Differentiation of antitumor-specific cytotoxic T lymphocytes from autologous tumor infiltrating lymphocytes in non-Hodgkin's lymphomas.

The present study describes a new culture protocol allowing the activation and proliferation of autologous tumor infiltrating T lymphocytes (TIL), and the generation of antitumor specific CTL in non-Hodgkin's lymphoma (NHL). Cells from eight patients with indolent NHL were used. We performed 3-week co-cultures of TIL with irradiated autologous malignant B cells in the presence of low doses of IL-1beta, IL-2 and IL-12. The proliferation, phenotype and cytotoxicity, and antitumor specificity of T cells recovered were studied. T-cell clonality was analyzed using TCRgamma gene rearrangement amplification by a multiplex PCR. Under these culture conditions, TIL proliferated, and the CD8+ T lymphocytes that were in a minority at the beginning of the culture increased dramatically in 6 out of 8 cases. In two cases, CD4+ T lymphocytes expanded. We showed that an oligoclonal selection of reactive T cells occurred in culture. Specific cytotoxicity developed against autologous malignant B cells in the 6 cases where there was an expansion of CD8+ T lymphocytes. Inhibition experiments performed with mAb directed against HLA class I and II molecules, CD4, CD8 and TCRgammadelta showed that the cytotoxic effector cells were CD8+ T lymphocytes probably expressing TCRalphabeta+. Cytokine secretion was analyzed in culture medium, and we detected significant levels of IFN-gamma, TNF-alpha, and IL-10 and no IL-4 (except in one case). Our results demonstrate that memory T cells from lymphoma patients can be amplified and differentiated into antitumor cytotoxic cells using a combination of the cytokines IL-1beta, IL-2, and IL-12 in association with non modified tumor cells.     

CD40反义RNA对系统性红斑狼疮患者B淋巴细胞功能的影响

目的　探讨瞬间表达的CD4 0反义RNA对EB病毒转染的系统性红斑狼疮 (SLE)患者B淋巴细胞CD4 0分子表达、细胞增生以及免疫球蛋白 (Ig)分泌功能的影响。 方法　构建人CD4 0反义RNA的真核表达载体CD4 0 /pcDNA3,并将其转染入EB病毒转染的SLE患者B淋巴细胞中。应用流式细胞仪 (FACS)检测观察B淋巴细胞膜上CD4 0分子表达的变化 ;应用四甲基偶氮唑盐微量酶反应比色法 (MTT)观察反义CD4RNA对B淋巴细胞增生能力的影响 ;应用酶联免疫吸附试验(ELISA)测定转染后的B淋巴细胞的Ig分泌功能。结果　与转染pcDNA3空载体组相比 ,转染CD4 0 / pcDNA3组的CD4 0分子的表达明显降低 (P <0 0 1) ;细胞的增生能力明显降低 (P <0 0 5 ) ;细胞的Ig分泌功能明显受抑制 (P <0 0 1)。结论　CD4 0反义RNA对SLE患者的B淋巴细胞有明显的免疫调控作用。     

Defects in pokeweed mitogen (PWM) induced immunoglobulin (Ig) synthesis by lymphocytes of patients with juvenile rheumatoid arthritis

In vitro pokeweed mitogen (PWM) induced immunoglobulin (Ig) synthesis by lymphocytes of 33 patients with juvenile rheumatoid arthritis (JRA) was assessed and the results were correlated with clinical characteristics and laboratory measurements of disease activity. Comparisons with results of lymphocytes from adult controls and age related controls, greater than or equal to 12 years, showed reduced responses in patients with JRA. Low responders had significantly higher sedimentation rates (p = .0052) and platelet counts (p = .033), than patients with normal results. No correlations with onset subtype, medications, or age were found. These findings suggest a reduction in in vitro PWM induced B cell differentiation in patients with JRA, which may be related to disease activity.     

