Increased IFN-gamma synthesis by T cells from patients on imatinib therapy for chronic myeloid leukemia

Decreased Type 1 cytokine production has been observed in T cells of patients with untreated chronic myeloid leukemia (CML). The important role of T cells and T-cell cytokines in the long-term control of CML is well established, for example in allogeneic stem-cell graft recipients. This study examined whether or not molecularly targeted therapy with imatinib, an inhibitor of the BCR-ABL tyrosine kinase, improved endogenous T-cell function in patients resistant to or intolerant of previous IFN-alpha therapy. Intracellular cytokine staining and detection by flow cytometry was used to analyze the expression of the T1 cytokine IFN-gamma in T cells. To secure independence from changes in white blood cell counts during treatment, a constant number of T cells was purified from the peripheral blood before analysis of the proportion of IFN-gamma synthesizing T cells. Twenty-nine patients with CML were tested before and after a median follow-up of 3 month on imatinib. In addition, late follow-up (past the median time to best cytogenetic response) of 15 patients were obtained Twenty-nine age- and gender-matched individuals were used as healthy controls. The frequency of IFN-gamma producing T cells in CML patients resistant to or intolerant to previous IFN-alpha therapy was lower than in healthy individuals (p=0.0181, Mann-Whitney test). Imatinib therapy led to a significant increase over pre-treatment values (p<0.0001, Mann-Whitney test). Late follow-up indicated that the increase was sustained in patients not in major cytogenetic response. In contrast, in major responders levels returned towards values comparable to healthy individuals. In conclusion, treatment with imatinib achieves a significant increase in Type 1 (IFN-gamma) cytokine-producing T cells in patients with CML. This is consistent with the view that enhanced T-cell function is achievable in patients with CML, even in the absence of allo-mechanisms.     

Interferon alpha increases the frequency of interferon gamma-producing human CD4+ T cells

An increased ratio of T helper type 2 (Th2)- vs Th1-like cells contributes to the immune dysregulation in allergic disease situations and in many chronic infections, including AIDS. Th2-type immune responses are characterized by Th cells that produce increased levels of interleukin-4 (IL-4) and decreased levels of interferon gamma (IFN- gamma). The induction of either a Th1- or a Th2-like phenotype may be critically controlled by the antigen-presenting cells and their cytokines, e.g., IFN-alpha. In this study we have determined the frequencies of potential IL-4- and/or IFN-gamma-producing T cells in the peripheral blood of randomly selected healthy individuals, and analyzed whether IFN-alpha controls IL-4 and/or IFN-gamma production. Purified CD4+ or CD8+ T cells were stimulated for 24 h via the T cell receptor/CD3 complex in the presence or absence of IFN-alpha, and single IL-4- and IFN-gamma-secreting cells were detected in enzyme- linked immunospot assays. In the absence of IFN-alpha, CD4 cells produced IFN-gamma at frequencies of 1:50-300, and produced IL-4 at frequencies of 1:110-<1:100,000. Addition of IFN-alpha during the activation of CD4 cells increased the levels of IFN-gamma mRNA. As a consequence, the numbers of IFN-gamma-producing CD4 cells and the amounts of secreted IFN-gamma increased 10-fold. In contrast, IFN-alpha did not increase the frequency of IL-4-secreting CD4 cells. In the absence of IFN-alpha, addition of exogenous IL-4 to cultures of CD4 cells suppressed IFN-gamma secretion by 70%. However, in the presence of IFN-alpha, IL-4 did not display any suppressive effect. Compared with CD4 cells, CD8 cells produced IFN-gamma more frequently (1:5-10) but IL-4 less frequently (1:5,300 to < 1:100,000). IFN-alpha did not display any effect on the frequency of either IFN-gamma or IL-4 production by CD8 cells. Taken together the results indicate that IFN- alpha increases the frequency of IFN-gamma-secreting CD4 Th cells and antagonizes the suppressive effect of IL-4 on IFN-gamma production. As a consequence, IFN-alpha may favor the induction and maintenance of Th1- like cells and thereby counteract Th2-driven allergic immune responses.     

