Intravesical Evans strain BCG therapy: quantitative immunohistochemical analysis of the immune response within the bladder wall

Preclinical evaluation of a gene therapy treatment for transitional cell carcinoma

Three drugs were compared for their efficacy in treating murine transitional cell carcinoma (TCC) of the bladder. Intravesical gene therapy treatments utilizing expression-targeted plasmids, where the murine cyclooxygenase-2 (Cox-2) promoter was used to drive the expression of exogenously inducible forms of caspases 3 and 9, were compared with treatment modalities employing Bacille Calmette-Guérin (BCG) and celecoxib. When administered via lavage, only the gene therapy regimen was found to be effective at restricting tumor progression following a 7-day incubation of tumor tissues. Celecoxib was also administered via the diet to allow for systemic delivery of the drug. The most efficacious celecoxib use tested yielded tumors with masses of (18.3±8.4 mg) versus the gene delivery method, which yielded tumors with masses of (3.6±7.7 mg). The difference was significant (t-test, n≥4, P<0.025). The results showed that the Cox-2 expression-targeted gene therapy system could efficiently bypass the bladder permeability barrier and more effectively inhibit tumor growth and development than either BCG or celecoxib treatments. Long-term data further demonstrated that the gene therapy system could effectively inhibit tumor growth and elongate life expectancy.

Mycobacterium bovis bacillus Calmette-Guérin-induced macrophage cytotoxicity against bladder cancer cells

Many details of the molecular and cellular mechanisms involved in Mycobacterium bovis bacillus Calmette-Guérin (BCG) immunotherapy of bladder cancer have been discovered in the past decades. However, information on a potential role for macrophage cytotoxicity as an effector mechanism is limited. Macrophages play pivotal roles in the host innate immunity and serve as a first line of defense in mycobacterial infection. In addition to their function as professional antigen-presenting cells, the tumoricidal activity of macrophages has also been studied with considerable interest. Studies have shown that activated macrophages are potent in killing malignant cells of various tissue origins. This review summarizes the current understanding of the BCG-induced macrophage cytotoxicity toward bladder cancer cells with an intention to inspire investigation on this important but underdeveloped research field.

Interleukin-10 inhibits Mycobacterium bovis bacillus Calmette-Guérin (BCG)-induced macrophage cytotoxicity against bladder cancer cells

The mechanisms underlying bacillus Calmette-Guérin (BCG) immunotherapy of bladder cancer currently remain elusive. Previously, we demonstrated that macrophages were cytotoxic to bladder cancer cells upon BCG stimulation in vitro. However, macrophages from C57BL/6 mice were less potent than those from C3H/HeN mice for the killing of bladder cancer cells. This study was to determine whether interleukin (IL)-10 produced by macrophages in response to BCG is a causative factor for the reduced cytotoxicity in BCG-stimulated C57BL/6 macrophages. Thioglycollate-elicited peritoneal macrophages were prepared and analysed for the BCG induction of cytotoxicity, cytokines and nitric oxide (NO) in vitro. Compared to BCG-stimulated C3H/HeN macrophages, BCG-stimulated C57BL/6 macrophages exhibited reduced killing of bladder cancer MBT-2 cells and MB49 cells. Studies demonstrated further that BCG-stimulated C57BL/6 macrophages produced a high level of IL-10, which correlated with reduced production of tumour necrosis factor (TNF)-alpha, IL-6 and NO. Neutralizing endogenous IL-10 during BCG stimulation increased C57BL/6 macrophage cytotoxicity against MB49 cells by 3.2-fold, along with increased production of TNF-alpha by 6.4-fold and NO by 3.6-fold, respectively. Macrophages from C57BL/6 IL-10(-/-) mice also exhibited increased killing of MB49 cells and production of TNF-alpha and NO upon BCG stimulation. In addition, supplementation of exogenous recombinant IL-10 reduced BCG-induced C3H/HeN macrophage cytotoxicity against both MBT-2 cells and MB49 cells in a dose-dependent manner. These results reveal the inhibitory role of IL-10 in BCG-induced macrophage cytotoxicity, suggesting that blockage of IL-10 may potentially enhance the effect of BCG in the treatment of bladder cancer patients.

Recombinant bacillus Calmette-Guérin (BCG) expressing interferon-alpha 2B enhances human mononuclear cell cytotoxicity against bladder cancer cell lines in vitro

PURPOSE

The proper induction of cellular immunity is required for effective bacillus Calmette-Guérin (BCG) immunotherapy of bladder cancer. It has been known that BCG stimulation of human peripheral blood mononuclear cells (PBMC) leads to the generation of effector cells cytotoxic to bladder cancer cells in vitro. To improve BCG therapy, we previously developed human interferon (IFN)-alpha 2B secreting recombinant (r) BCG (rBCG-IFN-alpha). We demonstrated that rBCG-IFN-alpha augmented T helper type 1 (Th1) cytokine IFN-gamma production by PBMC. In this study, we further investigated whether rBCG-IFN-alpha could also enhance PBMC cytotoxicity toward bladder cancer cells.

MATERIALS AND METHODS

PBMC were prepared from healthy individuals, left alone or stimulated with rBCG-IFN-alpha or control MV261 BCG, and used as effector cells in (51)Cr-release assays. Human bladder cancer cell lines T24, J82, 5637, TCCSUP, and UMUC-3 were used as target cells. To determine the role of secreted rIFN-alpha as well as endogenously expressed IFN-gamma and IL-2 in inducing the cytotoxicity, PBMC were stimulated with rBCG-IFN-alpha in the presence of neutralizing antibodies to IFN-alpha, IFN-gamma or IL-2. To determine the role of natural killer (NK) and CD8(+) T cells in inducing the cytotoxicity, both cell types were isolated after BCG stimulation of PBMC and used as effector cells in (51)Cr-release assays.

