Radio-immunoassay detection of interferon-gamma in urine after intravesical Evans BCG therapy

The double-sided effects of Mycobacterium Bovis bacillus Calmette-Guérin vaccine

Bacillus Calmette-Guérin (BCG), the only vaccine proven to be effective against tuberculosis (TB), is the most commonly used vaccine globally. In addition to its effects on mycobacterial diseases, an increasing amount of epidemiological and experimental evidence accumulated since its introduction in 1921 has shown that BCG also exerts non-specific effects against a number of diseases, such as non-mycobacterial infections, allergies and certain malignancies. Recent Corona Virus Disease 2019 (COVID-19) outbreak has put BCG, a classic vaccine with significant non-specific protection, into the spotlight again. This literature review briefly covers the diverse facets of BCG vaccine, providing new perspectives in terms of specific and non-specific protection mechanisms of this old, multifaceted, and controversial vaccine.

BCG immune activation reduces growth and angiogenesis in an in vitro model of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancers worldwide and is associated with poor survival and significant treatment morbidity. The immune profile in patients with HNSCC is immunosuppressive and presents cytokine-mediated adaptive immune responses, triggered apoptosis of T cells, and alterations in antigen processing machinery. Bacille Calmette-Guerin (BCG) immunotherapy has been used successfully as a treatment for several types of cancer. In the present study, we sought to determine the antitumor effect of soluble mediators from peripheral blood mononuclear immune cells (PBMCs) activated with BCG vaccine in a three-dimensional coculture model of HNSCC growth using FaDu hypopharynx carcinoma squamous cells. BCG activation of PBMCs led to an increase in CD4+ and CD8+ lymphocyte subsets concomitant with an elevation in the levels of the antitumor cytokines IL-6, TNF-α and IFN-γ, and a EGFR in FaDu cells. In addition, coculture with BCG-activated PBMCs reduced FaDu proliferation and increased cytotoxicity and apoptosis in parallel with an increase in caspase-3 activity and p53 expression. Finally, conditioned medium from BCG-activated PBMCs reduced the levels of the angiogenic factors vascular endothelial growth factor and angiopoietin-2 produced by human aortic endothelial cells (HAECs), and inhibited their proliferation and differentiation into capillary-like structures. Taken together, these results demonstrate that BCG vaccination induces antitumor responses in an HNSCC in vitro model and suggest that the BCG vaccine could be an effective alternative therapy for the treatment of HNSCC.

Immunotherapy for bladder cancer

It is nearly 40 years since Bacillus Calmette-Guérin (BCG) was first used as an immunotherapy to treat superficial bladder cancer. Despite its limitations, to date it has not been surpassed by any other treatment. As a better understanding of its mechanism of action and the clinical response to it have evolved, some of the questions around optimal dosing and treatment protocols have been answered. However, its potential for toxicity and failure to produce the desired clinical effect in a significant cohort of patients presents an ongoing challenge to clinicians and researchers alike. This review summarizes the evidence behind the established mechanism of action of BCG in bladder cancer, highlighting the extensive array of immune molecules that have been implicated in its action. The clinical aspects of BCG are discussed, including its role in reducing recurrence and progression, the optimal treatment regime, toxicity and, in light of new evidence, whether or not there is a superior BCG strain. The problems of toxicity and non-responders to BCG have led to development of new techniques aimed at addressing these pitfalls. The progress made in the laboratory has led to the identification of novel targets for the development of new immunotherapies. This includes the potential augmentation of BCG with various immune factors through to techniques avoiding the use of BCG altogether; for example, using interferon-activated mononuclear cells, BCG cell wall, or BCG cell wall skeleton. The potential role of gene, virus, or photodynamic therapy as an alternative to BCG is also reviewed. Recent interest in the immune check point system has led to the development of monoclonal antibodies against proteins involved in this pathway. Early findings suggest benefit in metastatic disease, although the role in superficial bladder cancer remains unclear.

Intravesical ALT-803 and BCG treatment reduces tumor burden in a carcinogen induced bladder cancer rat model; a role for cytokine production and NK cell expansion

Intravesical Bacillus Calmette-Guérin (BCG) has been shown to induce a specific immunologic response (i.e., activation of IL-2 and effector T-cells), while preclinical studies using ALT-803 (mutated IL-15 analogue combined with IL-15Rα-Fc fusion) have shown promising results by prolonging the agent's half-life and stimulating CD8+ T-cells. Based on these results, we hypothesized that the intravesical administration of ALT-803 along with BCG will generate an immunologic response leading to significant bladder tumor burden reduction. Using a well-established carcinogen induced rat non-muscle invasive bladder cancer (NMIBC) model, we studied the effects of intravesical ALT-803 with and without BCG. Rat tissues were evaluated to document treatment response. Intravesical ALT-803 was safe and well tolerated alone and in combination with BCG. As a single treatment agent, ALT-803 reduced tumor burden by 35% compared to control whereas BCG alone only reduced tumor burden by 15%. However, the combination of ALT-803 plus BCG reduced tumor burden by 46% compared to control. Immune monitoring suggested that the antitumor response was linked to the production and secretion of IL-1α, IL-1β and RANTES, which in turn, induced the proliferation and activation of NK cells. Lastly, tumoral responses of the combinational treatment were associated with 76% reduction in angiogenesis, which is significantly higher than when assessed with either agent alone. The enhanced therapeutic index seen with this duplet provides justification for the development of this regimen for future clinical trials.

Subclinical miliary Mycobacterium bovis following BCG immunotherapy for transitional cell carcinoma of the bladder

The authors present an unusual case of a 51-year-old man who developed relatively mild non-specific symptoms following intravesical BCG instillation for superficial transitional cell carcinoma of the bladder, with radiological investigations demonstrating typical features of miliary tuberculosis (TB). Transbronchial biopsy showed small foci of poorly formed granuloma suggestive of Mycobacterium infection. The patient's respiratory symptoms only became apparent 7 days after discharge having had 4 weeks of unremarkable inpatient stay where he remained clinically well. Prompt anti-TB treatment resulted in a remarkable improvement in his symptoms and radiological appearance, supporting the diagnosis of disseminated Mycobacterium bovis infection. This case highlights the importance of recognising miliary M bovis as a potential complication in patients receiving BCG immunotherapy, and that the disease course can be subclinical with delayed onset of symptoms.

