Tumor-infiltrating lymphocytes from nonrenal urological malignancies

The tumor microenvironment and immune targeting therapy in pediatric renal tumors

This review highlights the role of several immunomodulating elements contributing to the tumor microenvironment of various pediatric renal tumors including Wilms tumor. The roles of innate and adaptive immune cells in renal tumors are summarized as well as immunomodulatory cytokines and other proteins. The expression and the predictive role of checkpoint modulators like PD-L1 and immunomodulating proteins like glypican-3, B7-H3, COX-2 are highlighted with a translational view toward potential therapeutic innovations. We further discuss the current state of preclinical models in advancing this field of study. Finally, examples of clinical trials of immunomodulating strategies such as monoclonal antibodies and chimeric antigen receptor T (CAR-T) cells for relapsed/refractory/progressive pediatric renal tumors are described.

Why do tumor-infiltrating lymphocytes have variable efficacy in the treatment of solid tumors?

Lymphocytes in tumor tissue are called tumor-infiltrating lymphocytes (TILs), and they play a key role in the control and treatment of tumor diseases. Since the discovery in 1987 that cultured TILs can kill tumor cells more than 100 times more effectively than T-cells cultured from peripheral blood in melanoma, it has been confirmed that cultured TILs can successfully cure clinical patients with melanoma. Since 1989, after we investigated TIL isolation performance from solid tumors, we modified some procedures to increase efficacy, and thus successfully established new TIL isolation and culture methods in 1994. Moreover, our laboratory and clinicians using our cultured TILs have published more than 30 papers. To improve the efficacy of TILs, we have been carrying out studies of TIL efficacy to treat solid tumor diseases for approximately 30 years. The three main questions of TIL study have been "How do TILs remain silent in solid tumor tissue?", "How do TILs attack homologous and heterologous antigens from tumor cells of solid tumors?", and "How do TILs infiltrate solid tumor tissue from a distance into tumor sites to kill tumor cells?". Research on these three issues has increasingly answered these questions. In this review I summarize the main issues surrounding TILs in treating solid tumors. This review aims to study the killing function of TILs from solid tumor tissues, thereby ultimately introducing the optimal strategy for patients suffering from solid tumors through personalized immunotherapy in the near future.

Expansion of Lymphocytes from Prostatic Adenocarcinoma and Adjacent Nonmalignant Tissue

Background

The evaluation of tumour-infiltrating lymphocytes (TILs) in solid malignancies has yielded insights into immune regulation within the tumour microenvironment and has also led to the development and optimisation of adoptive T cell therapies.

Objectives

This study examined the in vitro expansion of TILs from prostate adenocarcinoma, as a preliminary step to evaluate the potential of TILs for adoptive T cell therapy. Design, Setting, and Participants. Malignant and adjacent nonmalignant tissues were obtained from fifteen men undergoing radical prostatectomy. Interventions. There were no study interventions. Outcome Measurements and Statistical Analysis. Expanded cells were analysed by flow cytometry, and the data was assessed for associations between cell subpopulations and expansion rate.

Results

Tumour-infiltrating lymphocytes could be expanded to numbers that would be needed to generate a therapeutic infusion product from nine of 15 malignant specimens (60%). The CD4⁺ T cells predominated over CD8⁺ T cells (median 56.8% CD4⁺, 30.0% CD8⁺), and furthermore, faster TIL expansion was associated with a higher proportion of CD4⁺ T cells (median 69.8% in faster-growing cultures; 36.8% in slower-growing cultures). A higher proportion of CD3⁻CD56⁺ cells versus CD3⁺ cells was associated with slower TIL expansion in cultures from malignant specimens (median 13.3% in slower-growing cultures versus 2.05% in faster-growing cultures), but not from nonmalignant specimens.

Conclusions

The expansion of TILs for potential therapeutic use is feasible. Our findings also indicate that further examination of TILs from prostate adenocarcinomas may yield insights into mechanisms of regulation of T cells within the tumour microenvironment. Further research is required to evaluate their therapeutic potential.

Immunotherapy in Advanced Prostate Cancer: Current Knowledge and Future Directions

The advent of immunotherapy has revolutionized cancer treatment. Unfortunately, this has not been the case for metastatic castration-resistant prostate cancer (mCRPC), likely due to the heterogeneous and immune-suppressive microenvironment present in prostate cancer. The identification of molecular biomarkers that could predict response to immunotherapy represents one of the current challenges in this clinical scenario. The management of advanced castration-resistant prostate cancer is rapidly evolving and immunotherapy treatments, mostly consisting of immune checkpoint inhibitors combinations, BiTE® (bispecific T-cell engager) immune therapies, and chimeric antigen receptors (CAR) are in development with promising results. This review analyses the current evidence of immunotherapy treatments for mCRPC, evaluating past failures and promising approaches and discussing the directions for future research.

Systematic review of the immunological landscape of Wilms tumors

Results of immunotherapy in childhood solid cancer have been so far, with the exception of neuroblastoma, quite disappointing. Lack of knowledge of the immune contexture of these tumors may have contributed to the failure of immunotherapies so far. Here, we systematically reviewed the literature regarding the immunology of Wilms tumor (WT), one of the most frequent pediatric solid tumors of the abdomen. In Wilms tumor patients the high cure rate of >90%, achieved by the combination of surgery and radio-chemotherapy, is at the expense of a high early and late toxicity. Moreover, treatment-resistant entities, such as diffuse anaplastic tumors or recurrent disease, still pose unsolved clinical problems. Successful immunotherapy could represent a novel and possibly less-toxic treatment option. Employing the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) method of literature search, we analyzed the current knowledge of the immunological landscape of Wilms tumors in terms of tumor microenvironment, prognostic implications of single biomarkers, and immunotherapy response.