RESULTS

Non-stimulated PBMC showed basal levels of cytotoxicity against all target cell lines tested. MV261 BCG increased the PBMC cytotoxicity by 1.8- to 4.2-fold. rBCG-IFN-alpha further increased the PBMC cytotoxicity by up to 2-fold. Elevated production of IFN-gamma and IL-2 by PBMC was observed after rBCG-IFN-alpha stimulation. Blockage of IFN-alpha, IFN-gamma or IL-2 by neutralizing antibodies during rBCG-IFN-alpha stimulation reduced or abolished the induction of PBMC cytotoxicity. Both NK and CD8(+) T cells were found to be responsible for the enhanced PBMC cytotoxicity induced by rBCG-IFN-alpha with the former cell type being more predominant.

CONCLUSIONS

rBCG-IFN-alpha is an improved BCG agent that induces enhanced PBMC cytotoxicity against bladder cancer cells in vitro. This rBCG strain may serve as an alternative to BCG for the treatment of superficial bladder cancer.

A possible mechanism of intravesical BCG therapy for human bladder carcinoma: involvement of innate effector cells for the inhibition of tumor growth

Intravesical bacillus Calmette-Guerin (BCG) therapy is considered the most successful immunotherapy against solid tumors of human bladder carcinoma. To determine the actual effector cells activated by intravesical BCG therapy to inhibit the growth of bladder carcinoma, T24 human bladder tumor cells, expressing very low levels of class I MHC, were co-cultured with allogeneic peripheral blood mononuclear cells (PBMCs) with live BCG. The proliferation of T24 cells was markedly inhibited when BCG-infected dendritic cells (DCs) were added to the culture although the addition of either BCG or uninfected DCs alone did not result in any inhibition. The inhibitory effect was much stronger when the DCs were infected with live BCG rather than with heat-inactivated BCG. The live BCG-infected DCs secreted TNF-alpha and IL-12 within a day and this secretion continued for at least a week, while the heat-inactivated BCG-infected DCs secreted no IL-12 and little TNF-alpha. Such secretion of cytokines may activate innate alert cells, and indeed NKT cells expressing IL-12 receptors apparently proliferated and were activated to produce cytocidal perforin among the PBMCs when live BCG-infected DCs were externally added. Moreover, depletion of gammadelta T-cells from PBMCs significantly reduced the cytotoxic effect on T24 cells, while depletion of CD8beta cells did not affect T24 cell growth. Furthermore, the innate effectors seem to recognize MICA/MICB molecules on T24 via NKG2D receptors. These findings suggest the involvement of innate alert cells activated by the live BCG-infected DCs to inhibit the growth of bladder carcinoma and provide a possible mechanism of intravesical BCG therapy.

Peritoneal tuberculosis and granulomatous hepatitis secondary to treatment of bladder cancer with Bacillus Calmette-Guérin

Intravesical administration of Bacillus Calmette-Guérin is used as a treatment method in superficial bladder cancer. While it is generally well tolerated, serious side effects may develop. Granulomatous hepatitis cases have been previously reported; however, only one case with tuberculous peritonitis exists in the current literature. We hereby present two cases, one of which is the second tubercular peritonitis case following Bacillus Calmette-Guérin treatment to be reported, and the other a case with granulomatous hepatitis. Complete cure was achieved in both cases with specific therapy. In the patient who developed peritonitis, intravesical Bacillus Calmette-Guérin therapy was recommenced after antituberculosis treatment, and completed without further complications.

A new strategy to induce effective antitumour response in vitro and in vivo

To induce Her2-specific cell immune response, we used xenogeneic antigen rat neu L2-S2 domains as the vaccine antigen. The antigenic protein was engineered as a chimeric protein with human IgG1 Fc region (neu-Fc). Neu-Fc could stimulate the cell proliferation in mixed lymphocyte reaction effectively. Simultaneous neu-Fc and IFN-gamma stimulation dramatically elevated IL-12 secretion and reduced IL-10 production in PBMC. To further augment the activating effects on Th1-type response, Bacille Calmette-Guerin (BCG) was utilized as a non-specific stimulus. Neu-Fc, IFN-gamma and BCG costimulation exhibited the most conspicuous effects on the reversal of the Th1-type inhibitory effects by MCF-7 cell supernatant compared with neu-Fc alone or IFN-gamma and BCG costimulation. The lytic activity of effector cells to Her2 overexpressing cells was greatly promoted by neu-Fc, IFN-gamma and BCG stimulation simultaneously. Neu-Fc led to considerable retardation in EMT6/Her2 tumour growth in Balb/c mice. IFN-gamma and BCG efficiently enhanced the antitumour activity. A large amount of inflammatory cells were found to be accumulated in the tumour tissues or surrounded tumours in mice treated with neu-Fc, IFN-gamma and BCG but no inflammatory cell infiltration was observed in control tumours, indicating that the strategy is potent enough to support the initiation and propagation of tumour-specific immune response in an established tumour and generate a proinflammatory environment.

Role of neutrophils in BCG immunotherapy for bladder cancer

Bladder cancer accounts for approximately 13,000 deaths annually, and >60,000 new cases will appear this year, making it the fourth and tenth most common cancer among men and women, respectively. The majority of the newly diagnosed cases will be diagnosed prior to muscle invasion, and are thus potentially completely curable. Unfortunately, >20% of patients initially diagnosed with non-muscle invasive bladder cancer will eventually die of their disease despite local endoscopic surgery. Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been used for the treatment of bladder cancer since 1976, and continues to be at the forefront of therapeutic options for this malignancy. Despite its success and worldwide acceptance, the antitumor effector mechanisms remain elusive. BCG therapy induces a massive local immune response characterized by the expression of multiple cytokines in the urine and bladder tissue, and the influx of granulocytes and mononuclear cells into the bladder wall. Findings from our laboratory have demonstrated that tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is induced by BCG treatment, and TRAIL was expressed on polymorphonuclear neutrophils (PMN) in the urine obtained from patients after intravesical BCG instillation. Subsequently, we have determined that BCG and components of the mycobacterial cell wall can directly stimulate the release of soluble TRAIL from PMN through toll-like receptor-2 (TLR2) recognition that is augmented by interferon (IFN). Based on our work and that of others implicating the need for T helper type 1 (Th-1) cytokine responses to BCG therapy for therapeutic results, we propose that TRAIL is released by PMN migrating to the bladder in response to BCG treatment. In addition, IFN acts to augment and prolong the amount of TRAIL released by PMN, resulting in an effective therapeutic outcome.

