小细胞和非小细胞肺癌晚期患者NK细胞表达的差异

目的:探索小细胞和非小细胞肺癌晚期患者NK细胞是否存在差异,并为治疗提供参考。方法:选取肺癌晚期患者共65例,其中包括小细胞肺癌14例,非小细胞肺癌51例以及20例健康对照。用流式细胞仪检测研究对象外周血淋巴细胞表面CD3-CD16+CD56+的表达情况。结果:小细胞肺癌晚期的患者较健康对照NK细胞显著升高;非小细胞肺癌晚期的患者较健康对照NK细胞无显著变化;肺癌晚期患者外周血NK细胞表达的百分比与CD4+T细胞表达的百分比呈负相关性。结论:小细胞肺癌晚期患者NK细胞升高,天然免疫可能成为已严重受损的细胞免疫的有力补充,但有待于进一步的研究。     

小细胞和非小细胞肺癌晚期患者CD3~- CD19~+ B细胞表达的差异

目的:探索小细胞和非小细胞肺癌晚期患者CD3-CD19+B细胞是否存在差异。方法:选取肺癌晚期患者共65例,其中包括小细胞肺癌14例,非小细胞肺癌51例以及20例健康对照。用流式细胞仪检测研究对象外周血淋巴细胞表面CD3-CD19+的表达情况。结果:非小细胞肺癌晚期的患者较健康对照CD3-CD19+B细胞的百分比显著降低;小细胞肺癌晚期的患者较健康对照CD3-CD19+B细胞的百分比无显著性差异;非小细胞肺癌和小细胞肺癌晚期患者CD3-CD19+B细胞的百分比无显著性差异。结论:非小细胞肺癌晚期患者CD3-CD19+B细胞的百分比降低,体液免疫在细胞免疫严重受损时也削弱,但具体机制有待进一步的研究。     

慢性乙型肝炎患者外周血CD4~+CD25~+Treg与CD4~+和CD8~+ T淋巴细胞亚群的相关研究

目的:探讨慢性乙型肝炎患者外周血中CD4+CD25+调节性T细胞的含量和CD4+CD8+T淋巴细胞亚群分布,两者之间相关性及与HBV的相关性。方法:采用流式细胞术检测50例慢性乙型肝炎患者和20例健康对照者外周血中CD4+CD25high、CD4+CD25+Foxp3+Treg细胞表达及CD3/CD4/CD8 T淋巴细胞亚群,荧光定量PCR法检测HBV DNA含量。结果:慢性乙型肝炎患者外周血中CD4+CD25highTreg明显高于健康对照组(P0.01),且随HBV DNA载量增加,患者外周血中CD4+CD25highTreg细胞的水平逐渐升高。慢性乙型肝炎患者外周血中CD4+CD25+Foxp3+Treg细胞也相应增高,且与CD4+CD25highTreg细胞的变化成正相关(r=0.890,P0.001)。与健康对照组比较,患者组CD4+T细胞百分率及CD4+/CD8+比值均降低,而CD3+T细胞和CD8+T细胞百分率差异无显著性(P0.05)。CD4+CD25highTreg细胞与HBV DNA取对数后成正相关(r=0.782,P0.001),与谷丙转氨酶(ALT)成正相关(r=0.432,P0.005);与CD3+、CD4+、CD8+T细胞水平及CD4+/CD8+比值均无相关性(P0.05)。CD3+、CD4+、CD8+T淋巴细胞及CD4+/CD8+比值与HBV DNA载量之间亦无相关性(P0.05)。结论:慢性乙型肝炎患者外周血中CD4+CD25+Treg细胞增高,且与HBV的复制水平及ALT增高具有一致性,而T细胞亚群是否可作为监测CHB患者免疫状态的指标需进一步探讨。     