Preoperative systemic inflammatory markers are prognostic indicators in recurrent adrenocortical carcinoma

BACKGROUND

Recurrent adrenocortical carcinoma (ACC) has a poor prognosis with minimal clinical and biochemical factors to guide management. The aim of this study was to evaluate the prognostic significance of systemic inflammatory response in patients with recurrent ACC.

METHODS

Patients who underwent resection for recurrent ACC were retrospectively analyzed. Preoperative neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio (LMR), and mean platelet volume were calculated.

RESULTS

Twenty-five patients (age at operation 52.2 ± 9.5 years) were identified. We observed a statistically significant shorter disease-specific survival (DSS) in patients with LMR less than 4 (41 ± 7.4 months vs 71 ± 12.3, P = .023) and male sex (26.6 ± 4.2 months vs 57.6 ± 9.5 months, P = .079), while time-to-recurrence (TTR) less than 12 months (40 ± 7.7 months vs 70.3 ± 13.1 months, P = .059) had a trend on univariate analysis for worse DSS. On multivariable analysis, LMR < 4 (hazard ratio [HR] 4.18; 95% confidence interval [CI]: 1.18-14.76; P = .027) and TTR less than 12 months (HR 2.77 95% CI: 1-7.62; P = .049) were found to be significantly associated with worse DSS.

CONCLUSION

Preoperative LMR greater than 4 and TTR greater than 12 months are associated with longer DSS. Patients with LMR greater than 4 and TTR greater than 12 months may benefit from a more aggressive therapeutic approach and may require less frequent surveillance.

Identification of Neoantigen-Reactive Tumor-Infiltrating Lymphocytes in Primary Bladder Cancer

Immune checkpoint inhibitors are effective in treating a variety of malignancies, including metastatic bladder cancer. A generally accepted hypothesis suggests that immune checkpoint inhibitors induce tumor regressions by reactivating a population of endogenous tumor-infiltrating lymphocytes (TILs) that recognize cancer neoantigens. Although previous studies have identified neoantigen-reactive TILs from several types of cancer, no study to date has shown whether neoantigen-reactive TILs can be found in bladder tumors. To address this, we generated TIL cultures from patients with primary bladder cancer and tested their ability to recognize tumor-specific mutations. We found that CD4+ TILs from one patient recognized mutated C-terminal binding protein 1 in an MHC class II-restricted manner. This finding suggests that neoantigen-reactive TILs reside in bladder cancer, which may help explain the effectiveness of immune checkpoint blockade in this disease and also provides a rationale for the future use of adoptive T cell therapy targeting neoantigens in bladder cancer.

Immune mechanisms and possible immune therapy in testicular germ cell tumours

BACKGROUND

Testicular germ cell tumours (GCTs) are the only universally curable solid malignancy. The long-term cure rate of >95% is attributed to the extraordinary sensitivity to cisplatin-based treatment but a proportion of patients die due to a progression of the chemotherapy-refractory disease. While treatment of a variety of solid cancers was significantly improved with recent immune therapies, the immunology and immunotherapy remained underinvestigated in GCTs.

OBJECTIVES

In this narrative review, we summarize evidence about immune-related mechanisms and possible immune therapies in GCTs and provide insights and implications for future research and clinical practice.

MATERIALS AND METHODS

We performed a comprehensive search of PubMed/MEDLINE to identify original and review articles reporting on immune mechanisms and immunotherapy in GCTs. Review articles were further searched for additional original articles.

RESULTS

Clear link of immune surveillance and the presence of GCT have been identified with several novel immune-related prognostic biomarkers published recently. Several case reports, case series, and preliminary results from phase I-II studies are emerging to report on the efficacy of immune checkpoint inhibitors.

DISCUSSION

Newly discovered immune biomarkers provide an evidence supporting the role of immune environment in the GCT biology. While these discoveries provide only an initial insight into the immunobiology, strong correlation with prognosis is evident. This provided a premise to investigate the treatment efficacy of novel immunotherapy. Some efficacy of these treatments has been reported in clinical setting; however, the results of published studies with immune checkpoint inhibitor monotherapy seem to be disappointing.

CONCLUSION

Immune-related mechanisms and efficacy of immune checkpoint blockade in GCTs should be further investigated in preclinical and clinical studies.

Expansion of tumor infiltrating lymphocytes (TIL) from bladder cancer

Advanced bladder cancer patients have limited therapeutic options resulting in a median overall survival (OS) between 12 and 15 months. Adoptive cell therapy (ACT) using tumor infiltrating lymphocytes (TIL) has been used successfully in treating patients with metastatic melanoma, resulting in a median OS of 52 months. In this study, we investigated the feasibility of expanding TIL from the tumors of bladder cancer patients. Primary bladder tumors and lymph node (LN) metastases were collected. Tumor specimens were minced into fragments, placed in individual wells of a 24-well plate, and propagated in high dose IL-2 for four weeks. Expanded TIL were phenotyped by flow cytometry and anti-tumor reactivity was assessed after co-culture with autologous tumor digest and IFN-gamma ELISA. Of the 28 transitional cell bladder or LN tumors collected, 14/20 (70%) primary tumors and all of the LN metastases demonstrated TIL expansion. Expanded TIL were predominantly CD3⁺ (median 63%, range 10-87%) with a median of 30% CD8 + T cells (range 5-70%). TIL secreted IFN-gamma in response to autologous tumor. Addition of agonisitic 4-1BB antibody improved TIL expansion from primary bladder tumors regardless of pre-treatment with chemotherapy. This study establishes the practical first step towards an autologous TIL therapy process for therapeutic testing in patients with bladder cancer.

