Properties of recombinant interleukin 2-cultured tumor-infiltrating lymphocytes in human lung cancer

It is thought that TIL can be activated in vitro by rIL-2 and acquire specific anti-tumor activity. In this study, we investigated this possibility, using lymphocytes isolated from primary lung cancer tissues. In a first series of experiments, TILs and autologous PBLs from 16 patients were cultured in rIL-2 from 7 to 14 days under identical conditions, and were compared for proliferation (16 cases), cytolytic activity (11 cases), gamma interferon (IFN-gamma) production (8 cases), and phenotypes (10 cases). TILs grew in response to rIL-2 as well as PBLs. However, the induced cytolytic activity of TIL was significantly lower than that of PBL against autologous tumor cells and 2 human tumor cell lines. IL-2-mediated IFN-gamma production by TILs was also significantly lower than that of PBLs. TILs were phenotypically characterized by their high CD4/CD8 ratio and lack of Leu11-positive cells. Further investigations with 7 other cases showed that exogenous addition of IFN-gamma to rIL-2 cultures of TILs enhanced cytolytic activity in 4 cases. Our results indicate that IL-2 alone is sufficient for TILs to proliferate but not to acquire new functions (cytotoxicity and production of IFN-gamma).     

Clonal and functional analysis for the augmentation of tumour-infiltrating lymphocytes by interleukin 4.

In the adoptive immunotherapy for cancer, the amounts of induced effector cells play a major role in improving therapeutic efficacy. We have already demonstrated that interleukin 4 (IL-4) augments proliferation of tumour-infiltrating lymphocytes (TILs) without altering the cytotoxic activity against autologous tumour cells. The present study is designed to investigate how IL-4 augments TILs by using established TIL clones in terms of IL-2/IL-2 receptor system. CD4+, CD8+ and CD4+ CD8+ (double positive) TIL clones were established from cancer patients. At clonal level, IL-4 augmented the proliferation of IL-2-activated TIL clones irrespective of phenotypes. In order to clarify the mechanism of IL-4 at clonal level, the blocking assay by anti-IL-2 receptor alpha and beta chain and binding assay of IL-2 on the cell surface and the measurement of the internalisation of IL-2 in the cell were performed. It was clarified that IL-4 up-regulated the IL-2 receptor and then augmented the action of IL-2 molecule on the cell surface stimulated by IL-4. Furthermore, binding IL-2 internalised rapidly into the cells. Thus, it is suggested that signal transduction is augmented and proliferation of TILs is enhanced by IL-4 via the action of IL-2/IL-2 receptor system.     

MHC class I-restricted recognition of a melanoma antigen by a human CD4+ tumor infiltrating lymphocyte

It is generally considered that MHC class I-restricted antigens are recognized by CD8+ T cells, whereas MHC class II-restricted antigens are recognized by CD4+ T cells. In the present study, we report an MHC class I-restricted CD4+ T cell isolated from the tumor infiltrating lymphocytes (TILs) of a patient with metastatic melanoma. TIL 1383 I recognized HLA-A2+ melanoma cell lines but not autologous transformed B cells or fibroblasts. The antigen recognized by TIL 1383 I was tyrosinase, and the epitope was the 368-376 peptide. Antibody blocking assays confirmed that TIL 1383 I was MHC class I restricted, and the CD4 and CD8 coreceptors did not contribute significantly to antigen recognition. TIL 1383 I was weakly cytolytic and secreted cytokines in a pattern consistent with it being a Th1 cell. The avidity of TIL 1383 I for peptide pulsed targets is 10-100-fold lower than most melanoma-reactive CD8+ T cell clones. These CD4+ T cells may represent a relatively rare population of T cells that express a T-cell receptor capable of cross-reacting with an MHC class I/peptide complex with sufficient affinity to allow triggering in the absence of the CD4 coreceptor.     