重症肌无力患者外周血中CD4~+CD25~+调节性T细胞的变化及意义

研究CD4 + CD2 5 + 调节性T细胞在重症肌无力 (MG )发病中的作用。本文采用三色流式细胞术对 2 9例MG患者和 2 3例健康对照者外周血中CD4 + CD2 5 + T细胞 (CD3+ CD4 + CD2 5 + )的百分率进行测定。结果显示病情未能很好控制的MG患者外周血CD4 + CD2 5 + T细胞比率略低于健康对照组 (分别为 3 79%± 1 4 0 %、 4 5 3%± 0 96 % ,P =0 12 ) ,病情稳定或缓解的MG患者CD4 + CD2 5 + T细胞比率 (8 4 5 %± 1 96 % )显著高于健康对照组 (P =0 0 0 0 1) ;胸腺切除的MG患者CD4 + CD2 5 + T细胞比率 (8 4 4 %± 2 39% )显著高于非胸腺切除的MG患者 (5 88%± 2 89% ,P =0 0 38)和健康对照组 (4 5 3%± 0 96 % ,P =0 0 0 3)。提示MG患者外周血中存在异常比例的CD4 + CD2 5 + 调节性T细胞 ,可能参与疾病的发生与发展。     

CD4~+ CD25~+调节性T细胞及Foxp3基因在不同淋巴结转移状态的非小细胞肺癌患者中的表达差异

目的:比较CD4+CD25+调节性T细胞及Foxp3基因在不同淋巴结转移状态的非小细胞肺癌患者外周血及肿瘤微环境中的表达差异。方法:46例初诊、初治的非小细胞肺癌患者根据有无淋巴结转移分为两组,采用流式细胞仪检测两组患者外周血中CD4+CD25+调节性T细胞的比例,Real-time PCR检测Foxp3基因的表达,免疫组化法检测肿瘤微环境中Foxp3的表达情况,ELISA法检测外周血及肿瘤组织匀浆中的TGF-β和IFN-γ水平。结果:Foxp3基因在转移淋巴结中的表达明显强于无转移的淋巴结,有淋巴结转移的非小细胞肺癌患者肿瘤微环境中的Foxp3表达明显强于无淋巴结转移的非小细胞肺癌患者,前者肿瘤组织匀浆中的TGF-β水平也明显高于后者,差异均具有显著性。两组患者外周血中CD4+CD25+调节性T细胞比例、Foxp3基因的表达及TGF-β、IFN-γ水平比较无显著性差异。结论:有淋巴结转移的非小细胞肺癌患者肿瘤微环境中存在Foxp3基因表达增强及TGF-β水平增高的现象,提示该类患者存在较为严重的局部肿瘤免疫抑制状态。     

重型肝炎CD4~+及CD8~+淋巴细胞亚群的检测和意义

目的:研究重型肝炎患者CD4+及CD8+淋巴细胞亚群的变化及对疾病的预后的影响。方法:收集21例重型肝炎患者及30例健康体检者作为对照组,通过流式细胞仪检测其T淋巴细胞亚群,并与临床预后进行比较。结果:重型肝炎患者T淋巴细胞亚群计数CD4+ CD8-、CD4- CD8+细胞明显低于对照组(P0.05),而CD4+/CD8+比值高于对照组(P0.05);而重症肝炎患者中死亡患者的CD4+CD8-、CD4-CD8+细胞数则较存活患者降低(P0.05),而CD4+/CD8+比值较存活者降低,但无统计学差异。结论:T淋巴细胞亚群的变化特别是CD4+ CD8+细胞数及其比值的变化对预后判断有重要参考价值。     