Long-term in vitro culture of Plasmodium vivax isolates from Madagascar maintained in Saimiri boliviensis blood

Background

Plasmodium vivax is the most prevalent human malaria parasite and is likely to increase proportionally as malaria control efforts more rapidly impact the prevalence of Plasmodium falciparum. Despite the prominence of P. vivax as a major human pathogen, vivax malaria qualifies as a neglected and under-studied tropical disease. Significant challenges bringing P. vivax into the laboratory, particularly the capacity for long-term propagation of well-characterized strains, have limited the study of this parasite’s red blood cell (RBC) invasion mechanism, blood-stage development, gene expression, and genetic manipulation.

Methods and results

Patient isolates of P. vivax have been collected and cryopreserved in the rural community of Ampasimpotsy, located in the Tsiroanomandidy Health District of Madagascar. Periodic, monthly overland transport of these cryopreserved isolates to the country’s National Malaria Control Programme laboratory in Antananarivo preceded onward sample transfer to laboratories at Case Western Reserve University, USA. There, the P. vivax isolates have been cultured through propagation in the RBCs of Saimiri boliviensis. For the four patient isolates studied to-date, the median time interval between sample collection and in vitro culture has been 454 days (range 166–961 days). The median time in culture, continually documented by light microscopy, has been 159 days; isolate AMP2014.01 was continuously propagated for 233 days. Further studies show that the P. vivax parasites propagated in Saimiri RBCs retain their ability to invade human RBCs, and can be cryopreserved, thawed and successfully returned to productive in vitro culture.

Conclusions/significance

Long-term culture of P. vivax is possible in the RBCs of Saimiri boliviensis. These studies provide an alternative to propagation of P. vivax in live animals that are becoming more restricted. In vitro culture of P. vivax in Saimiri RBCs provides an opening to stabilize patient isolates, which would serve as precious resources to apply new strategies for investigating the molecular and cellular biology of this important malaria parasite.

Electronic supplementary material

The online version of this article (10.1186/s12936-017-2090-7) contains supplementary material, which is available to authorized users.

The immune infiltrate in prostate, bladder and testicular tumors: An old friend for new challenges

In genito-urinary tumors immunotherapy has been administered for a long time: Calmette-Guèrin Bacillus as adjuvant treatment in high risk patients with non muscle invasive urothelial bladder cancer and interleukin-2 and interferon-α in metastatic kidney cancer. The vaccine Sipuleucel-T has been approved by United States Food and Drug Administration for the treatment of castration resistant prostate cancer patients with asymptomatic or minimally symptomatic disease, given the 22% reduction of mortality risk in this group. Recently immunotherapeutic agents targeting inhibitory immune checkpoint molecules lead to improved outcomes and lasting anti-tumor effects in a variety of hematological and solid malignancies, including urogenital tumors. The benefit from these treatments has been observed only in a proportion of subjects, raising a need in optimizing patients' selection for immune checkpoint blockade. The composition and activity of a pre-existing immune infiltrate may aid in identifying ideal candidates to immunotherapy, with possible implications for the clinical management of neoplastic diseases from earlier to later stages.

Exploiting the curative potential of adoptive T-cell therapy for cancer

Adoptive T-cell therapy (ACT) is a potent and flexible cancer treatment modality that can induce complete, durable regression of certain human malignancies. Long-term follow-up of patients receiving tumor-infiltrating lymphocytes (TILs) for metastatic melanoma reveals a substantial subset that experienced complete, lasting tumor regression - and may be cured. Increasing evidence points to mutated gene products as the primary immunological targets of TILs from melanomas. Recent technological advances permit rapid identification of the neoepitopes resulting from these somatic gene mutations and of T cells with reactivity against these targets. Isolation and adoptive transfer of these T cells may improve TIL therapy for melanoma and permit its broader application to non-melanoma tumors. Extension of ACT to other malignancies may also be possible through antigen receptor gene engineering. Tumor regression has been observed following transfer of T cells engineered to express chimeric antigen receptors against CD19 in B-cell malignancies or a T-cell receptor against NY-ESO-1 in synovial cell sarcoma and melanoma. Herein, we review recent clinical trials of TILs and antigen receptor gene therapy for advanced cancers. We discuss lessons from this experience and consider how they might be applied to realize the full curative potential of ACT.

In vitro modulation of natural killer activity of human peripheral blood mononuclear cells against prostate tumor cell line

OBJECTIVE

Natural killer (NK) cells have long been known to be involved in the recognition and lysis of tumor cells but the mechanisms contributing to deficient NK activity in patients with cancer remains unclear. Manipulation of them is likely essential to the success of cancer immunotherapy protocols although optimal stimulation and maintenance of NK activity remains elusive. Here we studied the stimulatory effects of PHA and K562, on NK activity of human peripheral blood mononuclear cells (PBMCs).

MATERIALS AND METHODS

The NK activity of PBMCs against DU-145 was determined with 51Cr-release assay. The PBMCs were stimulated with PHA, either on one occasion or repetitively on three occasions (1-PHA-PBMC or 3-PHA-PBMC, respectively), and were incubated with irradiated K562 (iK562). The expression of CD56, NKG2D and MICA/B were detected on PBMCs and cell lines with flow cytometry.

RESULTS

PHA stimulation increased the proportion of CD56+ cells and upregulated NKG2D expression on 1-PHA-PBMC and 3-PHA-PBMC, but co-incubation with iK562 decreased NKG2D expression on 1-PHA-PBMC without change of NKG2D expression on the 3-PHA-PBMC. NK activity of 1-PHA-PBMC appeared to decrease with co-incubation with iK562 compared to a significant increase in activity of 3-PHA-PBMC. A similar increase in interferon-γ (IFN-γ) secretion from 3-PHA-PBMC was demonstrated compared to 1-PHA-PBMC.

