IL-18在体外培养系统中诱导肿瘤快速杀伤效应及肿瘤特异性CTL

目的应用rhlL-18在体外培养系统(Coculture system in vitro，CCs)中诱导快速肿瘤杀伤效应及诱导肿瘤特异性细胞毒性T淋巴细胞(Cytotoxic T Lymphocyte，CTL)。方法 采用StemSep^TM免疫磁性细胞分离法分离人外周血NK细胞、T细胞及树突细胞(DCs)，流式细胞仪分析细胞表型，125I-UdR标记的细胞毒实验检测杀伤活性，ELISA方法检测IFN-7的产生量。结果 在CCs中，rhIL-18诱导出快速肿瘤杀伤效应，这种杀伤效应无抗原特异性、不受MHC限制，DCs和T细胞的存在与否对其无明显影响。在同一培养系统中，肿瘤抗原存在的条件下，96h后，rhIL-18能够诱导并促进CTL介导的肿瘤特异性杀伤效应。结论 rhIL-18能够在体外培养系统中相继诱导肿瘤快速杀伤效应及肿瘤特异性CTL。     

抗原致敏树突状细胞诱导CTLs杀伤HL-60细胞作用研究

 目的　探讨树突状细胞 (DC)在体外诱导针对白血病细胞的CTLs杀伤活性。方法　用IL 4和GM CSF培养正常人外周血DC ,以HL 6 0细胞裂解液致敏DC ,再与淋巴细胞共孵育 ,激活T淋巴细胞 ,用LDH释放法测定致敏DC诱导杀伤性细胞对HL 6 0细胞的杀伤活性。结果　外周血单个核细胞经体外扩增培养出可见树突状形状的DC ,流式细胞仪检测细胞表面CD1α及CD86表达阳性 ,CD14表达阴性。混合淋巴细胞反应 (MLR)观察DC刺激的异体淋巴细胞增殖明显较对照组高 ,两者比较有显著性差异 (n =15 ,P <0 .0 1)。在效靶比为 2 0∶1时 ,抗原致敏的DC诱导的杀伤性T细胞对HL 6 0细胞的杀伤率是 39.9%± 2 1.5 % ,直接以抗原刺激的T细胞的杀伤率是 2 6 .3%± 15 .6 %。两组比较差异有非常显著性 (n =16 ,P <0 .0 0 1)。效靶比为 2∶1时 ,抗原致敏的DC诱导的杀伤性T细胞对靶细胞就有明显的杀伤作用 ,随着效靶比增加 ,杀伤作用增强。实验组和对照组不同效靶比杀伤率比较 ,差异有非常显著性 (n =16 ,P <0 .0 0 1)。结论　DC...     

Association between the HLA-G molecule and lymph node metastasis in papillary thyroid cancer

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer and can present as lymph node metastasis in 30 to 65% of cases when initially diagnosed. High frequency recurrence, distant metastasis and treatment resistance can be found in cases of PTC so early diagnosis and treatment are critical for improved prognosis and better survival rates. The characterization of new biomarkers has proved useful for the diagnosis and follow-up of these patients. HLA-G is a non-classical HLA class I molecule whose expression in cancer cells has been associated with tumor evasion of immune response. Therefore, the aim of this study was to investigate the HLA-G expression and its clinical significance in PTC. Paraffin-embedded thyroid biopsies of 70 PTC patients (40 of whom had presented with metastasis) were evaluated. HLA-G-staining was observed in tumor cells in PTC, and the HLA-G expression was significantly associated with an increased occurrence of lymph node metastasis (p = 0.0006) and capsular invasion (p = 0.02). This preliminary data shows the HLA-G expression in thyroid carcinoma specimens for the first time and suggests that this expression could impair efficient anti-tumor immunity in PTC. This would indicate that HLA-G could have an independent prognostic value in PTC, principally for tumor recurrence.     