肿瘤浸润淋巴细胞的体外培养及临床应用研究

目的:研究肺癌患者胸腔积液中肿瘤浸润淋巴细胞(tumorinfiltratinglymphocytes,TIL)对瘤细胞的杀伤活性及其表型变化,并对其回输后毒副反应及患者免疫功能进行观察。方法:应用贴壁法分离恶性胸腔积液中TIL,并经rIL2诱导培养;用间接免疫荧光法测定CD3+、CD4+和CD8+比例;应用3HTdR释放法测定TIL对自体瘤细胞和801D细胞的杀伤作用;用活化的自体TIL注入患者胸腔内,观察胸腔积液变化。结果:第21天时CD3+和CD8+比例明显提高,而CD4+比例和CD4+/CD8+比值变化不大;对自体瘤细胞和801D细胞的杀伤力明显提高;40例自体回输治疗胸腔积液的患者,有效率为72.5%,且一般状况好,毒副反应小,辅助检查无异常改变,免疫功能增强。结论:肺癌TIL过继免疫治疗对恶性胸腔积液患者是一种安全、有效的免疫治疗方法。     

Characterization of the cytolytic activity of CD4+ and CD8+ tumor-infiltrating lymphocytes in human renal cell carcinoma

Previously we showed that IL2 expanded tumor-infiltrating lymphocytes (TILs) from renal cell carcinoma mediated non-major histocompatibility complex-restricted cytotoxicity. Phenotypic analysis showed that cultured TILs were composed mostly of T-lymphocytes with varying numbers of CD4+, CD8+, and CD56+ (Leu19+) populations. Here we compared the cytolytic activity of the two predominant TIL subsets, CD3+CD4+ and CD3+CD8+, to that of the CD56+ populations. Using magnetic beads coated with antibodies to either CD4 or CD8, CD3+CD4+, and CD3+CD8+ TILs were isolated in a highly enriched form (greater than 92%) and could be expanded for over 40 days in vitro with 1000 units/ml IL2. In a 4-h 51Cr release assay the CD4+ and CD8+ TILs showed minimal lytic activity, whereas unseparated cells exhibited significant levels of non-major histocompatibility complex-restricted cytotoxicity. The lytic activity seen in the 4-h assay with unseparated TILs appeared to be related to the presence of CD56+ populations. With one exception none of the purified CD4+ or CD8+ TILs expressed any significant levels of CD56, while the unseparated TILs contained varying numbers of CD3+CD56+ and CD3-CD56+ populations. Cell-sorting experiments verified that the CD56+ populations were responsible for most of the lytic activity in 4 h even though CD3+CD56- cells represented the predominant cell type. Although CD3+CD56- TILs were minimally lytic in 4 h, we show here that both CD3+CD4+ and CD3+CD8+ subsets displayed substantial cytotoxicity in long-term assays. In the 18-h 51Cr release assay 5 of 6 CD4+ and 2 of 3 CD8+ TILs were lytic for the autologous tumor. In two cases, restimulation with the autologous tumor induced augmented cytolytic activity of TIL subsets and in one case induced lytic activity in 4 h. The cytotoxic activity of TIL subsets was further examined using a 72-h assay in which TILs were cocultured with a confluent layer of tumor cells. The degree of cytotoxicity was quantitated by measuring the amount of crystal violet dye that was incorporated by tumor cells which remained after the incubation period. CD4+ and CD8+ TILs typically caused greater than a 50% reduction of tumor cells in 3 days and the level of reduction was increased when IL2 was added to the cultures. All the CD4+ and CD8+ subset preparations were cytotoxic in the 3-day assay even though some were not lytic for certain targets in the 18-h 51Cr release assay.(ABSTRACT TRUNCATED AT 400 WORDS)     

TIL from renal-cell carcinoma: restimulation with tumor influences proliferation and cytolytic activity

TIL were cultured from human renal-cell carcinoma (RCC) in 1,000 U/ml rIL2 and restimulated with autologous tumor in efforts to establish which conditions would best expand the number of lymphocytes cytotoxic for autologous tumor. Greater cell yields resulted from multiple restimulations of TIL with autologous tumor. In most instances, these TIL lysed autologous tumor better than TIL grown in rIL2 alone. Enhanced proliferation was seen also after restimulation of TIL with allogeneic RCC as well as with tumor cells of non-renal origin. Although in some instances lysis of autologous tumor appeared to be specific, restimulation with autologous tumor did not consistently result in the generation of specific cytolytic T cells. Attempts to culture more specific cytolytic T cells by using 50 U/ml rIL2 were successful in expanding TIL with enhanced lytic activity; however, this activity was not specific for autologous tumor. The phenotype of the tumor-restimulated TIL generally did not change. In most of the TIL cultures, CD3+CD4+ cells were predominant with low numbers of CD3+Leu19+ cells and minimal numbers of CD3-Leu19+ cells. Thus, the cytotoxic response to tumor was mediated by T cells and not NK cells. Overall, our data indicate that restimulation of TIL with autologous tumor may be beneficial for growing larger numbers of cells which have increased lytic activity and for prolonging the presence of lytic activity among the expanded TIL.     

