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1.
Marie-Pierre Piccinni Lucio Beloni Loretta Giannarini Claudia Livi Gianfranco Scarselli Sergio Romagnani Enrico Maggi 《European journal of immunology》1996,26(10):2293-2298
T cell clones were generated from umbelical cord blood lymphocytes (UCBL) of nine newborns with atopic or nonatopic parents and their cytokine secretion profile was assessed. Both phytohemagglutinin-induced and Dermatophagoides pteronyssinus-spetific T cell clones from newborns with atopic parents exhibited an enhanced ability to produce the Th2 cytokines interleukin (IL)-4 and IL-5, compared to T cell clones from newborns with nonatopic parents. In contrast, the ability to produce interferon-γ by UCBL from the two groups of newborns was not different. Of the five children who could be followed up to 3 years after birth, four with atopic parents developed clinical and/or biological atopic manifestations, whereas one without atopic parents did not. Thus, the pronounced production of IL-4 and IL-5 by UCBL not only appears to be related to the atopic status of parents, but also associates with the subsequent development of atopy in childhood. 相似文献
2.
组胺对T细胞IL-2产生及增殖活性影响的实验研究 总被引:3,自引:0,他引:3
目的:了解组胺对 CD4 和 CD8 T细胞IL-2产生和细胞增殖活性的影响。方法:密度梯度离心及吸附法分离PBMC和PBLC,采用抗CD4 和CD8 抗体分别制备CD8 和CD4 T细胞进行培养,然后采用ELISA法和MTT比色法测上清液IL-2含量及增殖活性。结果:①组胺 CD4 (CD8 )培养上清液中IL-2水平及MTT增殖指数与T细胞自然培养孔比较明显降低(P<0.05)。②组胺 CD4 (CD8 ) 西咪替丁培养孔上清液中IL-2水平及 MTT增殖指数明显高于未加西咪替丁孔(P<0.05)。③CD4 T细胞自然培养孔上清液中IL-2水平显著高于CD8 T细胞自然培养孔。结论:组胺可抑制T细胞IL-2产生及增殖。西咪替丁可阻断组胺对T细胞的抑制作用。CD8 T细胞也可产生IL-2,但其功能较 CD4 T细胞为低。 相似文献
3.
Specific inhibition of TH2-type cytokine production from human peripheral T cells by terfenadine in vitro 总被引:1,自引:0,他引:1
Munakata Umezawa Iwata Dong Yoshida Ishii & Morimoto 《Clinical and experimental allergy》1999,29(9):1281-1286
BACKGROUND: Cytokine imbalance is thought to be one of the causes for allergic diseases. The effect of anti-allergic drugs on cytokine production from T cells should be examined in a convenient way. OBJECTIVES: To study the in vitro effect of terfenadine, a prototype non-sedating H1 receptor antagonist, on cytokine production from activated T cells. METHODS: T cells were cultured in the presence of terfenadine on anti-CD3 mAb and anti-CD26 mAb-coated wells, anti-CD3 mAb and anti-CD28 mAb-coated wells, and anti-CD3 mAb wells with PMA. T-cell proliferation, along with the concentrations of interleukin (IL) -2, interferon (IFN) -gamma, IL-4, and IL-5 were measured. RESULTS: Terfenadine inhibited T-cell proliferation and IL-4 and IL-5 production under each costimulatory condition tested, whereas it had no effect on IL-2 and IFN-gamma production. CONCLUSIONS: These results indicate that terfenadine has a specific inhibitory effect on TH2-type cytokine production induced by several ways of costimulatory activation. 相似文献
4.
QIU YAN LIU TAO YONG CHEN HUA BIAO CHEN NAN LI MING HUI ZHANG PENG CHENG MA XUE TAO CAO Institute of Immunology Zhejiang University Hangzhou P.R.China Institute of Immunology Second Military Medical University Shanghai P.R.China Institute of Dermatology Chinese Academy of Medical Sciences Nanjing P.R.China 《中华微生物学和免疫学杂志(英文版)》2005,3(1):66-72
Extracts of Tripterygium wilfordii Hook F.(TWHF ) are effective in traditional Chinesemedicine for treatment of autoimmune diseasessuch as rheumatoid arthritis, systemic lupus ery thematosus, nephritis and asthma [1, 2]. Trip tolide, a diterpenoid triepoxide, is derived fromTWHF and is responsible for most of the immuno suppressive and anti inflammatory effects ofTWHF. Triptolide has been shown to be effectivein the treatment of autoimmune diseases, … 相似文献
5.