DISCUSSION AND CONCLUSION

Our results demonstrated that varying the mitogen exposure to PBMCs affect the influence of iK562 on NK activity. This effect appeared to be unrelated to the subsequent expression of NKG2D or IFN-γ secretion. These results may be beneficial in the development of future cancer immunotherapy protocols.

Detection of immune responses against urinary bladder cancer in sentinel lymph nodes

OBJECTIVE

The lymphatic drainage from a tumour is received in the sentinel node where the immune system encounters tumour derived antigens. We investigated anti-tumoural lymphocyte function in sentinel nodes from patients with urinary bladder cancer.

METHODS

In 14 patients undergoing cystectomy due to bladder cancer, radioactive tracer and blue dye were used to identify the sentinel node. Cell suspensions from the tumour, sentinel- and non-sentinel nodes and peripheral blood were analyzed by flow cytometry with antibodies against lymphocyte surface antigens and against the tumour cell marker cytokeratin-20. Reactivity against autologous tumour extract and the mitogen Concanavalin A was tested in proliferation assays with 3H-Thymidine incorporation. Lymphocytes were put in long-term culture with IL-2 and autologous tumour extract.

RESULTS

Sentinel nodes were detected in 12 of the 14 patients. Antigen dependent proliferation in response to autologous tumour extract was detected in 6 patients, in 5 cases in sentinel nodes, in the remaining case in a non-sentinel node. Proliferation against Concanavalin A was vigorous in lymph nodes from all patients, whereas tumour infiltrating lymphocytes were unresponsive. Lymphocytes from sentinel nodes could be expanded in vitro.

CONCLUSION

Tumour reactive lymphocytes are present in sentinel nodes draining human bladder cancers. These cells display immunologic function upon restimulation in vitro, and provide a promising source for expansion and subsequent adoptive T cell immunotherapy.

Expansion and activation of natural killer cells from PBMC for immunotherapy of hepatocellular carcinoma

AIM: To induce efficient expansion of natural killer (NK) cells from peripheral blood mononuclear cells (PBMCs) using a culture of anchorage-dependent Wilms tumor cell lines, and to provide a reliable supply for adoptive immunotherapy of hepatocellular carcinoma.

METHODS: Culture expansion of NK cells was achieved using PBMCs cultured with Wilms tumor cells. Cytotoxicity was measured using a standard ⁵¹Cr release assay and crystal violet staining technique. The proportions of CD3+, CD4+, CD8+, CD16+, and CD56+ cells were determined by flow cytometry.

RESULTS: After PBMCs from healthy donors and hepatocellular carcinoma (HCC) were cultured with irradiated HFWT cells for 10-21 d, CD56+CD16+ cells shared more than 50% of the cell population, and more than 80% of fresh HFWT cells were killed at an effector/target ratio of 2 over 24 h. NK-enriched lymphocyte population from HCC patients killed HCC-1 and 2 cells with sensitivities comparable to fresh TKB-17RGB cells. HCC cells proliferated 196-fold with the irradiated HFWT cells at 18 d. Stimulation by HFWT cells required intimate cell-cell interaction with PBMC. However, neither the soluble factors released from HFWT cells nor the fixed HFWT cells were effective for NK expansion. The lymphocytes expanded with IL-2 killed fresh HFWT target cells more effectively than the lymphocytes expanded with the 4-cytokine cocktail (IL-l β, IL-2, IL-4 and IL-6). IL-2 was the sole cytokine required for NK expansion.

CONCLUSION: Wilms tumor is sensitive to human NK cells and is highly efficient for selective expansion of NK cells from PBMCs.

Spontaneous regression of neoplasms: new possibilities for immunotherapy

In mammalian cells, neoplastic transformation is directly associated with the expression of oncogenes, loss or simple inactivation of the function of tumour suppressor genes and the production of certain growth factors. Genes for suppression of the development of the neoplastic cellular immunophenotype, as well as inhibitory growth factors, have regulatory functions within the normal processes of cell division and differentiation. Telomerase (a ribonucleoprotein polymerase) activation is frequently detected in various neoplasms. Telomerase activation is regarded as essential for cell immortalisation and its inhibition may result in spontaneous regression of neoplasms. This phenomenon of neoplasms occurs when the malignant tissue mass partially or completely disappears without any treatment or as a result of a therapy considered inadequate to influence systemic neoplastic growth. This definition makes it clear that the term 'spontaneous regression' applies to neoplasms in which the overall malignant disease is not necessarily cured and to cases where the regression may not be complete or permanent. A number of possible mechanisms of spontaneous regression are reviewed, with the understanding that no single mechanism can completely account for this phenomenon. The application of the newest immunological, molecular biological and genetic insights for more individualised and adequate antineoplastic immunotherapy (alternative biotherapy) is also discussed.

Interleukin 2 gene therapy for prostate cancer: phase I clinical trial and basic biology

