Increase in Ksp37-positive peripheral blood lymphocytes in mild extrinsic asthma

Killer-specific secretory protein of 37 kDa (Ksp37), identified as a Th1/Tc1 specific secretory protein is expressed preferentially in cytotoxic T lymphocytes (CTL) and natural killer (NK) cells and might be involved in essential processes of CTL-mediated immunity. Although extrinsic asthma is linked currently to a Th2-dominated pathogenesis, there is increasing evidence for Th1/Tc1-mediated processes in the aetiopathology of asthma. CTL from patients with asthma have been shown to express cytokines and effector molecules which were different from healthy controls. We hypothesized that Ksp37 could indicate the involvement of CTL in the pathogenesis of extrinsic asthma. We therefore investigated Ksp37 expression in PBMC from patients with mild extrinsic asthma (n = 7) and healthy controls (n = 7). Flow cytometric analysis was used to quantify Ksp37+ cells and to investigate cellular Ksp37 expression as relative mean fluorescence intensities (MFI). We found a significantly (P = 0.016) higher percentage of Ksp37+ cells within the total lymphocyte population obtained from patients with mild extrinsic asthma compared with healthy controls. Subdifferentiation revealed a significant difference limited exclusively to the CD8+ subset (P = 0.010). In addition, Ksp37 secretion from cultured peripheral blood mononuclear cells (PBMC) and MFI of Ksp37+ lymphocytes were increased in patients with asthma compared with healthy controls. We conclude that mild extrinsic asthma appears to be associated with an increased expression of the Tc1 related protein Ksp37. The functional role of Ksp37 in the pathogenesis of asthma remains to be elucidated.     

Increased secretion of IL-18 in vitro by peripheral blood mononuclear cells of patients with bronchial asthma and atopic dermatitis.

This study was performed to determine whether or not IL-18, formerly called IFN-gamma-inducing factor, is involved in the pathogeneses of allergic disorders. Peripheral blood mononuclear cells (PBMC) were obtained from patients with allergic bronchial asthma (BA), patients with atopic dermatitis (AD) and controls who did not have any allergic disease, and then cultured with lipopolysaccharide (LPS) or phytohaemagglutinin (PHA). The concentrations of IL-18, IFN-gamma and IL-13 in supernatant fluids were determined by enzymatic immunoassaying, and the expression of IFN-gamma messenger (m) RNA in the cells was measured by colorimetric microplate assaying. IL-18 secretion in the BA patients (geometric mean (gm) = 189 pg/ml) and AD patients (gm = 172 pg/ml) was significantly higher than that in non-allergic controls (gm = 118 pg/ml). In contrast, IFN-gamma secretion in the BA patients (gm = 7.3 IU/ml) and AD patients (gm = 6.8 IU/ml) was significantly lower than that in non-allergic controls (gm = 20.7 IU/ml). The amounts of IL-13 in supernatant fluids and IFN-gamma mRNA in cells were not statistically different among the BA patients, AD patients and non-allergic controls. The possible involvement of IL-18 in allergic disorders is discussed.     

癌灶CD4~+CD25~+和CD8~+ T细胞亚群与卵巢浆液性癌患者生存期相关

检测卵巢浆液性癌患者癌组织中CD4+CD25+及CD8+T细胞的数目,探讨其两种T细胞介导的免疫功能对疾病发展及预后的影响。免疫组织化学双标及单标的染色方法检测41例卵巢浆液性癌患者手术切除癌组织标本中CD4+CD25+和CD8+T细胞的数目。结果显示,癌灶中CD4+CD25+T淋巴细胞为(19.95±11.50)个/10HPF,CD8+T淋巴细胞为(43.46±16.69)个/10HPF。生存分析发现高CD4+CD25+T细胞组患者总生存期较低CD4+CD25+T细胞组缩短,差异有显著性(P<0.05);而高CD8+T细胞组患者总生存期与低CD8+T细胞组相比延长,且差异有显著性(P<0.05),此外两种T细胞数目与患者年龄、病理分级、临床分期、腹水细胞学及淋巴结转移等临床病理因素均无关(P>0.05)。结果表明,卵巢浆液性癌中高CD4+CD25+T细胞提示患者预后不良,可能与CD4+CD25+T细胞介导的免疫抑制导致肿瘤免疫逃逸有关;癌组织中高CD8+T细胞提示患者预后较好,两种T细胞对卵巢浆液性癌预后的评估有重要的价值,同时可以通过阻断CD4+CD25+T细胞的免疫抑制作用改善卵巢浆液性癌患者的预后,为卵巢癌治疗提供靶目标。     