The safety and efficacy of different doses of bacillus Calmette Guérin in superficial bladder transitional cell carcinoma

OBJECTIVES

To conduct a trial using three different doses of bacillus Calmette-Guérin (BCG) to determine whether lowering the dose of BCG could reduce toxicity without compromising its efficacy in the treatment of superficial bladder cancer.

METHODS

From July 2002 to June 2005, 152 patients with superficial bladder cancer entered the trial. The patients were randomized to receive three different doses of BCG: 40, 80, and 120 mg. There were no significant differences in clinical and pathologic characteristics among the three groups. Twenty-four patients could not be followed to the end of the study because of poor compliance. At completion of the study, 40 patients could be evaluated in group A (40 mg), 48 in group B (80 mg), and 40 in group C (120 mg).

RESULTS

After treatment patients were evaluated for a mean follow-up period of 36 months (range 18 to 52 months). No significant difference in recurrence rate (20% versus 25% versus 20% respectively; P >0.05) was observed among the groups, and no progression of the disease was seen. Significant differences were observed among groups A, B, and C in local toxicity (30% versus 41.7% versus 70%, respectively; P <0.01). Systemic toxicity was more common in group C compared with groups B and A (P <0.01).

CONCLUSIONS

Reduction in the dose of intravesical BCG can reduce the toxicity associated with the treatment of superficial bladder cancer without affecting the efficacy of therapy.

Neutrophil granulocytes are required for effective Bacillus Calmette-Guérin immunotherapy of bladder cancer and orchestrate local immune responses

The role of polymorphonuclear neutrophil granulocytes (PMN) in antitumoral immune responses displays a striking dichotomy. Under inflammatory conditions, PMN may promote tumor growth and progression. In contrast, especially in the context of therapeutic interventions, PMN can exert important antitumor functions. However, until now, the mechanisms of PMN-mediated activation of tumor immunity are poorly defined. Based on a murine model of Bacillus Calmette-Guérin (BCG) immunotherapy of bladder cancer, we provide evidence for a novel immunoregulatory role of this leukocyte subset. PMN immigrate into the bladder after intravesical BCG instillation and depletion of PMN from tumor-bearing mice completely abrogated antitumor efficacy of BCG. PMN stimulated with BCG in vitro as well as PMN isolated from the urine of BCG-treated patients were a major source of the chemokines interleukin-8, growth-related oncogene-alpha, macrophage inflammatory protein-1 alpha and of the inflammatory cytokine migration inhibitory factor. In vitro, BCG-stimulated PMN indirectly induced T-cell chemotaxis via the accessory function of activated monocytes. In vivo, depletion of PMN from BCG-treated mice significantly impaired CD4(+) T-cell trafficking to the bladder. These data show that PMN direct the migration of effector cells to the bladder and by this means are indispensable for effective tumor immunotherapy. Thus, our findings provide evidence for a novel early immunoregulatory role of these innate immune cells in local antitumor immunity.

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.

Dose-dependent synergy of Th1-stimulating cytokines on bacille Calmette-Guérin-induced interferon-gamma production by human mononuclear cells

Successful bacille Calmette-Guérin (BCG) immunotherapy of bladder cancer depends on the proper induction of a T helper-type 1 (Th1) immune response. In this study we investigated the possible involvement of Th1-stimulating cytokines in BCG-induced interferon (IFN)-gamma production as well as their potential roles in enhancing BCG-induced IFN-gamma from human peripheral blood mononuclear cells (PBMCs). BCG efficiently induced IFN-gamma production by PBMCs in a dose-dependent manner. Neutralization of endogenous cytokines interleukin (IL)-2, IL-12 and IFN-alpha reduced BCG-induced IFN-gamma by 38%, 67% and 49%, respectively. Although single recombinant (r) IL-2, rIL-12 and rIFN-alpha induced no or a marginal amount of IFN-gamma, a combination of any two or three cytokines increased IFN-gamma production. When BCG (a subsaturated dose) was combined with mono, dual or triple cytokines, a synergy on IFN-gamma production was observed. Such a synergy was readily achievable even when minimal or low doses of cytokines were used. No saturation of IFN-gamma production was observed even when a subsaturated BCG dose was combined with very high doses of cytokines. A robust IFN-gamma production was also observed when a minimal BCG dose was combined with minimal doses of triple cytokines. In addition, we demonstrated that IL-2- and IFN-alpha-expressing rBCGs were superior to wild-type BCG for PBMC IFN-gamma induction and that combination of both rBCGs showed a synergy in IFN-gamma production. Taken together, these results suggest that combination of BCG with certain exogenous or endogenous (expressed by rBCGs) Th1-stimulating cytokines is a rational candidate for further study in bladder cancer treatment.

Discriminators of mouse bladder response to intravesical Bacillus Calmette-Guerin (BCG)

Background

Intravesical Bacillus Calmette-Guerin (BCG) is an effective treatment for bladder superficial carcinoma and it is being tested in interstitial cystitis patients, but its precise mechanism of action remains poorly understood. It is not clear whether BCG induces the release of a unique set of cytokines apart from its pro-inflammatory effects. Therefore, we quantified bladder inflammatory responses and alterations in urinary cytokine protein induced by intravesical BCG and compared the results to non-specific pro-inflammatory stimuli (LPS and TNF-α). We went further to determine whether BCG treatment alters cytokine gene expression in the urinary bladder.