Twenty-four patients with locally advanced prostate cancer (CaP) were enrolled in a phase I clinical trial using gene-based immunotherapy. A functional DNA-lipid complex encoding the interleukin 2 (IL-2) gene (Leuvectin; Vical, San Diego, CA) was administered intraprostatically into the hypoecogenic tumor lesion, using transrectal ultrasound guidance. Two groups of patients having locally advanced tumors were enrolled to receive a treatment regimen composed of two serial intraprostatic injections of the IL-2 gene agent administered 1 week apart. The first groups of patients included radical prostatectomy candidates who subsequently underwent surgery after the completion of the treatment regimen. The second group consisted of patients who had failed a prior therapy. Prostate specimens of the treated areas were attained after treatment and compared with the transrectal biopsies performed at baseline to assess for any responses. IL-2 gene therapy was well tolerated, with no grade 3 or 4 toxic reactions occurring. The most commonly reported symptoms were mild hematuria, transient rectal bleeding, and perineal discomfort that are likely attributable to the injection itself. During the entire course of treatment, there were no significant changes in American Urologic Association (AUA) symptom scores, in hematologic disturbances, electrolyte imbalances, or hepatic functions. Evidence of systemic immune activation was observed after IL-2 gene therapy, based on an increase in the intensity of T cell infiltration seen on immunohistochemical analysis of tissue samples from the injected tumor sites, and based on increased proliferation rates of peripheral blood lymphocytes that were cocultured with patient serum collected after treatment. Furthermore, transient decreases in serum prostate-specific antigen (PSA) (responders) were seen in 16 of 24 patients (67%) on day 1. Fourteen of the patients persisted in this decrease to day 8 (58%). In eight patients the PSA level rose (nonresponders). More patients (9 to 10) in the group that failed prior therapy responded to the IL-2 gene injections (chi-square test, p = 0.04), and 6 of the 9 also had lower than baseline PSA levels at week 10 after treatment. To the best of our knowledge, this is the first clinical study of its kind aimed at exploring the role of IL-2-based gene therapy in CaP patients. This phase I trial demonstrated the safety of intraprostatic Leuvectin injection, with transient PSA-based responses seen after therapy.

Exogenous antigen targeted to FcgammaRI on myeloid cells is presented in association with MHC class I

Vaccine therapy is attractive for prostate cancer patients because the tumor is slow growing (allowing time to augment host responses) and occurs in an older population less likely to tolerate more toxic treatments. We have constructed an expression vector based on a monoclonal antibody (mAb) that targets the high affinity receptor for IgG (FcgammaRI, CD64) which is exclusively expressed on myeloid cells including dendritic cells (DC). The heavy chain of mAb H22 CH2 and CH3 domains were removed and replaced with the gene for prostate specific antigen (PSA). Using that vector, we have constructed and purified FPH22.PSA, a fusion protein that targets PSA to FcgammaRI on antigen presenting cells (APC). This fusion protein has an apparent molecular mass of 80-83 kDa, binds to FcgammaRI with high affinity and expresses PSA. We demonstrate that FPH22.PSA targeted PSA was internalized and processed by the human myeloid THP-1 cell line resulting in presentation of MHC class I-associated PSA peptides and lysis of THP-1 by PSA-specific human CTL. Moreover, pretreatment of THP-1 cells with antibodies to block either FcgammaRI or MHC class I, blocked lysis indicating that targeting to FcgammaRI results in presentation of exogenous antigen on MHC class I molecules. These data demonstrate that FPH22.PSA was processed in such a manner by the myeloid cell line to allow for presentation of immunodominant peptides in MHC class I molecules and suggests that uptake of antigen via FcgammaRI results in cross-priming.

Phase I pilot trial of the bispecific antibody MDXH210 (anti-Fc gamma RI X anti-HER-2/neu) in patients whose prostate cancer overexpresses HER-2/neu

The goal of this study was to evaluate, in patients with prostate cancer, the toxicity profile and biologic activity of the bispecific antibody MDXH210, which has specificity for the non-ligand-binding site of the high-affinity immunoglobulin G receptor (Fc gamma RI) and the extracellular domain of the HER-2/neu proto-oncogene product. Patients with prostate cancer that expressed HER-2/neu were entered into a phase I dose-escalation trial of MDXH210. Patients received an intravenous infusion MDXH210 during a period of 2 h three times per week for 2 weeks and were monitored for toxicity. Pharmacokinetic and pharmacodynamic parameters were measured and included the biologic end points of monocyte-bound MDXH210, cytokine production, and clinical response. Seven patients were treated with MDXH210 doses ranging from 1 to 8 mg/m2. In general, MDXH210 was well tolerated, with only mild infusion-related malaise, fever, chills, and myalgias. No dose-limiting toxic effects were observed. Biologic effects included induction of low plasma concentrations of tumor necrosis factor-alpha and interleukin-6 observed immediately after MDXH210 infusion and 70% saturation of circulating monocyte-associated Fc gamma RI with MDXH210 at a dose level of 4 to 8 mg/m2. Five of six patients had stable prostate-specific antigen levels during the course of 40 days or more. Circulating plasma HER-2/neu levels decreased by 80% at days 12 and 29 (p = 0.03 and 0.06, respectively, by the Wilcoxon signed rank test). MDXH210 can be given safely to patients with HER-2/neu-positive prostate cancer in doses of at least 8 mg/m2. At the doses studied, biologic activity was demonstrated and characterized by binding of MDXH210 to circulating monocytes, release of monocyte-derived cytokines, a decrease in circulating HER-2/neu, and short-term stabilization of prostate-specific antigen levels.

An Antigen Recognized by Autologous CTLs on a Human Bladder Carcinoma

By stimulating blood lymphocytes with autologous bladder carcinoma cells that had been transfected with B7-1, we obtained a panel of CTL clones which lyse specifically the bladder tumor cells in an MHC class I-restricted fashion. Based on inhibition with anti-HLA Abs and the recognition of allogeneic tumor cells, we could distribute our clones in three groups that recognized three distinct Ags. We characterized one of these Ags by screening a cDNA library prepared with the RNA from this bladder tumor line. This new tumor Ag is a peptide presented by HLA-B4403 molecules. It is produced by a point mutation in a gene that is recorded in databases under the name KIAA0205, is ubiquitously expressed, and whose function is unknown. We also found this mutation in the tumor sample that was originally resected from this patient, but the mutation was not found in the 100 or more independent tumors of various histologic types that were tested. This report is the first to describe the isolation of CTL clones directed against human bladder cancer and the molecular characterization of a bladder tumor Ag.