BSF-2/IL-6 does not augment Ig secretion but stimulates proliferation in myeloma cells

Human myeloma cells were highly purified from bone marrow aspirates of 21 patients with advanced immunoglobulin G (IgG)-type multiple myeloma. B-cell stimulatory factor 2 (BSF-2)/interleukin-6 (IL-6) was originally characterized as a cytokine that can enhance immunoglobulin secretion from activated normal B cells and increase the expression of secretory-type Ig mRNA in these B cells, but that does not augment proliferation of activated B cells. However, recombinant IL-6 (rIL-6) could not enhance M-protein (IgG) secretion in freshly isolated myeloma cells in vitro but could augment proliferation of myeloma cells, although myeloma cells constitutively expressed IL-6 receptors. Furthermore, expression of secretory-type IgG (gamma-chain) mRNA in myeloma cells was not changed in the presence of IL-6. These results show that IL-6 is not an enhancing factor in Ig secretion from myeloma cells, and thus signal transduction through IL-6 in myeloma cells may be altered as opposed to activated B cells.     

Immunopathogenesis of juvenile rheumatoid arthritis.

The immunopathogenic mechanisms of juvenile rheumatoid arthritis (JRA) have been debated. A possible cellular-mediated hypothesis versus a possible B cell hyperreactivity have been entertained. This review will focus on some recent cellular work in JRA and also further evaluation of cytokine levels and their role in inflammation in JRA. Recent studies have evaluated the interrelationship of Th1/Th2 immune responses in the immunopathogenesis of JRA, and their effect on cytokine release. Studies have indicated a pro-inflammatory response in systemic-onset JRA manifested by increased secretion of interleukin-6, whereas an anti-inflammatory response has been noted by increases of IL-4 mRNA and IL-10 mRNA in pauciarticular-onset JRA. The continued finding of elevated levels of tumor necrosis factor-alpha (TNF-alpha) and its receptors in association with inflammatory activity has been seen. The recent use of a TNF fusion protein to block TNF-alpha activity in JRA has further contributed to this finding. Further studies on specific cytokines will be helpful in the future in trying to determine the different roles cytokines play in JRA subtypes and would contribute to the development of better therapeutic regimens.     

Responsiveness of chronic lymphocytic leukemia B cells activated via surface Igs or CD40 to B-cell tropic factors.

Recent studies performed in the laboratory have established that interleukin-4 (IL-4) used in combination with anti-CD40 monoclonal antibody (MoAb) 89 presented on Ltk- mouse fibroblasts stably expressing human Fc gamma RII/CDw32 (referred to as the CD40 system) sustains long-term proliferation of normal human B cells. In the present study, B-cell chronic lymphocytic leukemias (B-CLLs) activated through slgs or CD40 were examined for their capacity to proliferate and differentiate in response to various cytokines. Our results indicate that the outcome of IL-4 stimulation on the in vitro growth of B-CLL depends on the signalling pathway used for their activation. Whereas IL-4 did not display any growth-stimulatory effect on B-CLL activated by Ig cross-linking agents, it could stimulate DNA synthesis and enhance the viable cell recovery when leukemic B cells were cultured in the CD40 system. Most B-CLL samples were induced for IgM synthesis upon Staphylococcus aureus strain Cowan I stimulation. This Ig response was potentiated by IL-2 and antagonized by IL-4. Anti-CD40 MoAb used alone or in combination with cytokines (IL-1 alpha to IL-6, interferon gamma, tumor necrosis factor gamma, and transforming growth factor beta) failed to induce Ig secretion from B-CLL cells. No evidence for Ig isotype switching was obtained with the cytokines listed above, regardless of the mode of activation. Taken together, our results suggest that B-CLL cells can be partially released from their apparent maturation block by IL-2 and Ig cross-linking agents. In contrast, combinations of IL-4 and cross-linked anti-CD40 antibodies induced entry of B-CLL cell into cycle, but poorly stimulated their differentiation into Ig secreting cells.     

Interleukin-11 promotes accessory cell-dependent B-cell differentiation in humans.

