Study on construction of c-Met specific CAR-T cells and its killing effect on non-small cell lung carcinoma / 中华肿瘤杂志

Objective: To produce chimeric antigen receptor T cells (CAR-T) targeting human hepatocyte growth factor/c-Met (HGF/c-Met) protein and detect its cytotoxicity against non-small cell lung cancer (NSCLC) cells H1975 in vitro. Methods: The whole gene sequence of c-Met CAR containing c-Met single-chain fragment variable was synthesized and linked to lentiviral vector plasmid, plasmid electrophoresis was used to detect the correctness of target gene. HEK293 cells were transfected with plasmid and the concentrated solution of the virus particles was collected. c-Met CAR lentivirus was transfected into T cells to obtain second-generation c-Met CAR-T and the expression of CAR sequences was verified by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and western blot, and the positive rate and cell subtypes of c-Met CAR-T cells were detected by flow cytometry. The positive expression of c-Met protein in NSCLC cell line H1975 was verified by flow cytometry, and the negative expression of c-Met protein in ovarian cancer cell line A2780 was selected as the control. The cytotoxicity of c-Met CAR-T to H1975 was detected by lactate dehydrogenase (LDH) cytotoxicity assay at 1∶1, 5∶1, 10∶1 and 20∶1 of effector: target cell ratio (E∶T). Enzyme-linked immunosorbent assay (ELISA) was used to detect the release of cytokines such as TNF-α, IL-2 and IFN-γ from c-Met CAR-T co-cultured with H1975. Results: The size of band was consistent with that of designed c-Met CAR, suggesting that the c-Met CAR plasmid was successfully constructed. The results of gene sequencing were consistent with the original design sequence and lentivirus was successfully constructed. CAR molecules expression in T cells infected with lentivirus was detected by western blot and RT-qPCR, which showed c-Met CAR-T were successfully constructed. Flow cytometry results showed that the infection efficiency of c-Met CAR in T cells was over 38.4%, and the proportion of CD8(+) T cells was increased after lentivirus infection. The NSCLC cell line H1975 highly expressed c-Met while ovarian cancer cell line A2780 negatively expressed c-Met. LDH cytotoxicity assay indicated that the killing efficiency was positively correlated with the E∶T, and higher than that of control group, and the killing rate reached 51.12% when the E∶T was 20∶1. ELISA results showed that c-Met CAR-T cells released more IL-2, TNF-α and IFN-γ in target cell stimulation, but there was no statistical difference between c-Met CAR-T and T cells in the non-target group. Conclusions: Human NSCLC cell H1975 expresses high level of c-Met which can be used as a target for immunotherapy. CAR-T cells targeting c-Met have been successfully produced and have high killing effect on c-Met positive NSCLC cells in vitro.

Effect of suicide gene therapy in combination with immunotherapy on antitumour immune response & tumour regression in a xenograft mouse model for head & neck squamous cell carcinoma.

Background & objectives: Prodrug activation strategy as well as immunotherapy have been widely used for cancer gene therapy. In the present study, using a head and neck squamous cell carcinoma (HNSCC) xenograft nude mouse model, we have investigated whether the two therapies in combination could improve tumour cell kill. We also investigated induction of immune effector cells viz., NK (DX5+) and DC (CD11c+) in vivo, post-combination gene therapy. Methods: A retroviral vector producing cell line (PLTK47.1 VPC) carrying Herpes simplex virus thymidine kinase gene (HSVtk) was used for intratumoural injection into NT8e xenograft tumours followed by the prodrug ganciclovir (GCV). IL-2 plasmid DNA was injected intramuscularly. Immune cells were analyzed by flow-cytometry. Non parametric ANOVA was performed with Kruskal Wallis test. Results: IL-2 could induce proliferation of both NK cells (DX5+) and dendritic cells (CD11c+) in vivo. Apoptosis was higher in combination therapy group as compared to HSVtk/GCV alone or IL-2 alone and was mediated through caspase-3 dependent pathway. Significant reduction in tumour volume was seen in all 3 treatment arms as compared to controls. Interpretation & conclusions: Combination of suicide gene therapy and immunotherapy leads to successful tumour regression in a HNSCC xenograft mouse model. Immunotherapy could help in a systemic long lived anti-tumour immune response which would prove powerful for the treatment of metastatic cancers, and also for minimal residual disease. The results of this study may form the basis for Phase 1 clinical trials.