Effects of tumour necrosis factor alpha and melphalan on the cytokine production of circulating T cells in patients with cancer

BACKGROUND: The objective of the present study was to investigate the effects of isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF-alpha) and melphalan on circulating T cells from cancer patients using two different methods. DESIGN: Eight patients undergoing an ILP entered the study. At first, the number of T cells at several time points was determined using FACScan. Subsequently, production of interferon gamma (IFN-gamma) (T-helper 1) and interleukin (IL) 4 (T-helper 2) was measured at the intracytoplasmic level after stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin. IFN-gamma, IL-4 and IL-2 (also T-helper 1) production in the whole-blood cell culture system was then determined after stimulation with a combination of anti-CD3/anti-CD28 monoclonal antibodies. RESULTS: An enormous decrease in the number of circulating T cells was observed. In the remaining T-cell population cytokine production (IL-2, IL-4, IFN-gamma) was depressed, showing the same pattern in both methods. No difference could be detected between the effect of TNF-alpha and melphalan on Th1 cells and Th2 cells. CONCLUSIONS: The results demonstrate that TNF-alpha and melphalan reduce the number of circulating T cells and at the single-cell level decrease cytokine production in the remaining circulating T cells. No selective effect of TNF-alpha on Th1 or Th2 cells could be detected. If the impaired T-cell function is representative of all T cells remaining in the systemic circulation, this could help to explain the tolerability of high TNF concentrations after ILP, perhaps by decreasing the synthesis and production of T-cell-derived cytokines.     

Interleukin-12 primes human CD4 and CD8 T cell clones for high production of both interferon-gamma and interleukin-10

Interleukin-12 (IL-12) induces differentiation of T helper 1 (Th1) cells, primarily through its ability to prime T cells for high interferon-gamma (IFN-gamma) production. We now report that the presence of IL-12 during the first several days of in vitro clonal expansion in limiting dilution cultures of polyclonally stimulated human peripheral blood CD4+ and CD8+ T cells also induces stable priming for high IL-10 production. This effect was demonstrated with T cells from both healthy donors and HIV+ patients. Priming for IL-4 production, which requires IL-4, was maximum in cultures containing both IL-12 and IL-4. IL-4 modestly inhibited the IL-12-induced priming for IFN-gamma, but almost completely suppressed the priming for IL-10 production. A proportion of the clones generated from memory CD45RO+ cells, but not those generated from naive CD45RO- CD4+ T cells, produced some combinations of IFN-gamma, IL-10, and IL-4 even in the absence of IL-12 and IL-4, suggesting in vivo cytokine priming; virtually all CD4+ clones generated from either CD45RO(-) or (+) cells, however, produced high levels of both IFN-gamma and IL-10 when IL-12 was present during expansion. These results indicate that each Th1-type (IFN-gamma) and Th2-type (IL-4 and IL-10) cytokine gene is independently regulated in human T cells and that the dichotomy between T cells with the cytokine production pattern of Th1 and Th2 cells is not due to a direct differentiation-inducing effect of immunoregulatory cytokines, but rather to secondary selective mechanisms. Particular combinations of cytokines induce a predominant generation of T cell clones with anomalous patterns of cytokine production (e.g., IFN-gamma and IL-4 or IFN-gamma and IL-10) that can also be found in a proportion of fresh peripheral blood T cells with "memory" phenotype or clones generated from them and that may identify novel Th subsets with immunoregulatory functions.     

Generation of chronic myelogenous leukemia-specific T cells in cytokine-modified autologous mixed lymphocyte/tumor cell cultures.