Increased hepatitis C virus (HCV)-specific CD4+CD25+ regulatory T lymphocytes and reduced HCV-specific CD4+ T cell response in HCV-infected patients with normal versus abnormal alanine aminotransferase levels

CD4+CD25+ T regulatory cells may play a role in the different clinical presentations of chronic hepatitis C virus (HCV) infection by suppressing CD4+ T cell responses. Peripheral CD4+CD25+ T cells from chronic HCV carriers with normal and abnormal alanine aminotransferase (ALT) were analysed for specificity and effect on HCV-specific CD4+ T cell reactivity by flow cytometry for intracellular cytokine production and proliferation assay. HCV-specific CD4+CD25(+high) T cells consistently produced transforming growth factor (TGF)-beta but only limited amounts of interleukin (IL)-10 and no IL-2 and interferon (IFN)-gamma. The HCV-specific TGF-beta response by CD4+CD25(+high) T cells was significantly greater in patients with normal ALT compared to patients with elevated ALT. In addition, a significant inverse correlation was found between the HCV-specific TGF-beta response by CD4+CD25(+high) T cells and liver inflammation. In peripheral blood mononuclear cells (PBMC), both HCV antigen-induced IFN-gamma production and proliferation of CD4+ T cells were greater in patients with elevated ALT compared with patients with normal ALT. Depletion of CD4+CD25+ cells from PBMC resulted in an increase of both IFN-gamma production and proliferation of HCV-specific CD4+ T cells that was significantly greater in patients with normal ALT levels compared with patients with elevated ALT. In addition, CD4+CD25+ T cells from patients with normal ALT levels proved to be significantly more potent to suppress CD4+ T cell reactivity with respect to those from patients with elevated ALT. In conclusion, these data support the hypothesis that CD4+CD25+ cells may play a role in controlling chronic inflammatory response and hepatic damage in chronic HCV carriers.     

Circulating CD4+CD8+ T lymphocytes in patients with Kawasaki disease

We serially monitored cell surface antigen expression on mononuclear cells in peripheral blood isolated from patients with Kawasaki disease (KD), and found, for the first time, that a markedly increased number of CD4⁺CD8⁺ T lymphocytes was present in some of the patients (11 of the 24 cases). The cases of five of these 11 patients were complicated with coronary artery lesion (CAL); the 13 patients with normal numbers of CD4⁺CD8⁺ T lymphocytes did not have CAL. The patients' age, sex and grade of systemic inflammation evaluated by peripheral leucocyte count and serum C-reactive protein levels were not correlated to the number of CD4⁺CD8⁺ T lymphocytes. Other cell surface antigen characteristics of the CD4⁺CD8⁺ T lymphocytes included CD3⁺, CD45RA⁺, CD45RO⁺, CD16^?, and HLA-DR⁺. These results indicate that the surface antigen characteristics of the KD peripheral blood examined were the same as those of Epstein–Barr virus infection without CD45RA⁺. These findings provide useful information for the analysis of the pathogenesis of KD.     

The levels of CD4+CD25+ regulatory T cells in paediatric patients with allergic rhinitis and bronchial asthma

Our purpose was to determine whether numbers of CD4(+)CD25(+) T [T regulatory (T(reg))] cells and mRNA expression of functional molecules of T(reg) are related to airway allergy and disease severity in 51 paediatric patients with allergic rhinitis or bronchial asthma and 47 healthy controls. Surface markers were evaluated with flow cytometry, and mRNA was determined with real-time polymerase chain reaction. Children with allergic disease had fewer CD4(+)CD25(+) T cells (8 x 49% +/- 2 x 41% versus 9 x 58% +/- 2 x 43%, P<0 x 05) and CD4(+)CD25(hi) T cells (1 x 32% +/- 0 x 68% versus 1 x 70% +/- 0 x 68%, P<0 x 01) than control subjects. Numbers of CD4(+)CD25(+) and CD4(+)CD25(hi) T lymphocytes were higher in children with persistent allergic rhinitis and/or moderate-severe bronchial asthma than in those with respective milder disease. The number of T(reg) cells was correlated positively with total immunoglobulin E level. The mRNA expression of forkhead box P3 (FoxP3) was increased in moderate-severe versus mild asthma (2 x 93 +/- 0 x 38 versus 1 x 60 +/- 0 x 31, P< 0 x 01). Patients with moderate-severe bronchial asthma also had increased mRNA expression of interleukin (IL)-10 compared with patients with mild asthma (15 x 24 +/- 4 x 07 versus 3 x 77 +/- 2 x 18, P<0 x 01). The suppressive function of T(reg) cells from patients with more severe asthma was competent in vitro. On average, decreased numbers of T(reg) cells in children with allergic airway disease might represent a defect of the T(reg) population. With increased expression of FoxP3 and IL-10 in T(reg) from patients with relatively severe allergic disease, adaptive and functional T(reg) might be generated in response to aggravated atopy and disease severity.     