Methods

C57BL/6 female mice received four weekly instillations of BCG, LPS, or TNF-α. Morphometric analyses were conducted in bladders isolated from all groups and urine was collected for multiplex analysis of 18 cytokines. In addition, chromatin immune precipitation combined with real-time polymerase chain reaction assay (CHIP/Q-PCR) was used to test whether intravesical BCG would alter bladder cytokine gene expression.

Results

Acute BCG instillation induced edema which was progressively replaced by an inflammatory infiltrate, composed primarily of neutrophils, in response to weekly administrations. Our morphological analysis suggests that these polymorphonuclear neutrophils are of prime importance for the bladder responses to BCG. Overall, the inflammation induced by BCG was higher than LPS or TNF-α treatment but the major difference observed was the unique granuloma formation in response to BCG. Among the cytokines measured, this study highlighted the importance of IL-1β, IL-2, IL-3, IL-4, IL-6, IL-10, IL-17, GM-CSF, KC, and Rantes as discriminators between generalized inflammation and BCG-specific inflammatory responses. CHIP/Q-PCR indicates that acute BCG instillation induced an up-regulation of IL-17A, IL-17B, and IL-17RA, whereas chronic BCG induced IL-17B, IL-17RA, and IL-17RB.

Conclusion

To the best of our knowledge, the present work is the first to report that BCG induces an increase in the IL-17 family genes. In addition, BCG induces a unique type of persisting bladder inflammation different from TNF-α, LPS, and, most likely, other classical pro-inflammatory stimuli.

Mycobacterium bovis bacillus Calmette-Guérin (BCG) induces human CC- and CXC-chemokines in vitro and in vivo

Both CC- and CXC-chemokines are known to be potent leucocyte activators and chemoattractants and play important roles in inflammatory responses. However, chemokine response to bacillus Calmette-Guérin (BCG) infection remains incompletely defined. In this study, we investigated human CC- [macrophage-derived chemokine (MDC), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha and eosinophil chemoattractant activity (eotaxin)] and CXC-interferon-inducible protein (IP)-10 chemokine production in response to BCG stimulation. BCG efficiently induced all chemokines tested in the urine of four bladder cancer patients undergoing intravesical BCG immunotherapy. The peak urinary chemokine responses occurred generally between the fourth and sixth weekly treatment, except eotaxin, which was less predictable. To evaluate the effect of BCG on induction of chemokines in vitro, urothelial cell lines and peripheral blood mononuclear cells (PBMCs) were used. Although BCG induced no or marginal chemokines from urothelial SV-HUC-1, RT4 and T24 cells, BCG-derived cytokines [interleukin (IL)-1beta, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha] induced all chemokines tested except eotaxin from these cell lines. BCG also efficiently induced all chemokines tested except eotaxin from PBMCs of both BCG-naive and BCG-vaccinated subjects. MCP-1 and MIP-1alpha emerged at 4-5 h post-BCG exposure (early chemokines); IP-10 elevated at day 1 and peaked at day 2 (intermediate chemokine); and MDC elevated at day 1 and peaked at day 7 (late chemokine). This kinetic pattern was paralleled with that of BCG-induced cytokines [early: TNF-alpha; intermediate: IL-6 and IL-10; and late: IFN-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF)]. Taken together, these results indicate that BCG directly or indirectly induces human CC- and CXC-chemokine production, which may represent one of the mechanisms by which BCG exerts its anti-tumour activity.

Poliartritis secundaria a instilaciones intravesicales de BCG, a propósito de un caso

Immunotherapy with intravesical instillation of Bacillus Calmette is the best complementary after TUR treatment against T1 grade 2- 3 and CIS bladder cancer. However, this therapy is associated with several side- effects, incluiding joint symptoms. In this article we describe a case of polyarthritis associated with intravesical instillation, a rare complication. We review the clinical features, the pathogenic mechanisms and treatments described previously in the medical literature. Finally, we expose our brief experience and our final result.

Role of Th1-stimulating cytokines in bacillus Calmette-Guérin (BCG)-induced macrophage cytotoxicity against mouse bladder cancer MBT-2 cells

Previously, we have demonstrated that macrophages exhibited cytotoxicity toward mouse bladder cancer MBT-2 cells upon bacille Calmette-Guérin (BCG) stimulation. In this study, we have investigated the role of Th1-stimulating cytokines in BCG-induced macrophage cytotoxicity. Thioglycollate-elicited peritoneal exudate cells (PECs) were used as a conventional source for macrophages and the induction of PEC effector functions (cytolytic activity and cytokine production) by BCG was evaluated in vitro. The BCG-activated PECs showed potent cytotoxicity and killed MBT-2 cells in a dose-dependent manner. Depletion of T cells, natural killer (NK) cells, or both, in PEC preparations exhibited a marginal or small reduction of MBT-2 cell killing, suggesting that macrophages played a primary role in PEC cytotoxicity. Transwell assays indicated that the maximal PEC cytotoxicity required both direct cell-cell contact and soluble factors such as interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha. Neutralizing endogenous cytokines interleukin (IL)-12, IL-18, IFN-gamma or TNF-alpha reduced PEC cytotoxicity by 38%, 22%, 15% and 94%, respectively. Supplementation of BCG with recombinant (r)IL-2, rIL-12 or rIL-18 increased PEC cytotoxicity by approximately twofold. Compared with control BCG for PEC stimulation, rBCGs expressing IL-2 or IL-18 showed enhanced MBT-2 cell killing by PECs. Increased cytokine production (IFN-gamma, TNF-alpha and IL-6) was also observed in rBCG-stimulated PEC cultures. Taken together, these results suggest that Th1-stimulating cytokines play an important role in BCG-induced macrophage cytotoxicity and that combination of BCG with selected Th1-stimulating cytokines, either supplemented or expressed by BCG, may enhance the effect of BCG in the treatment of bladder cancer patients.