Analysis of HLA-G gene polymorphism and protein expression in invasive breast ductal carcinoma

The human leukocyte antigen G (HLA-G) is a non-classical HLA class I molecule predominantly expressed in trophoblastic placental cells to protect the fetus during pregnancy. However, evidence has shown that this molecule may be implicated in the immune escape mechanism of tumor cells. Thus, the aim of this study was to evaluate the frequency of 14-bp insertion/deletion HLA-G polymorphism, as well as the expression of this molecule in patients with invasive breast ductal carcinoma (IDC). A significant association between the expression of HLA-G and the presence of metastasis in lymph nodes (p = 0.01) was observed and the expression of HLA-G was significantly higher in patients with shorter survival time (p = 0.03). The analysis suggests that the polymorphism observed in patients with IDC may be inducing a higher expression of the HLA-G molecule, which may possibly contribute to shorter survival time and a worse clinical prognosis for such patients.     

Genetic polymorphisms in the Toll-like receptor signalling pathway in Helicobacter pylori infection and related gastric cancer

Background

Gastric cancer (GC) is a progressive process initiated by Helicobacter pylori-induced inflammation. Initial recognition of H. pylori involves Toll-like receptors (TLRs), central molecules in the host inflammatory response. Here, we investigated the association between novel polymorphisms in genes involved in the TLR signalling pathway, including TLR2, TLR4, LBP, MD-2, CD14 and TIRAP, and risk of H. pylori infection and related GC.

Methods

A case-control study comprising 310 ethnic Chinese individuals (87 non-cardia GC cases and 223 controls with functional dyspepsia) was conducted. Twenty-five polymorphisms were detected by MALDI-TOF mass spectrometry, PCR, PCR–RFLP and real-time PCR.

Results

Seven polymorphisms showed significant associations with GC (TLR4 rs11536889, TLR4 rs10759931, TLR4 rs1927911, TLR4 rs10116253, TLR4 rs10759932, TLR4 rs2149356 and CD14 −260 C/T). In multivariate analyses, TLR4 rs11536889 remained a risk factor for GC (OR: 3.58, 95% CI: 1.20–10.65). TLR4 rs10759932 decreased the risk of H. pylori infection (OR: 0.59, 95% CI: 0.41–0.86). Statistical analyses assessing the joint effect of H. pylori infection and the selected polymorphisms revealed strong associations with GC (TLR2, TLR4, MD-2, LBP and TIRAP polymorphisms).

Conclusions

Novel polymorphisms in TLR2, TLR4, MD-2, LBP, CD14 and TIRAP, genes encoding important molecules of the TLR signalling pathway, showed clear associations with H. pylori-related GC in Chinese.     

CD8+ T‐cell immunosurveillance constrains lymphoid premetastatic myeloid cell accumulation

Increasing evidence suggests that premetastatic niches, consisting mainly of myeloid cells, provide microenvironment critical for cancer cell recruitment and survival to facilitate metastasis. While CD8⁺ T cells exert immunosurveillance in primary human tumors, whether they can exert similar effects on myeloid cells in the premetastatic environment is unknown. Here, we show that CD8⁺ T cells are capable of constraining premetastatic myeloid cell accumulation by inducing myeloid cell apoptosis in C57BL/6 mice. Ag‐specific CD8⁺ T‐cell cytotoxicity against myeloid cells in premetastatic lymph nodes is compromised by Stat3. We demonstrate here that Stat3 ablation in myeloid cells leads to CD8⁺ T‐cell activation and increased levels of IFN‐γ and granzyme B in the premetastatic environment. Furthermore, Stat3 negatively regulates soluble Ag cross‐presentation by myeloid cells to CD8⁺ T cells in the premetastatic niche. Importantly, in tumor‐free lymph nodes of melanoma patients, infiltration of activated CD8⁺ T cells inversely correlates with STAT3 activity, which is associated with a decrease in number of myeloid cells. Our study suggested a novel role for CD8⁺ T cells in constraining myeloid cell activity through direct killing in the premetastatic environment, and the therapeutic potential by targeting Stat3 in myeloid cells to improve CD8⁺ T‐cell immunosurveillance against metastasis.     