CD244抑制活动性肺结核患者CD8+T细胞细胞因子分泌的实验研究

目的 探讨表面受体CD244在活动性肺结核患者CD8+T细胞中的功能.方法 密度梯度离心法提取活动性肺结核患者和健康对照者的外周血单个核细胞,通过流式细胞术检测CD244在CD3+ CD8+细胞中的表达;通过细胞内染色方法检测CD244与细胞因子IFN-γ和TNF-α表达的关系.结果 CD244在活动性肺结核患者CD8+T细胞表达强度显著高于健康对照者(P=0.0003);复治肺结核患者的CD244表达强度显著高于新发肺结核患者(P=0.0011);CD244-细胞表达IFN-γ比例显著高于CD244+细胞(P=0.0013);CD244-细胞表达TNF-α比例显著高于CD244+细胞(P =0.0016).结论 CD244抑制活动性肺结核患者CD8+T细胞的细胞因子分泌表达.     

Lower percentage of CD8+ T cells in peripheral blood of patients with sporotrichosis

PurposeTo characterize the peripheral immunity and immunity response of patients with sporotrichosis, in this study we determined the lymphocyte subsets in the peripheral blood of Chinese patients with sporotrichosis.MethodsIn this retrospective study, peripheral blood was collected from 69 sporotrichosis patients (37, fixed cutaneous form; 32 lymphocutaneous) and 66 healthy controls. Lymphocyte subsets were analyzed using flow cytometry.ResultsCompared to controls, the percentage of CD8+ T cells was lower in sporotrichosis patients. The percentage of CD8+ T cells in peripheral blood tended to become lower with disease duration and disease severity, although the difference was not statistically significant for either acute, subacute and chronic patients or fixed cutaneous and lymphocutaneous patients.ConclusionOur data indicate that the decrease of CD8+ T cells in peripheral blood of patients with sporotrichosis is associated with disease severity, although the difference was not statistically significant for either duration or clinical forms of the disease. Combining antifungal agents and immunomodulators in patients with long disease duration and lymphocutaneous may be more beneficial than antifungal monotherapy.     

Non-antigen specific CD8+ T suppressor lymphocytes

Abstract. The homeostasis of peripheral immune system function is maintained by the activity of regulatory lymphocytes. Among these cells, a subset of CD8+CD28- T suppressor lymphocytes has recently been characterized for the capacity to mediate their effects without antigen restriction. These non-antigen-specific CD8+ T suppressor lymphocytes originate from circulating CD8+CD28- T lymphocytes after stimulation with interleukin-2 and interleukin- 10. CD8+ suppressor cells inhibit both antigen-specific CD4+ T cell proliferation and cellular cytoxicity through secretion of cytokines such as interferon-, interleukin-6, and interleukin-10. The function of CD8+ suppressor cells is impaired in patients with systemic lupus erythematosus in relapse as well as in patients with systemic sclerosis with disease progression, suggesting the involvement of CD8+ suppressor cells in the pathogenesis of autoimmune diseases. Interestingly, CD8+ suppressor cells have been found among tumor-infiltrating lymphocytes, which could be related to tumor-induced-immunosuppression. Failure to generate CD8+ suppressor cells from the peripheral blood is frequently observed in HIV-infected patients. It remains to be clarified whether this phenomenon is due to depletion and/or functional impairment of this cell subset or to their compartmentalization in peripheral tissues and immunocompetent organs where they could contribute to the induction of immunodeficiency.     

Decreases in alpha beta T cell receptor negative T cells and CD8 cells, and an increase in CD4+ CD8+ cells in active Hashimoto''s disease and subacute thyroiditis.

