma

Multiple myeloma(MM) is the second most common hematologic malignancy, and is characterized by the clonal expansion of malignant plasma cells. Despite the recent improvement in patient outcome due to the use of novel therapeutic agents and stem cell transplantation, all patients eventually relapse due to clone evolution. B cell maturation antigen(BCMA) is highly expressed in and specific for MM cells, and has been implicated in the pathogenesis as well as treatment development for MM. In this review, we will summarize representative anti-BCMA immune therapeutic strategies, including BCMA-targeted vaccines, anti-BCMA antibodies and BCMA-targeted CAR cells. Combination of different immunotherapeutic strategies of targeting BCMA, multi-target immune therapeutic strategies, and adding immune modulatory agents to normalize anti-MM immune system in minimal residual disease(MRD) negative patients, will also be discussed.

Manifestation of severe pneumonia in anti-PL-7 antisynthetase syndrome and B cell lymphoma:A case report

BACKGROUND Antisynthetase syndrome(ASS)is characterized by the presence of antisynthetase antibodies coupled with clinical findings such as fever,polymyositis-dermatomyositis and interstitial lung disease.It is,however,rare to observe ASS association with B cell lymphoma presenting severe pneumonia as the first clinical manifestation.CASE SUMMARY We evaluated a 59-year-old male patient who presented with cough with sputum,shortness of breath and fever for 13 d.A chest computed tomography radiograph revealed bilateral diffuse ground-glass infiltrates in both upper fields,left lingual lobe and right middle lobe.Initially,the patient was diagnosed with severe community-acquired pneumonia and respiratory failure.He was empirically treated with broad-spectrum antibiotics,without improvement.Further analysis showed an ASS panel with anti-PL7 antibodies.Besides,electromyography evaluation demonstrated a manifestation of myogenic damage,while deltoid muscle biopsy showed irregular muscle fiber bundles especially abnormal lymphocyte infiltration.In addition,bone marrow biopsy revealed high invasive B cell lymphoma.Thus,the patient was diagnosed with a relatively rare anti–PL7 antibody positive ASS associated with B cell lymphoma.CONCLUSION This case highlights that rapidly progressive lung lesions and acute hypoxemic respiratory failure associated with heliotrope rash and extremely high lactate dehydrogenase level should be considered as the characteristics of non-infectious diseases,especially ASS and B cell lymphoma.

The Regulatory B Cell in Active Systemic Lupus Erythematosus Patients:A Systemic Review and Meta-analysis

Background:The study of regulatory B cells(Bregs)in systemic lupus erythematosus(SLE)has been in full swing in recent years,but the number and function of Bregs in SLE patients have also present quite contradictory results.Therefore,we conducted a meta-analysis to verify the changes in Bregs in active SLE.Methods:We identified studies reporting the proportions of Bregs in SLE patients by searching Pubmed,Embase,Web of Science,Cochrane and CNKI.Due to the degree of heterogeneity is very high,we used a random effects model to assess the mean differences in percentages of Bregs between active SLE and controls.Then,sensitivity analysis and subgroup analysis were performed to verify potential sources of heterogeneity.Results:Seven eligible articles involving 301 active SLE patients and 218 controls were included in the meta-analysis.The pooled percentages of Bregs were found no significant difference between active SLE patients and healthy controls[0.259,(−1.150,1.668),p=0.719],with great heterogeneity(I2=97.5%).The result of sensitivity analysis showed that exclusion of any single study or single article did not materially resolve the heterogeneity,but after excluding the article conducted by Cai X and his colleagues,the percentages of Bregs were significantly higher in active SLE than those in controls[1.394,(0.114,2.675),p=0.033].The results of subgroup analysis revealed that when the disease activity was judged by SLEDAI score≥5,the percentages of Bregs were significantly lower in the SLE groups than in the control groups[-1.99,(-3.241,-0.739),p=0.002],but when the threshold of SLEDAI score≥6 chosen for active SLE,the percentages of Bregs were significantly increased in the SLE groups[2.546,(1.333,3.759),p<0.001].Meanwhile,other subgroup analysis based on the different phenotypes of Bregs,diagnostic criteria,enrolled research countries,treatment status,and organ involvement did not differ in proportion of Bregs between SLE patients and controls.Conclusions:The study implies that Bregs may play a role in the pathogenesis of active SLE,and the thresholds of SLEDAI score to distinguish between active and inactive SLE patients are important factors affecting the percentages of Bregs.

