Combinational IL-2/IL-15 induction does not further enhance IL-15-induced lymphokine-activated killer cell cytotoxicity against human leukemia/lymphoma cells

In vitro comparisons of induction of perforin (PFP), granzyme B (GRB), production of cytokines, and cell-mediated cytotoxicity by interleukin-2 (IL-2), interleukin-15 (IL-15), or combinational IL-2/IL-15-induced lymphokine-activated killer cells were studied in this study. Whereas IL-2-induction was associated with a decrease in cultured cell population over a 7-day period, IL-15 alone or in combination with IL-2 resulted in significant increase including cytotoxic T lymphocytes and subsets of CD56+ lymphocytes, particularly cytokine-induced killer and cytolytic natural killer-T lymphocytes. The overall PFP, GRB, and tumor necrosis factor-alpha expression in different subtypes were also significantly higher with IL-15 alone or in combination with IL-2 induction with resultant superior cytotoxicity compared to IL-2 treatment. There was no significant advantage of addition of IL-2 over IL-15 induction. These results offer further information on the cytotoxic potency of these cytokines and their mechanisms of action implicating potential use of IL-15 as part of cytokine adoptive immunotherapy.     

Perforin dependence of natural killer cell-mediated tumor control in vivo

Adaptive immune surveillance by T cells against infections and tumors depends on the presence of antigenic peptides presented by major histocompatibility complex (MHC) molecules. If antigenic tumor-specific peptides or MHC class I molecules are absent, the adaptive T cell immune response fails. Natural killer (NK) cells seem to complement the specific T cells by recognizing target cells lacking MHC class I (e.g. RMA-S). The role of perforin, which is crucially involved in T cell and NK cell-mediated target cell lysis, was evaluated in mice lacking perforin with respect to their capacity to eliminate a syngeneic lymphoid tumor. Here, we show that growth of MHC class I^? RMA-S tumor cells in unprimed mice was controlled by NK cells through perforin-dependent cytotoxicity.     

Differential expression of human granzymes A, B, and K in natural killer cells and during CD8+ T cell differentiation in peripheral blood

NK cells and cytotoxic T lymphocytes can induce apoptosis in virus-infected and transformed target cells via the granule exocytosis pathway. The key components of the cytolytic granules are perforin and several serine esterases, termed granzymes. While the cellular distribution of human granzymes A (GrA) and B (GrB) has been well characterized much less is known about the expression pattern of human granzyme K (GrK). In this study GrA, GrB, and GrK expression was analyzed in human peripheral blood lymphocytes using flow cytometry. There was a distinct population of GrK expressing CD8+ T cells with a CD27+/CD28+/CCR5high/CCR7-/perforin-/low/IFN-gamma+ memory-like phenotype, while all CD56bright NK cells were also positive for GrK. In addition, GrK was also expressed in subpopulations of CD56+ T cells, CD4+ T cells, and TCRgammadelta+ T cells. In contrast, GrB was primarily expressed in CD56dim NK cells and differentiated memory CD8+ T cells with the CD27-/low/CD28-/low/CCR5-/low/CCR7-/CD11b+/perforinhigh phenotype. Only few CD8+ T cells expressed both GrB and GrK. GrA was found to be co-expressed in all GrB- and GrK-expressing T cells. Our findings suggest that granzyme expression during the differentiation process of memory CD8+ T cells might be as follows: GrA+/GrB-/GrK+ --> GrA+/GrB+/GrK+ --> GrA+/GrB+/GrK-.     

Decreased perforin and granzyme B expression in senescent HIV-1-specific cytotoxic T lymphocytes

Cytotoxic T lymphocyte (CTL) senescence may be an important mechanism of immune failure in HIV-1 infection. We find that senescence of HIV-1-specific CTL clones causes loss of killing activity, preventable by transduction with telomerase. Furthermore, senescence is associated with reduced expression of the effector molecules granzyme and perforin, suggesting CTL "exhaustion" can result in hypofunction. These results agree with other studies showing that HIV-1-specific CTL exhibit abnormal phenotypes in vivo, and suggest the possibility that chronic turnover is an important mechanism of antiviral failure in HIV-1 infection.     