We examined peripheral lymphocyte subsets in patients with autoimmune thyroid disease, or subacute thyroiditis, in the active stage when possible. During destructive thyrotoxicosis arising from alpha beta T cell receptor (TCR) negative T (WT31-CD3+) cells and CD8 (CD4-CD8+) cells decreased and those of CD4+CD8+ cells increased slightly, resulting in proportional increases in CD4 (CD4+CD8-) cells, non-T, non-B (CD5-CD19-) cells, and the CD4/CD8 cell ratio. Changes were similar in active subacute thyroiditis. During stimulative thyrotoxicosis in active Graves' disease, the numbers of such T lymphocyte subsets were not changed, but only the number of CD5+ B (CD5+CD19+) cells increased markedly, resulting in proportional decreases in total T (CD3+) cells, alpha beta+ TCR T (WT31+CD3+) cells, CD8 cells, and non-T, non-B cells. A serial study of some of the patients showed opposite changes in alpha beta TCR- T cells, the CD4/CD8 cell ratio, and CD5+ B cells between the active stages of Graves' and Hashimoto's diseases. alpha beta TCR- T cells were mostly gamma delta TCR+ T (IIF2+ CD3+) cells in these patients. These data suggest that alpha beta TCR-T (gamma delta TCR+ T), CD8, and CD4+ CD8+ cells are important in thyroid destruction in Hashimoto's disease and subacute thyroiditis, and that CD5+ B cells are important in thyroid stimulation in Graves' disease.     

CD8+ CD28- and CD8+ CD57+ T cells and their role in health and disease

Chronic antigenic stimulation leads to gradual accumulation of late-differentiated, antigen-specific, oligoclonal T cells, particularly within the CD8(+) T-cell compartment. They are characterized by critically shortened telomeres, loss of CD28 and/or gain of CD57 expression and are defined as either CD8(+) CD28(-) or CD8(+) CD57(+) T lymphocytes. There is growing evidence that the CD8(+) CD28(-) (CD8(+) CD57(+)) T-cell population plays a significant role in various diseases or conditions, associated with chronic immune activation such as cancer, chronic intracellular infections, chronic alcoholism, some chronic pulmonary diseases, autoimmune diseases, allogeneic transplantation, as well as has a great influence on age-related changes in the immune system status. CD8(+) CD28(-) (CD8(+) CD57(+)) T-cell population is heterogeneous and composed of various functionally competing (cytotoxic and immunosuppressive) subsets thus the overall effect of CD8(+) CD28(-) (CD8(+) CD57(+)) T-cell-mediated immunity depends on the predominance of a particular subset. Many articles claim that CD8(+) CD28(-) (CD8(+) CD57(+)) T cells have lost their proliferative capacity during process of replicative senescence triggered by repeated antigenic stimulation. However recent data indicate that CD8(+) CD28(-) (CD8(+) CD57(+)) T cells can transiently up-regulate telomerase activity and proliferate under certain stimulation conditions. Similarly, conflicting data is provided regarding CD8(+) CD28(-) (CD8(+) CD57(+)) T-cell sensitivity to apoptosis, finally leading to the conclusion that this T-cell population is also heterogeneous in terms of its apoptotic potential. This review provides a comprehensive approach to the CD8(+) CD28(-) (CD8(+) CD57(+)) T-cell population: we describe in detail its origins, molecular and functional characteristics, subsets, role in various diseases or conditions, associated with persistent antigenic stimulation.     

A novel peripheral CD4+CD8+ T cell population: Inheritance of CD8α expression on CD4+ T cells

In this study we show the inheritance of a CD4⁺CD8⁺ peripheral T cell population in the H.B15 chicken strain. A large proportion of αβ T cells in peripheral blood (20–40%), spleen (10–20%) and intestinal epithelium (5–10%) co-express CD4 and CD8α, but not CD8β. CD4⁺ CD8αα cells are functionally normal T cells, since they proliferate in response to mitogens and signals delivered via the αβT cell receptor as well as via the CD28 co-receptor. These cells induce in vivo a graft versus host-reaction, providing further evidence for their function as CD4⁺ T cells. The CD4⁺CD8αα T cell population was found in 75% of the first progeny and in 100% of further progenies, demonstrating that co-expression of CD4 and CD8 on peripheral T cells is an inherited phenomenon. In addition, cross-breeding data suggest a dominant Mendelian form of inheritance. The hereditary expression of CD8α on peripheral CD4⁺ T cells in chicken provides a unique model in which to study the regulation of CD4 and CD8 expression.     