Antitumor killer lymphocytes in the peripheral blood of a patient with transitional cell carcinoma of the bladder

BACKGROUND

Peripheral blood lymphocytes (PBL) from patients with bladder cancer also contain cells possessing cytotoxic activity against autologous tumor cells. These cells are phenotypically heterogenous and include natural killer (NK) and cytotoxic T cells. This study investigated the role of cytotoxic lymphocytes directed against autologous bladder cancer cells.

METHODS

PBL were obtained at intervals before and after surgery and analyzed for cytotoxic activity against autologous bladder cancer cells in 4-hour 51Cr release assay. PBL stimulated with autologous tumor cells were also transformed with human T-lymphotropic virus type-1, establishing a cell line (KB31) which was analyzed for phenotype and cytotoxic activity against the autologous tumor cells.

RESULTS

PBL preoperative cytotoxic activity was low, but increased after surgery. Cytotoxic activity was found not only against autologous bladder cancer cells, but also against heterologous bladder cancer (KK-47) and myeloid leukemia (K562) cells, with the highest activity against the heterologous cell lines. The cytotoxic activity of KB31 was 40% against autologous tumor cells 6 weeks after initiation of the cell line, but decreased to 5% by 6 months. This activity was lower than that against the other cell lines, and was similar to that of PBL in short-term culture. Fluorescence-activated cell sorter (FACS) analysis demonstrated that in KB31 cells at 6 weeks, CD8+ cells were dominant, but CD56+ cells predominated at 6 months.

CONCLUSION

These results suggest that the presence of cytotoxic activity in the peripheral blood of the patient was due to both cytotoxic T cells and NK cells. The cytotoxic activity was lowest prior to surgery and increased postoperatively.

HLA-A2402-restricted and tumor-specific cytotoxic T lymphocytes from tumor-infiltrating lymphocytes of a child with Wilms' tumor

The existence of specific immunity against pediatric tumors is not well studied. We report here the CD3+CD4-CD8+ cytotoxic T lymphocyte (CTL) line established from tumor-infiltrating lymphocytes (TIL) of a 3-mo-old child with Wilms' tumor. This CD3+CD4-CD8+ CTL line showed cytotoxicity against the HLA-A2402+ tumor cells including the autologous tumor, adenocarcinomas from various organs (colon, stomach, lung, and ovary), and an esophageal squamous cell carcinoma. No other cell lines examined, including HLA-A2402- tumors, K562 cells, or HLA-A2402+ normal cells were lysed by this CTL line. This CTL line recognized an HLA-A2402- ovarian adenocarcinoma transfected with HLA-A2402 cDNA. These results suggest the existence of HLA-A2402-restricted and tumor-specific CTL at the tumor site of a child with Wilms' tumor.

MHC-dependent cytolysis of autologous tumor cells by lymphocytes infiltrating urothelial carcinomas

Tumor-infiltrating lymphocytes (TIL) were grown from 23 urothelial carcinomas. Phenotyping analysis showed that the TIL cultures were mainly CD3+. Although CD4+ and CD8+ T-cell sub-sets were grown in culture, CD4+ T-cell sub-sets predominated over CD8+ T cells. Immunohistochemical studies performed on 5 tumor specimens confirmed this observation, and indicated that CD4+ T cells surrounded the tumor islets, whereas CD8+ T lymphocytes were localized among the tumor cells. Five short-term carcinoma cell lines established from these urothelial tumors were used as target cells in cytolysis assays in order to investigate the functional anti-tumor activity of autologous TIL. TIL from 4/5 tumors were lytic and 3 TIL lines displayed MHC-class-I-dependent cytotoxicity directed against autologous tumor cells. CD4+ T-cell-depletion experiments performed on TIL line 07 confirmed that CD8+ MHC-class-I-dependent CTL were the predominant effectors. Finally, experiments performed on 6 allogeneic urothelial-cancer cell lines matched for HLA-class-I molecules showed that TIL07 exhibited selective lytic activity toward tumor 07. These data indicate that CD8+ MHC-class-I-dependent CTL present in urothelial carcinomas are functional and may participate in the anti-tumor immune response.

Activated long-term peripheral blood cultures as preparation for adoptive alloreactive cell therapy in cancer patients

Different modes of in vitro activation of peripheral blood mononuclear cells (PBMC) were compared for their effect on long-term propagation. PBMC cultures were activated by short exposures to the mitogen phytohemagglutinin (PHA) and the CD3 complex, with or without secondary signals provided by ligands of CD28 costimulatory molecules. Activation and long-term cultures were carried out in the presence of recombinant interleukin-2 (rIL-2). Addition of supernatant derived from IL-2-activated PBMC improved culture cell yield. Cumulative fold expansions ranged between 10(3) and 10(5) within 21 days. The highest cell yield was found after PHA activation. Fewer cells were obtained after activation with a combination of CD3 and CD28, and even fewer were obtained after CD3 activation alone. An increase in CD8+ and CD56+ cells, without change in CD4+ cells, was found in activated cultures when compared with fresh PBMC. Non-MHC-restricted cytotoxic activity was documented in all activated cultures. Cytotoxic activity per culture was highest in PHA-activated PBMC because of the high cell yield on the day of harvest. Successful in vitro expansion of PBMC might be helpful for gene transfer into T lymphocytes, as well as for the induction of an antitumor response, particularly for prevention and treatment of relapse of hematologic malignancies following allogeneic or autologous bone marrow transplantation.