Virgin T cells do not provide help for antigen-specific B cells in the absence of IL-4, IL-5, and IL-6 总被引:4,自引:0,他引:4
We have used a mAb, 23G2, directed against the B exon of themurine CD45 molecule to identify and separate two subpopulationsof normal peripheral CD4+ T cells. Examination of these twosubpopulatlons indicates that they correspond to virgin (Tv)(CD45RBhl) and memory (Tm) (CD45RB10) cells. In this reportwe have determined the abilities of Tv and Tm cells to provideantigen-specific, cognate help to hapten-specific antigen-bindingB cells. To this end we have enriched Tv and Tm cell populationsfrom splenic CD4+ T cells and have cultured these cells withTNP-specific antigen-binding cells (TNP-ABCs) and specific antigen.We then examined the ability of Tv and Tm cells to promote Igsecretion by the B cells. Both Tm and Tv cells Interact withantigen-presenting B cells as assessed by proliferation andlymphoklne secretion. However, Tm, but not Tv, cells promotesubstantial Ig secretion by TNP-ABCs in the presence of antigen.When either IL-6 or IL-4 plus IL-5 are added to cultures ofTv cells, B cells and antigen, Ig secretion is restored. Thus,Tv cells Interact effectively with B cells to Induce an activationsignal, but in the absence of IL-4 plus IL-5 or IL-6 lymphoklnes,which are not secreted by Tv cells, these cells do not providehelp for an antibody response. Hence, naive, peripheral Tv cellsmust undergo an antigen-dependent differentiation step intoTm and secrete IL-4, IL-5, and IL-6 before they can Induce Bcells to secrete antibody. 相似文献
6.
Liang-Peng Yang Dae-Gyoo Byun Christian E. Demeure Nadia Vezzio Guy Delespesse 《European journal of immunology》1995,25(12):3517-3520
It was recently demonstrated that naive human and mouse CD4 T cells release low but sufficient levels of interleukin (IL)-4 at priming to support their development into IL-4 producers. To determine whether this IL-4 is produced by a minor subset of cells, freshly isolated human naive CD4 T cells were directly cloned by limiting dilution in the absence of exogenous IL-4. More than 95% of neonatal and 60% of adult naive T cells seeded in single-cell cultures could be expanded upon stimulation with anti-CD3 mAb immobilized on CD32-B7.1 L cell transfectants in the presence of IL-2. All 171 clones derived from four neonates and two adults produced IL-4 and IL-5 at generally high levels. Like the allergen-specific human Th2 clones described in the literature, these T cell clones produced little or no interferon γ upon stimulation via their T cell receptor/CD3 complex, whereas they released high levels of this cytokine when activated with phorbol 12-myristate 13-acetate + ionomycin. Cells cloned and expanded in the presence of anti-IL4 + anti-IL-4R mAb produced much lower levels of IL-4 and IL-5. It is concluded that almost every single naive human CD4 T cell primed and expanded in the absence of exogenous IL-4 releases sufficient autocrine IL-4 to support its clonal expansion into high IL-4/IL-5 producers. 相似文献
7.
Thomas Jung Uwe Schauer Christian Rieger Kathrin Wagner Karin Einsle Christine Neumann Christoph Heusser 《European journal of immunology》1995,25(8):2413-2416
Interleukin (IL)-4 and IL-5 are two cytokines which synergize in the induction of several biological effector functions. They are produced by mouse and human T helper 2 (Th2) and T helper 0 (Th0) cells. Little is known about the regulation of the two cytokines at the single-cell level. Here we show, using a flow cytometric intracellular staining technique, that IL-4 and IL-5 are predominantly produced by different human peripheral CD4+ and CD8+ T cells, whereas interferon (IFN)-γ and IL-2 are produced by the same cells. In contrast, cloned human Th0 and Th2 cells were able to produce IL-4 and IL-5 simultaneously. The segregation of IL-4 and IL-5 in activated peripheral T cells was found within 72 h of activation upon anti-CD3 or phorbol ester + ionomycin stimulation. The kinetics of IL-4 and IL-5 production were different at the mRNA and the intra-and extracellular protein level, indicating that the cytokines are regulated differently. T cells from three patients with hyper-IgE syndrome did not display a substantial proportion of IL-4/IL-5 double-positive cells. However, simultaneous production could be induced in normal human T cells after prolonged stimulation with a minimum of two restimulation cycles. We conclude that the simultaneous production of IL-4 and IL-5 is a feature of repetitively activated human T cells. 相似文献
8.