The role of granulocytes following intravesical BCG prophylaxis

OBJECTIVES

The antitumour effect of bacillus Calmette-Guérin (BCG) still remains relatively undefined. Most investigations on its mechanism of action have focused on mononuclear cells; little consideration has been given to granulocytes. We analysed urine of patients with bladder cancer during 8 wk of intravesical BCG prophylaxis. The number of polymorphonuclear neutrophils (PMNs) and urothelial cells (UCs) was evaluated. We examined the in vitro response of the T24 UC line to human PMNs after BCG treatment.

METHODS

Seventeen patients were enrolled in the study. Cytologic analyses were performed on urine samples collected before each BCG instillation and after 2 h from the first voided urine after BCG instillation. Elastase activity was determined on these samples to evaluate PMN activation. PMN-induced damage was measured on the T24 cell line treated with BCG.

RESULTS

After BCG treatment, a large number of PMNs transmigrated through the urothelium and PMNs adherent to detached UCs were found. One patient, who did not respond with significant PMN transmigration, experienced recurrent disease. The number of eosinophils that transmigrated was low, with the exception of three patients with recurrent disease. In vitro, PMNs adhered to BCG-primed T24 cells and damaged the monolayer.

CONCLUSIONS

The results agree with recent evidence that PMNs may play an important role in the antitumour action of BCG during the BCG induction period. This role is probably nonspecific because both normal UCs in vivo and tumour cells in vitro appeared to be injured. As suggested by results obtained from a limited number of patients, a high number of eosinophils in the urine may indicate therapy failure.

Flow cytometric analysis of Th1 and Th2 cytokines in PBMCs as a parameter of immunological dysfunction in patients of superficial transitional cell carcinoma of bladder

Transitional cell carcinoma (TCC) is the commonest cancer of the bladder. Although majority of TCC can be diagnosed at an early stage and removed easily by transurethral resection of tumor (TURT), the management of this carcinoma is complicated due to frequent recurrences usually within 6 months to one-year period. An imbalance between the Th1 and Th2 immune responses has been attributed to immune dysregulation in various malignancies. The present study aims to evaluate the Th1 and Th2 balance in Peripheral Blood Mononuclear Cells of 41 TCC patients (20 recurrent and 21 non-recurrent) using flow cytometry. It also further assesses immunological and cellular factors influencing the anti-neoplastic activity of the TCC patients and in 21 normal healthy subjects in terms of their cytokine expression and various cell surface markers. The findings of the study revealed that the cell surface markers CD3+, CD4+ and CD8+ along with NK cells were found to be significantly lower in patients than healthy controls (p < 0.01). The mean percent expression of CD4+ was significantly lower in patients showing recurrence (23.9 +/- 9.84) as compared to patients with non-recurrence (31.1 +/- 12.27). The percentage of CD4+T-cells (mean +/- SD) producing IFN-gamma, IL-2 and TNF-alpha were statistically significantly reduced in patients (19.1 +/- 4.94, 52.3 +/- 20.86 and 12.8 +/- 4.49) as compared to healthy controls (23.3 +/- 3.67, 67.5 +/- 12.0 and 17.6 +/- 5.96 respectively), (p < 0.01, 0.018, 0.001). On the contrary, the mean levels of IL-4, IL-6 and IL-10 in patients (63.8+/-17.01, 60.4+/-14.79 and 65.7 +/- 14.84 respectively) were significantly higher as compared to healthy controls (24.4 +/- 8.77, 26.5 +/- 5.28 and 20.6 +/- 3.81 respectively), (p < 0.001). No statistically significant difference was observed in the cytokine expression between patients showing recurrence and non-recurrence. Patients with bladder cancer seem to develop a Th2 dominant status with a deficient type1 immune response. The lymphocyte evaluation along with cytokine measurement can provide a sensitive and valuable tool for evaluating the function of cell-mediated immunity in these patients and can also find application in therapeutic monitoring of bladder cancer patients as new targets for immunotherapy.

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.

Reactive arthritis following BCG immunotherapy for urinary bladder carcinoma: a systematic review

Intravesical instillation of Bacillus Calmette-Guerin (BCG) is used with efficacy and safety in the treatment of patients with intermediate and high-risk superficial bladder carcinoma. Arthralgia and/or arthritis is one of the rare severe complications following intravesical BCG immunotherapy. We searched MEDLINE in order to analyze the frequency of this clinical complication, its pathogenesis and outcome. The electronic search was conducted using the following key words: "BCG immunotherapy" and "Arthritis, arthralgias and BCG immunotherapy". At the end of a process of abstract analysis, 48 papers were included in the systematic review. All the selected papers, except one that was a clinical review, described at least one case of arthritis after BCG therapy. The BCG immunotherapy resulted to be safe and efficacious in the treatment of bladder cancer; the development of reactive arthritis is rare and can evolve in a chronic process. The review of the literature highlighted that reactive arthritis following BCG intravesical instillation is a complication usually well controlled with the discontinuation of the immunotherapy and nonsteroidal anti-inflammatory drugs (NSAIDs) treatment. Only a small portion of patients with a particular genetic background will develop a chronic process.