Production of stable cytolytic T-cell clones directed against autologous human melanoma

We have attempted to optimize the production of stable human cytolytic T lymphocyte clones directed against autologous melanoma cell lines. MLTC were restimulated every week with irradiated melanoma cells in medium containing human serum and IL-2. After 21 to 35 days, in 5 out of 6 patients, these cultures expressed a preferential cytolytic activity against the autologous melanoma cells, as compared to autologous EBV-B cells or NK target K562. Limiting dilution of MLTC responder cells was performed at times varying from days 7 to 28, in medium containing IL-2 and allogeneic EBV-B cells as feeders. Approximately 1% of these responder cells gave rise to CTL clones that lysed the autologous melanoma cells, but did not lyse K562 or autologous B cells. It was possible to maintain in culture for several months a large number of CTL clones that retained this specificity with high activity, and multiplied more than 5-fold every week. Some of these CTL clones were dependent on the presence of the autologous melanoma cells for their growth. With one melanoma, the use of autologous CTL clones made it possible to identify 3 different antigens on the tumor cells.     

Isolation and characterization of tumor-infiltrating lymphocytes from cervical carcinoma

The evidence that virus-induced tumors generally elicit T-cell responses prompts the notion that HPV-related cervical carcinoma would be amenable to treatment by T-cell-mediated adoptive therapy. Therefore, we cultured and cloned tumorinfiltrating lymphocytes (TIL) from a patient with cervical carcinoma and studied the in vitro characteristics of these TIL by using the established autologous tumor-cell line. After stimulation of bulk TIL cultures with 1,000 Units/ml recombinant interleukin 2 (rIL-2), followed by limiting dilution, T-cell clones were generated in the presence of 20 U/ml rIL-2 and irradiated autologous tumor cells, PBLs and EBV-transformed B-cell lines. Phenotypically, all clones were CD3/CD8-positive with a heterogeneous CD56 expression. All expressed preferential cytolytic activity against autologous tumor cells, did not lyse autologous lymphoblasts, and were cytotoxic against the NK-sensitive cell line K562. A minor lytic capacity was detectable on allogeneic cervical tumor-cell lines or tumor-cell lines of other histologic types. Cytotoxicity against the autologous tumor could be inhibited by anti-CD3, anti-CD8 and anti-ICAMI but not by anti-HLA class-1 (W6/32, B9.12.I), anti-allele-specific HLA determinants and anti-LFA-3 antibodies. We demonstrate a highly specific autologous lytic activity of cervical carcinoma TIL, in which a CD3-associated surface antigen recognition is involved. These results may prove useful in further studies on adoptive immunotherapy of cervical cancer patients. © 1994 Wiley-Liss, Inc.     

Effects of HC antibody in autologous tumor-specific cytotoxicity by human melanoma tumor-infiltrating lymphocytes

Heteroconjugate (HC) antibody has a potential use in cancer biotherapy because of its ability to mimic antigenic specificity and induce cytotoxicity in the activated lymphocytes against various tumor cells. This study investigated the effects of HC antibody (anti-CD3 MAb x anti-p97 melanoma cell MAb) in autologous tumor-specific cytotoxicity by interleukin-2 (IL-2)-activated melanoma tumor-infiltrating lymphocytes (TILs). HC antibody significantly augmented p97pos uncultured autologous tumor cell lysis mediated by effector TILs or cytotoxic T lymphocyte (CTL) clones derived from TIL. It did not significantly increase p97mix autologous tumor-cell lysis and slightly inhibited the lysis only at higher E:T ratios and higher concentrations (greater than or equal to 100 ng/ml). It inhibited p97neg autologous tumor-cell lysis. HC antibody respectively induced potent lysis of p97pos or modest lysis of p97mix tumor cells by allogeneic effector TILs as well as PBMC. In contrast, parental anti-CD3 MAb primarily suppressed the autologous tumor-specific cytotoxicity, and did not induce lysis of uncultured melanoma cells, regardless of differences in expression of p97 antigens on tumor cells. Although parental anti-p97 MAb did not augment or suppress the autologous tumor-specific cytotoxicity, it completely abrogated HC antibody-mediated augmentation of p97pos autologous tumor cell lysis by effector TILs. Anti-class-I MAb, but not anti-DR MAb, suppressed the autologous tumor-specific cytotoxicity, but failed to block HC antibody-mediated augmentation of p97pos autologous tumor-cell lysis. These results suggest that the levels of p97 antigen expression largely influenced HC antibody-mediated modulation of TIL cytotoxicity against uncultured autologous tumor cells.     