9.
Yisong Y Wan 《Immunology》2010,130(2):166-171
CD4 T helper cells (Th) are critical in combating pathogens and maintaining immune homeostasis. Since the establishment of the Th1–Th2 paradigm in the 1980s, many types of specialized Th cells, including Th1, Th2, Th17, Th9, follicular helper T and regulatory T, have been identified. We have become accustomed to the idea that different Th cells are ‘committed’ to their paths but recent emerging evidence suggests that under certain conditions, seemingly committed Th cells possess plasticity and may convert into other types of effector cells. In this review, we will first introduce the major sub‐types of Th cells that are involved in immune regulation. Then, we will describe in detail the inter‐convertibility of Th cells among different sub‐types under in vitro and in vivo conditions. Finally, we will discuss our current understanding of the underlying mechanisms on how a particular type of Th cells may convert into other types of Th cells. 相似文献
10.
目的 研究不同激活状态下T辅助细胞(Th)中IL-2R各亚基的表达变化及对IL-2反应的相关性.方法 以包被的抗CD3抗体激活Th1细胞,同时设立未激活对照.3H掺入法测定其对IL-2的促增殖反应;real-time PCR检测IL-2R各亚基编码基因的表达;流式细胞术检测CD25及CD122的含量;以I125标记的IL-2检测不同状态的Th1细胞对IL-2的亲和力.脂质体法转染IL-2Rα siRNA至激活的Th1细胞,比较不同CD25含量时Th1细胞对IL-2的反应性.自小鼠体内分离CD4细胞,以抗CD3抗体激活后在不同时间点收集细胞,比较它们的CD25含量及对1L-2的反应性.结果 较未激活对照相比,激活的Th1细胞中IL-2Rα亚基,即CD25的表达显著增加,而其他两个亚基则无变化;同时伴有对IL-2亲和力的升高,但对IL-2的促增殖反应性却显著降低.以siRNA适当下调IL-2Rα基因的表达则可显著提高激活的Th1细胞对IL-2的反应性.虽然激活后的na(i)ve CD4细胞对IL-2的反应性明显增加,但却不与CD25的含量及激活度正相关.最高的IL-2反应性出现在低度激活的CD4细胞中.结论 CD25在激活后的Th细胞中显著增多,并可通过自身数量的变化来调节所在细胞对IL-2的促增殖反应性.适度高表达的CD25可使靶细胞具有最高的IL-2反应性,过度表达的CD25则可导致对IL-2反应性的降低. 相似文献
11.
DC-SIGN, but not sDC-SIGN, can modulate IL-2 production from PMA- and anti-CD3-stimulated primary human CD4 T cells 总被引:1,自引:0,他引:1
Martinez O Brackenridge S El-Idrissi Mel-A Prabhakar BS 《International immunology》2005,17(6):769-778
Dendritic cell (DC)-specific intercellular cell adhesion molecule-3 (ICAM-3)-grabbing non-integrin (DC-SIGN) is expressed on the surface of DCs and specialized macrophages and can support T cell proliferation. Antibody-mediated co-ligation of CD3 and ICAM-3, the ligand for both DC-SIGN and leukocyte function-associated antigen-1, leads to T cell activation. Therefore, we tested to see whether DC-SIGN or a splice variant of dendritic cell-specific intercellular cell adhesion molecule-3-grabbing non-integrin (sDC-SIGN) can co-stimulate primary human T cells. The sDC-SIGN lacking the transmembrane domain encoded by exon 3 localizes to the cytoplasm of cells and is not secreted. Both B7 and DC-SIGN co-stimulated phorbol myristate acetate-stimulated CD4+ cells as compared with controls. However, unlike B7, both DC-SIGN and sDC-SIGN failed to co-stimulate CD4+ T cells treated with sub-optimal amounts of anti-CD3 (2 microg ml(-1)) as defined by a lack of CD69 and CD25 up-regulation, cell division and cytokine secretion. Instead, DC-SIGN, and not sDC-SIGN, induced a small but consistent down-regulation of IL-2 production by these CD4+ T cells. In contrast, DC-SIGN in the presence of 30 mug ml(-1) of anti-CD3 modestly up-regulated cytokine production as compared with control. These results suggest that DC-SIGN can differentially modulate T cell stimulation. 相似文献
12.