Neutrophil stimulation with Mycobacterium bovis bacillus Calmette-Guerin (BCG) results in the release of functional soluble TRAIL/Apo-2L

Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been used to treat bladder cancer for almost 30 years; however, the effector mechanism of the BCG-induced antitumor response remains enigmatic. Most BCG research has focused on the mononuclear-cell infiltrate, but growing evidence supports a role for neutrophils in the antitumor response. Previously, we demonstrated increased urinary tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/Apo-2L) levels from BCG-responsive patients compared to nonresponders. Interestingly, neutrophils isolated from the urine expressed TRAIL/Apo-2L, leading us to investigate the neutrophil response to BCG. BCG-stimulated neutrophils expressed surface-bound and released functional soluble TRAIL/Apo-2L. Whereas neither interferon alpha (IFN-alpha) nor IFN-gamma directly induced TRAIL/Apo2L expression by neutrophils, IFN-alpha did stimulate TRAIL gene transcription, and IFN-primed neutrophils contained and released more TRAIL/Apo-2L after BCG stimulation than did unprimed neutrophils. In unstimulated neutrophils TRAIL/Apo-2L was present predominantly in the azurophilic granules and plasma-membrane-enriched/secretory-granule fraction. Finally, we observed that killed BCG, Toll-like receptor 2 (TLR2) and TLR4 agonists, and an M tuberculosis cell-wall fraction were each capable of inducing the release of soluble TRAIL/Apo-2L from neutrophils. These results further characterize the potential role neutrophils may play in initiating the antitumor response described with BCG treatment for superficial bladder cancer.

Analysis of local T lymphocyte subsets upon stimulation with intravesical BCG: a model to study tuberculosis immunity

Cell-mediated immune response can control tuberculosis infection. A significant role for immune cells like CD4, CD8 and gammadelta T lymphocytes have been recognized, but little is known about the kinetics of activation and accumulation of these cells in course of Tuberculosis infection in humans. This is due to both the difficult to access to human lung and the fact that most subjects are examined in different periods of infection which may condition T cell changes. To overcome these problems, we have used intravesical BCG (Bacillus Calmette-Guerin) treatment for preventing the recurrences of bladder cancer as an in vivo experimental model of human tuberculosis infection. 20 male caucasian patients with proven bladder superficial transitional cell carcinoma treated with transurethral resection followed by six weekly intravesical instillations of BCG (T0-T6) were enrolled. Changes in T lymphocyte subsets were assessed by flow cytometry in the bladder wash recovered after each BCG instillation. Our study shows that the action of BCG appears to be T cell dependent. Lymphocytes increase at any new instillation and tend towards the reduction with the suspension of the stimulus. BCG induces a massive increase in the proportion of CD4 Th1 subset followed by an increase in gammadelta T cells, while no significant variation for CD8 and NK cells is found. Our results suggest that BCG infection model represents a valid experimental tool to study the immunological events evoked in vivo by Mycobacterium tuberculosis in humans at the site of infection.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand

Mycobacterium bovis Bacillus Calmette-Guérin (BCG) use in the treatment of bladder cancer was first reported in 1976, but the mechanism of the induced antitumor activity has still not been fully explained. BCG is a potent immunostimulant, normally producing a Th1 cytokine response, including IFN. Recent studies have shown CpG oligodeoxynucleotide induce tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression via IFN production. Given that Mycobacterial DNA contains high amounts of CpG motifs, we hypothesized that BCG's antitumor properties are akin to CpG oligodeoxynucleotide, where the cytokine response to BCG induces TRAIL up-regulation. Using ELISA, urine IFN-gamma, and TRAIL levels were initially undetectable in BCG therapy patients but were high after later induction treatments. More importantly, patients that responded to BCG therapy had significantly higher urine TRAIL levels, which killed bladder tumor cells in vitro versus nonresponders. Flow cytometry of fresh urine revealed TRAIL-expressing neutrophils. Given these data, we propose TRAIL plays a role in BCG-induced antitumor effects.

Primary care update on kidney and bladder cancer: a urologic perspective

The past decade has witnessed many substantive changes in the approach to the diagnosis and treatment of both kidney and bladder cancer. In part, this is based on changes in the understanding of their carcinogenesis and pathogenesis, an appreciation of new concepts in their classification, and the incorporation of new technologies that have emerged. This article reviews advances and updates changes that have been made in the understanding of and approaches to these malignancies from the perspective of their urologic assessment and management while in the context of primary care issues.

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.

The anti-tumor activity of bacillus Calmette-Guerin in bladder cancer is associated with an increase in the circulating level of interleukin-2

Bacillus Calmette-Guerin (BCG) is currently employed in the treatment of superficial bladder cancer but, despite its recognized effectiveness in preventing recurrences and progression, the immune mechanisms behind its antitumor activity remain to be delineated. In this study we provide evidence that a prolonged increase in the plasma levels of IL-2, but not IL-1beta, IL-4, IL-10, IL-2R or TNF-alpha occured in patients affected by bladder cancer following effective BCG treatment. Conversely, a drop in circulating IL-2 was consistently associated with tumor relapse. The level of IL-2 was elevated even further 15 days after the last BCG administration in patients who did not experience tumor recurrence, suggesting a prolonged T cell-mediated response against antigens other than BCG. Our results indicate that a specific type 1 immune response plays a major role in the anti-cancer activity of BCG. In addition, monitoring IL-2 plasma levels may offer a useful tool for predicting tumor recurrences.

Indinavir-associated interstitial nephritis and urothelial inflammation: clinical and cytologic findings

The objective of the present study was to characterize the genitourinary syndromes that accompany indinavir-associated pyuria. Of 23 indinavir-treated patients with persistent pyuria, 4 had isolated interstitial nephritis, 10 had both interstitial nephritis and urothelial inflammation, 7 had isolated urothelial inflammation, and 2 had pyuria with nonspecific urinary tract inflammation. A total of 21 patients had multinucleated histiocytes identified by cytologic testing of urine specimens. Urine abnormalities resolved in all 20 patients who stopped receiving indinavir therapy. Pyuria continued in the 3 patients who continued receiving indinavir. Six patients had elevated serum creatinine levels, which returned to baseline levels when indinavir was discontinued. In conclusion, indinavir-associated pyuria was frequently associated with evidence of interstitial nephritis and/or urothelial inflammation, multinucleated histiocytes were commonly present in urine specimens, and cessation of indinavir therapy was associated with prompt resolution of urine abnormalities.

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.