Expansion and Activation of Natural Killer Cells for Cancer Immunotherapy / 대한진단검사의학회지

Natural killer (NK) cells can kill a wide range of cancer cells and are a promising tool for cell therapy of cancer. NK cells cytotoxicity is regulated by a balance between stimulatory and inhibitory signals. Interleukin-2 is known to increase NK cell cytotoxicity. Although many cytokines have been studied in efforts to induce durable NK cell expansions, most reports indicate a rather modest effect and the requirement for additional stimuli. We found that contact with the K562 myeloid leukemia cell line, genetically modified to express a membrane-bound form of interleukin-15 and the ligand for the costimulatory molecule 4-1BB, induced vigorous expansion of NK cells from peripheral blood. Based on these findings, we developed a method for large-scale clinical-grade expansion of NK cells. This method is currently used to expand allogeneic NK cells for infusion in patients with leukemia and solid tumors. We here summarize methods for expansion and activation of NK cells from human peripheral blood mononuclear cells as well as clinical-scale methods to produce NK cells for immunotherapy under Current Good Manufacturing Practices (cGMP) conditions.

Protection of chicken against very virulent IBDV provided by in ovo priming with DNA vaccine and boosting with killed vaccine and the adjuvant effects of plasmid-encoded chicken interleukin-2 and interferon-gamma

The aim of this study was to examine the efficacy of in ovo prime-boost vaccination against infectious bursal disease virus (IBDV) using a DNA vaccine to prime in ovo followed by a killed-vaccine boost post hatching. In addition, the adjuvant effects of plasmid-encoded chicken interleukin-2 and chicken interferon-gamma were tested in conjunction with the vaccine. A plasmid DNA vaccine (pcDNA-VP243) encoding the VP2, VP4, and VP3 proteins of the very virulent IBDV (vvIBDV) SH/92 strain was injected into the amniotic sac alone or in combination with a plasmid encoding chicken IL-2 (ChIL-2) or chicken IFN-gamma (ChIFN-gamma) at embryonation day 18, followed by an intramuscular injection of a commercial killed IBD vaccine at 1 week of age. The chickens were orally challenged with the vvIBDV SH/92 strain at 3 weeks of age and observed for 10 days. In ovo DNA immunization followed by a killed-vaccine boost provided significantly better immunity than the other options. No mortality was observed in this group after a challenge with the vvIBDV. The prime-boost strategy was moderately effective against bursal damage, which was measured by the bursa weight/body weight ratio, the presence of IBDV RNA, and the bursal lesion score. In ovo DNA vaccination with no boost did not provide sufficient immunity, and the addition of ChIL-2 or ChIFN-gamma did not enhance protective immunity. In the ConA-induced lymphocyte proliferation assay of peripheral blood lymphocyte collected 10 days post-challenge, there was greater proliferation responses in the DNA vaccine plus boost and DNA vaccine with ChIL-2 plus boost groups compared to the other groups. These findings suggest that priming with DNA vaccine and boosting with killed vaccine is an effective strategy for protecting chickens against vvIBDV.

Modulation of the Surface Expression of CD158 Killer Cell Ig-like Receptor by Interleukin-2 and Transforming Growth Factor-beta

Killer cell Ig-like receptor (KIR) binds to HLA class I molecules on the surface of target cells, and it confers inhibitory signals to NK cells. Although NK cytotoxicity can be affected by the change of the surface expression of KIR on NK cells, the effect of cytokines on the regulation of KIR expression has not been thoroughly investigated. Here in our study, we investigated the effect of several cytokines, including IL-2, TGF-beta, IFN-gamma, IL-12 and IL-18, on the surface expression of CD158 KIR, which binds to HLA-C, by the use of FACS analysis. In the isolated NK cells, IL-2 obviously increased the surface expression of CD158 KIR after 72 hr in vitro culture, and this was evidenced by the increased percentage of CD158+ NK cells and the increased mean fluorescence intensity of CD158 in CD158+ NK cells. In contrast, TGF-beta decreased the surface expression of CD158 KIR after 72 hr culture. However, IFN-gamma, IL-12 and IL-18 did not change the expression of CD158 KIR. The modulated expression of KIR by IL-2 and TGF-beta can be associated with the changed NK-cytotoxic target-discriminating ability of NK cells upon their exposure to IL-2 and TGF-beta.