The mechanisms behind the effects of immunotherapy (IT) with birch-pollen extract are largely unknown. In this pilot study, we measured the cytokine secretion in vitro from peripheral blood mononuclear cells (PBMC) obtained from birch-pollen-allergic patients undergoing IT treatment ( n =4) or placebo administration (n=4), collected before treatment, 1 and 4 weeks after start of treatment, and during and just after the pollen season (12–14 weeks after start of treatment). The PBMC were stimulated with birch-pollen extract in vitro for 7 days, followed by restimulation with the mitogens phytohemagglutinin (PHA) and phorbol 12-myristate 13-acetate (PMA) for 24 h, to enhance the production of cytokines. The supernatants were analyzed with ELISA and radioimmunoassay for interferon-gamma (IFN-y), interleukin (IL)-4, and IL-5. In the therapy group, we noted an increased secretion of IL-4 and IL-5 from PBMC collected at 4 weeks after the start of treatment (IL-4: 29±21 pg/ml [day 0] to 3741448 pg/ml [week 4], mean± SD; IL-5: 95+48 pg/ml to 11471697 pg/ml). No increase was seen in the placebo group. During the pollen season, we noted a trend toward increased IL-4 and IL-5 secretion in both groups. We conclude that the temporary increase in serum IgE observed in many IT studies may be a consequence of increased IL-4 production due to the allergen exposure. 相似文献
13.
Juha Punnonen MD PhD Hans Yssel PhD Jan de Vries PhD 《The Journal of allergy and clinical immunology》1997,100(6):792-801
The relative contribution of IL-4 and IL-13 to the regulation of IgE synthesis has remained relatively poorly characterized, partially because of lack of suitable animal models. We have studied the roles of IL-4 and IL-13 in human IgE synthesis induced by supernatants derived from activated CD4++ or CD8+ T cell clones. Neutralizing anti–IL-4 and anti–IL-13 monoclonal antibodies (mAbs) inhibited IgE synthesis induced by anti-CD40 mAbs and supernatants from CD4+ T cells by an average 61% and 42%, respectively (n = 25). Recombinant IL-13 had additive effects on IL-4-induced IgE synthesis, but only when IL-4 was present at low concentrations. Accordingly, IL-4 was the dominant IgE synthesis–inducing cytokine derived from highly polarized T helper (TH)2 cells. However, anti–IL-13 mAbs also significantly inhibited IgE synthesis induced by two of three supernatants derived from allergen-specific TH2-like cell lines generated from the skin of patients with atopic dermatitis. Furthermore, anti–IL-13 mAbs almost completely inhibited IgE synthesis induced by supernatants from TH1 cells or CD8+ T cell clones. Taken together, these data indicate that IL-13, in addition to IL-4, contributes to IgE synthesis induced by all T helper cell subsets, including allergen-specific TH2 cells. Moreover, IL-13 appears to be the major IgE synthesis–inducing cytokine derived from TH1 cells or CD8+ T cells. (J Allergy Clin Immunol 1997;100:792-801.) 相似文献
14.
抗CD4单抗增强抗CD3单抗/IL—2活化的肿瘤特异性T细胞的抗瘤活性 总被引:3,自引:4,他引:3
目的探讨抗CD4mAb增强抗CD3mAb刺激的肿瘤特异性T细胞增殖和杀瘤活性的作用。方法将肿瘤细胞免疫的小鼠脾细胞,采用4种不同的方案培养1单独加2×104U/LrIL2IL2组2单独加抗CD3mAb抗CD3组3加抗CD3mAb48h后,再加入抗CD3mAb和2×104U/LrIL2抗CD3 IL2组4同时加抗CD3mAb和抗CD4mAb48h后,再加入抗CD3mAb、抗CD4mAb和2×104U/LrIL2抗CD3 IL2 抗CD4组。然后分别检测4组效应细胞的增殖水平、杀瘤活性及表型。结果抗CD3 IL2组细胞的3HTdR掺入量在第6,12和20d分别为:22045、13986和1931;抗CD3 IL2 抗CD4组细胞的3HTdR掺入量在第6、12和20d,分别为46193、31047和7443,后者明显高于前者P0.05。在培养12d时,抗CD3 IL2组的细胞对FBL3细胞株的最大杀伤率为83.6%;抗CD3 IL2 抗CD4组细胞的最大杀伤率为91.7%。细胞表型:FACS分析表明,抗CD3 IL2 抗CD4组培养12d的细胞,99%以上为Thy1.2 细胞,且CD4 、CD25 细胞的百分率均高于抗CD3 IL2组。结论抗CD4mAb对抗CD3mAb刺激、IL2诱导的肿瘤特异性T细胞的增殖和杀瘤活性具有增强作用。 相似文献
15.