Secondary stimulation from Bacillus Calmette-Guérin induced macrophages induce nitric oxide independent cell-death in bladder cancer cells

The anti-tumour mechanisms following Bacillus Calmette-Guérin (BCG) treatment of bladder-cancer remain largely unknown. Previous studies have shown involvement of nitric-oxide (NO) formation in the BCG-mediated effect. We analyzed the effects of macrophage secreted factors (MSFs) from BCG-stimulated RAW264.7 cells on the bladder-cancer cell line MBT2. Direct treatment with BCG did not induce NO in MBT2-cells whereas supernatant from BCG-stimulated macrophages increased NOS2 mRNA and protein expression, NO concentrations and cell-death. Blocking NO-synthesis with the NOS-inhibitor L-NAME did not affect levels of cell-death suggesting cytotoxic pathways involving other signalling molecules than NO. Several such candidate genes were identified in a microarray.

Bacillus Calmette-Guerin (BCG) immunotherapy for bladder cancer: current understanding and perspectives on engineered BCG vaccine

Since the first report in 1976, accumulated clinical evidence has supported intravesical Bacillus Calmette-Guerin (BCG) therapy as one of the standard methods of management of intermediate- and high-risk non-muscle invasive bladder cancer. Despite its efficacy, intravesical BCG therapy is associated with a variety of adverse events (AEs), most of which are tolerable or controllable with supportive care. However, some patients receiving intravesical BCG therapy may experience uncommon but severe AEs, leading to cessation of BCG therapy. Not all, but most severe AEs result from either local or systemic infection with live BCG. Intravesical instillation of BCG elicits multiple immune reactions, although the precise immunological mechanism of BCG therapy is not clear. It is convenient to separate the complex reactions into the following three categories: infection of urothelial cells or bladder cancer cells, induction of immune reactions, and induction of antitumor effects. Recently, our knowledge about each category has increased. Based on this understanding, predictors of the efficacy of intravesical BCG therapy, such as urinary cytokine measurement and cytokine gene polymorphism, have been investigated. Recently, preclinical studies using a novel engineered mycobacterium vaccine have been conducted to overcome the limitations of BCG therapy. One approach is Th1 cytokine-expressing recombinant forms of BCG; another approach is development of non-live bacterial agents to avoid AEs due to live BCG infection. We also briefly describe our approach using an octaarginine-modified liposome-incorporating BCG cell wall component to develop future substitutes for live BCG.

Serum Th1 and Th2 cytokine balance in patients of superficial transitional cell carcinoma of bladder pre- and post-intravesical combination immunotherapy

Combination therapy with intravesical bacillus Calmette-Guerin (BCG) plus interferon-alpha2b (IFN-alpha2b) for superficial transitional cell carcinoma (TCC) seems to be immune-dependent and activation of Th1 immune response is required for clinical efficacy. The present study evaluates circulating serum cytokine profiles (Th1/Th2 cytokines IFN-gamma, IL-2 TNF-alpha, IL-4, IL-6 and IL-10) in 41 bladder cancer patients prior to transurethral resection of tumor (TURBT) (pre-therapy), and following intravesical combination immunotherapy (post-therapy) and their association with recurrence. Mean levels of IL-2 and TNF-alpha were significantly reduced while IL-4, IL-6 and IL-10 were significantly enhanced in pre-therapy samples as compared to controls. Mean levels of IFN-gamma, IL-2 and TNF-alpha were significantly increased while IL-4 and IL-10 were significantly reduced in patients after instillation of combination immunotherapy. These findings suggest that bladder cancer patients develop Th2 dominant status with deficient type 1 immune response that shows tendency to reversal following therapy.

Intravesical therapy for bladder cancer

IMPORTANCE OF THE FIELD

Although transurethral resection of bladder tumor (TURBT) is effective therapy, up to 45% of patients will have a recurrence within 1 year after TURBT alone. Further, there is a 3 - 15% risk of tumor progression to muscle invasive and/or metastatic cancer. Depending on patient and tumor characteristics, a number of patients may benefit from some form of intravesical therapy. Adjuvant therapy is effective in avoiding post-TURBT implantation of tumor cells, eradicating residual disease, preventing tumor recurrence, and to delay or reduce tumor progression through direct cytoablation or immunostimulation.

AREAS COVERED IN THIS REVIEW

The role of risk assessment in the management of nonmuscle invasive bladder cancer (NMIBC) and the indications for the use of intravesical agents are discussed. Findings from major randomized clinical trials on BCG, interferon and various chemotherapeutic agents are summarized; key aspects of drug pharmacology, drug efficacy, side effects, and toxicity are also covered.

WHAT THE READER WILL GAIN

The reader will gain a basic understanding of the role of risk assessment in determining the need for intravesical therapy, as well as an overview of the different types of agents in use in the United States today.

TAKE HOME MESSAGE

The type of intravesical therapy used is based on the risk groups as noted in the European prognostic tables. Bacillus Calmette-Guerin (BCG) is the most commonly used first-line agent immunotherapeutic agent for prophylaxis and treatment of carcinoma in situ and high-grade bladder cancer. Other immunotherapeutic options include the interferons, interleukins 2 and 12, and tumor necrosis factor, all of which have activity in BCG refractory patients, although with low durable remission rates. Studies have shown that chemotherapy prevents recurrence but not progression. The available data on intravesical chemotherapy do not indicate that any single agent currently in use is clearly better than any other. Therefore, the selection of a chemotherapeutic agent is usually based on cost, toxicity, and availability as well as on physician preference and experience.