Chronic myelogenous leukemia (CML) may be amenable to cell-based adoptive immunotherapy, as suggested by the graft-versus-leukemia effect of bone marrow transplantation and the therapeutic benefit of donor leukocyte infusions. Specific adoptive immunotherapy without bone marrow transplantation might be more effective and less cost-intensive. Professional antigen-presenting cells, the dendritic cells, from patients with CML are derived from the malignant clone and may stimulate antileukemia T-cell responses. Autologous T cells may also be able to recognize tumor antigens on CML cells directly. Here, the authors show that CD4 and CD8 T-cell responses to autologous CML cells can be generated in vitro rapidly and effectively by performing modified autologous mixed lymphocyte/tumor cell cultures (MLTC) in serum-free medium in the presence of cytokines known to support dendritic cell differentiation. MLTC-sensitized T cells secreted large amounts of the type 1 cytokine interferon-gamma, as well as interleukin (IL)-2. However, they also secreted a variety of other cytokines, including the type 2-subtype cytokine IL-13 but not the classic type 2 cytokines IL-4, IL-5, and IL-10. Monoclonal populations of CML-specific CD4 cells could be derived from these lines in limited numbers but showed markedly enhanced reactivity. This suggests that CML-specific T cells are relatively rare in these autologous MTLC-derived sensitized populations, but that their isolation and propagation would yield much more potent antitumor effector cells for use in adoptive immunotherapy without the need for bone marrow transplantation.     

Differential effects of the absence of interferon-gamma and IL-4 in acute graft-versus-host disease after allogeneic bone marrow transplantation in mice.

Graft-versus-host disease (GVHD), in which immunocompetent donor cells attack the host, remains a major cause of morbidity after allogeneic bone marrow transplantation (BMT). To understand the role of cytokines in the pathobiology of GVHD, we used cytokine knockout (KO) mice as a source of donor T cells. Two different MHC-disparate strain combinations were examined: BALB/c (H2(d)) donors into lethally irradiated C57BL/6 (H2(b)) recipients or C57BL/6 (H2(b)) donors into B10.BR (H2(k)) recipients. Donor cells were from mice in which either the interferon-gamma (IFN-gamma) or the IL-4 gene was selectively disrupted to understand the role of these cytokines in acute GVHD. In both strain combinations the same pattern was noted with regard to GVHD onset and morbidity. All mice exhibited the classic signs of acute GVHD: weight loss with skin, gut, and liver pathology resulting in morbidity and mortality. Surprisingly, donor cells obtained from mice lacking IFN-gamma gave rise to accelerated morbidity from GVHD when compared with cells from wild-type control donors. Similar results were obtained using normal donors when neutralizing antibodies to IFN-gamma were administered immediately after the BMT. These results suggest that IFN-gamma plays a role in protection from acute GVHD. In marked contrast, cells obtained from IL-4 KO mice resulted in protection from GVHD compared with control donors. Splenocytes from IFN KO mice stimulated with a mitogen proliferated to a significantly greater extent and produced more IL-2 compared with splenocytes obtained from IL-4 KO or control mice. Additionally, there was increased IL-2 production in the spleens of mice undergoing GVHD using IFN-gamma KO donors. These results therefore indicate, with regard to the TH1/ TH2 cytokine paradigm, the absence of a TH1-type cytokine can be deleterious in acute GVHD, whereas absence of a TH2 cytokine can be protective.     

T-Cell Derived Lymphokines as Regulators of Chronic Inflammation: Potential Targets for Immunomodulation?

In recent years, compelling evidence has accumulated that inflammation results from a cascade of events that are orchestrated by cytokines. Cytokines are products of nonimmune and immune cells which regulate the recruitment, differentiation, and proliferation of inflammatory cells. Although there is redundancy in cytokine production and function, major pathways of cytokines have been identified. Besides macrophages, T cells represent important sources of pro- and anti-inflammatory cytokines. In support of a critical regulatory role of T cells in inflammation, two T cell subtypes characterized by different cytokine profiles have been described. TH1 cells produce interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) and are prone to interact with macrophages. TH2 cells are producers of IL-4, IL-5, and IL-10 and are capable of supporting B cells and eosinophils. Here, we are providing evidence that different human inflammatory diseases are characterized by distinct in situ cytokine patterns. Giant cell vasculitis represents a typical TH1-like disease, whereas TH2 helper cells appear to be more important in rheumatoid arthritis. Given the association of different diseases with cytokine profiles, the question arises how the microenvironment influences cytokine pattern and thus disease and whether mediators produced at the site of inflammation could serve as therapeutic targets to modulate the cytokine cascade. Prostaglandin E(2) (PGE(2)) is an important inflammatory mediator. We have examined the influence of PGE(2) and the PGE analog misoprostol on T-cell function and T-cell cytokine production. Here, we describe that IL-2 and IFN-gamma production are sensitive to PGE(2) and misoprostol, whereas IL-4 and IL-5 are unaffected. Thus, in the presence of PGE(2), TH0 cells acquire a TH2-like function, whereas TH1-like aspects are suppressed. We suggest that PGE(2) and misoprostol might represent useful modulators of the cytokine network.     