Clinical results and characterization of tumor-infiltrating lymphocytes with or without recombinant interleukin 2 in human metastatic renal cell carcinoma

A Phase I trial of tumor-infiltrating lymphocytes (TIL) expanded in vitro and administered on Days 1 and 8, with or without continuous infusion recombinant interleukin 2 (rIL-2) in 25 patients with metastatic renal cell carcinoma, was conducted. Eighteen of the 25 eligible patients were treated with TIL and escalating doses of rIL-2 (0.0, 3.0, 4.5 x 10(6) units/m2) on Days 1 to 5 and 8 to 12. Dose-limiting toxicity was pulmonary, and the maximum tolerated dose of rIL-2 was 3.0 x 10(6) units/m2. No clinical responses were observed. Immunological monitoring of peripheral blood lymphocytes demonstrated significant increases in CD3+ and CD56+ cells, including the activated T-cell subsets. Phenotypic analysis of cultured TILs demonstrated significant heterogeneity and the presence of CD3+CD4+ and CD3+CD8+ T-cells, with CD3-CD56+ and CD3+CD56+ populations also present. The majority of cultured TILs expressed HLA-DR and CD45RO, with a variable number expressing CD25. The rIL-2-expanded TILs possessed cytotoxicity against allogeneic and autologous tumor, with cytolytic activity against only autologous tumor seen in one patient. Results demonstrate that in vitro expansion of TILs is possible, but further studies are needed to define the biology of TILs in renal cancer and to isolate and expand tumor-specific T-cells.     

Cellular and molecular analysis of tumor-infiltrating T-lymphocytes from human breast-cancer at clonal level

51 T cell lines/clones were established from tumor-infiltrating lymphocytes of nine breast tumors by limiting dilution. All the lines/clones were exclusively CD3+ and expressed either CD4 (57%) or CD8 (26%) phenotype. In addition, 17% of the lines/clones displayed a dual expression of CD4+CD8+ antigens. No CD3-CD16+ NK clones were obtained. A vast majority of the T cell lines and clones (84%) exhibited cytolytic activity in a lectin-dependent assay which allows the detection of cytolytic T cells of any antigen specificity. 17% of the lines/clones lysed two allogeneic breast tumor cell lines, MCF-7 and HBL-100. 11% of the cells showed NK-like cytolysis by lysing an NK-sensitive cell line K562. Of the 17 lines tested against autologous tumor cells, only two exhibited cytolytic activity via T cell receptor and CD3 molecule in an MHC-restricted manner. Southern blot analysis of T cell receptor of 39 lines/clones revealed a limited heterogeneity of TCR-B chain gene rearrangements, which suggests oligoclonal expansion of T cells infiltrating into the tumor.     

粒─-巨细胞集落刺激因子对人胃腺癌TIL增殖及体外杀瘤活性的影响

本研究观察粒-巨细胞集落刺激因子（GM－CSF）对胃腺癌TIL增殖及体外杀瘤活性的影响。结果发现，单独GM－CSF刺激不诱导TIL增殖扩增，而在400U／ml的IL－2培养条件下，各剂量GM－CSF均可促进TIL增殖，其中，100μg／mlGM－CSF协同IL－2促增殖效应显著。体外杀瘤活性试验（MTT法）证实100ug／mlGM－CSF协同IL－2诱导TIL细胞增强了其杀瘤活性，无论是对同种异体细胞，亦或是自体肿瘤细胞。本文探讨了GM－CSF促TIL增殖及增强杀瘤活性的可能机制。     

Characterization of autologous tumor-specific T-helper 2 cells in tumor-infiltrating lymphocytes from a patient with metastatic melanoma