The fibronectin attachment protein of bacillus Calmette-Guerin (BCG) mediates antitumor activity

PURPOSE

The receptor responsible for the attachment of bacillus Calmette-Guerin (BCG) to fibronectin, fibronectin attachment protein (FAP), has been cloned. Studies targeting FAP as an inducer of immunity in mycobacterial infections suggest that FAP is a highly immunogenic protein. In light of these findings and the need to find effective alternatives to BCG treatment for bladder cancer, we tested the ability of FAP to induce antitumor activity.

MATERIALS AND METHODS

The ability of FAP to bind to bladder tumor cells and the bladder wall was established using (125)I-FAP. For testing antitumor activity in vivo, mice were catheterized and 5 x 10(4) MB-49 bladder tumor cells were implanted orthotopically on day 0. Test groups were treated with PBS only, FAP, or BCG on day 1 and day 8. A subset of mice was preimmunized with FAP prior to treatment.

RESULTS

FAP was observed to bind to bladder tumor cells in a fibronectin-dependent manner. Attachment of FAP within the bladder followed the pattern established for BCG binding. Antitumor studies showed a significant reduction in tumor growth in FAP-treated mice that had been preimmunized with FAP. Tumor growth was not inhibited in naïve mice treated with FAP. Dose-response studies showed that FAP-induced antitumor activity is dose dependent, and experiments comparing BCG with FAP showed equivalent antitumor effects. In vitro experiments showed antigen-specific lymphocyte proliferation and a cytokine profile indicative of Th-1 polarization of the FAP-induced immune response. CD8+ T cells and natural killer cells were found to be required for the FAP-induced antitumor response.

CONCLUSIONS

FAP is an effective antitumor agent that inhibits tumor growth at a level equivalent to that observed for BCG. This protein may thus provide an alternative to BCG for treatment of superficial bladder cancer.

Thirty years of BCG immunotherapy for non-muscle invasive bladder cancer: A success story with room for improvement

Over the last three decades, intravesical immunotherapy with the biological response modifier Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been established as the most effective adjuvant treatment for preventing local recurrences and tumor progression following transurethral resection of non-muscle invasive bladder cancer. A large number of clinical trials have established a major role for BCG immunotherapy in urological oncology. In parallel, the major principles of the immunological mechanism have been revealed. In spite of this success, questions still remain regarding its clinical use, mechanism of action and potential improvement. This review provides a comprehensive insight into the historical era of BCG immunotherapy, the current indications for clinical application, the complex mechanism of action and possible future developments.

Immunotherapeutic strategies for high-risk bladder cancer

Transitional cell carcinoma (TCC), which is the pathological diagnosis for the majority of bladder cancers, is a solid tumor entity that is responsive to immunotherapy as evidenced by a substantial cure rate documented with the use of intravesical bacillus Calmette-Guérin (BCG) therapy in selected patients with high-grade superficial disease. The nonspecific immune modulation that occurs as a result of BCG therapy is not well understood; however, the success of BCG therapy provides a basis for the exploration of mechanisms related to immune responses and the development of novel immunotherapeutic agents for the treatment of high-risk disease. In this review, we discuss the complexity of the immune system and therapies that are considered capable of manipulating it to potentially benefit patients with bladder cancer.

Wirkmechanismen der intravesikalen BCG-Immuntherapie des oberflächlichen Harnblasenkarzinoms

Immunotherapy for treatment of solid cancer mostly is an experimental treatment. In contrast, intravesical immunotherapy of superficial bladder cancer with bacille Calmette-Guérin (BCG) is clinically well established and accepted worldwide because of better results compared to topical chemotherapy. BCG is currently regarded as the most successful immunotherapy of cancer. Unfortunately the mechanism of action has not yet been fully clarified. This article gives an overview on the complex research on the mechanisms of actionhighly successful therapy.

Fas Ligand and TNF-Related Apoptosis-Inducing Ligand Induction on Infiltrating Lymphocytes in Bladder Carcinoma by Bacillus Calmette-Guérin Treatment

AIM

To determine the molecular mechanisms underlying the efficacy of bacillus Calmette-Guérin (BCG) therapy against superficial carcinoma of the urinary bladder, we evaluated the expression of cytotoxic molecules on tumor-infiltrating lymphocytes before and after therapy.

METHODS

Immunofluorescence staining allowed the specific detection of Fas, Fas ligand (FasL), and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) expression on tumor cells and the respective leukocyte populations in biopsy samples from 6 patients.

RESULTS

Significant increases in the infiltration of FasL- and TRAIL-expressing CD4+ T cells and macrophages and FasL-expressing CD8+ T and NK cells were observed after BCG instillation in bladder carcinoma. Moreover, Fas expression was upregulated on tumor cells after BCG instillation.

CONCLUSION

The data suggested that the enhanced infiltration of FasL- and/or TRAIL-expressing leukocytes (CD4+ T cells, CD8+ T cells, natural killer cells and macrophages) and the induction of Fas expression on tumor cells may play an important role in the therapeutic effect of BCG instillation.

Recombinant Mycobacterium bovis bacillus Calmette-Guérin (BCG) expressing mouse IL-18 augments Th1 immunity and macrophage cytotoxicity