Human major group rhinoviruses downmodulate the accessory function of monocytes by inducing IL-10

Human rhinoviruses (HRVs) are the predominant cause of the common cold. Although this disease is per se rather harmless, HRV infection is considered to set the stage for more dangerous pathogens in vivo. Here we demonstrate that HRV-14, a member of the major group HRV family, can efficiently inhibit antigen-induced T-cell proliferation and T-cell responses to allogeneic monocytes. HRV-14 triggered a significant downregulation of MHC class II molecules on monocytes. Moreover, supernatants from monocytes cultured in the presence of HRV-14 strongly reduced the allogeneic T-cell stimulatory property of untreated monocytes and monocyte-derived dendritic cells (md-DCs), whereas Epstein Barr virus-transformed B-lymphoblastoid cells were not sensitive. Analysis of the supernatant revealed that HRV-14 induced the production of significant amounts of the immunosuppressive cytokine IL-10. The important T-cell stimulatory cytokine IL-12 or the proinflammatory cytokines IL-1beta or TNF-alpha were not detected or were only minimally detected. Finally, monocytes pretreated with HRV-14 were greatly inhibited in their production of IL-12 upon stimulation with IFN-gamma/LPS. These observations suggest that altered cytokine production in mononuclear phagocytes upon interaction with HRV downmodulates appropriate immune responses during the viral infection.     

Serum levels of IL-12 and the production of IFN-gamma, IL-2 and IL-4 by peripheral blood mononuclear cells (PBMC) in cancer patients treated with Viscum album extract.

A dysregulation between cellular immunity (Th1 cells) and humoral immunity (Th2 cells) is a characteristic of cancerous diseases. Viscum album (VA) extract has an immunomodulatory effect and can be used in the treatment of cancer patients, either following or in combination with chemo- /radiotherapy. In this pilot study, we investigated the effect of VA extract on the serum levels and production of cytokines in a group of cancer patients undergoing treatment (N = 16) in comparison with healthy untreated controls (N = 11). The serum levels of interleukin-12 (IL-12) (p40 and p70), and the production of gamma interferon (IFN-gamma), interleukin 2 (IL-2), and interleukin-4 (IL-4) in peripheral blood mononuclear cells (PBMC) were measured in patients before treatment and on days 3, 5, 8, 15, and 21-29 during therapy, and in the control group at the same time intervals over a two-week period. Cytokine levels were determined by ELISA. In cancer patients, the serum levels of IL-12 (p40 and p70) before therapy were about 3-fold higher than in controls. They increased during therapy, with a borderline significance (Wilcoxon paired signed-rank test, P = 0.06). In PBMC the production of IFN-gamma and IL-2 (before therapy respectively 3-fold and 9-fold lower than in controls) increased significantly (Wilcoxon paired signed-rank test and Mann-Whitney U-test, P < 0.05) during treatment. In PBMC, IL-4 production was in the same range as in controls, and remained unaltered during therapy. In conclusion, the results of this study show that treatment with VA extract leads an increase in Th1 cytokine levels (IFN-gamma and IL-2), which suggests that cell-mediated immunity could be positively affected.     