Analysis of the in vitro cytokine production by liver-infiltrating T cells of patients with autoimmune hepatitis. 总被引:2,自引:1,他引:1 下载免费PDF全文
J F Schlaak H Lhr H Gallati K H Meyer zum Büschenfelde B Fleischer 《Clinical and experimental immunology》1993,94(1):168-173
The pathogenic mechanisms underlying the development of autoimmune hepatitis (AIH) are still unclear. Since AIH is associated with the presence of various autoantibodies and certain HLA subtypes, it is likely that T and B cells play a major role in this disease. In this study we have determined the functional capacities of in vivo preactivated liver-infiltrating T cells (LTC) from patients with AIH. As controls we used LTC from patients with non-autoimmune hepatitis (non-AIH). Our results show that preactivated LTC from patients with AIH predominantly (190/255 clones) reside in the CD4+ population, whereas LTC in non-AIH are dominated by the CD8+ phenotype (148/254 clones). In view of this finding we have investigated the cytokine secretion patterns of 102 randomly chosen CD4+ T cell clones from six patients with AIH. As controls we have used 58 CD4+ LTC from 11 patients with non-AIH. All clones were stimulated by lectin and irradiated accessory cells and subsequent cytokine production was evaluated. LTC from patients with AIH have a lower interferon-gamma (IFN-gamma)/IL-4 ratio compared with LTC from non-AIH. Although clones from some patients with AIH produced very high amounts of IL-4 in vitro, this was not a constant finding. These results show that in vivo preactivated LTC from patients with AIH are mostly CD4+ T cells that produce more IL-4 than IFN-gamma. In contrast, LTC from patients with non-AIH are dominated by CD8+ and CD4+ T cells that produce significantly less IL-4 than IFN-gamma. Thus, liver-infiltrating T cells from patients with AIH and non-AIH belong to different functional T cell subsets. This may have implications for the regulation of humoral and cellular immune responses in inflammatory liver disease. 相似文献
16.
The identification that T follicular helper (Tfh) cells is critical for the emergence of germinal centre responses prompted the study of CXCR5-expressing CD4+ T cell subsets in autoimmunity. However, circulating CXCR5-expressing T cells are heterogeneous by containing Forkhead box protein 3 (FoxP3)+ T follicular regulatory (Tfr) cells in addition to bona fide Tfh cells. Such heterogeneity may hamper the analysis of the contribution of specific follicular T cell subsets for autoimmune pathogenesis. Therefore, separate assessment of Tfh and Tfr populations offer greater opportunities for stratification of autoimmune patients, such as Sjögren’s syndrome patients. 相似文献
17.
A critical role of IL-2 for the production and gene transcription of IL-5 in allergen-specific human T cell clones 总被引:1,自引:0,他引:1
Mori Akio; Suko Matsunobu; Kaminuma Osamu; Nishizaki Yoko; Mikami Tadashi; Ohmura Takeo; Hoshino Akihiko; Inoue Satoshi; Tsuruoka Nobuo; Okumura Yasushi; Sato Gen; Ito Koji; Okudaira Hirokazu 《International immunology》1996,8(12):1889-1895
18.
Pascale Jeannin Yves Delneste Paul Life Jean-Franois Gauchat Dominique Kaiserlian Jean-Yves Bonnefoy 《European journal of immunology》1995,25(8):2247-2252
Interleukin (IL)-12 is a potent inducer of cell-mediated immunity: it favors the generation of interferon (IFN)-γ-producing T cells, increases IFN-γ production by T cells and natural killer cells and prevents the generation of a Th2 response in murine in vivo models. Nevertheless, the effects of IL-12 on an established Th2 response remain poorly documented. In the present paper, we analyzed the effect of IL-12 on the profile of lymphokines produced by established IL-4-producing Th0 and Th2-like human T cell clones (TCC) and by polyclonal T cells. We found that IL-12 (i) enhances, as previously reported, IFN-γ production by Th0 TCC and, to a smaller extent, by Th2-like TCC, (ii) increases the proliferation of Th0 and Th2-like TCC and (iii) unexpectedly, synergizes with T cell receptor-associated or nonspecific stimuli in increasing IL-4 production by these TCC. Thus, IL-12 potentiates the production of IFN-γ and also of IL-4 by established IL-4-producing TCC. Although IL-12 has been widely reported to induce a Th1 response and to prevent the development of a Th2 response in vivo, IL-12 may on the contrary potentiate an established Th2 response in humans. 相似文献
19.