Interleukin-18 (IL-18) has been demonstrated to synergize with BCG for induction of a T-helper-type 1 (Th1) immune response. Since successful treatment of superficial bladder cancer with BCG requires proper induction of Th1 immunity, we have developed a recombinant (r) BCG strain that functionally secretes mouse (m) IL-18. This rBCG-mIL-18 strain significantly increased production of the major Th1 cytokine IFN-gamma in splenocyte cultures, at levels comparable to that elicited by control BCG plus exogenous rIL-18. IFN-gamma production by splenocytes was eliminated by addition of neutralizing anti-IL-18 antibody. Endogenous IL-12 played a favourable role whereas IL-10 played an adverse role in rBCG-mIL-18-induced IFN-gamma production. Enhanced host antimycobacterial immunity was observed in mice infected with rBCG-mIL-18 which showed less splenic enlargement and reduced bacterial load compared to control mice infected with BCG. Further, splenocytes from rBCG-mIL-18-infected mice, in response to BCG antigen, displayed increased production of IFN-gamma and GMCSF, decreased production of IL-10, elevated cellular proliferation and higher differentiation of IFN-gamma-secreting cells. rBCG-mIL-18 also enhanced BCG-induced macrophage cytotoxicity against bladder cancer MBT-2 cells in a dose-dependent manner. Neutralizing all endogenous macrophage-derived cytokines tested (IL-12, IL-18 and TNF-alpha) as well as IFN-gamma severely diminished the rBCG-mIL-18-induced macrophage cytolytic activity, indicating a critical role for these cytokines in this process. Cytokine analysis for supernatants of macrophage-BCG mixture cultures manifested higher levels of IFN-gamma and TNF-alpha in rBCG-mIL-18 cultures than in control BCG cultures. Taken together, this rBCG-mIL-18 strain augments BCG's immunostimulatory property and may serve as a better agent for bladder cancer immunotherapy and antimycobacterial immunization.

Immunotherapy of Experimental Bladder Cancer with Recombinant BCG Expressing Interferon-γ

One of the most potent immunotherapies presently used is the application of Bacillus Calmette Guérin (BCG) to prevent recurrences of superficial bladder cancer. Despite its successful use, nonresponders and certain side effects remain a major obstacle. Therefore, current studies aim at developing recombinant BCG (rBCG) strains to further improve the effectiveness of the therapy. In BCG-treated patients a strong local induction of Th1-like cytokines was observed. For this reason rBCG-strains secreting Th1-like cytokines might be potentially useful agents to improve this type of immunotherapy. Because we previously demonstrated the essential role of IFNgamma in BCG-induced antitumor responses, in this study a rBCG strain secreting murine IFNgamma (rBCG-IFNgamma) was generated and tested for its immunostimulatory capacity in several in vitro and in vivo test systems. In vitro rBCG-IFNgamma specifically up-regulated expression of MHC class I molecules on a murine bladder cancer cell line (MB49), compared to the rBCG control strain (transfected with an empty vector). In a murine model of experimental bladder cancer, intravesical instillation of rBCG-IFNgamma resulted in an enhanced recruitment of CD4+ T-cells into the bladder and further induced the local expression of IL-2 and IL-4 cytokines (mRNA) compared to control rBCG. With a low-dose treatment regimen for murine orthotopic bladder cancer, rBCG-IFNgamma significantly prolonged survival, whereas the therapeutic effect of wild-type control BCG did not reach statistical significance. We conclude that this recombinant BCG strain has enhanced immunostimulatory potential and might offer new opportunities in the treatment of bladder cancer.

Immune mechanisms in bacillus Calmette-Guerin immunotherapy for superficial bladder cancer

PURPOSE

Of all medical disciplines it is exclusively in urology in which immunotherapy for cancer has an established position today with intravesical bacillus Calmette-Guerin (BCG) against superficial bladder carcinoma recurrences. BCG is regarded as the most successful immunotherapy to date. However, the mode of action has not yet been fully elucidated. We provide a thorough overview of this complex field of research.

MATERIALS AND METHODS

Rather than simply reporting all experimental data available for better understanding the involved immune mechanisms, we chose to provide comprehensively only information supported by several independent pathways of evidence.

RESULTS

Major findings made during the last few years include systematic analyses of patient material, detailed in vitro studies and investigations in animal models, which have led to a substantially greater understanding of the mechanisms involved.

CONCLUSIONS

The efficacy of BCG is based on a complex and long lasting local immune activation. The bladder as a confined compartment, in which high local concentrations of the immunotherapy agent and effective recruitment of immune cells can be achieved, serves as an ideal target organ for this type of immunotherapy approach.

Interleukin 10 induced augmentation of delayed-type hypersensitivity (DTH) enhances Mycobacterium bovis bacillus Calmette-Guérin (BCG) mediated antitumour activity

Intravesical BCG therapy is effective in the treatment of superficial bladder cancer. Both clinical and experimental results suggest a role for cytokines and delayed-type hypersensitivity (DTH) in BCG-induced antitumour immunity. We characterized the modulatory effects of BCG on bladder cytokine expression and determined the relationship between DTH and BCG antitumour activity. The bladders of mice were instilled with BCG through a catheter. Bladder tissue RNA and urine were collected for evaluation of cytokine expression using reverse transcriptase-polymerase chain reaction (RT-PCR) and/or ELISA. IFN-gamma and TNF-alpha, the two major cytokines associated with DTH, were efficiently induced by BCG. IL10, an important down-regulator of DTH, was also induced by BCG. Constitutive levels of IL4 and IL5 were observed, but neither IL4 nor IL5 were modulated by BCG. Similar results were observed in the kinetic analysis of urinary cytokines in patients after intravesical BCG therapy. Production of Th1 (T helper type 1) cytokines (IFN-gamma, IL2 and IL12) preceded that of the Th2 (T helper type 2) cytokine IL10. A tendency toward higher ratios of IFN-gamma versus IL10 for BCG responders also was observed. In animal studies the absence of IL10 abrogated either by antibody inhibition or the use of genetically modified, IL10 deficient (IL10-/-) mice resulted in enhanced DTH responses. Under conditions of enhanced DTH, a significant enhancement in antitumour activity was observed. These data demonstrate that DTH and its associated mononuclear infiltration and cytokine production are important to the antitumour activity of intravesical BCG therapy, and suggest that effects to diminish IL10 production may have therapeutic value.