Confirmation of Mycobacterium tuberculosis infection by flow cytometry after ex vivo incubation of peripheral blood T cells with an ESAT-6-derived peptide pool

BACKGROUND: The presence of a T-cell response to the early secretory antigenic target-6 (ESAT-6) indicates previous infection with or exposure to Mycobacterium tuberculosis. Measuring this response is useful for identifying individuals infected with M. tuberculosis. It was also reported that the frequencies of ESAT-6-specific T cells correlate with disease state. Established procedures measure secreted T-cell cytokines following whole blood stimulation with recombinant ESAT-6 protein or use Elispot as a read-out. METHODS: A single ESAT-6- spanning pool of overlapping peptides (15 amino acids length with 11 overlaps) was used for overnight stimulation of peripheral blood mononuclear cells (PBMCs) from 15 patients infected with Mycobacterium tuberculosis and 11 healthy controls. T-cell responses were rated positive if interferon-gamma (IFN-gamma)-producing T cells were identified above background level, using 4-color cytokine flow cytometry. RESULTS: Thirteen of 15 (87%) patients, but none of the healthy controls, had a positive CD4 T-cell response to the ESAT-6 spanning peptide pool. The frequencies of IFN-gamma-producing cells varied between 1 and 167 per 10,000 CD4 T cells. The test performed as well as the tests described in the literature. CONCLUSIONS: Cytokine flow cytometry following PBMC stimulation with an ESAT-6 spanning peptide pool is a useful laboratory test for ESAT-6-specific T cells combining precise counting and multi-parameter phenotyping.     

Cytokines and HIV-1: interactions and clinical implications

Cytokines play an important role in controlling the homoeostasis of the immune system. Infection with HIV results in dysregulation of the cytokine profile in vivo and in vitro. During the course of HIV-1 infection secretion of T-helper type 1 (Th1) cytokines, such as interleukin (IL)-2, and antiviral interferon (IFN)-gamma, is generally decreased, whereas production of T helper type 2 (Th2) cytokines, IL-4, IL-10, proinflammatory cytokines (IL-1, IL-6, IL-8) and tumour necrosis factor (TNF)-alpha, is increased. Such abnormal cytokine production contributes to the pathogenesis of the disease by impairing cell-mediated immunity. A number of cytokines have been shown to modulate in vitro HIV-1 infection and replication in both CD4 T lymphocytes and cells of macrophage lineage. HIV-inductive cytokines include: TNF-alpha, TNF-beta, IL-1 and IL-6, which stimulate HIV-1 replication in T cells and monocyte-derived macrophages (MDM), IL-2, IL-7 and IL-15, which upregulate HIV-1 in T cells, and macrophage-colony stimulating factor, which stimulates HIV-1 in MDM. HIV-suppressive cytokines include: IFN-alpha, IFN-beta and IL-16, which inhibit HIV-1 replication in T cells and MDM, and IL-10 and IL-13, which inhibit HIV-1 in MDM. Bifunctional cytokines such as IFN-gamma, IL-4 and granulocyte-macrophage colony-stimulating factor have been shown to have both inhibitory and stimulatory effects on HIV-1. The beta-chemokines, macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta and RANTES are important inhibitors of macrophage-tropic strains of HIV-1, whereas the alpha-chemokine stromal-derived factor-1 suppresses infection of T-tropic strains of HIV-1. This review outlines the interactions between cytokines and HIV-1, and presents clinical applications of cytokine therapy combined with highly active antiretroviral therapy or vaccines.     

CD^＋34干／祖细胞与纤维连接蛋白的粘附在慢性粒细胞白血？…

探讨ＣＤ＾＋３４干／祖细胞与纤维连接蛋白（ＦＮ）的粘附在慢性粒细胞白血病（ＣＭＬ）发病中的作用。方法①采用细胞术双标记法检测初治ＣＭＬ慢性期３０例正常骨髓１０份ＣＤ＾＋３４细胞上整合素β１链（ＣＤ２９）和α４链（ＣＤ４９ｄ）的表达;②结晶紫染色法观察免疫磁珠分选的ＣＭＬ慢性期５例和５名正常人骨髓ＣＤ＾＋３４细胞ＦＮ的粘附功能;③极限稀释液体微培养观察ＦＮ对正常和ＣＭＬ慢性期骨髓粒细胞－巨噬细胞祖细     

Induction of pro-inflammatory cytokines by human T-cell leukemia virus type-1 Tax protein as determined by multiplexed cytokine protein array analyses of human dendritic cells.