Growth of tumor-infiltrating lymphocytes from human solid cancers: summary of a 5-year experience

Between 1989 and 1993, 255 tumor biopsies representing 4 tumor histologies (melanoma, breast cancer, colon cancer and renal cell cancer) were received by the Surgery Branch of the National Cancer Institute. Tumor-infiltrating lymphocytes (TIL) were grown from single-cell suspensions of tumor biopsies over the course of 30-45 days. The TIL were grown in medium containing IL-2. To obtain numbers suitable for therapy (>10(11)), TIL were expanded using a large-scale system of cell culture and harvesting. While the largest number of biopsies was obtained from melanoma patients, TIL were successfully grown from 160 of 255 tumor biopsies representing all 4 histologies. Under the culture conditions employed, several characteristics of TIL expansion were observed. The cell surface phenotype of TIL which grew out from the tumor biopsies was generally a mix of CD3+/CD4+ or CD3+/CD8+ lymphocytes. Only TIL from melanoma biopsies were found to be consistently cytolytic and, in many cases, lysed autologous tumor cells preferentially. Interestingly, TIL derived from extra-nodal sites of metastatic melanoma biopsies (subcutaneous, lung, bowel; 36 of 67, 54%) were more likely to have these cytolytic characteristics than TIL derived from tumor-involved lymph node biopsies (7 of 39, 18%). The present study summarizes 5 years of laboratory effort and validates the technologies developed for the large-scale growth and harvesting of TIL. In addition, it summarizes the laboratory effort supporting previously published clinical reports on TIL from our group.

Distinct cytotoxicity against neuroblastoma cells of peripheral blood and tumor-infiltrating lymphocytes from patients with neuroblastoma

The cytotoxicity against neuroblastoma cells of IL-2-activated peripheral blood (PBL) and tumor-infiltrating lymphocytes (TIL) was evaluated in seventeen patients with neuroblastoma. Regional lymph node lymphocytes (LNL) were similarly studied in some patients. Three allogeneic neuroblastoma cell lines, LA2D2, LA2B4 and SIFA, established from the different metastases of the same patient were used as targets. Of the three neuroblastoma lines, LA2D2, with low CD56 expression, was the most susceptible to IL-2-activated lymphocytes, while SIFA, with high CD56 expression, was resistant in the greatest degree. LA2B4 showed moderate susceptibility. Although TIL (73.9 +/- 2.1%), LNL (81.0%) and PBL (76.2 +/- 3.1%) revealed similar cytotoxic activity to K562, they demonstrated distinct cytotoxic activities to each neuroblastoma cell line, as follows: against LA2D2: TIL 56.3 +/- 4.2%, LNL 52.1%, PBL 33.6 +/- 4.9% (P < 0.01); against LA2B4: TIL 47.3 +/- 3.3%, LNL 37.8%, PBL 33.7 +/- 4.8% (P < 0.05); against SIFA: TIL 27.0 +/- 6.2%, LNL 20.7%, PBL 13.9 +/- 2.4% (P = 0.056). TIL always showed higher cytotoxic activity against neuroblastoma cells than those of LNL and PBL, whereas LNL were more cytotoxic than PBL. This data showed that TIL from neuroblastoma patients preferentially killed neuroblastoma cells. It was suggested that lymphocytes in the tumor site and regional lymph node could have been sensitized with neuroblastoma-related antigens and exert preferential killing activity against neuroblastoma cells. Phenotypical analysis revealed that TIL had a larger population of CD56+ cells than PBL. Conversely, PBL had a higher population of CD16+ cells than TIL. The cytotoxic activity of TIL significantly decreased by the depletion of CD56+ cells (10.9 +/- 6.2 from 49.9 +/- 5.9% against LA2D2, P < 0.001). These results indicated that CD56+ cells were most responsible for the killing of neuroblastoma cells, and that TIL, with a high proportion of CD56+ cells with strong activity, would be the best source for the immunotherapy of neuroblastoma. Additionally, since neuroblastoma cell lines used in the present study were derived from the different metastases of the same patient, heterogeneity in the susceptibility to lymphocytes might result from the differential expression of tumor-related antigens on these cell lines.

Adoptive immunotherapy of cancer: biological response modifiers and cytotoxic cell therapy

Immunotherapy has been developed for the treatment of metastatic cancers refractory to conventional therapies. Immunotherapy utilizes immune cells and/or biological response modifiers (BRMs) to induce an anti-tumor response mediated by the patient's immune system. BRMs, including lymphokines and cytokines, are used as single agents or in combination for cancer therapy. Some BRMs, particularly interleukin 2 (IL-2), can activate and expand in vitro lymphocytes with anti-tumor reactivity which will be adoptively transferred to the patient. To enhance the therapeutic effect of immunotherapy, gene therapy is currently under investigation and involves the insertion of cytokine genes in immune cells or in tumor cells. The development and future of cancer immunotherapy will be discussed in this review.

Induction of B16 melanoma melanogenesis by a serum-free synthetic medium

Cultured murine B16 melanoma cells normally grow as spindle-shaped cells firmly attached to tissue culture flasks. Pellets obtained from harvested B16 melanoma cells are white to grey in color. When the same cells were grown in synthetic, serum-free AIM V medium, cellular morphology and pigmentation were radically altered. Within 3 days of subculture in AIM V, cells rounded up and grew in clusters in suspension. Melanin content increased to greater than 30 times and tyrosinase activity was found to be 10-50 times higher in cells grown in AIM V medium compared to those cultured in normal medium. A concomitant increase in the level of immunoreactive tyrosinase was also induced. The individual growth factors and hormones present in AIM V medium were examined to determine which component(s) stimulates melanogenesis. Only those cells grown in the presence of 2.5% human albumin were stimulated to synthesize melanin. These findings suggest that albumin, or a component associated with albumin, has a major effect upon the regulation of melanogenesis in these cells.

