Baseline Cytokine Profiles of Tuberculin-Specific CD4+ T Cells in Non-Muscle-Invasive Bladder Cancer May Predict Outcomes of BCG Immunotherapy

Tumour microenvironment as a predictive factor for immunotherapy in non-muscle-invasive bladder cancer

Bladder cancer (BC) can be divided into two subgroups depending on invasion of the muscular layer: non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Its aggressiveness is associated, inter alia, with genetic aberrations like losses of 1p, 6q, 9p, 9q and 13q; gain of 5p; or alterations in the p53 and p16 pathways. Moreover, there are reported metabolic disturbances connected with poor diagnosis-for example, enhanced aerobic glycolysis, gluconeogenesis or haem catabolism.Currently, the primary way of treatment method is transurethral resection of the bladder tumour (TURBT) with adjuvant Bacillus Calmette-Guérin (BCG) therapy for NMIBC or radical cystectomy for MIBC combined with chemotherapy or immunotherapy. However, intravesical BCG immunotherapy and immune checkpoint inhibitors are not efficient in every case, so appropriate biomarkers are needed in order to select the proper treatment options. It seems that the success of immunotherapy depends mainly on the tumour microenvironment (TME), which reflects the molecular disturbances in the tumour. TME consists of specific conditions like hypoxia or local acidosis and different populations of immune cells including tumour-infiltrating lymphocytes, natural killer cells, neutrophils and B lymphocytes, which are responsible for shaping the response against tumour neoantigens and crucial pathways like the PD-L1/PD-1 axis.In this review, we summarise holistically the impact of the immune system, genetic alterations and metabolic changes that are key factors in immunotherapy success. These findings should enable better understanding of the TME complexity in case of NMIBC and causes of failures of current therapies.

Peripheral tuberculin purified protein derivative specific T cell immunoreactivity dynamics in non-muscle invasive bladder cancer patients receiving bacillus Calmette-Guerin instillation treatment

Intravesical bacillus Calmette-Guerin (BCG) instillation is recommended as an adjuvant therapy for intermediate-risk and high-risk non-muscle invasive bladder cancer (NMIBC) after transurethral resection of bladder tumor (TURBt) with nearly 70% reoccurrence. In the present study, we investigated the dynamics of peripheral purified protein derivative (PPD)-specific immune responses along the treatment. Intravesical BCG instillation caused a significant increase in peripheral PPD-specific IFN-γ release of NMIBC patients, when compared to those receiving chemo-drug instillation. Through a follow-up study, we detected rapid increase in PPD-specific IFN-γ, IL-2, and IL-17A producing CD4⁺ and CD8⁺ T cells in the induction phase. Interestingly, the frequencies of PPD-specific IFN-γ and IL-2 producing CD4⁺ and CD8⁺ T cells decreased dramatically after induction treatment and were restored after BCG re-instillation, whereas IL-17A-producing T cells remained at the maintenance phase. However, we only observed that the percentages of peripheral CD8⁺ T cells were significantly higher in BCG responder patients than those in BCG refractory patients at the baseline with the potential of predicting the recurrence. A more dramatic increase in PPD-specific IFN-γ and IL-2 producing CD4⁺ and CD8⁺ T cells after one and two dose BCG instillations was observed in refractory NMIBC patients. Therefore, regional BCG instillation induced transient peripheral PPD-specific T cell responses, which could be restored through repetitive BCG instillation. Higher proportions of peripheral CD8⁺ T cells at baseline were associated with better responses to BCG instillation for the prevention of recurrence of bladder cancer.

Tuberculosis-Cancer Parallels in Immune Response Regulation

Mycobacterium tuberculosis and cancer are two diseases with proclivity for the development of resistance to the host immune system. Mechanisms behind resistance can be host derived or disease mediated, but they usually depend on the balance of pro-inflammatory to anti-inflammatory immune signals. Immunotherapies have been the focus of efforts to shift that balance and drive the response required for diseases eradication. The immune response to tuberculosis has widely been thought to be T cell dependent, with the majority of research focused on T cell responses. However, the past decade has seen greater recognition of the importance of the innate immune response, highlighting factors such as trained innate immunity and macrophage polarization to mycobacterial clearance. At the same time, there has been a renaissance of immunotherapy treatments for cancer since the first checkpoint inhibitor passed clinical trials, in addition to work highlighting the importance of innate immune responses to cancer. However, there is still much to learn about host-derived responses and the development of resistance to new cancer therapies. This review examines the similarities between the immune responses to cancer and tuberculosis with the hope that their commonalities will facilitate research collaboration and discovery.

Serum CCL27 predicts the response to Bacillus Calmette-Guerin immunotherapy in non-muscle-invasive bladder cancer

The prediction of the response to Bacillus Calmette-Guerin (BCG) can help identify non-muscle-invasive bladder cancer (NMIBC) patients that may be better served with alternative therapy. Several cytokine profiles present promising results, but they are difficult to use in clinical practice. In this prospective, longitudinal study, we tried to identify reliable serum cytokines/chemokines to predict the response to BCG using samples collected before and during BCG induction therapy. We used the Bio-plex multiplex assays to identify potential BCG failure-related serum cytokines/chemokines in the discovery set (n = 13). After screening, we identified CCL27 as the top candidate biomarker for predicting the response to BCG (P = .003). In the validation set, we found that the AUC of the baseline CCL27 was 0.730 (95% CI 0.515-0.945, P = .040) along with 67% sensitivity, 78% specificity. The changes from baseline to last timepoint can also distinguish BCG responders from non-responders (AUC: 0.726, 95% CI 0.474-0.979, P = .044). Moreover, the combination score of serum CCL27 (CS_CCL27), based on the baseline and changes of CCL27, could further improve the predictive accuracy with an AUC of 0.897 (95% CI 0.790-1.000, P < .001). The correlations between CCL27 and local/systemic immunologic parameters were further analyzed. The level of serum CCL27 was strongly correlated with regulatory T cells (Tregs) in the tumor microenvironment (P = .002), indicating that CCL27 may promote the recruitment of Tregs into the tumor microenvironment. Our results show that serum CCL27 may represent a practical and reliable marker for the prediction of the response to BCG in NMIBC.