Human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is characterized by a hyperstimulated immune response, including elevated levels of inflammatory cytokines/chemokines and oligoclonal expansion of virus-specific CD8(+) T cells in the cerebrospinal fluid. Studies have shown that the HTLV-1 transactivator protein Tax is available for immune recognition by antigen presenting cells (APCs), such as dendritic cells (DCs). DCs are relevant to the pathogenesis of HAM/TSP because the presentation of Tax peptides by activated DCs to na?ve CD8(+) T cells may play an important role in the induction of the Tax-specific immune response that is observed in HAM/TSP. In this study, a human cytokine protein array was used to study the secretion of cytokines by monocyte-derived DCs (MDDCs) exposed to Tax. Of the 16 cytokines analyzed, 6 cytokines were secreted in significantly high amounts (> or =2-fold), including Th1 cytokines (IFN-gamma, IL-12, and TNF-alpha) and C-C chemokines (Eotaxin, MCP-1, and MCP-3). Selected cytokines were further examined at two concentrations of Tax and at two time periods. Furthermore, a transient exposure to Tax did not result in any cytokine production when examined at three different time points after exposure, indicating that a prolonged presence of Tax is required for its activity. Finally, inhibition of the NF-kappaB signaling pathway by specific inhibitors, abrogated Tax-mediated cytokine secretion. Collectively, these findings suggest a role for Tax-induced cytokine secretion from MDDCs, which may be critical for the cellular activation and tissue damage that has been observed in HAM/TSP.     

重组人IL-11、G-CSF单独或联合应用对小鼠淋巴细胞免疫功能影响的比较研究

目的探讨重组人(rh)IL-11、rhG-CSF联合应用对小鼠脾脏T淋巴细胞数量和功能的影响及其机制。方法应用流式细胞仪对细胞因子处理后的各组T淋巴细胞和亚群、共刺激分子CD28以及抑制性T淋巴细胞(CD3+CD4-CD8-、CD8+CD28-、CD4+CD25+)的数量进行测定;应用MTT法检测各组T淋巴细胞的增殖能力、混合淋巴细胞反应;测定细胞内IL-4、IFN-γ的分泌情况。结果经rhG-CSF单独及rhIL-11、rhG-CSF联合处理淋巴细胞总数和T细胞亚群与对照组比较均下降(P<0.05),而联合处理组CD3+、CD4+、CD8+细胞下降较明显,与其它各组比较差异有统计学意义(P<0.01),CD4+/CD8+细胞的比值联合处理组亦低于其它各组;G-CSF组及联合处理组CD3+CD28+细胞比例与对照组比较下降(P<0.01),CD4+CD28+、CD8+CD28+细胞联合处理组虽较其它各组低,但各组间差异无统计学意义;CD3+CD4-CD8-和CD4+CD25+抑制性T淋巴细胞各组间均无明显差异,而联合处理组CD8+CD28-抑制性T淋巴细胞较其它各组增加(P<0.05);细胞因子动员后各组T淋巴细胞增殖能力、供鼠对异种抗原的反应能力均降低(P<0.05),而联合处理组比其它各组下降更明显;联合处理组、G-CSF组与对照组比较细胞内细胞因子IFN-γ水平下降、IL-4水平升高,联合处理组与G-CSF组比较差异无统计学意义,但IFN-γ/IL-4的比值联合组低于其它各组(P<0.05)。结论rhIL-11与rhG-CSF体内应用后可产生协同作用,通过对T淋巴细胞数量和功能的影响来诱导机体免疫耐受。     

异基因骨髓移植治疗慢性髓系白血病118例分析

目的 分析异基因骨髓移植治疗慢性髓系白血病患者长期存活的影响因素。方法采用ＴＢＩ 或改良ＢＵ／ＣＹ 预处理方案进行异基因骨髓移植，治疗慢性髓系白血病。１１８ 例患者中慢性期９１ 例，加速期１９ 例，急变期２ 例，第２ 次以上慢性期６ 例。结果 １０９ 例植活。慢性期和加速期患者的５ 年存活概率分别为６９ ．６ ％ 和５１ ．０ ％ ；５ 年复发概率分别为３ ．２ ％ 和１２ ．５ ％ 。结论 病期、预处理方案和脾大对植活时间无影响， 慢性期患者脾大与复发呈正相关； 两种预处理方案对慢性期患者移植效果的影响，差异无显著性。     