Evaluation of cellular tumour rejection mechanisms in the peritumoral bladder wall after bacillus Calmette-Guérin treatment

OBJECTIVE

To compare the immunological status of normal and peritumoral bladder walls, and to characterize immunocompetent cells before and during intravesical instillations of bacillus Calmette-Guérin (BCG).

PATIENTS AND METHODS

Twenty-three patients with superficial urothelial bladder carcinoma (stages pTa to pT1, grades 1-3) were treated with six weekly instillations of 150 mg of BCG (Pasteur strain). Biopsies of cystoscopically normal bladder wall were taken before, 3 weeks and 3 months after BCG instillation. The controls comprised bladder biopsy specimens from 13 brain-dead ventilated kidney donors. Local infiltrating cell types, i.e. lymphocyte infiltrates (CD4, CD8, CD20, CD3, interleukin-2-receptor-positive, natural killer, gammadelta), macrophages and dendritic cells, adhesion and costimulatory molecules (ICAM-1 and B7-BB1) and major histocompatibility complex (MHC) class I and class II antigens were assessed using semi-quantitative immunohistochemical analysis.

RESULTS

Before BCG the peritumoral bladder wall had fewer macrophages than control bladder wall. BCG treatment restored normal numbers of macrophages and enhanced T helper lymphocytes, B lymphocytes, natural killer cells, activated lymphocytes, dendritic cells, normal MHC class I, adhesion (ICAM-1) and costimulatory (B7-BB1) expression. The enhancement of these immunological variables was transient, with a return to baseline 3 months after BCG instillation.

CONCLUSIONS

These results support the concept that there is a host-immune escape associated with bladder cancer. BCG therapy may temporarily restore impaired tumour rejection mechanisms in the peritumoral bladder wall, suggesting a need for maintenance therapy after the first course of BCG.

NK cells are essential for effective BCG immunotherapy

Adjuvant intravesical bacillus Calmette-Guérin (BCG) therapy is a well-established and successful adjuvant immunotherapy in the treatment of superficial bladder cancer. Although the function of natural killer (NK) cells in other immunotherapeutic regimens (e.g., lymphokine-activated killer [LAK] cell or interleukin-2 [IL-2] therapy) has been established, the contribution of NK cells to effective BCG immunotherapy is not clear. We used a human in vitro system to analyze the role of NK cells in BCG-induced cellular cytotoxicity. After stimulation of mononuclear cells with BCG for 7 days, these BCG-activated killer (BAK) cells displayed substantial cytotoxicity against bladder tumor cells. Magnetic depletion experiments and fluorescence activated cell sorting revealed that NK cells were the major effector cell population. To address NK cell function in vivo, we studied a syngeneic orthotopic murine bladder cancer model and compared BCG immunotherapy in C57BL/6 wild-type mice, NK-deficient beige mice and mice treated with anti-NK1.1 monoclonal antibody. Four weekly instillations of viable BCG significantly prolonged survival in wild-type mice compared with control mice treated with solvent alone. In contrast, BCG therapy was completely ineffective in NK-deficient beige mice and in mice treated with anti-NK1.1 monoclonal antibody. These findings suggest a key role for NK cells during BCG immunotherapy.

Do bacteriostatic urethral lubricants affect the clinical efficacy of intravesical bacillus Calmette-Guérin therapy?

OBJECTIVES

To investigate the effect of a bacteriostatic urethral lubricant on the clinical efficacy of intravesical bacillus Calmette-Guérin (BCG) therapy.

METHODS

Between July 1987 and August 1999, 389 patients with superficial urothelial carcinoma of the bladder (pTa [multilocular, size greater than 2 cm, recurrent tumor], pT1, pTis) were treated adjuvantly with BCG in a 6-week intravesical cycle after complete transurethral tumor resection of the bladder. Within the framework of a prospective study on recurrence and progression of superficial urothelial carcinoma of the bladder after transurethral resection and BCG therapy, we retrospectively studied the clinical value of the observation that the use of bacteriostatic urethral lubricants reduces the viability and thus the efficacy of BCG. If a lubricant induces a clinically relevant reduction in the viability of BCG, instillation without lubricant should lead to a lower rate of recurrence and possibly a lower rate of progression. Lubricant (11 mL) was used during catheterization in every male patient in our population (group 1, n = 317, 81.5%); no lubricant was used in the women serving as the control group (group 2, n = 72, 18.5%). The two groups were similar with respect to age, distribution of tumor stage and grade, multifocality, and frequency of previous bladder carcinoma (Levene test, P = 0.008). The median follow-up was 54 months (range 4 to 143).

RESULTS

Of the 389 patients, 90 (23.1%) developed recurrence during the follow-up period: 73 (23%) in group 1 and 17 (23.6%) in group 2 (P value not significant). Progression occurred in 14 patients in group 1 (4.4%) and in 8 patients in group 2 (11%) (P = 0.043). In groups 1 and 2, 19.2% and 47.1%, respectively, of the recurrences were progressive (P = 0.026).

CONCLUSIONS

The use of bacteriostatic lubricants in the usual dose before BCG instillation had no detectable adverse effect on the clinical efficacy of intravesical BCG immunotherapy. To avoid traumatic catheterization with possible systemic BCG administration, we therefore recommend, especially in men, the additional use of a sufficient quantity of urethral lubricant.

Leukocyturia as a predictor of tolerance and efficacy of intravesical BCG maintenance therapy for superficial bladder cancer

OBJECTIVES

To examine leukocyturia as a predictor of tumor recurrence and occurrence of adverse events after bacille Calmette-Guérin (BCG) immunotherapy. The use of BCG immunotherapy, a very major advance in the management of superficial bladder cancer, is limited by the frequency of adverse events. As yet, we have no way of predicting the efficacy and tolerability of BCG instillation in clinical practice. This problem is even more acute during BCG maintenance therapy.

METHODS

Adverse events in 72 patients who received 518 instillations were prospectively assessed using a four-class scale based on severity and duration. Urinary leukocytes were counted 3 days after each instillation, using the KOVA-Slide 10 method.