Interleukin-11 (IL-11) is a recently described stromal-derived cytokine that supports the growth of an IL-6-dependent murine plasmacytoma line in the presence of antibody to IL-6 and appears to act in a manner similar to IL-6 on hematopoietic stem cells. Because IL-6 is known to promote differentiation of normal human B cells, the role of IL-11 on B-cell differentiation in vitro was characterized. IL-11 does not result in significantly increased DNA synthesis or Ig secretion by purified B cells alone or B cells cultured with Staphylococcus Cowan I, a T-cell-independent B-cell mitogen. In contrast, purified B cells cultured in the presence of pokeweed mitogen (PWM), irradiated T cells, and monocytes show increased DNA synthesis at day 3 and increased IgG and IgM secretion at day 7 of culture; addition of IL-11 further augments Ig secretion without change in DNA synthesis, an effect that can only be partially blocked by monoclonal antibody to IL-6. Similar experiments confirmed that increased IgG secretion was demonstrable when either IL-11 or IL-6 was added to B cells + CD4+/45RA- T cells + monocytes + PWM; in contrast, Ig secretion was low and equivalent when CD4+/45RA+ T cells were cultured with B cells+monocytes+PWM with or without IL-6 or IL-11. Neither IL-6 nor IL-11 could significantly increase phytohemagglutinin (PHA)-induced DNA synthesis by CD4+/45RA- or CD4+/45RA+ T cells. Although PWM or IL-11 induced IL-6 mRNA expression in both CD4+/45RA- T cells and monocytes, in neither cell did IL-11 increase IL-6 mRNA expression over that noted to PWM alone. These observations support the view that IL-11 promotes differentiation of human B lymphocytes only in the presence of accessory T cells and monocytes and that a minor component of this effect may be through stimulation of IL-6 production by CD4+/45RA- T cells and monocytes.     

阿司匹林诱导小鼠脾源性树突状细胞产生免疫耐受的机制

目的探讨阿司匹林(ASP)诱导小鼠脾源性树突状细胞(DCs)产生免疫耐受的机制。方法将16只小鼠随机均分为空白对照组(对照组)、ASP1组、ASP2组、ASP3组[分别腹腔注射ASP 0.01、0.02、0.03 mg/(kg.d)]各4只。1个月后取各组小鼠脾脏制备脾细胞,观察细胞生长情况,计算脾源性DCs数量,检测脾源性DCs表型变化、脾源性DCs刺激T细胞增殖的能力、DCs培养液中的IL-10、IL-12表达。结果除对照组外,ASP1组、ASP2组、ASP3组大部分细胞有典型树枝样突起;与对照组比较,ASP组脾源性DCs表型33D1表达、DCs培养液中的IL-10表达升高,CD80与CD86表达、T细胞增殖活性、DCs培养液中的IL-12表达降低(P均<0.05),以ASP3组变化最明显。结论小鼠体内输注ASP后,其脾源性DCs表型33D1表达升高,CD80、CD86表达降低,刺激T细胞增殖能力减弱,DCs培养液中IL-10升高、IL-12降低。     

IgE secretion by Epstein-Barr virus-infected purified human B lymphocytes is stimulated by interleukin 4 and suppressed by interferon gamma.

The cytokine interleukin 4 (IL-4) has been shown to induce lipopolysaccharide-activated murine B cells to differentiate into IgE-secreting cells and to stimulate IgE secretion by cultured human peripheral blood lymphoid cells. It is unclear, however, whether this effect of IL-4 on human peripheral blood lymphoid cells is a direct effect on the B cell because IL-4 can stimulate T cells and monocytes as well as B cells and does not induce purified human B cells to secrete immunoglobulin. To investigate this issue we studied the ability of IL-4 to induce IgE secretion by purified human B cells (93-96% CD20+, less than 1% CD3+) that were cultured with Epstein-Barr virus (EBV). Although B cells cultured with IL-4 alone did not secrete Ig and B cells cultured with EBV alone secreted IgM, IgG, and IgA but less than 150 pg of IgE per ml, the combination of EBV and IL-4 induced an IgE response that ranged from 11.4 to 40.3 ng/ml of culture supernatant after 26 days of culture. While IL-4 also enhanced IgM, IgG, and IgA secretion, as well as proliferation by EBV-infected B cells, these effects were less pronounced, occurred earlier during culture, and required a lower concentration of IL-4 than did the stimulation of IgE secretion. Furthermore, interferon gamma at 10 units per ml was found to inhibit IL-4/EBV-induced IgE secretion without inhibiting the other stimulatory effects of IL-4. We conclude that (i) IL-4 and interferon gamma can act directly on polyclonally activated human B cells to respectively stimulate and suppress IgE secretion and (ii) IL-4, in addition to its specific effect on IgE secretion, has a general stimulatory effect on the growth and differentiation of EBV-infected human B cells.     