Type I interferons regulate inflammatory cell trafficking and macrophage inflammatory protein 1alpha delivery to the liver

Macrophage inflammatory protein 1alpha (MIP-1alpha, CCL3) is critical for liver NK cell inflammation and delivery of IFN-gamma to mediate downstream protective responses against murine cytomegalovirus (MCMV) infections. This system was used to evaluate the upstream contribution of the type 1 IFNs, IFN-alpha/beta, in promotion of MIP-1alpha production. Mice deficient in IFN-alpha/beta functions, as a result of mutation in the receptor for these cytokines (IFN-alpha/betaR(-)), were profoundly deficient in MIP-1alpha expression and accumulation of NK cells and macrophages in the liver and had increased sensitivity to MCMV infection. The cytokines themselves were responsible for the immunoregulatory effects, since administration of recombinant IFN-alpha (rIFN-alpha) to immunocompetent mice also induced these changes. IFN-alpha/beta was required for NK cell accumulation during infection, and MIP-1alpha was required for NK cell accumulation in response to administered rIFN-alpha. In vivo trafficking assays demonstrated a requirement for IFN-alpha/betaR signaling for leukocyte localization in, and delivery of MIP-1alpha-producing macrophages to, the liver. These results extend characterization of the cytokine and chemokine cascade required for protection against viral infections in tissues by defining IFN-alpha/beta-dependent mechanisms promoting MIP-1alpha production and the resulting hepatic accumulation of NK cells.     

细胞因子体外诱导慢性髓细胞性白血病树突状细胞分化的研究

本研究探讨干扰素（IFN）治疗慢性粒细胞性白血病（CML）的可能新机制，为临床治疗CML提供新的思路。用Ficoll密度离心法分离骨髓单个核细胞（BMMNC），用不同细胞因子组合体外诱导培养树突状细胞（DC），在倒置显微镜及光镜下观察DC形态，应用流式细胞术检测其表面标志（CD1a，CD83，CD86，HIA-ABC，HIA-DR，CD54）。MTT法检测其混合淋巴细胞反应（MLR）能力。结果表明：经不同细胞因子组合所诱导出的DC，其特征性表面分子表达率均高于培养前的DC（P〈0．01）；IFN-α＋GM-CSF组DC表达HLA—ABC、HLA-DR明显高于IL-4＋GM-CSF培养组（P〈0．05）；而IFN-α＋GM-CSF4-IL-4组DC的CD86表达率及MLR水平均高于其它细胞因子组合组（P〈0．05）。干扰素耐药组DC表面分子表达率及MLR水平较新诊断组和干扰素治疗有效组均明显减低（P〈0．05），但A、B、C各组的CD86表达率及MLR水平在IFN-α＋GM-CSF4-IL-4因子组合条件下无明显差异。结论：CML骨髓单个核细胞在含有IFN-α的细胞因子组合条件下可分化为具有形态和免疫表型特征的DC，且表达较高的Ⅰ类和Ⅱ类分子、共刺激分子、黏附分子及MLR，表明干扰素治疗CML的机理可能与DC有关，这一结果提示通过增强内源性DC功能可能提高CML临床疗效。     

Cytokine secretion in nasal mucus of normal subjects and patients with allergic rhinitis.