结核性胸膜炎患者外周血及胸水中CD4~+ CD25~+ CD127~-调节性T细胞表达水平的临床意义

目的:探讨结核性胸膜炎外周血和胸水中CD4+ CD25+ CD127-调节性T细胞表达水平及其临床意义。方法:收集住院收治的初治结核性胸膜炎患者30例和非结核性胸膜炎患者20例,另选择健康体检人员20例为正常对照组。流式细胞术检测外周血及胸水中CD4+ CD25+ CD127-调节性T细胞的百分率。结果:结核性胸膜炎组外周血中CD4+ CD25+ CD127- Treg细胞占CD4+T细胞总数的百分比显著高于正常对照组和非结核性胸膜炎组(P<0.05)。结核性胸膜炎组胸水中CD4+ CD25+ CD127- Treg细胞占CD4+T细胞总数的百分比明显高于非结核性胸膜炎组(P<0.05)。结核性胸膜炎组患者在规则治疗1、3、7、14 d时,外周血和胸水中CD4+ CD25+ CD127- Treg细胞占CD4+T细胞总数的百分比均逐渐下降,外周血中CD4+ CD25+ CD127- Treg细胞占CD4+ T细胞总数的百分比于治疗3 d时显著低于入院时水平(P<0.05),胸水中CD4+ CD25+ CD127- Treg细胞占CD4+ T细胞总数的百分比于治疗7 d时显著低于入院时水平(P<0.05)。结论:CD4+ CD25+ CD127-调节性T细胞参与了结核性胸膜炎的发病机制,且可作为判断肺结核患者的免疫状态、指导用药、疗效观察的指标。     

肺癌患者CD4+ CD25+调节性T细胞的检测及临床意义

目的:检测肺癌患者外周血CD4 CD25 调节性T细胞的分布并探讨相关机制.方法:采用流式细胞仪分析66例肺癌患者外周血CD4 CD25 调节性T细胞占CD4 T淋巴细胞的比例.结果:66例肺癌患者外周血中CD4 CD25 调节性T细胞占CD4 T淋巴细胞的比例为(16.2±2.4)%,与对照组(6.19±1.5)%比较差异有显著性(P＜0.05). 25例鳞癌、29例腺癌、12例小细胞癌患者外周血中CD4 CD25 调节性T细胞比例分别为(18.3±2.9)%、(15.6±1.8)%、(17.3±2.2)%,各组间比较差异无显著性(P＞0.05);均显著高于对照组(6.19±1.5)%,P＜0.05;34例Ⅲ期,14例Ⅳ期肺癌患者外周血中CD4 CD25 调节性T细胞比例为(15.3±2.6)%,(20.4±3.1%),均显著高于18例Ⅱ期患者(9.4±1.3)%,P均＜0.05.结论:肺癌患者外周血中有CD4 CD25 调节性T细胞比例增高,且与分期有关.它可能与肺癌患者免疫功能受损有关,可作为评估肺癌患者预后的一项指标.     

肺部恶性肿瘤患者CD4+CD25+Treg等指标的临床测定及意义

目的:探讨研究肺部恶性肿瘤患者CD4+ CD25+调节性T细胞(Treg)等指标的临床测定及意义.方法:对我院2008-12/2010-08呼吸科或胸外科收治的86例肺癌患者为研究对象作为研究组,与本院同期收治的门诊体检健康人群81例作为对照组进行了对比研究.结果:研究组患者的外周血CD4+ CD25+ Treg占CD4 +T细胞的比例水平显著高于对照组健康人群且具有统计学差异.对于不同临床分期的肺癌患者CD4+ CD25+ Treg水平比较发现,Ⅰ～Ⅱ期患者较对照组高但无统计学差异,而Ⅲ期、Ⅳ期患者则显著高于对照组与Ⅰ～Ⅱ期患者水平.对于不同病理类型的肺癌患者外周血CD4+CD25+ Treg水平对比发现,腺癌、鳞癌及小细胞癌患者显著高于对照组,并具有显著的统计学差异.结论:CD4+ CID25+Treg的水平与肺癌的进展密切相关,同时还与肿瘤分期存在直接关联,通过抑制肿瘤免疫可以使得肿瘤发生免疫逃逸,进而提示去除人的CD4+ CD25+Treg或是一种有效的治疗肿瘤的免疫方法.     