γ射线诱导癌细胞凋亡致敏树突状细胞后的免疫应答

目的 观察树突状细胞（DCs）从γ射线诱导的凋亡胆管癌细胞获取抗原后，抗肿瘤免疫应答及对胆管癌细胞的特异性免疫杀伤效果。方法 用粒－巨噬细胞集落刺激因子（GM－CSF）加白介素－4（IL－4）从人外周血分化、诱导DCs,γ射线在体外诱导培养的人胆管癌细胞凋亡，将DCs、T淋巴细胞和凋亡胆管癌细胞共培养，同时设计不同类型肿瘤细胞（坏死胆管癌细胞及培养胆管癌细胞）作对照，7d后，分离、富集DCs、T淋巴细胞进行免疫应答及肿瘤细胞杀伤试验。结果 与凋亡胆管癌细胞共培养之DCs可以有效提呈胆管癌细胞抗原，有强烈的免疫应答，刺激的细胞毒T淋巴细胞（CTLs)特异性地杀伤胆管癌细胞。结论 γ射线诱导癌细胞凋亡可以致敏rhGM-CSF加rhIL-4从人外周血单核细胞诱导、扩增出的DCs并产生显著的杀伤胆管癌细胞的免疫反应，可望成为特异性免疫治疗肿瘤的一条新途径。     

Establishment of shared antigen reactive cytotoxic T lymphocyte using co-stimulatory molecule introduced autologous cancer cells

Cytotoxic T lymphocytes (CTLs) play an essential role in immunological responses for tumor rejection. In the past decade, many tumor-associated antigens (TAAs) have been identified predominantly in melanomas. Several clinical trials based on such antigenic peptides with or without adjuvants brought about partially favorable results, suggesting that identification of more immunogenic TAAs is needed. We show here the successful establishment of human leukocyte antigen (HLA)-A24-restricted CTL (TcLHK2 line1) from a pleural effusion of lung cancer patient, using B7.1 (CD80) transduced autologous lung cancer cells as an antigen-presenting cell (APC). TcLHK2 line1 recognized autologous lung adenocarcinoma cell line LHK2 in an HLA-A24-restricted fashion. Moreover, this CTL line also recognized allogeneic HLA-A24-positive lung adenocarcinoma cell line, gastric carcinoma cell line and melanoma cell line. These data raise the possibility that co-stimulatory molecule B7.1 (CD80) plays important role to overcome the immunological tolerance. Furthermore, TcLHK2 line1 is a useful tool for the identification of widely expressed shared antigens restricted by HLA-A24. Further analysis of this CTL and autologous cancer cell line will bring about novel TAAs.     

ProtEx technology for the generation of novel therapeutic cancer vaccines

Therapeutic vaccines present an attractive alternative to conventional treatments for cancer. However, tumors have evolved various immune evasion mechanisms to modulate innate, adaptive, and regulatory immunity for survival. Therefore, successful vaccine formulations may require a non-toxic immunomodulator or adjuvant that not only induces/stimulates innate and adaptive tumor-specific immune responses, but also overcomes immune evasion mechanisms. Given the paramount role costimulation plays in modulating innate, adaptive, and regulatory immune responses, costimulatory ligands may serve as effective immunomodulating components of therapeutic cancer vaccines. Our laboratory has developed a novel technology designated as ProtEx^™ that allows for the generation of recombinant costimulatory ligands with potent immunomodulatory activities and the display of these molecules on the cell surface in a rapid and efficient manner as a practical and safe alternative to gene therapy for immunomodulation. Importantly, the costimulatory ligands not only function when displayed on tumor cells, but also as soluble proteins that can be used as immunomodulatory components of conventional vaccine formulations containing tumor-associated antigens (TAAs). We herein discuss the application of the ProtEx^™ technology to the development of effective cell-based as well as cell-free conventional therapeutic cancer vaccines.     

Adoptive cellular therapy with T cells specific for EBV-derived tumor antigens

Adoptive T-cell therapy is an attractive option for targeting tumors associated with Epstein-Barr virus. In immunogenic Type III latency tumors such as post transplant lymphoproliferative disease, EBV-specific CTL have been used successfully as prophylaxis and treatment. In Type II latency malignancies such as Hodgkin's disease and nasopharyngeal cancer, a more restricted array of EBV antigens are encoded and the clinical response rates after infusion of EBV-specific CTLs have been lower. Current strategies to increase response rates include targeting CTL to subdominant EBV antigens and genetically modifying CTL to increase their potency.