Enhancement of lymphocyte proliferation assays by use of serum-free medium

Fetal bovine serum (FBS)-supplemented cell culture medium has been the standard medium used in assays of murine lymphocyte proliferation. While FBS allows cell growth and viability, it requires screening and contains uncharacterized elements which may yield inconsistent results from batch to batch. It also may include growth factors and immunologically reactive proteins that obscure assays for specific responses because of high background proliferation. Recently, chemically defined serum-free media have become available for human lymphocyte culture. We compared several of these media against FBS-supplemented medium and found that one of them, AIM V (Gibco), produced a marked increase in the ratio of positive to background counts in [3H]thymidine incorporation assays of antigen-specific proliferation. Similar results were obtained when responses to mitogenic lectins were examined. AIM V supported proliferation of lymphocytes in a variety of haplotypes, it supported MHC-specific proliferation in response to soluble antigens in a manner consistent with previous reports, and it supported proliferation in response to alloantigen as displayed in the mixed lymphocyte culture. A high ratio of positive to background counts was consistently observed. The results indicate that this serum-free medium enhances the analytic power of proliferation assays.

An investigation of factors influencing the in vitro induction of LAK activity against a variety of human bladder cancer cell lines

We investigated the sensitivity of transitional cell carcinoma cells, derived from the human bladder, to lymphokine activated killer cells. Recombinant interleukin-2 activated peripheral blood mononuclear cells were studied for their ability to mediate the cytolysis of a panel of four established human bladder transitional cell carcinoma cell lines. Lymphokine activated killer activity was assessed using a standard four hour chromium release assay. All four bladder cancer cell lines proved to be susceptible to lymphokine activated killer mediated cytolysis. This was found to be dependent upon the dose of cytokine and upon the duration of the activation period. The four cell lines were differentially susceptible to lysis (specific cytotoxicity at effector to target ratio of 40:1; RT112 = 22.9%, RT4 = 49.2%, MGH-U1 = 49.1%, EJ18 = 62.3%). The varying susceptibility of lymphokine activated killer mediated cytotoxicity was found to be independent of the histological grade of the parent tumour or the donor of effector cells. Both interferon-alpha and tumour necrosis factor-alpha also elicited lymphokine activated killer cell activity, although the maximum specific cytotoxicity achieved was considerably lower than that obtained with interleukin-2 alone. Interleukin-2, at optimal concentration, and tumour necrosis factor-alpha were found to behave synergistically in the generation of lymphokine activated killer effectors. However, concentrations of tumour necrosis factor-alpha higher than 100 Uml.-1 resulted in a decrease in specific cytotoxicity. These findings suggest a possible use of adoptive immunotherapy in human bladder cancer and indicate the optimum conditions for the generation of such effector cells.

Phenotypic and functional analysis of lymphocytes infiltrating paediatric tumours, with a characterization of the tumour phenotype

Tumour-infiltrating lymphocytes (TIL) of paediatric tumours obtained from 37 lesions of different histotype (12 osteosarcomas, 5 Wilms' tumours, 7 soft-tissue sarcomas, 5 neuroblastomas and 8 miscellaneous) were studied to establish their potential for therapy. Fresh isolated TIL were cultured for the first 2 weeks with low doses of interleukin-2 (IL-2) (20 Cetus U/ml) to select for "tumour-specific" lymphocytes potentially present in the neoplastic lesion, followed by culture with high doses of IL-2 (1000 Cetus U/ml) to achieve TIL expansion. TIL were grown with more than 10-fold expansion in only 9 cases (mean expansion: 58-fold, range 13.5-346). In 17 cases no viable cells were obtained. After 30 days of culture with IL-2 the proliferative ability of TIL declined sharply in the majority of cases and TIL became refractory to any further stimulus, including addition of IL-4, tumour necrosis factor alpha (TNF alpha) or interferon gamma, and activation with OKT3 in solid phase. In 20 out of 37 cases TIL were available for phenotypic and functional analysis. TIL after long-term culture were predominantly CD3+ but 2 cases of osteosarcoma showed a predominance of CD3+TcR gamma/delta cells. The CD4/CD8 ratio was more than 1 in 10 cases, without correlation with tumour histology, site of lesion or TIL growth. The number of CD16+ and CD25+ lymphocytes decreased progressively during culture, the latter concomitantly with a reduction of TIL growth rate. The lytic pattern of TIL against allogenic and autologous tumour (Auto-Tu) cells was variable, but specific lysis of Auto-Tu was seen in only one case (Wilms' tumour) after culture with TNF alpha and irradiated Auto-Tu cells. The immunohistochemical analysis of tumour lesions revealed a limited lymphocyte infiltrate, a low expression of histocompatibility leukocyte antigens (HLA) class I and of the adhesion molecules ICAM1, LFA3, and a significant production of transforming growth factor beta (TGF beta). These data indicate that TIL obtained from paediatric patients are difficult to expand at levels required for immunotherapy and lack a significant number of tumour-specific T lymphocytes. A low expression of immunomodulatory molecules on tumour cells or the production of suppressive factors may prevent activation and expansion of TIL in paediatric tumours.

Immunotherapy. Neuroblastoma as a model

Combinations of aggressive therapy and radiotherapy directed at the primary tumor site as well as dose intensive chemotherapy against metastases can effectively induce complete remissions in patients with stage IV neuroblastomas. By virtue of its tumor specificity, the use of immunotherapy at the time when microscopic residual disease is present holds great promise in eradicating the tumors permanently. Monoclonal antibodies can accumulate selectively and at high concentrations in neuroblastomas. They have the potential of initiating complement activation and inflammation at the tumor site. Hematopoietic factors and cytokines can reinforce the body with tumoricidal leukocytes. Ex vivo activation of autologous white cells as well as arming by genetic manipulation can also produce tumor-seeking vehicles that may be therapeutically useful. As the knowledge of tumor and host immunobiology accumulates, the optimal combination of these approaches will become apparent.