晚期肺癌患者血CD4+CD25+调节T细胞水平的变化

为探讨晚期肺癌患者CD 4CD 25去调节T细胞水平的变化及其与其它T细胞亚群和NK细胞的相互关系,对86例肺癌组患者和64名对照组测定和比较CD 4CD 25调节T细胞、T细胞亚群(CD 3、CD 4、CD 8、CD 8CD 28)和NK细胞的水平,探讨其临床意义.CD 4CD 25细胞和T细胞亚群均用流式细胞仪检测.结果表明,晚期肺癌患者血CD 4CD 25细胞明显高于对照组(18.4%±6.2%vs7.1%±0.4%,P<0.01),CD 4细胞、CD 8CD 28细胞和NK细胞明显低于对照组(32.4%±8.7%vs44.9%±8.4%,P<0.01;7.4%±3.5%vs16.5%±2.7%,P<0.01;10.2%±4.1%vs18.5%±7.2%,P<0.01),CD 8细胞明显高于对照组(36.7%±7.5%vs31.8%±5.1%,P<0.01).CD 4CD 25细胞与CD 8CD 28细胞、NK细胞呈明显负相关.表明CD 4CD 25细胞增多是晚期肺癌患者免疫功能紊乱的一个证据.     

IL-24对非小细胞肺癌患者CD8+T细胞体外功能的影响

目的观察IL-24在体外对非小细胞肺癌(non-small cell lung cancer,NSCLC)患者CD8⁺T细胞功能的影响。方法本研究入组28例NSCLC患者和17例健康对照者,收集外周血单个核细胞(peripheral blood mononuclear cells,PBMC)和支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF),分选CD8⁺T细胞,反转录实时定量PCR检测CD8⁺T细胞中IL-24受体(IL-20R1、IL-20R2和IL-22R1)mRNA的相对表达量。不同浓度重组人IL-24(10 ng/ml和100 ng/ml)刺激纯化CD8⁺T细胞后,流式细胞术检测穿孔素和颗粒酶B的表达变化。建立CD8⁺T细胞和NSCLC细胞系NCI-H1882细胞的直接接触和间接接触体外共培养系统,观察IL-24刺激后CD8⁺T细胞诱导靶细胞死亡比例,以及IFN-γ和TNF-α的表达变化。组间比较采用t检验或LSD-t检验。结果CD8⁺T细胞中未检测到IL-22R1 mRNA表达,CD8⁺T细胞中IL-20R1和IL-20R2 mRNA相对表达量在健康对照者和NSCLC患者之间以及在非肿瘤部位和肿瘤部位之间的差异均无统计学意义(P>0.05)。NSCLC患者外周血和肿瘤部位CD8⁺T细胞中穿孔素和颗粒酶B水平显著低于健康对照者和非肿瘤部位(P<0.05),低浓度IL-24(10 ng/ml)刺激不影响CD8⁺T细胞中穿孔素和颗粒酶B水平(P>0.05),而高浓度IL-24(100 ng/ml)则显著提升NSCLC患者CD8⁺T细胞中穿孔素和颗粒酶B水平(P<0.05)。直接接触共培养系统中,高浓度IL-24(100 ng/ml)刺激NSCLC患者肿瘤部位CD8⁺T细胞后可诱导靶细胞死亡比例升高,以及IFN-γ和TNF-α表达升高,而低浓度IL-24(10 ng/ml)刺激对CD8⁺T细胞诱导的靶细胞死亡和细胞因子分泌无显著影响。间接接触共培养系统中,IL-24刺激对CD8⁺T细胞诱导的靶细胞死亡和细胞因子分泌均无显著影响。结论高浓度IL-24在体外可增强NSCLC患者CD8⁺T细胞的直接细胞杀伤功能,但在体内IL-24可能并不影响CD8⁺T细胞的功能。     

Insufficient CD100 shedding contributes to suppression of CD8+ T-cell activity in non-small cell lung cancer