The Comparison of Cytotoxic T-Lymphocyte Effects of Dendritic Cells Stimulated by the Folate Binding Protein Peptide Cultured with IL-15 and IL-2 in Solid Tumor

The current modalities for treating cancer employ not only single but multiple approaches involving surgery, radiotherapy and chemotherapy. Unfortunately, the survival outcome is not promising even with these approaches. Alternative approaches for cancer therapy are now emerging. Immunotherapy is aiming at both increasing the power, and in redirecting the specificity of the patients' immune system to attack the tumor cells. Recently, many studies using tumor associated lymphocytes (TAL) isolated from malignant ascites cultured in a media containing interleukin-2 exhibit antitumor responses. IL-2 is a lymphokine produced by T-cells. It facilitates activation, sustained growth and rescue from apoptosis. Lately, newly developed IL-15 has also exhibited antitumor activity similar to IL-2. IL-15 is a newly described cytokine produced from monocytes-marcrophages and T-cells. It has a different molecular structure but it functions like IL-2 by binding to the IL-2R beta and gamma c chain. These antitumor responses are mediated by the cytotoxic T lymphocytes (CTL) that recognize the antigen in the context of the MHC molecules using the T cell receptors. CD8+-CTL recognize the peptide epitopes that are processed from the cellular proteins in the context of the MHC class I molecules. These peptides have a restricted length of 8-11 amino acids. The folate binding protein (FBP) is overexpressed in over 90% of ovarian and 20-50% in breast cancers. The FBP is the source of the antigenic peptides that are recognized by a number of these CTL-TAL, and is antigenic to both ovarian and breast cancer in vivo. To define the antitumor response of IL-15 and its' FBP immunogenicity, a peptide defining epitope E39 and E75 were presented by the PMBC derived dendritic cells (DC) from healthy donors isolated by the CD14 method to ovarian and breast CTL-TAL. Stimulating both ovarian and breast CTL- TAL by E39 or E75 pulsed DC (DC-E39, DC-E75), in the presence of IL-15 and IL-2 can rapidly enhance or induce the E39 or E75 specific CTL activity. The antitumor activities were measured by a chromium release assay for the tumor specific lysis activity using the ovarian and breast cancer cell lines. The tumor specific lysis activity for the ovarian TALs for IL-15 vs IL-2 were 28.6+/-3.9% and 30.3+/-3.2%, respectively and in the breast TALs, they were 14.8+/-3.1% vs 13.5+/-2.9%, respectively. Using autologous tumor cells, a slightly higher tumor specific lysis activity was obtained for the ovarian TALs cultured in IL-15 compared to IL-2 (72.0+/-8.2% vs 68.5+/-3.6%). However, for the breast TALs, they were 39.5+/-4.2% vs 41.5+/-3.3%, respectively. IL-15 is a newly developed cytokine that shows promising antitumor activity similar to IL-2. However, it requires lower dosage and is less toxic. Therefore, IL-15 might be a potential anticancer immunotherapeutic agent.

Interleukin-2 as a therapeutic agent.

Interleukin-2 (IL-2) belongs to a class of soluble, regulatory proteins known as cytokines. It is a 133 amino acid glycoprotein secreted by T(H) lymphocytes and other cells following activation by antigens, mitogens and other cytokines. It stimulates the proliferation and cytotoxicity of T lymphocytes. It also enhances the microbicidal and cytotoxic activities of NK cells, B lymphocytes, macrophages and monocytes. IL-2 can now be produced in unlimited quantities by recombinant DNA technology and used therapeutically to modulate the immune system in a number of diseases. A number of different studies have demonstrated its therapeutic value in HIV +ve and AIDS patients. It has been approved by US-FDA for treatment of metastatic renal cell carcinoma (RCC) and metastatic melanoma. Routine detection of soluble IL-2 receptor in blood could be useful as a diagnostic marker in some autoimmune diseases. Agents that antagonize IL-2 find application as immunosuppressants. The main adverse effect of IL-2 is capillary leak syndrome caused by increased capillary permeability and extravasation of fluid. In days to come, IL-2 is likely to play an increasingly important role in management of viral infections, malignancies and a number of other diseases conditions.

Interleukin 2 induction of proliferation in resting T lymphocytes requires contact with monocytes

Resting human T cells are known to express significant numbers of intermediate but none or barely detectable low and high a affinity IL-2 receptors (IL-2R). IL-2 alone failed to induce proliferation in these cells, However, in presence of small proportion of autologous monocytes, as low as 22 pM, IL-2 induced high levels of proliferation in resting T cells. Introduction of a semi permeable between the two cell types or addition of an anti-CD 11b mAb inhibited such induction of proliferation by IL-2. Neither recombinant IL-1 por IL-1 containing cell-free extracts from activated monocytes substituted for intact monocytes. Autologous B cells failed to replace monocytes. Using antigen-specific cloned human T cells we have shown a lack of requirement for antigen. The proliferation was inhibited by anti-IL-2R alpha mAb. IL-2 appears to be unique since neither IL-4 nor IL-6, alone or in presence of monocytes, led to induction of proliferation in resting T cells. Combination of IL-2 and monocytes induced proliferation in all T cell subpopulations (CD4, CD8, CD45RA and CD45RO) and antigen-specific clones examined. It also induces mRNA and surface expression of IL-2R alpha, appearance of high affinity IL-2R and induction of proliferation in large proportions of T cells. As in humans, the IL-2 induction of proliferation in murine resting T cell required contact with syngeneic monocytes, suggesting that such a mechanism of cells activation is highly conserved.