Role of Th1 and Th2 cytokines in BCG-induced IFN-gamma production: cytokine promotion and simulation of BCG effect

Induction of a T-helper-type 1 (Th1) immune response is indispensable for successful treatment of superficial bladder cancer with BCG. In this study possible involvement of various cytokines in BCG action as well as their potential roles in enhancing and mimicking BCG effect were explored. In immunocompetent cell cultures, IFN-gamma, a major Th1 cytokine, appears to be a late responsive cytokine to BCG stimulation. Its induction requires involvement of various endogenously produced Th1 and Th2 cytokines. Functional abolishment of any one of these cytokines (IL-2, IL-6, IL-12, IL-18, GMCSF, TNF-alpha, or IFN-alpha, except IL-10) by neutralizing antibodies leads to reduced IFN-gamma production (19-82% inhibition in mouse and 44-77% inhibition in human systems, respectively). In mice cytokines IL-2, IL-12, IL-18, and GMCSF are observed to synergize with BCG for IFN-gamma production, whereas in human cytokines IL-2, IL-12, TNF-alpha, and IFN-alpha exhibit similar synergistic effects. Rational combinations of these Th1-stimulating cytokines (IL-12 plus IL-18 in mice and IL-2 plus IL-12 in humans, respectively) dramatically up-regulate IFN-gamma production that is incomparably superior to BCG for induction of this cytokine. These results suggest that combined Th1-stimulating cytokines and combinations of BCG plus selected Th1-stimulating cytokines are rational candidates for further study in the treatment of bladder cancer patients.

Identification of bladder cancer antigens recognized by IgG antibodies of a patient with metastatic bladder cancer

To identify tumor antigens useful for the diagnosis and treatment of patients with bladder cancer, a lambda phage cDNA library constructed from a high-grade bladder cancer cell line was screened with autologous serum from a patient with metastatic bladder cancer. Forty-eight distinct antigens were isolated. By evaluating the immunogenicity and the tissue-specific expression, KU-BL-1 and KU-BL-2 were identified as immunogenic antigens with restricted tissue expression. KU-BL-1 was found to be a putative human lipoic acid synthetase with a metal-binding site, CXXXCXXC, that was expressed in bladder cancer cell lines and most bladder cancer tissues, as well as normal bladder mucosa and testis tissues. Immunoglobulin (Ig)G antibody to KU-BL-1 was detected in 2 of 28 patients with bladder cancer, but not in 30 healthy individuals. KU-BL-2 was found to be a putative human kelch-like protein that was homologous to Drosophila kelch, with a BTB/POZ domain and kelch repeats. KU-BL-2 was expressed in bladder cancer cell lines, most bladder cancer tissues, testis and heart, but not in normal bladder mucosa. IgG antibody to KU-BL-2 was detected in 8 of 28 patients with bladder cancer, but not in 16 healthy individuals. Tumor reactive T cells were induced from peripheral blood mononuclear cells (PBMC) by stimulation with one of the HLA-A24 binding KU-BL-2 peptides. Therefore, KU-BL-1 and KU-BL-2, which showed preferential expression in bladder cancer with restricted expression in normal tissues, as well as immunogenicity in multiple patients with bladder cancer, may be useful for the development of diagnostic and therapeutic methods for patients with bladder cancer.

Adoptive immunotherapy for superficial bladder cancer with autologous macrophage activated killer cells

PURPOSE

We assessed the efficacy and safety of adoptive immunotherapy administered to 17 patients with TaGIII or recurrent TaGII superficial bladder cancer following transurethral tumor resection.

MATERIALS AND METHODS

Macrophage activated killer (MAK) cells were obtained from autologous mononuclear cells harvested by apheresis, after in vitro culture for 7 days and activation with interferon-gamma on the last day of culture. The patients received 6 weekly intravesical infusions of approximately 2 x 10(8) cells each. Additionally, 5 patients received 2 or 3 more infusions at 3-month intervals. Each patient was followed for 1 year or until tumor recurrence, whichever came first.

RESULTS

A total of 112 intravesical infusions were performed. During the 12-month followup period 8 patients experienced 11 common toxicity criteria grade 1 or grade 2 adverse events considered possibly related to protocol. No clinically relevant grade 1 or 2 laboratory test results were reported while the patients received treatment. In 17 patients 8 tumors recurred compared to 34 recurrences during the year before the first MAK cell infusion. This difference was highly significant (p </=0.0005).

CONCLUSIONS

The promising efficacy and safety results of this study and the fact that the MAK cell treatment regimen proved feasible should encourage initiation of further large scale studies to confirm these data.

Local immunostimulation induced by intravesical administration of autologous interferon-gamma-activated macrophages in patients with superficial bladder cancer

We conducted a phase I/II clinical trial of the safety and efficacy of intravesical administration of autologous IFN-gamma-activated macrophages (MAK) in patients with superficial bladder cancer. Monocyte-derived MAK cells were prepared in vitro and patients received six instillations of 1.4 x 10(8) to 2.5 x 10(8) cells, once a week, for five consecutive weeks. Treatment was well tolerated, with seven grade 1 and five Grade 2 protocol-related adverse effects. Nine out of 17 included patients had no recurrences during the year following the first instillation of MAK. The aim of the present study was to search for immune parameters related to local immunostimulation induced by MAK. Monitoring of the patients showed that urinary IL-8, GM-CSF and, to a lesser extent, IL-18 were increased following MAK instillations, with inter-individual differences. The urinary IL-8 level was about 10-fold higher than that observed for other cytokines, and its biological activity was reflected by a concomitant increase of urinary elastase, indicating neutrophil activation and degranulation. We also showed that nine out of 12 patients investigated presented an increase of urinary neopterin, a marker of IFN-gamma-activated macrophages, 7 days after MAK instillation, while serum neopterin levels were almost stable. These results are in line with persistence of activated macrophages in the bladder wall after infusions. Moreover, there was evidence of macrophages in urine smears 2 months after the sixth MAK instillation, and the score of macrophages correlated with the quantity of neutrophils in the urine. Overall, this study provides evidence of a local immunostimulation induced by this novel and safe immunotherapeutic approach of MAK instillations in patients with superficial bladder cancer.