T lymphocytes downregulate granulocyte-macrophage colony-stimulating factor secretion from stimulated monocytes by increasing the secretion of monocyte-derived interleukin-10

In previous studies we characterized the cytokine regulation of granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) secretion by endothelial cells and monocytes and found differences in secretion pattern within and between these cell systems. In this study, the regulatory effect of T lymphocytes on CSF secretion was examined. T lymphocytes had no effect on CSF secretion by endothelial cells. In contrast, the addition of T lymphocytes significantly and dose dependently downregulated GM-CSF, but not G-CSF, secretion by monocytes. In one of our previous studies it was shown that interleukin-4 (IL-4) and interleukin-10 (IL-10) were the most potent inhibitory cytokines of CSF secretion by monocytes. Both these cytokines are produced by T lymphocytes. However, the downregulating effect on monocyte GM-CSF secretion was not due to increased secretion of T-lymphocyte-derived IL-4 or IL-10. Instead, the presence of T lymphocytes increased the secretion of monocyte-derived IL-10. It was shown earlier than IL-10 regulates CSF secretion by monocytes in an autocrine manner. Our data indicate that T lymphocytes might interfere with this autocrine regulation and thereby influence monocyte function in immune response and cell proliferation.     

Adipogenic differentiation alters the immunoregulatory property of mesenchymal stem cells through BAFF secretion

Although it has been widely demonstrated that mesenchymal stem cells (MSCs) exert potent immunosuppressive effect, there is little information as to whether adipogenic-differentiated MSCs (adi-MSCs) share the same property. Here, adi-MSCs enhanced alloantigen or mitogen-stimulated lymphocyte proliferation, whereas undifferentiated MSCs (ud-MSCs) inhibited the proliferation. Transwell experiment showed that the stimulatory effect of adi-MSCs was cell-cell contact-independent, and required soluble factors. Furthermore, the supernatant of cultured adi-MSCs could effectively costimulate T and B-lymphocyte proliferation and activation in the presence of anti-CD3 and anti-mu chain treatment, respectively. Production of cytokines interferon-gamma and tumor necrosis factor-alpha by T cells, and Ig secretion by B cells also were increased by the supernatant of cultured adi-MSCs. Mechanism conducted showed that the mRNA and protein expression of costimulatory molecule B-cell activating factor (BAFF) was upregulated, and soluble BAFF was secreted in MSCs after adipogenic differentiation. By blocking the BAFF molecule with specific monoclonal antibody in the culture, T and B-lymphocyte proliferation and activation was stimulated by adi-MSCs or the supernatants were greatly reduced. In conclusion, adipogenic differentiation may alter the immunoregulatory property of MSCs, leading to stimulation of lymphocytes response. The BAFF molecule secreted by the adi-MSCs was responsible for this event.     

In vitro immunoglobulin production by lymphocytes of patients with juvenile rheumatoid arthritis: effects of Staphylococcus aureus Cowan I stimulation and monocyte depletion

Pokeweed mitogen (PWM) and Staphylococcus aureus Cowan I (SAC) were used to stimulate in vitro IgG and IgM production by lymphocytes of 27 patients with juvenile rheumatoid arthritis (JRA). Twelve had reduced stimulation indices for PWM stimulated cultures of T and non-T cells. Stimulation with SAC resulted in increased IgM production in half (5/10); and partial removal of monocytes resulted in improved PWM induced IgM production in 5/7. IgG production was less easily improved. The results of our study suggest that while PWM induced Ig production may be reduced, B cells responding to SAC may function normally in some patients with JRA. In others, monocyte mediated suppression may account for reduced responses to PWM.     

Interleukin 6 dependence of spontaneous in vitro differentiation of B cells from patients with IgM gammapathy.