Interleukin-2 restores natural killer activity inhibited by sera from HIV + Hemophilic patients

Natural killer (NK) activity is impaired in patients with positive serology for the human immunodeficiency virus (HIV). We previously found an inhibitory effect of sera from hemophilic (He) HIV+ patients on normal NK activity. In the present study, we have further characterized this effect by studying its reversibility, temperature and time incubation dependence. Since interleukin 2 (IL-2) is able to enhance NK levels, we analized the capacity of this lymphokine to reverse the effect of He HIV+ sera. We found that when IL-2 activation of NK activity occurred simultaneously or after HIV+ serum-treatment, a significant restoration of NK function was observed. In contrast, preincubation with IL-2 did not affect the inhibitory effect exerted by HIV+ sera.

Citocina. ¿La terapéutica del futuro? / Citokines. The therapy in the future?

Se definen qué son las citocinas y se describe el papel de la interleucina-1 como un ejemplo de las fuciones que desempeñan. Actualmente se han encontrado más de 40 citocinas que se han agrupado en 1) factores de crecimiento, 2) interleucinas, 3) interferones, 4) quimiocinas y 5) otras. Hoy en día, mediante transfección genética, se han preparado 11 citocinas para aplicación terapéutica; de éstas, la eritropoyetina, el factor estimulante de colonias granulocito-monocito y el factor estimulante de colonias granulocito-monocito y el factor estimulante de colonias de granulocitos se utilizan con buen éxito para estimular la producción de glóbulos rojos, granulocitos y de monocitos en algunas patologías con daño a la médula ósea. Después de varios años de aplicación clínica, el uso de los interferones alfa, beta y gamma se han visto limitados a infecciones como la hepatitis B o C y algunos tipos de cáncer como la leucemia de células peludas y la leucemia granolocítica crónica. Las otras citocinas, como las interleucinas 2, 3, 4, 6 y el factor estimulante de colonias de monocitos, empiezan a mostrar su utilidad terapéutica en algunos ensayos clínicos. Se espera que en el futuro algunas de ellas, solas o combinadas con otras u otros activadores inmunológicos curen enfermedades como el síndrome de inmunodeficiencia adquirida o el cáncer

Suppressor activity in Leishmania donovani-infected hamster serum: reversion by delipidated bovine serum albumin and role in cell cycle events

Visceral leishmaniasis caused by Leishmania donovani, is a chroníc disease with a high mortality rate. This protozoan induces a serious dysfunction of the immune system characterized by suppression of the cellular response to parasite antigens. We provide evidence for the involvement of lipids in the immunological alterations of experimental leishmaniasis. Sera obtained from 60-day-infected hamsters present increased triglyceride levels. Inhibition of cell proliferation was observed when splenocytes from normal hamsters were stimulated with concanavalin A in the presence of 3 per cent infected hamster serum (IHS) (Control 50 + 3 (x 10(3)) Cpm; IHS 5 ñ 1 (X 10(3)) cpm). This inhibition was reversed by the addition of 5 mg/ml of delipidated bovine serum albumin (BSA) to the cultures (Control 65 ñ 1 (X 10(3)) cpm; IHS 75 ñ 3 (x 10(3)) cpm). The inhibitory effect of IHS was demonstrable only when added to the culture simultaneously with the mitogen. This effect was not as intense on fresh, pre-activated cells or on the CTLL-2 cells. This cell line stimulated by IL-2 in the presence of IHS is only marginally inhibited (about 20 per cent inhibition). The suppressor effect on CTLL-2 was not reversed by the addition of increasing doses of IL-2 (up to 100 U/ml) to cultures. The inhibition of the proliferative response of the CTLL-2 cells caused by IHS was also reversed by the addition of delipidated BSA. Our data suggest a role for fatty acids in the infected hamster serum-induced suppression of normal or L. donovani-infected cell proliferation.