Characterization of normal human CD3+ CD5- and gamma delta T cell receptor positive T lymphocytes.

The functional and phenotypic properties of normal human CD3+CD5- T cells which have a higher frequency of cytotoxic cells than CD3+CD5+ T lymphocytes have been described. Using three- and four-colour immunofluorescence flow cytometric cell sorting, the CD3+CD5- and CD3+CD5+ populations were subdivided into alpha beta or gamma delta T cell receptor positive cells. The four subsets were examined for the in vitro cytotoxic activity and were also stimulated with mitogens in limiting-dilution assays to measure the frequencies of proliferating and interleukin-2 (IL-2) producing cells. CD3+CD5- alpha beta +, CD3+CD5- gamma delta + and CD3+CD5+ gamma delta + cells had lower frequencies of proliferating and IL-2-producing cells than did CD3+CD5+ alpha beta + cells. However, the cytotoxic activity of the different phenotypes was higher in the CD3+CD5- subsets, especially when these cells were gamma delta +. Expression of gamma delta or lack of expression of CD5 appeared to be associated with the acquisition of cytolytic potentials. CD8 was expressed on 20% of fresh CD3+ gamma delta + cells. Cultured gamma delta + cells retained the expression of gamma delta, but quickly lost that of CD8 and with time modulated the expression of CD5. The expression of CD5 was found to be higher on sorted CD3+CD5+ gamma delta - than on CD3+CD5+ gamma delta + cells. These observations indicate that gamma delta is preferentially expressed on CD5-negative or weakly positive T lymphocytes and that CD3+CD5- gamma delta + cells appear to constitute a discrete small subset of mature T lymphocytes which are cytotoxic in nature. However, the exact immunological function of these cells and their place in T cell ontogeny are yet to be elucidated.     

Expansion of regulatory CD8+ CD25+ T cells after neonatal alloimmunization

Transplantation tolerance induced by neonatal injection of semi-allogeneic spleen cells is associated with a pathological syndrome caused by T helper type 2 (Th2) differentiation of donor-specific CD4(+) T lymphocytes. We have shown previously that this Th2-biased response is inhibited by host CD8(+) T cells. Herein, we demonstrate that upon neonatal immunization with (A/J × BALB/c)F(1) spleen cells, BALB/c mice expand a population of CD8(+) T cells expressing both CD25 and forkhead box P3 (FoxP3) markers. In this setting, CD8(+) CD25(+) T cells predominantly produce interferon (IFN)-γ and interleukin (IL)-10 and are efficient in controlling IL-4, IL-5 and IL-13 production by donor-specific CD4(+) T cells in vitro. CD8(+) FoxP3(-) T cells are single producers of IFN-γ or IL-10, whereas CD8(+) FoxP3(+) T cells are double producers of IFN-γ and IL-10. We further demonstrate that IFN-γ and IL-10 are two major cytokines produced by CD8(+) T cells involved in the in vivo regulation of Th2-type pathology. In this setting, we conclude that neonatal alloimmunization induces the expansion of several regulatory CD8(+) T cells which may control Th2 activities via IFN-γ and IL-10.     

Reduced antigen concentration and costimulatory blockade increase IFN-gamma secretion in naive CD8+ T cells

CD8+ T cells are killer cells but also major producers of IFN-gamma. We have investigated the effects of peptide antigen titration and costimulatory blockade on IFN-gamma production and proliferation by naive CD8+ T cells. Mature dendritic cells (DC) pulsed with high amounts of agonist peptide triggered proliferation but little IFN-gamma secretion in individual T cells. In contrast, immature DC pulsed with similar amounts of peptide induced IFN-gamma secretion in a larger fraction of T cells but triggered less proliferation. Blocking B7.2 or lowering the amount of peptide on mature DC led to a response similar to that induced by immature DC, suggesting that differences in stimulatory strength were responsible for the different responses. Using splenic antigen-presenting cells (APC) we demonstrate that reducing the amount of peptide in combination with B7 blockage enhanced IFN-gamma secretion and decreased proliferation in naive CD8+ T cells in an additive way. Our data suggest that IFN-gamma secretion and proliferation are independently and inversely controlled by stimulatory strength in naive CD8+ T cells. This may enable CD8+ T cells to respond with IFN-gamma secretion to immature APC with few peptide ligands consistent with an early immunoregulatory role of CD8+ T cells.     