Human autologous tumor-specific T-helper 2 (Th2) cells were investigated in melanoma tumor-infiltrating lymphocytes (TILs). Both a CD4⁺ T-cell line and its 5 potential T-cell clones established from TILs of a patient with metastatic melanoma produced significant levels of IL-4, IL-6, IL-10 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in response to autologous, but not any of 12 allogeneic, melanoma cell lines. They also produced IL-3 and IL-8 but not IL-2, IFN-γ, TNF-α or TNF-β in response to autologous tumor cells. Furthermore, they showed autologous melanoma-specific cytotoxicity only in an 18-hr ⁵¹Cr-release assay. Specific IL-4, IL-6 or IL-10 production by the CD4⁺ M73 T-cell line and its clone was inhibited by anti-class 11 DR (but not anti-class 1) MAb, whereas their specific cytotoxicity was inhibited by anti-class 1 (but not anti-class 11) MAb. Anti-CD3 and -CD4 MAb (but not anti-CD8) abrogated both IL-4, IL6 and IL-10 production and cytotoxicity, while anti-IL-4 antibody did not inhibit cytotoxicity. CD4⁺ potential T-cell clones, but not CD8⁺ clones, that were established from freshly isolated TILs without in vitro sensitization by autologous tumor cells also produced IL-4, IL-6 and IL-10 but not IFN-γ or tumor necrosis factor (TNF)α in an autologous tumor-specific fashion. These Th2 cells were neither reactive to EBV-B cells nor suppressive against CD8⁺ T-cell clones. PMA and PHA stimulated these potential T-cell clones, regardless of their specific lymphokine production, to produce IL-3, IL-4, IL-6, IL-8, IL-10, GM-CSF, TNFα and IFN-γ. Our results demonstrate the presence of autologous tumor-specific Th2 cells at the melanoma sites.     

Clonal analysis of tumor-infiltrating lymphocytes from human primary and metastatic liver tumors

Phenotypic and functional characteristics of tumor-infiltrating lymphocytes (TIL) obtained from human primary and metastatic liver tumors were studied. Lymphocytes isolated from 18 tumors and autologous (A) peripheral blood (6 cases) were phenotyped by 2-color flow cytometry and cloned in a limiting dilution system, which allows virtually all normal T lymphocytes to proliferate; 70-80% of fresh TIL were T cells (i.e., CD3+), and the ratio of CD4+/CD8+ cells was 1.2 in both primary and metastatic liver tumors. TIL contained significantly more CD56+ (NKHI+) cells, half of which were CD3+CD56+, CD3+CD25+ cells and CD3+HLA-DR+ cells, than A-PBL. The frequencies of proliferating T-cell precursors (PTL-p) and cytolytic T-lymphocyte precursors (CTL-p) reactive with K562, allogeneic tumor cells and autologous tumor cells, were determined. Mean PTL-p frequencies for TIL from hepatocellular carcinomas, cholangiocarcinomas and metastatic liver tumors were 0.52 (0.22-0.83), 0.10 (0.05-0.16) and 0.16 (0.01-0.30), respectively. The frequency of CTL-p with natural-killer-like activity was lower in TIL than in A-PBL. The frequency of CTL-p for autologous tumor cells in fresh TIL isolated from primary liver tumors was 0.02-0.13 and 12/81 clones were reactive against autologous tumor. In contrast, only 1/66 TIL clones obtained from colon carcinomas metastatic to liver showed autotumor reactivity. No clones reactive with autologous tumor were obtained from peripheral blood of patients with liver cancer. These data indicate that substantial differences in anti-tumor functions of TIL between primary and metastatic liver tumors exist, which can be detected at a clonal level.     

Proliferative and cytolytic potentials of purified human tumor-infiltrating T lymphocytes. Impaired response to mitogen-driven stimulation despite T-cell receptor expression

Using limiting dilution analysis (LDA) we have previously shown that in most instances, the frequency (F) of proliferative T lymphocyte precursors (PTL-P) was strikingly reduced in tumor-infiltrating lymphocytes (TIL). In this study involving 19 cases, we show that the impaired clonogenic potential of CD2+ TILs is primarily caused by an intrinsic defect rather than to suppressor T cells or to a direct effect of the tumor cells usually present in the culture system. This was demonstrated by experiments in which the F of PTL-Ps was quantitated both in highly purified CD2+ TILs (using a cell-sorter) and in non-purified TIL suspensions (still containing tumor cells), which originated from the same biopsy specimen. The F of PTL-Ps was virtually identical in either sorted or nonsorted suspensions and the data from LDA were always consistent with the single-hit Poisson model, indicating that no suppressor cells interfered with growth of CD2+ TIL. Stimulation of sorted CD2+ TIL in low-density cultures by either phytohemagglutinin or anti-CD3-monoclonal antibody (MAb) indicated that the antigen-dependent activation pathway was impaired, although structurally intact T-cell receptor (TCR) complexes were apparently expressed, as assessed by immunofluorescence. The depressed proliferative response of CD2+ TIL could not be reversed in vitro when phorbol-esters were used in combination with ionomycin, which bypass the TCR. Nevertheless, 180 clones obtained from 8 cases were analyzed for their cytolytic activity. The majority mediated specific lytic activity (against unknown antigens), as assessed by lectin-dependent cell cytotoxicity, whereas only 6% of them manifested lymphokine-activated killing on appropriate targets.     