CD100 is an immune semaphorin constitutively expressed on T-cells. Matrix metalloproteinase (MMP) is an important mediator of membrane-bound CD100 (mCD100) cleavage to generate soluble CD100 (sCD100), which has immunoregulatory activity in immune cell responses. The aim of the study was to investigate the level and role of sCD100 and mCD100 in modulating CD8⁺ T-cell function in non-small cell lung cancer (NSCLC). sCD100 and MMP-14 levels in the serum and bronchoalveolar lavage fluid (BALF), and mCD100 expression on peripheral and lung-resident CD8⁺ T-cells were analysed in NSCLC patients. The ability to induce sCD100 and the effect of MMP-14 on mCD100 shedding for the regulation of non-cytolytic and cytolytic functions of CD8⁺ T-cells were also analysed in direct and indirect contact co-culture systems. NSCLC patients had lower serum sCD100 and higher mCD100 levels on CD8⁺ T-cells compared with healthy controls. BALF from the tumour site also had decreased sCD100 and increased mCD100 on CD8⁺ T-cells compared with the non-tumour site. Recombinant CD100 stimulation enhanced non-cytolytic and cytolytic functions of CD8⁺ T-cells from NSCLC patients, whereas blockade of CD100 receptor CD72 attenuated CD8⁺ T-cell activity. NSCLC patients had lower MMP-14 in the serum and in BALF from the tumour site. Recombinant MMP-14 mediated mCD100 shedding from CD8⁺ T-cell membrane, and led to promotion of CD8⁺ T-cell response in NSCLC patients. Overall, decreased MMP-14 resulted in insufficient CD100 shedding, leading to suppression of peripheral and lung-resident CD8⁺ T-cell activity in NSCLC.     

CD3-induced apoptosis of CD4+CD8+ thymocytes in the absence of clonotypic T cell antigen receptor

Clonal selection of T cells mediated through the T cell antigen receptor (TCR) mostly occurs at the CD4⁺CD8⁺ double positive thymocyte stage. Immature CD4⁺CD8⁺ thymocytes expressing self-reactive TCR are induced to die upon clonotypic engagement of TCR by self antigens. CD3 engagement by antibody of the surface TCR-CD3 complex is known to induce apoptosis of CD4⁺CD8⁺ thymocytes, a process that is generally thought to represent antigen-induced negative selection in the thymus. The present study shows that the CD3-induced apoptosis of CD4⁺CD8⁺ thymocytes can occur even in TCRα^? mutant mice which do not express the TCRαβ/CD3 antigen receptor. Anti-CD3 antibody induces death of CD4⁺CD8⁺ thymocytes in TCRα^? mice either in cell cultures or upon administration in vivo. Interestingly, most surface CD3 chains expressed on CD4⁺CD8⁺ thymocytes from TCRα^? mice are not associated with clonotypic TCR chains, including TCRβ. Thus, apoptosis of CD4⁺CD8⁺ thymocytes appear to be induced through the CD3 complex even in the absence of clonotypic antigen receptor chains. These results shed light on previously unknown functions of the clonotype-independent CD3 complex expressed on CD4⁺CD8⁺ thymocytes, and suggest its function as an apoptotic receptor inducing elimination of developing thymocytes.     

Dissection of a circulating CD3+CD20+ T cell subpopulation in patients with psoriasis

CD3⁺CD20⁺ T cells are a population of CD3⁺ T cells that express CD20 and identified in healthy donors and autoimmune diseases. However, the nature and role of these cells in patients with psoriasis remain unclear. In this study, we aimed to investigate the level, phenotype, functional and clinical relevance of CD3⁺CD20⁺ T cells in the peripheral blood of patients with psoriasis. We found that a small subset of CD3⁺ T cells expressed CD20 molecule in the peripheral blood of patients with psoriasis, and their levels were similar to those in healthy donors. Circulating CD3⁺CD20⁺ T cells in patients with psoriasis were enriched in CD4⁺ cells and displayed an activated effector phenotype, as these cells contained fewer CD45RA⁺‐naive and CCR7⁺ cells with increased activity than those of CD3⁺ T cells lacking CD20. In addition, compared with healthy donors, circulating CD3⁺CD20⁺ T cells in patients with psoriasis produced more cytokines, interleukin (IL)‐17A, tumour necrosis factor (TNF)‐α and IL‐21, but not IL‐4 and IFN‐γ. Furthermore, a significantly positive correlation was found between the levels of IL‐17A, TNF‐α and IL‐21‐production CD3⁺CD20⁺ T cells with Psoriasis Area and Severity Index scores. Our findings suggest that CD3⁺CD20⁺ T cells may play a role in the pathogenesis of psoriasis.     