慢性乙型肝炎患者外周血淋巴细胞穿孔素的表达

目的：了解慢性乙型肝炎患者外周血淋巴细胞（PBL）穿孔素（PFP）的表达情况及其与疾病的关系。方法：用抗人PFP单克隆抗体，采用免疫组化染色法，观察慢性乙型肝炎患者PBL中总的PFP阳性细胞的百分率，结果：慢性乙型肝炎PBL中PFP表达与正常对照组之间存在明显差异，结论：乙型肝炎病毒感染慢性化与机体PBL中PFP的表达水平低下密切相关。     

Clinical and Genetic Studies of Familial Hemophagocytic Lymphohistiocytosis in Oman: Need for Early Treatment

Hemophagocytic lymphohistiocytosis (HLH) embraces the frequently indistinguishable conditions of familial hemophagocytic lymphohistiocytosis (FHL) and virus-associated hemophagocytic syndrome (VAHS). Without therapy FHL is invariably fatal, but successful therapy, including chemotherapy and immunotherapy followed by bone marrow transplantation (BMT), has been presented. To clarify the outcome of HLH in a developing country, with regard to clinical, laboratory, and genetic features, a nationwide study on all patients diagnosed with HLH in Oman during the 5-year period 1997-2001 was performed. In 5 patients and their families, mutational analysis was made. Thirteen patients with HLH were identified, 5 of whom had clinical manifestations of central nervous system involvement at presentation. In none of the patients could an infectious cause be identified. Ten children were referred late in the disease course, and the concern about starting chemotherapy before exclusion of an acute viral infection resulted in delayed treatment in some patients. Two children were started early on the HLH-94-therapy followed by successful BMT in one child. In the successfully transplanted child, the response to intrathecal hydrocortisone appeared to be better than standard therapy with intrathecal methotrexate. Finally, a novel missense mutation in the perforin gene was identified in 2 patients and their family members, causing a transition of proline to threonine at codon 89. Early diagnosis and treatment is important to improve outcome. Intrathecal corticosteroids may be considered, in addition to intrathecal methotrexate, in certain patients. Since the novel perforin mutation has been reported in only 2 patients from Oman, and since similar polymorphism in the sequencing data of the members of their families has been identified, a founder effect is possible in this population.     

Co-expression of perforin and granzyme B genes induces apoptosis and inhibits the tumorigenicity of laryngeal cancer cell line Hep-2

Granzyme B and perforin, two of the most important components, have shown anticancer properties in various cancers, but their effects in laryngeal cancer remain unexplored. Here we decided to examine the effects of Granzyme B and perforin in Hep-2 cells and clarify the role of perforin and granzyme B in the tumorigenicity of laryngeal cancer cell line. Hep-2 cells were transfected with pVAX1-PIG co-expression vector (comprising perforin and granzyme B genes), and then the growth and apoptosis of these Hep-2 cells were evaluated. The tumorigenicity of Hep-2 cell line co-expressing perforin and granzyme B genes was tested in BALB/c nu/nu mice. We found that the co-expression of perforin and granzyme B genes could obviously inhibit cell focus formation and induce cell apoptosis in Hep-2 cells. Furthermore, after subcutaneous injection of Hep-2 cells transfected with pVAX1-PIG, an extensive delay in tumor growth was observed in BALB/c-nu/nu mice. Moreover, our studies demonstrated that the anticancer activity of perforin and granzyme B was sustainable in vivo as tumor development by inducing cell apoptosis. Taken together, our data indicate that the co-expression of perforin and granzyme B genes exhibits anticancer potential, and hopefully provide potential therapeutic applications in laryngeal cancer.     