Effects of tumor necrosis factor-alpha and interferon-gamma on expressions of matrix metalloproteinase-2 and -9 in human bladder cancer cells

We have investigated the effects of tumor necrosis factor-alpha (TNF-alpha) and interferon (INF-gamma), the potent Bacillus Calmette-Guerin (BCG)-induced cytokines on the production of MMP-2, MMP-9, TIMP-1, TIMP-2 and MT1-MMP in high grade human bladder cancer cell lines, T-24, J-82 and HT-1376 cell lines. MMP-2 expression and activity were decreased in T-24 cells treated with both cytokines in a dose dependent manner. However, J-82 cells treated with TNF-alpha and INF-gamma revealed dose dependent increases of MMP-9 expression and activity with similar baseline expression and activity of MMP-2. HT-1376 cells after exposure to TNF-alpha only enhanced the expression and activity of MMP-9. These results indicate that TNF-alpha and INF-gamma could regulate the production of MMP-2 or MMP-9 on bladder cancer cells and their patterns of regulation are cell specific. Furthermore, this diverse response of bladder cancer cells to TNF-alpha and INF-gamma suggests that BCG immunotherapy may enhance the invasiveness of bladder cancer in certain conditions with induction of MMPs.

Mechanisms of action of intravesical bacille Calmette-Guérin: local immune mechanisms

The local immune response to mycobacteria is complex, but mycobacterial antigen presentation by phagocytes to T helper cells is the pivotal interaction. Bacille Calmette-Guérin (BCG) vaccination is associated with the development of antituberculosis immunity but not necessarily with antitumor immunity. Animal studies have shown that an intact host immune system is required for the antitumor activity of BCG. Immunosuppressed and, particularly, T cell-depleted individuals fail to respond to BCG immunotherapy. Clinical and laboratory evidence suggest that the antitumor activity is concentrated at the site of BCG administration, which reinforces the view that local immune mechanisms are responsible for this phenomenon.

In vitro generation of bacillus Calmette-Guérin-activated killer cells

Tumor regression induced in cancer patients by local instillation of bacillus Calmette-Guérin (BCG) into the bladder is considered to be mediated by cellular immune and inflammatory reactions. In an attempt to elucidate which of these effects are relevant to tumoricidal activity, an in vitro system was employed in which the immunostimulatory effects of BCG could be studied. This report describes the induction of BCG-activated killer (BAK) cells, which effectively lyse bladder tumor cells. Human peripheral blood mononuclear cells (PBMC) were stimulated with viable and sonicated BCG (v-BCG and s-BCG, respectively) to generate BAK cells. Cytotoxicity of BAK cells was comparable with the cytotoxicity exerted by lymphokine-activated killer (LAK) cells generated by interferon (IFN)-gamma but did not reach the level of interleukin-2 (IL-2)-generated LAK cells. Induction of BAK cells was possible only with v-BCG and not with s-BCG. By depletion and enrichment of defined cell populations, the cytotoxic potential of BAK cells could be attributed to a population of CD8(+) and CD56(+) double-positive lymphocytes. Macrophages and CD4(+) cells were required for the induction of killing activity but had no such activity by themselves. Furthermore, the presence of IFN-gamma and IL-2 in the supernatants harvested during the generation of BAK cells was demonstrated. Monoclonal antibodies neutralizing these cytokines abolished BCG-mediated cytotoxicity. From these results, it is concluded that the known beneficial effect of local instillation of BCG on maintenance of the relapse-free state in superficial bladder cancer may be due to local generation of BAK cells.

Enhancing effect of an inhibitor of nitric oxide synthesis on bacillus Calmette-Guerin-induced macrophage cytotoxicity against murine bladder cancer cell line MBT-2 in vitro

We studied the effect of an inhibitor of nitric oxide (NO) synthesis, N(G)-monomethyl-L-arginine (L-NMMA), on the Bacillus Calmette-Guérin (BCG)-induced antitumor activity of murine peritoneal exudate cells (PEC) against murine bladder cancer cell line MBT-2 in vitro. L-NMMA enhanced BCG-induced cytotoxic activity of PEC, as well as interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha production. The L-NMMA-induced enhancement was due to the prolonged survival of BCG in macrophages, because no enhancement of cytotoxicity was observed and neither IFN-gamma nor TNF-alpha production was significantly enhanced by killed BCG. Anti-TNF-alpha antibody (Ab) and anti-IFN-gammaAb reduced the L-NMMA-induced enhancement of the cytotoxicity. The depletion of T cells from PEC reduced the production of both IFN-gamma and TNF-alpha, as well as the enhancement of cytotoxicity induced by viable BCG plus L-NMMA. These results suggest that L-NMMA has an enhancing effect on BCG-induced macrophage cytotoxicity and the enhancement is partially mediated by T cells and their soluble products. Accordingly, NO inhibitor should be a valuable adjunct to BCG immunotherapy for bladder cancer.

Measurement of cytokines in clinical samples using immunoassays: problems and pitfalls

With the explosion in interest in cytokines and an increasing understanding of their possible involvement in the pathogenesis of many diseases, the number of studies measuring cytokines in body fluids has increased markedly over the last 5 to 10 years. However, it is readily apparent from the literature that the level of awareness of the many factors that can potentially influence the results obtained is very low. Such factors are likely to contribute considerably to the disparities seen among similar types of study. These include assay properties such as standardization and specificity, type of sample and sample handling, and many biological influences such as age, sex, ethnic background, and diurnal rhythmicity. Clearly, it is not possible to control for all these factors, but a minimum evaluation of assays should be carried out as described, including recovery and parallelity studies using relevant samples and the establishment of reproducibility and normal healthy population levels. An awareness of these factors, which is the purpose of this review, may hopefully lead to an improvement in the quality of studies incorporating the measurement of cytokines in clinical samples and should aid in the interpretation of the data.

Non-specific, rapidly generated cytotoxicity in lymphocytes induced by BCG in vitro: no evidence of enhancing effect from preceding interaction between BCG and transitional cell line cells

PURPOSE

To study short-term events in the mechanism of action of BCG with an emphasis on the interaction between BCG and T24 cell line cells.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMNC) or/and several tumor cell lines were incubated with BCG (Oncotice) using various clinical and subclinical BCG concentrations.