Blood B cells from eight patients with clonal lymphoid disorders characterized by monoclonal IgM secretion (four with malignant plasmacytic proliferation typical of Waldenström macroglobulinemia and four without overt lymphoid neoplasia) were found to spontaneously differentiate in vitro into plasma cells. In all instances, monoclonal plasma cells (8-45% of the cells) were generated from extensively purified B cells or T-cell-depleted peripheral blood mononuclear cells after a 7-day culture period, with a corresponding high rate of IgM secretion into the culture medium. This differentiation occurred in the absence of any cell proliferation process as measured by [3H]thymidine uptake at day 2 or 4. Normal B cells did not differentiate under the same experimental conditions. Detection of interleukin 6 (IL-6) bioactivity in all patients'' B-cell culture supernatants as well as of IL-6 mRNA in freshly prepared, uncultured B cells in the two cases studied by in situ hybridization suggested that IL-6 secretion by B cells may play a role in this process. Moreover, in the four patients without overt lymphoid proliferation, B-cell differentiation was significantly inhibited (60-80%) in the presence of anti-IL-6 antibodies. In contrast, anti-IL-6 antibodies did not preclude the differentiation into plasma cells of B cells from the four patients with bona fide Waldenström macroglobulinemia. These results suggest a two-step pathogenesis for such human lymphoplasmacytic clonal proliferations, the initial stage being characterized by an IL-6-dependent autocrine differentiation pathway.     

Vitamin A potentiates CpG-mediated memory B-cell proliferation and differentiation: involvement of early activation of p38MAPK

Foreign CpG-DNA from viruses and bacteria can activate memory B cells through binding to toll-like receptor 9, and this pathway has been hypothesized to be involved in the continuous activation of memory B cells ensuring life-long humoral immunity. In this study, we demonstrate that retinoic acid (RA) is a potent coactivator of this pathway in human B cells. RA enhanced the CpG-mediated proliferation of CD27(+) memory B cells, and the proliferative response was accompanied by increased immunoglobulin (Ig) secretion indicative of plasma-cell formation. The RA-induced proliferation was preceded by enhanced expression of cyclin D3, and both the expression of cyclin D3 and the induced Ig secretion were found to be dependent on IL-10. Of importance, RA increased the CpG-induced phosphorylation of ERK1/2, p38MAPK, and IkappaB as early as 30 minutes after stimulation. By using specific inhibitors, all the RA-mediated events, including proliferation, cyclin D3 expression, IL-10 secretion, and Ig secretion, were shown to be dependent on p38MAPK. Hence, we propose that RA can strengthen humoral immunity by promoting CpG-mediated stimulation of CD27(+) B cells via activation of p38MAPK resulting in increased proliferation and differentiation to Ig-secreting plasma cells.     

Immunoregulatory lymphokines in rheumatoid joints. III. B cell growth promoting activity of cells eluted from rheumatoid synovial tissue

Synovial fluid (SF) from rheumatoid arthritis patients (RA) and culture-supernatants of synovial tissue (ST) cells from RA patients and juvenile rheumatoid arthritis (JRA) patients were examined for their ability to promote B cell growth. SF was not suitable for studying B cell growth promotion because with the anti-mu driven assay system employed, all 15 samples strongly inhibited B cell proliferation. Supernatants of in vitro unstimulated ST cells from RA and JRA patients affected B cell growth in different ways, ranging from strong inhibition to moderate stimulation. Supernatants of unstimulated peripheral blood mononuclear cells (MNC) from healthy donors did not influence B cell proliferation. After phytohaemagglutinin (PHA) stimulation of the ST cells and normal MNC, culture supernatants of RA ST cells and normal MNC all stimulated B-cell growth, while culture supernatants of PHA-stimulated JRA ST cells displayed a variable picture. The differences between PHA-supernatants from RA, JRA and normal MNC were not statistically significant. These results indicate that the inflamed synovia of JRA and RA patients contain cells that can produce soluble factors with B cell growth promoting activity. Some of the data in the study suggest that these factors are produced in vivo and thus might be responsible for the observed B-cell activation in joints of these patients.     