Immune checkpoints and the regulation of tolerogenicity in dendritic cells: Implications for autoimmunity and immunotherapy

The immune system is responsible for defending the host from a large variety of potential pathogens, while simultaneously avoiding immune reactivity towards self-components. Self-tolerance has to be tightly maintained throughout several central and peripheral processes; immune checkpoints are imperative for regulating the immunity/tolerance balance. Dendritic cells (DCs) are specialized cells that capture antigens, and either activate or inhibit antigen-specific T cells. Therefore, they play a key role at inducing and maintaining immune tolerance. DCs that suppress the immune response have been called tolerogenic dendritic cells (tolDCs). Given their potential as a therapy to prevent transplant rejection and autoimmune damage, several strategies are under development to generate tolDCs, in order to avoid activation and expansion of self-reactive T cells. In this article, we summarize the current knowledge relative to the main features of tolDCs, their mechanisms of action and their therapeutic use for autoimmune diseases. Based on the literature reviewed, autologous antigen-specific tolDCs might constitute a promising strategy to suppress autoreactive T cells and reduce detrimental inflammatory processes.     

IL-23单独或联合IL-2诱导人外周血单个核细胞对K562细胞杀伤效应的实验研究

本研究旨在探讨IL-23单独或联合IL-2诱导的人外周血单个核细胞（PBMNC）对白血病细胞的杀伤效应及作用机制.IL-23（50 ng/ml）单独或联合IL-2（100 U/ml）体外诱导正常人PBMNC 72 h,并与白血病细胞株K562共同培养.采用CCK-8法测定不同时间诱导后的PBMNC对K562细胞的杀伤效应;采用ELISA方法检测杀伤活性最大时细胞培养液中IFN-γ的水平;应用RQ-PCR法检测诱导后PBMNC的穿孔素、颗粒酶B的表达水平.结果表明,IL-23单独或联合IL-2作用后的PBMNC均对K562细胞有杀伤活性,随着时间延长,杀伤率明显增加,各个时间点比较,有显著性差异（P＜0.05）;各细胞因子组培养液中分泌IFN-γ水平均显著高于空白对照组（P＜0.05）,其中以IL-23联合IL-2组诱导PBMNC表达IFN-γ的水平最高,与其它两组比较,差异显著（P＜0.05）.各细胞因子组PBMNC的穿孔素、颗粒酶B mRNA的表达量均较对照组明显增加（P＜0.05）,且IL-23联合IL-2组的穿孔素、颗粒酶B mRNA表达量显著高于其他组（P＜0.05）.结论：IL-23能促进PBMNC对K562细胞的杀伤活性,与IL-2联合具有协同增强作用,并呈时间依赖性.IL-23作用于PBMNC后IFN-γ、穿孔素、颗粒酶B的表达均明显增加,且与IL-2具有协同作用.推测IL-23可能通过诱导PBMNC表达IFN-γ、穿孔素、颗粒酶B发挥抗白血病细胞作用.     

高强度聚焦超声治疗乳腺癌后局部TIL的细胞毒效应分子表达的研究

目的　研究高强度聚焦超声 (HIFU)治疗乳腺癌原发灶后靶区局部肿瘤浸润淋巴细胞 (TIL)的细胞毒性效应分子Fas配体 (FasL)、颗粒酶B(GzB)、穿孔素 (Pf)等表达变化。方法　应用SP免疫组织化学染色方法检测HIFU组 2 3例和对照组 2 5例病人局部TIL的细胞毒效应分子表达变化。结果　HIFU组局部 ,Fasl、GzB、Pf阳性的TIL平均数目分别为 :(2 9 6± 12 3)、(32 2± 11 3)、(12 2± 8 2 )个 mm2 ;对照组局部 ,Fasl、GzB、Pf阳性的TIL平均数目分别为 :(2 1 2± 9 8)、(17 5± 6 3)、(6 8± 5 2 )个 mm2 。比较两组对应指标 ,HIFU组FasL、GzB、Pf阳性的TIL与对照组差异有显著性意义 (P <0 0 5 )。结论　HIFU治疗乳腺癌后局部TIL中的FasL、GzB、Pf表达增加 ,增强了原发灶局部的抗肿瘤细胞毒活性