Construction,Expression and In Vitro Biological Behaviors of Ig scFv Fragment in Patients with Chronic B Cell Leukemia

The expression vector of SmIg scFv fragment was constructed in patient with B cell chronic lymphocyte leukemia （B-CLL） and expressed in E. coli to obtain scFv fragment, and the effect of the protein on the proliferation of stimulated peripheral blood mononuclear cells （PBMC） was investigated in vitro. Two pairs of primers were designed, and variable region genes of light chain and heavy chain were amplified by PCR respectively from the pGEM-T vectors previously constructed in our laboratory which containing light chain gene or Fd fragment of heavy chain gene. The PCR product was digested, purified and inserted into pHEN2 vector to construct the soluble expression vector pHEN2-scFv. After the induction by IPTG, the scFv protein was identified by SDS- PAGE electrophoresis and purified by Ni-NTA-Chromatography. MTT was used to determine the effect of purified protein on the proliferation of stimulated PBMC in vitro. Plasmid PCR and restriction enzyme digestion of pHEN2-scFv revealed the pHEN2-scFv vector was constructed successfully. Id-scFv protein was expressed in positive clone after induced by IPTG. SDS-PAGE analysis showed that the relative molecular weight of fusion protein was about 30 kD （1 kD= 0. 9921 ku）, which was consistent with the theoretically predicted value. Proliferation of PBMC could be induced by purified Id-scFv. It was suggested that the expression vector of SmIg scFv fragment was constructed successfully, and scFv protein was expressed and secreted from E. coil, which could induce proliferation of PBMC. This may lay an experimental foundation for further research of Id- HSP complex vaccine for B-CLL.

B cells in pancreatic cancer stroma

Pancreatic cancer is a disease with high unmet clinical need.Pancreatic cancer is also characterised by an intense fibrotic stroma,which harbours many immune cells.Studies in both human and animal models have demonstrated that the immune system plays a crucial role in modulating tumour onset and progression.In human pancreatic ductal adenocarcinoma,high B-cell infiltration correlates with better patient survival.Hence,B cells have received recent interest in pancreatic cancer as potential therapeutic targets.However,the data on the role of B cells in murine models is unclear as it is dependent on the pancreatic cancer model used to study.Nevertheless,it appears that B cells do organise along with other immune cells such as a network of follicular dendritic cells(DCs),surrounded by T cells and DCs to form tertiary lymphoid structures(TLS).TLS are increasingly recognised as sites for antigen presentation,T-cell activation,Bcell maturation and differentiation in plasma cells.In this review we dissect the role of B cells and provide directions for future studies to harness the role of B cells in treatment of human pancreatic cancer.

Gp350-anchored extracellular vesicles: promising vehicles for delivering therapeutic drugs of B cell malignancies

Although chimeric antigen receptor-modified(CAR)T cell therapy has been successfully applied in the treatment of acute B lymphocytic leukemia,its effect on Burkitt lymphoma(BL)and chronic B lymphocytic leukemia(B-CLL)is unsatisfactory.Moreover,fatal side effects greatly impede CAR T cell application.Extracellular vesicles(EVs)are excellent carriers of therapeutic agents.Nevertheless,EVs mainly accumulate in the liver when administered without modification.As an envelope glycoprotein of Epstein–Barr viruses,gp350 can efficiently bind CD21 on B cells.Here,gp350 was directly anchored onto red blood cell EVs(RBC-EVs)via its transmembrane region combined with low-voltage electroporation.The results showed that gp350 could anchor to RBC-EVs with high efficiency and that the resulting gp350-anchored RBC-EVs(RBC-EVs/gp350^(Etp))exhibited increased targeting to CD21+BL and B-CLL relative to RBC-EVs.After the loading of doxorubicin or fludarabine,RBC-EVs/gp350^(Etp) had powerful cytotoxicity and therapeutic efficacy on CD21+BL or B-CLL,respectively.Moreover,RBC-EVs/gp350^(Etp) loaded with a drug did not exhibit any apparent systemic toxicity and specifically induced the apoptosis of tumor B cells but not normal Bcells.Therefore,our findings indicate that drug-loaded RBC-EVs/gp350^(Etp) may be adopted in the treatment of CD21+B cell malignancies.

USE OF THE POLYMERASE CHAIN REACTION (PCR) TO DETECT MONOCLONALITY OF B CELL LYMPHO-PROLIFERATIVE DISORDERS

A technique has been developed using PCR to detect monoclonality of B-lymphoproliferative disorders. DNA was extracted from the blood, tissue and paraffin embedded sections by biochemical means or boiling. Forty cases of B-non Hodgkin's lymphoma (NHL), 15 cases of T-NHL, 8 cases of chronic lymphocytic leukemia, 17 cases of reactive lymphadenopathy and 12 cases of various non-lym-phocytic tumor were examined. Monoclonality of B-lymphocytes was detected in 86-92% of cases with B-lymphoproliferative diseases, but none in T-NHL, reactive disorders and non-lymphatic tumors. This technique provides a new molecular biologic method to diagnose malignant B-lymphoproliferative dicor-ders. It may be useful in Ig gene rearrangement study, differential diagnosis and retrospective investigation of lymphoproliferative disorders.