Phenotypic and functional characteristics of CD4+ CD39+ FOXP3+ and CD4+ CD39+ FOXP3neg T-cell subsets in cancer patients

Human CD4(+) CD39(+) regulatory T (Treg) cells hydrolyze exogenous adenosine triphosphate (ATP) and participate in immunosuppressive adenosine production. They contain two T-cell subsets whose role in mediating suppression is not understood. Frequencies of both CD4(+) CD39(+) subsets were evaluated in peripheral blood lymphocytes of 57 cancer patients and in tumor infiltrating lymphocytes (TILs) of 6 patients. CD4(+) CD39(+) and CD4(+) CD39(neg) T cells isolated using immunobeads and cell sorting were cultured under various conditions. Their conversion into CD39(+) FOXP3(+) CD25(+) or CD39(+) FOX(neg) CD25(neg) cells was monitored by multiparameter flow cytometry. Hydrolysis of exogenous ATP was measured in luminescence assays. Two CD4(+) CD39(+) cell subsets differing in expression of CD25, FOXP3, CTLA-4, CD121a, PD-1, latency associated peptide (LAP), glycoprotein A repetitions predominant (GARP), and the cytokine profile accumulated with equal frequencies in the blood and tumor tissues of cancer patients. The frequency of both subsets was significantly increased in cancer. CD39 expression levels correlated with the subsets' ability to hydrolyze ATP. Conventional CD4(+) CD39(neg) T cells incubated with IL-2 + TGF-β expanded to generate CD4(+) CD39(+) FOXP3(+) Treg cells, while CD4(+) CD39(+) FOXP3(neg) CD25(neg) subset cells stimulated via the TCR and IL-2 converted to FOXP3(+) CTLA4(+) CD25(+) TGF-β-expressing Treg cells. Among CD4(+) CD39(+) Treg cells, the CD4(+) CD39(+) FOXP3(neg) CD25(neg) subset serves as a reservoir of cells able to convert to Treg cells upon activation by environmental signals.     

Relation between the increase of circulating CD3+ CD57+ lymphocytes and T cell dysfunction in recipients of bone marrow transplantation.

Some patients undergoing bone marrow transplantation (BMT) persistently present increased proportions of circulating CD57+ T cells. We analysed the cell surface phenotype in peripheral blood mononuclear cells (PBMC) from 69 allogeneic and 11 autologous BMT recipients. In parallel samples from 49 patients, the proliferative response to T cell mitogens was assessed, either in the presence or absence of exogenous interleukin-2 (IL-2). PBMC samples from long-term allogeneic BMT patients with increased proportions of CD57+ cells displayed significantly (P less than 0.001) lower proliferative responses, compared with samples from patients with normal proportions of CD57+ cells and from healthy subjects. Elimination of the CD57+ population by C'-dependent lysis did not normalize the proliferative response. After positive selection by cell sorting, CD57+ cells responded poorly, but in the presence of IL-2 the proliferation appeared to be similar to that displayed by the CD57- subset and still suboptimal compared with normal controls. These data suggest that the hyporesponsiveness to mitogenic stimuli in the presence of exogenous IL-2 of PBMC from allogeneic BMT recipients cannot be simply attributed either to the putative suppressor activity of CD57+ cells, or to a poor proliferative capacity of this subset. Supporting this notion we report that PBMC from long-term autologous BMT recipients containing high proportions of CD57+ T cells respond normally to T cell mitogens.     

CD3、CD4、COX-2在非小细胞肺癌中的表达及意义

目的:探讨非小细胞肺癌(NSCLC)组织中CD3、CD4及环氧化酶-2(COX-2)的表达及临床意义。方法:用免疫组化法检测37例NSCLC手术标本中CD3、CD4、COX-2的表达情况,用Spearman秩和检验分析它们与患者总生存(OS)间的关系。结果:NSCLC患者组织中CD3平均面密度、CD4平均光密度均与患者OS相关(P<0.05),CD3高表达者OS较长,CD4低表达者OS更长。COX-2表达与患者术后生存时间无关(P>0.05)。结论:CD3表达越强,患者术后OS时间越长;CD4表达越强,患者术后生存时间越短;COX-2的表达强度与患者生存时间无明显相关。     