目的 观察类风湿关节炎(RA)患者外周血中滤泡辅助性T细胞(Tfh)及T辅助细胞9(Th9)的变化,并与病情活动性及脏器受累等临床资料进行相关性分析,探讨Tfh及Th9在RA发病过程中可能的免疫学发病机制.方法 选择36例RA患者和22例健康对照.根据病情活动度不同将病例组分为病情高度活动组(22例)、病情中度活动组(14例),流式细胞仪检测RA和正常对照组外周血单个核细胞( PBMCs)中CD4-FITC、CXCR5-PE、ICOS-APC标记的CD4+ CXCR5+ ICOS+(Tfh)及CD8-FITC、CD3-APC、IL9-PE标记的CD3+CD8-IL-9+( Th9)比例.分析Tfh及Th9与RA患者的血沉(ESR)、C反应蛋白(CRP)、类风湿因子(RF)、关节压痛数、肿胀数及骨质破坏等指标的相关性;分析Tfh与Th9的关系.结果 RA患者的Tfh表达率明显高于对照组(Z=-6.082,P=0.000),RA患者Th9的表达率亦高于对照组(0.989±0.498 vs 0.213 ±0.084,t=13.063,P=0.000);RA重度活动组Tfh表达率亦高于中度活动患者的表达率(3.880±1.255 vs 2.678±1.022,t=2.990,P=0.005),且两组Tfh的表达率均高于对照组(P均<0.01);RA重度活动患者Th9表达率高于中度患者(1.181±0.523 vs 0.686±0.254,t=4.043,P=0.000),且两组Th9的表达率亦均高于对照组(P均<0.01); Tfh 细胞数与RA患者DAS28(r=0.571,P=0.000)、ESR(r=0.375,P=0.029)、CRP(r=0.357,P=0.032)、关节压痛数(r=0.598,P=0.000)、RF(r=0.421,P=0.023)及抗CCP滴度(r=0.421,P=0.023)正相关;与病程、晨僵、关节肿胀数、骨质破坏、心电图异常无相关性.Th9表达的百分率与RA患者的DAS28( r=0.461,P=0.005)、ESR(r=0.347,P=0.042)、CRP(r=0.384,P=0210)、关节压痛数(r=0.341,P=0.042)、关节肿胀数(r=0.347,P=0.038)及RF(r=0.379,P=0.025)正相关,与病程、晨僵时间、抗CCP滴度、心电图异常及骨质破坏无相关性;Tfh与Th9在外周血中的表达率呈正相关(r=0.727,P=0.000).结论 RA患者外周血Tfh及Th9的比例显著升高,且与疾病活动度及相关炎症指标明显相关,提示Tfn及Th9可能参与RA的发病及病情发展. 相似文献
20.
Here we have investigated and compared the effects of anti-CD4 on helper function of CD4,45RA+ versus CD4,45RO+ T cells. Only CD4,45RO+ cells, but not CD4,45RA+ cells were able to promote B cell differentiation resulting in immunoglobulin production in vitro (IgM as well as IgG) which could be inhibited by anti-CD4 MoAbs (MAX.16H5 and T151). In pokeweed mitogen (PWM)-induced B cell proliferation a similar pattern of responsiveness was obtained. When we studied the anti-CD4 effects on cytokine production in T cells stimulated in mixed lymphocyte reaction (MLR) or by mitogens, we found that neither IL-2 nor IL-4 production was dramatically influenced by anti-CD4 in CD4,45RO+ cells. This led us to the conclusion that the inhibitory effect of anti-CD4 on B cell proliferation and immunoglobulin secretion was not due to inhibition of cytokine production. To clarify this point, we investigated the ability of anti-CD4 to inhibit conjugate formation between B and T cells. It was found that CD4,45RO+ T cells formed more conjugates than CD4,45RA+ cells, and that only the conjugate formation by CD4,45RO+ T cells was inhibited by anti-CD4. These results suggest that (i) anti-CD4 inhibits T helper functions primarily by affecting CD4,45RO+ cells, and (ii) this effect is probably mediated by contact inhibition in the early phase of T-B collaboration. 相似文献