RESULTS

3 h BCG incubation of PBMNC at 10(7) - 5*10(5) CFU/ml., followed by a 4 h cytotoxicity test, resulted in a significant augmentation of cytotoxicity of PBMNC against T24 cells, and the augmentation was almost significant at 10(5) CFU/ml. Overnight BCG incubation of PBMNC further augmented that cytotoxicity at all concentrations down to 10(4) CFU/ml. The minimum overall time (incubation with BCG + cytotoxicity test), where stimulation of PBMNC could be detected, was only 4 h. The BCG enhanced cytotoxicity of PBMNC could be demonstrated against all the tested cell line cells in a 4 h cytotoxicity test by using a preceding overnight BCG incubation of PBMNC, and against the majority of the cell lines by using a preceding 3 h BCG incubation of PBMNC. No convincing evidence was obtained to support the hypothesis that BCG should be first processed by T24 cells to make these cells more susceptible to cell mediated lysis by PBMNC.

CONCLUSIONS

Clinical and subclinical concentrations of BCG are directly stimulatory to PBMNC, which become, in a minimum time of a few hours, more capable of killing tumor cells, without a need for preceding interaction between BCG and tumor cells.

Role of IL-12 in the Induction and Potentiation of IFN-γ in Response to Bacillus Calmette-Guérin

Although Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been accepted as the most effective agent in clinical use against superficial bladder cancer, its mechanism of action remains incompletely understood. A kinetic analysis in assessing the potential role of cytokines from BCG-stimulated murine splenocytes showed that IL-12 expression preceded that of other cytokines. Experiments subtracting endogenous BCG-driven IL-12 using neutralizing Ab or augmenting its activity with supplemental rIL-12 revealed not only that IL-12 plays a dominant role in IFN-γ induction but also that it is normally dose limiting. A striking increase in IFN-γ production could be generated in both mouse and human immunocompetent cell culture by the addition of even a small amount of rIL-12. Moreover, this same synergistic effect could be replicated during in vivo administration of BCG plus rIL-12 into the mouse bladder and was observed in a patient receiving intravesical combination therapy. In costimulation cultures, this synergy appeared to partially rely on IL-18 and IL-2 and could be down-regulated by IL-10. This suggests that a dynamic interplay between Th1 and Th2 cytokines is responsible for net IFN-γ production. The ability of supplemental exogenous IL-12 to strongly shift this balance toward Th1 provides an immunological basis for using it in conjunction with intravesical BCG for bladder cancer immunotherapy.

Urinary interleukin-2 monitoring during prolonged bacillus Calmette-Guerin treatment: can it predict the optimal number of instillations?

PURPOSE

In patients with superficial bladder cancer treated with a first 6-week instillation course of bacillus Calmette-Guerin (BCG) the induction pattern of urinary interleukin (IL)-2 has been described, and the levels of urinary IL-2 were associated with the clinical response to BCG treatment. We evaluated urinary IL-2 kinetics in patients with recurrent superficial bladder tumor receiving a second or third 6-week BCG instillation course. To our knowledge there have been no studies of prolonged BCG treatment and urinary cytokine responses.

MATERIALS AND METHODS

Urinary IL-2 was determined in 12 patients with superficial transitional cell carcinoma of the bladder receiving a complete (6-week) second or third BCG instillation course and in 3 patients receiving 3 BCG instillations during a maintenance schedule at month 3. Urinary IL-2 was determined with an enzyme-linked immunosorbent assay using an oligoclonal system.

RESULTS

Of 12 patients 10 had a urinary IL-2 positive response during the subsequent BCG course and at week 1 urinary IL-2 was already increased. Comparing the urinary IL-2 kinetics observed during a second or third with a first course, urinary IL-2 tended to be higher during the first and lower during the last weeks. If the interval between subsequent courses was short (12 months or less) significantly higher urinary IL-2 levels at weeks 1 and 2, and a lower level at week 6 were observed.

CONCLUSIONS

During a repeat BCG instillation course urinary IL-2 reached a maximum at an earlier week, especially if the interval between the subsequent courses was short. Since an association between urinary IL-2 levels and response to BCG treatment during an induction course has been observed, these immunological data argue in favor of a limited number of instillations during prolonged BCG therapy which could reduce side effects as well as costs.

Systemic immune response after intravesical instillation of bacille Calmette-Guérin (BCG) for superficial bladder cancer

The mechanism of anti-tumour activity by BCG is not known clearly. However, many studies suggest that immunological response is related to effectiveness of intravesical instillation of BCG in the therapy for superficial bladder carcinoma. Peripheral blood mononuclear cells (PBMC), urine and serum were obtained from patients with superficial carcinoma at various times during the course of BCG instillation. Urine of patients showed increased levels of IL-1beta, IL-2, IL-6, tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and macrophage colony-stimulating factor (M-CSF) after BCG instillation. Levels of IL-2 and IFN-gamma in the serum also increased after BCG instillation, but IL-1beta, IL-6, TNF-alpha and M-CSF were not detectable. Maximal levels of IL-2 and IFN-gamma in the urine or serum were shown after the fourth instillation. BCG-induced killer cell activity in PBMC increased significantly after the third BCG instillation. These results suggest that BCG instillation involved not only local immunological efforts but also systemic immune responses. Tumour-free patients produced higher BCG-induced killer cell activity than tumour recurrence patients. BCG-induced killer cell activity may be useful for monitoring the effectiveness of intravesical BCG instillation.

Local immune response after intravesical interferon gamma in superficial bladder cancer

OBJECTIVE

To investigate the lymphocyte subpopulations (T4, T8 and macrophages) and major histocompatibility (MHC) II antigens in patients with superficial bladder cancer before and after intravesical instillations of recombinant interferon-gamma (IFN-gamma).