卡介菌多糖核酸提高复发性生殖器疱疹患者CD8+ T细胞的细胞因子表达

目的　研究卡介菌多糖核酸 (BCG PSN)对复发性生殖器疱疹 (RGH)患者外周血CD8 T细胞IL 12、IFN γ、IL 4表达的影响。方法　应用流式细胞仪对 4 5例RGH患者和 15名健康志愿者外周血CD8 T细胞IL 12、IFN γ和IL 4的表达进行检测。结果　治疗前RGH患者外周血IFN γ和IL 12阳性CD8 T细胞百分率均显著下降 (P <0 .0 5 ) ,Tc1 Tc2平衡失调 (P <0 .0 5 )。治疗后BCG PSN组外周血IL 12和IFN γ阳性CD8 T细胞百分率显著升高 (P <0 .0 5 ) ,Tc1 Tc2恢复平衡。病例对照组IL 12、IFN γ及IL 4阳性CD8 T细胞百分率于治疗前后变化差异均无显著性 (P >0 .0 5 )。BCG PSN组与病例对照组治疗前后IL 12、IFN γ阳性CD8 T细胞百分率间差异均有显著性 (P <0 .0 5 )。BCG PSN组复发率较低 ,复发病情较轻。结论　RGH患者存在以Tc1水平低下为主的Tc1 Tc2比例失衡和IL 12表达水平低下 ;BCG PSN通过上调外周血CD8 T细胞IFN γ、IL 12的表达 ,纠正机体细胞因子失衡状态而减少疾病的复发     

Low numbers of CD8+ T lymphocytes in hereditary haemochromatosis are explained by a decrease of the most mature CD8+ effector memory T cells

Low CD8⁺ T lymphocyte numbers have long been described in hereditary haemochromatosis (HH). Recently, two conserved haplotypes localized near the microsatellite D6S105 at the major histocompatibility complex (MHC) class I region were described predicting the clinical expression of HH and the CD8⁺ T lymphocyte numbers. The A‐A‐T haplotype was associated with a severe clinical expression of HH and low CD8⁺ T lymphocyte numbers, while the G‐G‐G haplotype was associated with a milder clinical expression of HH and high CD8⁺ T lymphocyte numbers. As CD8⁺ T lymphocytes are a very heterogeneous population, in this study we analysed the CD8⁺ subpopulations of naive, central memory (T_CM) and effector memory (T_EM), and further subsets of CD8⁺ T_EM cells in 47 HH patients and 68 controls. In addition, association studies were conducted between the conserved haplotypes and the CD8⁺ T cell subpopulations in HH. Variations of the numbers of naive and central memory cells with age were similar between HH patients and controls. For T_EM cells and the T_EM CD27^‐CD28^‐ subset no effect of age was observed in HH [R² = 0·001, not significant (n.s.) and R² = 0·01, n.s., respectively] contrasting with the increasing of these subpopulations with age in controls (R² = 0·09, P = 0·017 and R² = 0·22, P = 0·0005, respectively). Interestingly, patients homozygous for the A‐A‐T haplotype have lower numbers of CD8⁺ T_EM cells due especially to lower numbers of T_EM CD27^‐CD28^‐ (0·206 ± 0·119 and 0·066 ± 0·067 × 10⁶ cells/ml, respectively) than patients carrying the G‐G‐G haplotype (0·358 ± 0·195 and 0·246 ± 0·202 × 10⁶ cells/ml, respectively). This may suggest an inability of HH patients to differentiate the CD8⁺ T cells into the most mature phenotype.     

Defective lymphokine production by most CD8+ and CD4+ tumor-specific T cell clones derived from human melanoma-infiltrating lymphocytes in response to autologous tumor cells in vitro