Ex vivo expansion of tumor-infiltrating lymphocytes from nasopharyngeal carcinoma patients for adoptive immunotherapy

Establishing Epstein-Barr virus (EBV)-specific cytolytic T lymphocytes (EBV-CTLs) from peripheral blood mononuclear cells (PBMCs) for adoptive immunotherapy has been reported in EBV-associated malignancies including Hodgkin's lymphoma and nasopharyngeal carcinoma (NPC). In the current study,we performed ex vivo expansion of tumor-infiltrating lymphocytes (TILs) obtained from NPC biopsy specimens with a rapid expansion protocol using anti-CD3 monoclonal antibody (OKT3), recombinant human interleukin (IL)-2, and irradiated PBMCs from healthy donors to initiate the growth of TILs. Young TIL cultures comprised of more than 90% of CD3+T cells, a variable percentage of CD3+CD8+and CD3+CD4+T cells, and less than 10% of CD3-CD16+natural killer cells, a similar phenotype of EBV-CTL cultures from PBMCs. Interestingly, TIL cultures secreted high levels of the Th1 cytokines, interferon gamma (IFNγ) and tumor necrosis factor-alpha (TNF-α), and low levels of the Th2 cytokines, IL-4 and IL-10. Moreover, young TILs could recognize autologous EBV-transformed B lymphoblast cell lines, but not autologous EBV-negative blast cells or allogeneic EBV-negative tumor cells. Taken together, these data suggest that ex vivo expansion of TILs from NPC biopsy tissue is an appealing alternative method to establish T cell-based immunotherapy for NPC.     

Adoptive T-cell therapy using autologous tumor-infiltrating lymphocytes for metastatic melanoma: current status and future outlook

Immunotherapy using autologous T cells has emerged to be a powerful treatment option for patients with metastatic melanoma. These include the adoptive transfer of autologous tumor-infiltrating lymphocytes (TILs), T cells transduced with high-affinity T cell receptors against major tumor antigens, and T cells transduced with chimeric antigen receptors composed of hybrid immunoglobulin light chains with endodomains of T-cell signaling molecules. Among these and other options for T-cell therapy, TILs together with high-dose interleukin 2 have had the longest clinical history with multiple clinical trials in centers across the world consistently demonstrating durable clinical response rates near 50% or more. A distinct advantage of TIL therapy making it still the T-cell therapy of choice is the broad nature of the T-cell recognition against both defined and undefined tumors antigens against all possible major histocompatibility complex, rather than the single specificity and limited major histocompatibility complex coverage of the newer T cell receptors and chimeric antigen receptor transduction technologies. In the past decade, significant inroads have been made in defining the phenotypes of T cells in TIL-mediating tumor regression. CD8+ T cells are emerging to be critical, although the exact subset of CD8+ T cells exhibiting the highest clinical activity in terms of memory and effector markers is still controversial. We present a model in which both effector-memory and more differentiated effector T cells ultimately may need to cooperate to mediate long-term tumor control in responding patients. Although TIL therapy has shown great potential to treat metastatic melanoma, a number of issues have emerged that need to be addressed to bring it more into the mainstream of melanoma care. First, we have a reached the point where a pivotal phase II or phase III trial is needed in an attempt to gain regulatory approval of TILs as standard of care. Second, improvements in how we expand TILs for therapy are needed that minimize the time the T cells are in culture and improve the memory and effector characteristics of the T cells for longer persistence and enhanced anti-tumor activity in vivo. Third, there is a critical need to identify surrogate and predictive biomarkers to better select suitable patients for TIL therapy to improve response rate and duration. Overall, the outlook for TIL therapy for melanoma is very bright. We predict that TILs will indeed emerge to become an approved treatment in the upcoming years through pivotal clinical trials. Moreover, new approaches combining TILs with targeted signaling pathway drugs, such as mutant B-RAF inhibitors, and synergistic immunomodulatory interventions enhancing T-cell costimulation and preventing negative regulation should further increase therapeutic efficacy and durable complete response rates.     