PATIENTS AND METHODS

Four intravesical weekly instillations of either 1.3 mg (20 patients, group A) or 0.7 mg (11 patients, group B) IFN-gamma were administered in 31 evaluable patients (28 men and three women, mean age 68.5 years). The CD4+, CD8+, CD68+ and HLA-DR antigens were detected immunohistochemically in tumours and a marker tumour before and after intravesical instillations.

RESULTS

The median number of T4 lymphocytes increased from 15 per high-power field (HPF) to 27.5 in group A (P = 0.0029) and to 45 in group B (P = 0.0117). Macrophages increased from 6 cells/HPF to 15 cells/HPF in group A (P = 0.0029) and from 2 to 8.75 cells/HPF in group B (P = 0.0117). The T8 lymphocyte subpopulation decreased from 4 to 3 cells/HPF (P = 0.0231) in group A and from 5 to 2 cells/HPF (P = 0.0759) in group B. The median percentage of HLA-DR antigens increased from 1.5% to 18% in general, (P < 0.001), from 2.5% to 15% in group A (P = 0.0064) and from 0% to 20% in group B (P = 0.0077). The induction of HLA-DR antigens was statistically significant in those receiving the lower dose (from 0% before instillation to 20% afterward, P = 0.0277), while it was not with the higher dose (from 0% to 5%, P = 0.068). Irrespective of the dose of IFN used. T4 lymphocytes and macrophages increased significantly after treatment in patients in whom the tumour HLA-DR antigens were either up-regulated or remained stable. The median net increase in T4 cells was 17.5 and 30 cells/HPF for groups A and B, respectively (P = 0.0429).

CONCLUSION

T4 lymphocytes, macrophages and HLA-DR antigens increased after intravesical IFN-gamma in patients with superficial bladder cancer, but T8 lymphocytes decreased. Irrespective of the drug dose used, patients with either upregulated or stable HLA-DR antigens after treatment showed the same pattern of changes in the lymphocyte subpopulations. The two doses generally had the same effect on the immunological variables assessed but the lower dose was more effective in inducing HLA-DR antigens and in increasing the number of T4 lymphocytes in the tumours.

Intravesical immunoprophylaxis in recurrent superficial bladder cancer (Stage T1): multicenter trial comparing bacille Calmette-Guérin and interferon-alpha

OBJECTIVES

To estimate and compare recurrence rates, index of recurrence, and disease-free interval in patients with superficial recurrent bladder cancer receiving bacille Calmette-Guérin (BCG) or interferon (IFN) for immunoprophylaxis.

METHODS

One hundred twenty-two patients with recurrent superficial Stage pT1, grade 1 to 3 tumors were enrolled in a randomized, prospective, multicenter trial with two treatment arms of endovesical immunoprophylaxis: 150 mg of BCG versus 54 MU of recombinant IFN-alpha-2a. Administration was weekly during the first month, biweekly for 2 months, and monthly for 9 months. Both groups were similar with regard to tumor stage, grade, size, and number.

RESULTS

Sixty-one patients were evaluable in the BCG group and 49 in the IFN group. Tumors recurred in 34 (69.4%) of 49 patients in the IFN group (890 months of follow-up) and in 24 (39.3%) of 61 in the BCG group (1272 months of follow-up). The total number of recurrences (28 for BCG, 47 for IFN), disease-free interval (mean 19.3 months for BCG, 15.3 months for IFN), and index of recurrence (2.2 for BCG, 5.5 for IFN) were statistically significant (P = 0.001) in favor of BCG. Progression to invasive carcinoma was similar in both study arms. Neither systemic nor local side effects were seen in the IFN group. However, the previously reported toxicity of BCG was confirmed.

CONCLUSIONS

According to our trial, BCG remains the most efficacious agent for immunoprophylaxis of recurrent superficial bladder tumors.

Cytokine-mediated antitumor effect of OK-432 on urinary bladder tumor cells in vitro

Fatal complications from the intravesical instillation of bacillus Calmette-Guérin (BCG) for the treatment of superficial urinary bladder tumors have been reported. OK-432, an immunomodulating agent like BCG, may be an effective and safe agent for the treatment of urinary bladder tumors. We investigated the cytokine-mediated antitumor effect of OK-432 on established human bladder cancer cell lines (T24 and KK-47) in vitro. Peripheral blood mononuclear cells (PBMCs) from a healthy volunteer were cultured with OK-432 for various periods, and the culture supernatants were used as conditioned media. Cytokines in the culture supernatants were quantified. The antitumor effect of OK-432 was evaluated by colony-forming assays, using the conditioned media as the culture media. The colony survival of T24 and KK-47 cells was significantly inhibited by conditioned media from 24-h cultures of PBMCs incubated with OK-432 at concentrations of 0.05 and 0.1 Klinische Einheit (KE)/ml. Conditioned media from PBMCs cultivated with OK-432 for 7 days at 0.01 and 0.05 KE/ml also significantly inhibited the colony survival of both cell lines. Higher concentrations of interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF alpha) were detected in conditioned media cultivated with OK-432 for 24 h than in media from PBMCs alone. However, higher concentrations of interferon gamma (IFN gamma) were detected in conditioned media cultivated with OK-432 for 7 days. Approximately 90% of the inhibition of KK-47 cells by the 24-h conditioned media was neutralized by an anti-TNF monoclonal antibody. The inhibition of T24 cells was neutralized approximately 50% by the same antibody. The inhibition of T24 and KK-47 cells by 7-day conditioned media was completely neutralized by an anti-IFN gamma monoclonal antibody. The cultivation of PBMCs with OK-432 inhibited the production of granulocyte-colony-stimulating factor (G-CSF) by PBMCs. The inhibition may play a role in the mechanism of the antitumor effect of OK-432. Urinary bladder tumor cell lines have different sensitivities to cytokines. The cytokines induced by OK-432 vary with the concentration of OK-432 and the culture period. It is suggested that in intravesical instillation of OK-432 for treatment of urinary bladder tumor, the optimal dose and interval of instillation should be considered.