Human melanomas are infiltrated by tumor-reactive T lymphocytes. However, the ability of these cells to elicit a specific anti-tumor response in vivo remains to be established. Because lymphokine production is critical for T cell functions, we have analyzed the capacity of melanoma-specific tumor-infiltrating lymphocyte (TIL) clones to produce major lymphokines: interleukin-2 (IL-2), interferon-γ (IFN-γ) and interleukin-4 (IL-4), as well as tumor necrosis factor (TNF), in response to direct antigen presentation by autologous and allogeneic tumor cells. We report here that, upon stimulation by autologous melanoma cells, all TIL clones secreted TNF but only a few of them produced significant amounts of IL-2, IL-4 or IFN-γ. Nonetheless, all these clones consistently produced two or three of these last lymphokines upon stimulation with phorbol myristate acetate and calcium ionophore, as well as IL-2 upon CD3 stimulation, showing the existence of three lymphokine profiles among them: Th1, Th0 and a profile characterized by IL-2 and IL-4, but not IFN-γ secretion. Stimulation of TIL clones by allogeneic melanoma lines sharing the appropriate HLA-peptide complexes revealed that defective IL-2 production seemed to be a constant feature for some clones, while it was, for other clones, dependent on the antigen-presenting tumor cells. For this last type of clone, we further showed that defective IL-2 induction resulted from an LFA-3 defect of some melanoma cells or from distinct yet undefined defects of other melanoma lines. Our data suggest that defective lymphokine secretion may be an essential component of the in vivo failure of melanoma-reactive TIL to control tumor development. Interestingly both CD4⁺ and CD8⁺ TIL clones from one patient were fully activated by the autologous melanoma cells in vitro, supporting a potential role of such TIL in spontaneous or induced tumor rejection.     

程序性死亡蛋白配体-1/程序性死亡蛋白-1在老年胃癌患者外周血CD8+T淋巴细胞中的表达及临床意义

目的 通过分析程序性死亡蛋白配体-1/程序性死亡蛋白-1(programmed death ligand-1/programmed death-1,PD-L1/PD-1)在老年胃癌患者外周血CD8+T淋巴细胞中表达情况,探讨其临床意义.方法 选择同一时期90例老年胃癌患者(具有不同临床分期)及90例老年健康体检者,分别采取新鲜外周血后经流式细胞仪检测血中CD8+T淋巴细胞表面PD-L1/PD-1表达情况,结合老年胃癌患者的临床分期,分析PD-L1/PD-1在不同胃癌分期中的表达意义.结果 PD-L1/PD-1在老年胃癌患者外周血CD8+T淋巴细胞呈高表达,相较于老年健康者差异具有统计学意义(t=7.043,P<0.05);外周血CD8+T淋巴细胞的PD-L1/PD-1阳性表达均随着临床分期的增加而增加,呈明显的正相关性(r=0.883,P<0.05);外周血CD8+T淋巴细胞的PD-1阳性表达随着临床分期的增加而增加,两者之间呈正相关性(r=0.811,P<0.05);临床分期较晚的老年胃癌患者外周血CD8+T淋巴细胞PD-L1/PD-1表达比其他相对较早的临床分期老年胃癌患者显著上升(t=4.377,P<0.05).结论 PD-L1/PD-1信号通路异常在老年胃癌患者病变的发生发展过程中发挥了重要作用,外周血CD8+T淋巴细胞PD-L1/PD-1的表达对评判患者的预后具有指导作用.     

Interactions between peripheral blood CD8 T lymphocytes and intestinal epithelial cells (iEC)

Intestinal intraepithelial lymphocytes (iIEL) are primarily CD8 cells and most of them have a CD28^? phenotype, the phenotype of effector cytotoxic T cells. We asked whether the predominance of CD8⁺ CD28^? T cells in the gut may result from peripheral blood T cells preferentially migrating to the iIEL compartment and adhering to iEC. Compared with CD4 cells, adhesion of resting CD8⁺ T cells to iEC cell lines was significantly higher. Adhesion could be blocked with a MoAb to gp180, a molecule expressed on iEC which is known to interact with CD8/lck. No significant difference in the level of adhesion was observed between CD8⁺ CD28⁺ and CD8⁺ CD28^? T cells. Thus CD8 cells may preferentially migrate to the iIEL compartment, but loss of CD28 expression could occur in situ after migration. Consistent with this hypothesis, the CD8⁺ CD28^? cells became enriched after co-culturing T cells with iEC cell lines and primary iEC. Induction of the CD8⁺ CD28^? phenotype in cord blood and adult T cells was observed in co-cultures with iEC and also with mitogens and superantigens. In the latter case, CD28 down-modulation was seen specifically in the Vβ subset targeted by the superantigen, indicating that loss of CD28 expression is a direct result of T cell receptor (TCR)-mediated stimulation. The combined results suggest that CD8⁺ CD28^? T cells are antigen experienced T cells, and that they may have a survival advantage in the presence of gut epithelial cells in vitro. This may contribute to the predominance of CD8⁺ CD28^? T cells in the iIEL compartment.