RESULTS

High leukocyturia during BCG treatment (cutoff value 1.65 x 10(5)/mL urine) correlated with recurrence-free status (P = 0.009). The degree of leukocyturia correlated with the severity/duration of adverse events (P <0.0001); the median leukocyturia values associated with class I, II, and III adverse events were 4 x 10(4)/mL, 1.5 x 10(5)/mL, and 3.5 x 10(5)/mL, respectively. No class IV events occurred. The cutoff point indicating treatment cessation for adverse events was leukocyturia of 8.6 x 10(4)/mL.

CONCLUSIONS

These results suggest a link between adverse events and efficacy during BCG maintenance therapy. Leukocyturia appears to correlate with both efficacy and tolerability in this setting. Prospective randomized studies are required to evaluate leukocyturia as a basis on which to adapt the BCG instillation schedule to individual patient susceptibility.

Interaction between photodynamic therapy and BCG immunotherapy responsible for the reduced recurrence of treated mouse tumors

Subcutaneous mouse EMT6 tumors were treated by individual or combined regimens of a single Bacillus Calmette-Guérin (BCG) vaccine administration and photodynamic therapy (PDT). Six clinically relevant photosensitizers characterized by different action mechanisms were used: Photofrin, benzoporphyrin derivative, tetra(m-hydroxyphenyl)chlorin (foscan), mono-L-aspartylchlorin e6, lutetium texaphyrin or zinc phthalocyanine. Irrespective of the type of photosensitizer used, the optimized BCG protocols improved the cure rate of PDT-treated tumors. This indicates that the interaction does not take place during the early phase of tumor ablation but at later events involved in preventing tumor recurrence. Beneficial effects on tumor cure were observed even when the BCG injection was delayed to 7 days after PDT. The accumulation of activated myeloid cells that markedly increases in tumors treated by Photofrin-based PDT was not additionally affected by BCG treatment. However, the incidence of immune memory T cells in tumor-draining lymph nodes that almost doubled at 6 days after Photofrin-PDT further increased close to three-fold with adjuvant BCG. This suggests that BCG immunotherapy amplifies the T-lymphocyte-mediated immune response against PDT-treated tumors. Since both these modalities are established for the treatment of superficial bladder carcinomas, use of their combination for this condition should be clinically tested.

Clinical trials of immunotherapy for advanced prostate cancer

There is a lack of effective therapeutic regimens for advanced hormone-refractory prostate cancer (HRPC). Recent combination regimens of chemotherapy have improved management of HRPC. Neither systemic chemotherapy nor radiation regimens have significantly improved survival. Conventional systemic cytokine therapy has had limited efficacy in the treatment of advanced prostate cancer patients and its toxicity is severe. Combinations of multiple biological response modifiers for treatment of this disease also have limited efficacy. Results from phase II trials have shown that the combination of interferon-alpha and interleukin-2 therapy and the infusion of dendritic cells primed with peptides of prostate specific membrane antigen are promising. The former showed 31% response using the National Prostatic Cancer Project criteria, and the latter showed 27% of objective partial response with a reduction of >50% prostate specific antigen level. The toxicity of these two regimens was tolerated by patients. New approaches with tumor vaccines in conjunction with cytokine gene therapy have also been investigated. The clinical responses of these trials have been limited but promising. Immunotherapy may become an effective modality of prostate cancer treatment in the future.

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.

Immunostimulation in the urinary bladder by local application of Nocardia rubra cell-wall skeletons (Rubratin) and bacillus Calmette-Guérin as therapy for superficial bladder cancer: a comparative study

Twelve patients with superficial bladder cancer were treated with intravesical instillations of Rubratin (ASTA Pharma AG, Frankfurt, Germany), a cell-wall preparation of Nocardia rubra. The objective was to compare the immunostimulating effect of Rubratin with that of bacillus Calmette-Guérin (BCG). Local immunostimulation was determined by cytokine induction in serially collected urine samples during the first 24 h after each instillation, leukocyte influx into the urine, and phenotypic analysis of the lymphocyte fraction. Levels of Rubratin-induced interleukin (IL)-1 beta, IL-6, and tumor necrosis factor-alpha were significantly elevated compared with pretherapy levels. Rubratin induced leukocyte influx into the urine. T-cell activation (IL-2 receptor and human leukocyte antigen-DR expression) can be induced, and CD4:CD8 cell ratios can be increased. All parameters indicated that Rubratin-induced immunostimulation was less than that associated with BCG. In conclusion, although local Rubratin-induced immunostimulation occurs in a limited number of patients, the amount of immunocompetent cells attracted to the bladder seems to be less than that associated with BCG therapy, thus resulting in lower levels of cytokine production (which may reflect less clinical efficacy).

Reduction of side effects of intravesical therapy with bacille Calmette-Guérin by pentoxifylline?--an in vitro approach

Immunotherapy with intravesical bacille Calmette-Guérin (BCG) is the treatment of choice against superficial bladder cancer recurrences. However, this therapy is associated with side effects that are considered to be the result of inflammatory cytokines. Since pentoxifylline is known to interfere with the production of cytokines, this drug was tested in vitro with regard to a later clinical application in BCG-treated patients. The cytokine release and the cytotoxicity of interleukin-2 or BCG-stimulated mononuclear cells were analyzed, and the growth of BCG under the influence of pentoxifylline was assayed. The results showed an inhibition of cytokine release of stimulated mononuclear cells. The cytotoxicity of BCG-stimulated mononuclear cells but not of lymphokine-stimulated mononuclear cells against bladder carcinoma cells was significantly inhibited. Restimulation with fresh BCG restored cytotoxicity. Direct coincubation of BCG and pentoxifylline resulted in a reduction of mycobacterial metabolism. From these data, we conclude that the use of pentoxifylline to reduce BCG-related side effects should be tested further in a clinical study.