Prognostic value of cancer stem cell marker CD133 expression in non-small cell lung cancer: a systematic review

Objective: To investigate the correlation between CD133-positive non-small cell lung cancer (NSCLC) and clinicopathological features and its impact on survival. Methods: A search in the Pubmed, Embase and Wanfang databases (up to July 15, 2013) was performed. Only articles in which CD133 antigen was detected in situ localization by immunohistochemical staining were included. This meta-analysis was done using RevMan 5.2 software. Outcomes included overall survival and various clinicopathological features. Results: A total of 1004 NSCLC patients from 11 studies were included. Meta-analysis showed that CD133 expression patients had a significant worse 5-year overall survival compared to the low expression ones (RR = 3.19, 95% CI: 2.05-4.98, P<0.0001 fixed random). With respect to clinicopathological features, CD133 expression by IHC method was closely correlated with tumor T stage (OR = 0.91, 95% CI: 0.59-1.39, P = 0.67 fixed-effect) and tumor grade (OR = 1.20, 95% CI: 0.80-1.79, P = 0.37 fixed-effect). Conclusion: CD133-positive NSCLC patients had worse prognosis, and was associated with common clinicopathological poor prognostic factors.     

Interrupting CD28 costimulation before antigen rechallenge affects CD8+ T‐cell expansion and effector functions during secondary response in mice

The role of CD28‐mediated costimulation in secondary CD8⁺ T‐cell responses remains controversial. Here, we have used two tools — blocking mouse anti‐mouse CD28‐specific antibodies and inducible CD28‐deleting mice — to obtain definitive answers in mice infected with ovalbumin‐secreting Listeria monocytogenes. We report that both blockade and global deletion of CD28 reveal its requirement for full clonal expansion and effector functions such as degranulation and IFN‐γ production during the secondary immune response. In contrast, cell‐intrinsic deletion of CD28 in transferred TCR‐transgenic CD8⁺ T cells before primary infection leads to impaired clonal expansion but an increase in cells able to express effector functions in both primary and secondary responses. We suggest that the proliferation‐impaired CD8⁺ T cells respond to CD28‐dependent help from their environment by enhanced functional differentiation. Finally, we report that cell‐intrinsic deletion of CD28 after the peak of the primary response does not affect the establishment, maintenance, or recall of long‐term memory. Thus, if given sufficient time, the progeny of primed CD8⁺ T cells adapt to the absence of this costimulator.     

Bladder cancer immunogenicity: expression of CD80 and CD86 is insufficient to allow primary CD4+ T cell activation in vitro

Transitional cell carcinomas (TCC) of the urinary bladder are known to express proteins which can yield potentially immunogenic peptide epitopes for expression in the context of cell surface class I or class II MHC antigens. However, additional costimulatory ligands must also be expressed before such a cell might directly induce full activation and proliferation of resting, antigen-specific T lymphocytes. Intravesical therapy might be used to manipulate T cell costimulation in order to promote specific rejection of TCC cells. This in vitro study examined the potential of such a strategy by transfection of the prototypical TCC line J82 with the important costimulatory molecules CD80 (B7-1) and CD86 (B7-2). Untransfected J82 cells expressed class I and II MHC antigens, a range of cell adhesion molecules, though did not induce T cell proliferation in a robust, allogeneic co-culture system. Transfected J82 cells expressed CD80 or CD86 at levels comparable to an antigen-presenting B cell line. Furthermore, functional surface expression of CD80 and CD86 was demonstrated in a mitogen-dependent assay of costimulation. However, neither CD80+ nor CD86+ transfectant J82 cells could induce significant proliferation of antigen-specific CD4+ T cells. Further analysis showed that bystander J82 cells could inhibit independent T cell activation in an effect dependent on direct cell contact. This inhibitory effect was associated with increased cell death in the responding lymphocyte population and is concordant with surface expression of CD95L by the J82 cell line.