Clonal analysis of lymphocytes from tumor, peripheral blood, and nontumorous kidney in primary renal cell carcinoma

The immunological properties of lymphocytes from tumor, peripheral blood (PBL), and nontumorous kidney from 16 patients with renal cell carcinoma were characterized at the clonal level with respect to their clonogenic efficiency, phenotypic expression, and cytotoxicity against autologous and allogenic tumor cells. The objectives were to delineate: (a) the quantitative differences in the immunological properties of tumor-infiltrating lymphocytes (TIL) from patient to patient; and (b) the qualitative differences in immunological properties between TIL and lymphocytes from peripheral blood or nontumorous kidney from a single patient. A total of 926 clones were characterized for phenotype expression, and 465 clones were characterized for cytotoxicity. The clonogenic efficiency of TIL varied with individuals: high in one patient; relatively high to moderate in seven patients; low in seven patients, and extremely low in the remaining one patient. The levels of autologous tumor cell lysis by TIL clones also varied with individuals. More than one-third of the TIL clones established in 4 of 13 patients displayed significant (greater than or equal to 10%) lysis against autologous tumor cells, and in each of the four patients the average percentage of lysis in the total TIL clones was higher than 10%. In two patients, 5 of 26 or 3 of 13 TIL clones were cytotoxic, but averages of percentage of lysis in the total clones were less than 10%. One 1 or 2 TIL clones of 10-27 total clones were cytotoxic in each of 4 patients, while no cytotoxic TIL clones were found in the remaining 3 patients. Clonogenic efficiency did not correlate with the level of cytotoxicity, and TIL from no tumors displayed both high proliferation and high cytotoxicity at the clonal level. In a majority of patients (12 of 13), most cytotoxic TIL clones against autologous tumor cells also lysed allogenic tumor cells. In contrast, TIL clones lysed only autologous tumor cells in the remaining one patient (patient 2). The clonogenic efficiency of TIL was lower than that of PBL in 6 of 12 patients, while the opposite was true in the remaining 6 patients. The level of cytotoxicity in the PBL clones of these 12 patients primarily correlated with that of the TIL clones. With one exception (patient 2), most cytotoxic PBL clones against autologous tumor cells also lysed allogenic targets in a majority of patients. CD4+CD8-T-cell clones (70-85%) predominated in all patients regardless of the different lymphocyte sources.(ABSTRACT TRUNCATED AT 400 WORDS)     

Interleukin-12 Augments the Generation of Autologous Tumor-reactive CD8+ Cytotoxic T Lymphocytes from Tumor-infiltrating Lymphocytes

Human tumor-infiltrating lymphocytes (TIL) were obtained from breast cancer, renal cancer or neuroblastoma to investigate the generation of autologous tumor-reactive CD8⁺ cytotoxic T lymphocytes (CTL). When TIL were cultured with interleukin (IL)-2 (100 U/ml), the growth of TIL peaked around 8–10 days after the initiation of culture. In contrast, the proliferation of TIL cultured with IL-2 plus IL-12 peaked around 4–5 days after culture and tumor cells rapidly disappeared from the culture. To determine the generation of autologous tumor-reactive CD8⁺ CTL, TIL-derived CD8⁺ T cells were separated by FACStar. Both IL-2-activated and IL-2 plus IL-12-activated TIL-CD8⁺ T cells showed the same level of lymphokine-activated killer activity against a variety of tumor cells. However, TIL-CD8⁺ T cells activated with IL-2 plus IL-12 revealed greatly augmented cytotoxicity against autologous tumor cells compared with that induced by IL-2 alone. The autologous tumor cell-killing activity of TIL-CD8⁺ CTL was significantly inhibited by the addition of F(ab)₂ anti-CD3 monoclonal antibody, indicating that these CTL recognize autologous tumor antigen through T cell receptor. These results imply that IL-12 is a novel cytokine which facilitates the generation of autologous tumor-reactive CD8⁺ CTL from TIL.