Influence of immune complexes containing HBsAg and HBeAg on IL-2 dependent human lymphocyte proliferation

Studies were undertaken to evaluate the effect of hepatitis B virus (HBV) immune complexes (HBV-IC) on IL-2 dependent human lymphocyte proliferation. The following parameters were studied: 1) Effect of HBV-IC (HBsAg-IgG or HBeAg-IgG) on PHA-mediated lymphocyte proliferation; 2) Influence of HBV-IC on the ability of PHA-stimulated peripheral blood lymphocytes (PBL) for IL-2 production and IL-2 receptor expression. HBV-IC induced a dose dependent and antigenic dependent suppression of PHA stimulated lymphocytes. The suppressor effect exerted by HBsAg-IgG was irreversible. In contrast, the suppression mediated by HBeAg-IgG was reversible: lymphocytes preincubated with this preparation washed and activated with PHA responded well to mitogen. The presence of HBV-IC in the cultures of PHA-activated PBL decreased their ability to produce IL-2: HBeAg-IgG exerted a stronger suppressor effect. This effect was partially reversible: removal of HBV-IC from the culture by washing and subsequent stimulation of PBL with PHA increased the capacity of lymphocytes to produce IL-2. This was particularly evident with HBeAg-IgG. Decreased activity of IL-2 observed in the cultures, was also partially dependent on the ability of HBV-IC to bind IL-2 present in the culture medium. Experiments performed using ultracentrifugation indicated that HBV-IC, especially HBsAg-IgG, may bind to IL-2 and inactivate it. HBV-IC had also an effect on IL-2 receptor expression: 1) their presence in the cultures of PHA-stimulated PBL decreased the number of Tac positive cells; 2) the response of HTCL to exogenous IL-2 was decreased by HBV-IC present in the culture medium. This was especially observed in the case of HBsAg-IgG. We suggest that the observed inhibition of PHA-induced lymphocyte proliferation exerted by immune complexes containing HBsAg-IgG or HBeAg-IgG may be caused mainly by their influence on IL-2 dependent mechanism of lymphoproliferation.     

一氧化氮-核因子κB信号通路在支气管哮喘患者T细胞功能表达中的作用

目的　探讨NO 核因子κB(NF κB)信号通路在哮喘患者T细胞细胞因子表达及细胞增殖、凋亡中的调控作用。方法　采用细胞原位杂交、电泳迁移率改变试验(EMSA)、免疫荧光、流式细胞术、双抗夹心ELISA、四甲基偶氮唑蓝微量比色法,观察不同浓度的硝普钠(SNP)及二硫代氨基甲酸吡咯烷(PDTC)对IL 4、IL 5、IFNγ表达及T细胞增殖、凋亡的影响。结果　(1)哮喘患者T细胞IL 4、IL 5mRNA和蛋白表达及细胞增殖均较对照组高,IFNγmRNA和蛋白表达及T细胞凋亡率均较对照组低(P<0 05); (2)低浓度的SNP能上调上述3种细胞因子表达,并使T细胞增殖反应增强、凋亡反应减弱;而中、高浓度的SNP却使上述3种细胞因子表达及细胞增殖率呈剂量依赖性地降低,并使T细胞凋亡率增加; ( 3 )PDTC可抑制10μmol/LSNP对IL 5和IFNγ表达的促进作用,增强1mmol/LSNP对IL 5和IFNγ表达的抑制作用,同时PDTC可减弱10μmol/LSNP对T细胞增殖反应的促进作用,增强1mmol/LSNP对T细胞增殖反应的抑制作用; (4)低浓度的SNP能明显增加NF κB活化细胞百分率及NF κB活性(P<0 05),而中、高浓度的SNP却显著减少NF κB活化细胞百分率及NF κB活性(P<0 05)。结论　哮喘患者T细胞细胞因子表达增多及细胞增殖反应的增强、凋亡反应的减弱与NF κB活化的异常增高有关。N     