Opposite effects of interleukin-2 (IL-2) and interferon gamma (IFN gamma) on Rat atria contractility

Recientemente demostramos que la interleuqina 2(IL-2) es capaz de incrementar la tensión contráctil de aurículas de rata aisladas a través de la activación de las fosfolipasas y de la proteína quinasa C. Los resultados de este estudio confirman la participación de las proteínaquinasa C y no de las proteínas quinasas Ca++-calmodulina dependietes. Un activador directo de la proteína quinasa C, el promotor del crecimiento tumoral 12-miristato 13-acetato de forbol (PMA), tiene efectos similares a los de IL-2 sobre la contractilidad. La preincubación del tejido com PMA suprime el efecto de la IL-2, sugiriendo que las quinasas activadas por PMA e IL-2 compartem substratos comunes. Este efecto estimulante de IL-2 comparten substratos comunes. Este efecto estimulante de IL-2 sobre la contractilidad se opone al efecto colinomimético inhibitório del interferón ç(FNç). La preincubación de las aurículas con IL-2 o PMA suprime la respuesta al IFNç y viceversa. Aparentemente, la acción inhibitória de IL-2 sobre IFNç es el resultado de su interferencia con la activación de la vía colinérgica muscarínica, pues IL-2 desplaza hacia la derecha la curva dosis-respuesta de las auríchlas frente al carbachol. La proteína quinasa C es también necesaria para que ocurra la interferencia IL-2-IFNç. Los resultados de este estudio sugieren que, durante un proceso inflamatório en el corazón, el balance local de ambas linfoquinas puede determinar en la respuesta del tejido hacia agonistas propios del sistema nervioso autónomo y hacia las citoquinas que imitan los efectos de dichos neurotransmisores

Expansion of a subset of TCR gamma/delta human lymphocytes from various lymphoid organs cultured with recombinant IL-2

1. TCR1 cells are a minor component of CD3+ lymphocytes which bear the gamma/delta T-cell receptor. There are limited data concerning the activation of TCR1 cells or TCR1 cell subsets in human lymphoid organs. We analyzed a subset of TCR1 cells (delta TCS1+) in peripheral blood (PBL), spleen (SPL), lymph nodes (LN), bone marrow (BM), and thymus (THY) after activation with IL-2. Lymphoid cells from these organs were cultured with 1500 U/ml IL-2 for 14 days and analyzed at periodic intervals for delta TCS1+ cells. 2. We found increased numbers of delta TCS1+ cells in 6- and 14-day cultures from SPL (20.8 +/- 11.8 per cent positive cells after 14 days of culture), LN, BM and THY but not in peripheral blood (1.8 +/- 0.9 per cent ). These delta TCS1+ cells coexpressed CD2, CD3, CD8 and CD56, but were negative for TCR alpha/beta and CD4. We also detected an expansion of TCR1+ cells in IL-2-stimulated PBL employing the pan-gamma/delta marker TCR delta 1; however, in contrast to solid organs, these TCR1+ cells were delta TCS1 negative. 3. Sorting experiments demonstrated directly that delta TCS1 cells from spleen cultures mediate high cytotoxic activity against K562 cell targets (39.4 per cent median specific cytotoxicity) and low activity against Daudi (9.6 per cent ), COLO (2.7 per cent ) and an antibody-sensitized human B-cell line (17 per cent ). 4. These results show expansion and cytotoxic activation by IL-2 of a subset of human TCR1 cells in solid lymphoid organs

A modified assay for measuring thymocyte co-stimulatory activity

The observation that murine thymocytes increase their proliferation to interleukin 1 (IL-1) in the presence of phytohemagglutinin (PHA) when pre-incubated with interleukin 2 (IL-2) allowed the introduction of a modified assay for the measurement of IL-1 or the search of thymocyte-inducing proliferative activities in biological samples. Pre-incubation of thymocytes for 24 hr with 50 u/ml IL-2, followed by washings, elicited their maximal response to IL-1 in the usual lymphocyte activating factor (LAF) assay. This suggests that sequential events lead to thymocyte activation. The responsiveness is three to five fold greater than, and the total time of assay is the same as that of the LAF assay. Interestingly, pre-incubation with IL-2 renders thymocytes more sensitive than responsive to crude monocyte conditioned media. The use of the MTT colorimetric method for the assessment of thymocyte proliferation, and of the lectin jacalin as a co-mitogen are suggested as alternatives to be used in co-stimulatory assays

Effect of cyclosporin-A, antimalarial drug, on lymphocyte proliferation of Balb/c mice in vitro.

Cyclosporin-A(CsA) caused inhibition of lymphocyte proliferation at higher doses (5 and 10 micrograms/ml) compared to controls. When spleen cells were preincubated with high doses of CsA and washed, the normal lymphocyte response to stimulation with mitogen (concanavalin-A) and lymphokine (interleukin-2) was not affected. The results indicate that CsA's suppressive effect at higher doses, was a temporary one and potential use of CsA to control parasitic infections should be examined.