Allergic rhinitis is regulated by the local production and release of several cytokines. The levels of Th2 cytokines IL-4, IL-6, IL-10 and the Th1 cytokine IFN-gamma were studied in nasal mucus from 30 subjects with allergic rhinitis and 45 non-atopic healthy controls. In this study a sampling technique for collecting nasal mucus, well tolerated by the subjects and with a minimal stimulation of the mucosa, was performed. The cytokine concentrations in nasal mucus samples were detected and quantitated by a new paramagnetic particle-based immunofluorescent assay system more sensitive than the conventional ELISA techniques. The new technique showed reliable values of the measured parameters. The nasal mucus from allergic patients contained significantly higher concentrations of IL-4 (25.5 +/- 3.6 pg/ml; P < 0.001) and IL-10 (1300 +/- 190 pg/ml; P < 0.05) compared to the nasal mucus from control subjects (15.2 +/- 2.3 and 532 +/- 28 pg/ml, respectively, for IL-4 and IL-10). No significant modification in IFN-gamma levels of allergic patients was found when compared to control group (respectively, 19.9 +/- 3.3 vs. 25.7 +/- 5.1 pg/ml; P > 0.05). Moreover, the allergic patients showed lower levels of IL-6 concentrations in the nasal mucus compared to control subjects (64.8 +/- 9.1 vs. 129.0 +/- 18.1 pg/ml; P = 0.0099). These data can be interpreted by the hypothesis that in response to environmental allergens there is a preferential Th2 polarity by activated CD4+ T cells and that the cytokines IL-6 and IL-10 have, respectively, an important anti-inflammatory and counterregulatory action in the pathogenesis of allergic rhinitis.     

Attenuation of catecholamine-induced immunosuppression in whole blood from patients with sepsis

Studies performed on healthy volunteers have revealed that catecholamines down-regulate the lipopolysaccharide (LPS)-induced production of tumor necrosis factor (TNF)alpha, interleukin (IL)-6, and IL-1beta. We extended this observation and show that this effect is based on changes in the mRNA concentration of these cytokines. Catecholamines are increased in severe sepsis due to endogenous production and have to be administered exogenously when the disease has proceeded to the state of prolonged hypotension. We here investigated whether the immunomodulating effect of catecholamines could also be demonstrated in the blood of patients with prolonged severe sepsis and of those in prolonged septic shock. Blood was stimulated ex vivo with LPS in the presence and absence of epinephrine and the cytokine protein concentration was determined. In blood of healthy volunteers, epinephrine reduced the LPS-stimulated synthesis of TNFalpha by 62.5% (P< 0.0001), of IL-6 by 39% (P< 0.0001), and of IL-1beta by 40% (P= 0.015), and increased the LPS-stimulated IL-10 production by 77.8% (P < 0.0001). Correspondingly, in blood of patients with prolonged severe sepsis, TNFalpha was reduced by 67.2% (P < 0.0001) and IL-6 was reduced by 32.9% (P < 0.0001); IL-1beta and IL-10 were not modulated by catecholamines in these patients. In blood samples of patients in prolonged septic shock, epinephrine did not modulate cytokine levels of IL-6 and IL-10, and decreased TNFalpha only by 36.4% (P < 0.0001). Interestingly, epinephrine suppressed the IL-1beta production by 73% (P < 0.0001) in blood of patients in prolonged septic shock, which was twice as much as in blood samples of healthy volunteers. The altered response of septic blood to catecholamines might be due to an altered reactivity of leukocytes in the prolonged disease although an additional role of preexisting catecholamines cannot be completely excluded.     

PD-L1阻断对慢性髓系白血病源性树突状细胞的功能影响

程序性死亡-1配体-1(PD-L1)作为近年来发现的B7家族新的成员,已被证实有免疫负调节作用,白血病源性树突状细胞(DC)高表达PD-L1可能是影响其功能的原因之一,本研究试图阻断PD-L1在DC上的表达以增强白血病源性DC的免疫刺激功能。应用人rhGM-CSF、rhIL-4及TNF-α细胞因子组合诱导慢性髓系白血病细胞(CML)分化DC,观察给予加或不加PD-L1单克隆抗体对DC的影响。应用流式细胞术检测DC免疫表型及PD-L1,MTT法检测DC刺激自体T淋巴细胞的增殖能力,ELISA法测定上清液中IFN-γ、IL-2和IL-10的水平。结果显示,负性调节分子PD-L1随着慢性髓系白血病源性树突状细胞(CML-DC)成熟表达不断升高,阻断PD-L1能增强CML-DC刺激自体T淋巴细胞增殖的能力,促进T细胞分泌IFN-γ和IL-2并抑制IL-10的产生(p<0.05)。结论:阻断PD-L1可增强白血病源性DC的功能,为白血病DC瘤苗治疗技术提供了新的方法。