Response patterns of purified myeloma cells to hematopoietic growth factors

Tumor cells were isolated from the bone marrow of seven patients with multiple myeloma and from the peripheral blood of three patients with plasma cell leukemia using Ficoll-Hypaque (FH) density sedimentation followed by immune rosette depletion of T, myeloid, monocytoid, and natural killer (NK) cells. Enrichment to greater than or equal to 93% plasma cells was confirmed with Wright's-Giemsa staining, with intracytoplasmic immunoglobulin staining, and with staining using monoclonal antibodies (MoAbs) directed at B, T, myeloid, monocytoid, and myeloma antigens in indirect immunofluorescence assays. Myeloma cells neither proliferated nor secreted Ig in response to G/M-CSF, G- CSF, M-CSF, interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-2 (IL-2), or interleukin-4 (IL-4). Significant proliferation (SI greater than or equal to 3.0) was induced by interleukin-6 (IL-6) in six of ten patients (SI of 31 and 43 in two cases); and to interleukin-3 (IL-3) and interleukin-5 (IL-5), independently, in two patients each. Peak proliferation to IL-5 or IL-6 and to IL-3 occurred in cells pulsed with 3[H] thymidine at 24 and 48 hours, respectively; and proliferation to combinations of factors did not exceed that noted to IL-6 alone; Ig secretion was not documented under any culture conditions. Three myeloma-derived cell lines similarly studied demonstrated variable responses. The heterogeneity in the in vitro responses of myeloma cells and derived cell lines to exogenous growth factors enhances our understanding of abnormal plasma cell growth and may yield insight into the pathophysiology of plasma cell dyscrasias.     

A possible autocrine role for interleukin-6 in two lymphoma cell lines

Interleukin-6 (IL-6) is a growth factor with diverse biologic activity. Originally described as a T-cell product that enhances immunoglobulin (Ig) secretion in antigen-stimulated B cells, it also affects the growth of T cells, plasmacytomas, hybridomas, and hematopoietic stem cells. We report the expression and secretion of IL-6 by two lymphoma cell lines, OCI-LY3 and OCI-LY12. Addition of recombinant IL-6 stimulated their growth, whereas addition of polyclonal anti- recombinant IL-6 (anti-rIL-6) had a marked inhibitory effect on proliferation. These results suggest an autocrine role for IL-6 in the growth of these lymphoma cells in culture.     

In vitro Cytokine Treatment of B Cell Defects in HIV-Infected Hemophilia Patients

HIV-infected patients exhibit defects in B cell differentiation and in the IL-6 response of B cells, in association with autoantibody formation against T cells. These autoantibodies have been implicated as important factors in the development of immunodeficiency disease. As the restoration of defective B cell responses might prevent autoantibody formation and the resulting immunosuppression, we studied whether in vitro treatment with recombinant IL-2 (rIL-2), recombinant IL-4 (rIL-4) or recombinant IL-6 (rIL-6) might restore the response of B cells of HIV-infected patients. B cells of 6 HIV-negative hemophilia patients, 4 HIV-positive patients at CDC stage II, III, 4 HIV-positive patients at CDC stage IV, and 6 healthy controls were tested in Staphylococcus aureus Cowan I (SAC-I)-stimulated B cell cultures and Pokeweed mitogen (PWM)-stimulated allogeneic B and T cell cocultures. B cell differentiation was assessed in a reverse hemolytic plaque assay and by ELISA determination of IgM, IgG and IL-6 in culture supernatants. In vitro application of rIL-6 resulted in suppression of both elevated unstimulated and mitogen-stimulated B cell responses in a dose-dependent manner which was in part due to feedback inhibition. PWM- and SAC-I-stimulated IgG and IgM responses, respectively, could be restored after addition of 10 U/ml rIL-2 in HIV-negative patients, but not in HIV-positive patients. Addition of rIL-4 to cultures resulted in suppression of both unstimulated and mitogen-stimulated IL-6 secretion and B cell responses. Severely depressed B cell responses in CDC IV patients were not significantly affected by cytokine application. These results indicate that defective Ig responses in HIV-negative patients may be restored by rIL-2 treatment whereas HIV-induced B cell defects are not corrected by supply of T cell help or cytokines promoting B cell growth and differentiation.