BACKGROUND: Prostate cancer (PCa) is a malignancy with significant immunosuppressive properties and limited immune activation. This immunosuppression is linked to reduced cytotoxic T cell activity, impaired antigen presentation, and elevated levels of immunosuppressive cytokines and immune checkpoint molecules. Studies demonstrate that cytotoxic CD8+ T cell infiltration correlates with improved survival, while increased regulatory T cells (Tregs) and tumor-associated macrophages (TAMs) are associated with worse outcomes and therapeutic resistance. Th1 cells are beneficial, whereas Th17 cells, producing interleukin-17 (IL-17), contribute to tumor progression. Tumor-associated neutrophils (TANs) and immune checkpoint molecules, such as PD-1/PD-L1 and T cell immunoglobulin-3 (TIM-3) are also linked to advanced stages of PCa. Chemotherapy holds promise in converting the "cold" tumor microenvironment (TME) to a "hot" one by depleting immunosuppressive cells and enhancing tumor immunogenicity. SUMMARY: This comprehensive review examines the immune microenvironment in PCa, focusing on the intricate interactions between immune and tumor cells in the TME. It highlights how TAMs, Tregs, cytotoxic T cells, and other immune cell types contribute to tumor progression or suppression and how PCa's low immunogenicity complicates immunotherapy. KEY MESSAGES: The infiltration of cytotoxic CD8+ T cells and Th1 cells correlates with better outcomes, while elevated T regs and TAMs promote tumor growth, metastasis, and resistance. TANs and natural killer (NK) cells exhibit dual roles, with higher NK cell levels linked to better prognoses. Immune checkpoint molecules like PD-1, PD-L1, and TIM-3 are associated with advanced disease. Chemotherapy can improve tumor immunogenicity by depleting T regs and myeloid-derived suppressor cells, offering therapeutic promise.

• Klíčová slova
• CD4, CD8, Immunology, Immunotherapy, Metastatic, Myeloid-derived suppressor cells, Neutrophils, Prostate tumor, T cells, Tertiary lymphoid structures, Tumor-associated macrophages,
• MeSH
• imunoterapie metody   MeSH
• lidé MeSH
• makrofágy spojené s nádory imunologie   MeSH
• nádorové mikroprostředí * imunologie   MeSH
• nádory prostaty * imunologie   patologie   terapie   MeSH
• regulační T-lymfocyty imunologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

OBJECTIVE: Immunotherapy of cancer has the potential to be effective mostly in patients with a low tumour burden. Rising PSA (prostate-specific antigen) levels in patients with prostate cancer represents such a situation. We performed the present clinical study with dendritic cell (DC)-based immunotherapy in this patient population. MATERIALS AND METHODS: The single-arm phase I/II trial registered as EudraCT 2009-017259-91 involved 27 patients with rising PSA levels. The study medication consisted of autologous DCs pulsed with the killed LNCaP cell line (DCVAC/PCa). Twelve patients with a favourable PSA response continued with the second cycle of immunotherapy. The primary and secondary objectives of the study were to assess the safety and determine the PSA doubling time (PSADT), respectively. RESULTS: No significant side effects were recorded. The median PSADT in all treated patients increased from 5.67 months prior to immunotherapy to 18.85 months after 12 doses (p < 0.0018). Twelve patients who continued immunotherapy with the second cycle had a median PSADT of 58 months that remained stable after the second cycle. In the peripheral blood, specific PSA-reacting T lymphocytes were increased significantly already after the fourth dose, and a stable frequency was detected throughout the remainder of DCVAC/PCa treatment. Long-term immunotherapy of prostate cancer patients experiencing early signs of PSA recurrence using DCVAC/PCa was safe, induced an immune response and led to the significant prolongation of PSADT. Long-term follow-up may show whether the changes in PSADT might improve the clinical outcome in patients with biochemical recurrence of the prostate cancer.

• Klíčová slova
• Biochemically recurrent prostate cancer, Dendritic cell, Immunotherapy, PSA doubling time,
• MeSH
• dendritické buňky imunologie   transplantace   MeSH
• imunoterapie metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory prostaty imunologie   terapie   MeSH
• počet lymfocytů MeSH
• prostatektomie MeSH
• prostatický specifický antigen genetika   imunologie   metabolismus   MeSH
• radioterapie MeSH
• regulace genové exprese u nádorů MeSH
• senioři MeSH
• T-lymfocyty imunologie   MeSH
• tumor burden MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze I MeSH
• klinické zkoušky, fáze II MeSH
• práce podpořená grantem MeSH
• Názvy látek
• prostatický specifický antigen MeSH

Personalized peptide vaccination is a promising immunotherapeutic approach in prostate cancer (PCa). We therefore examined whether an approach, utilizing personalized multiple peptide-mediated ex vivo enrichment with effector T cells reactive to multiple tumor-associated antigens (TAAs), could be employed as a basis for the development of T cell immunotherapy of PCa. In this study, we used the non-adherent fraction (lymphocytes) of cryopreserved peripheral blood mononuclear cells from a leukapheretic product of biochemically recurrent (BR, n = 14) and metastatic hormone-refractory (HR, n = 12) PCa patients. The lymphocytes were primed with a pool of mixed overlapping peptides derived from 6 PCa TAAs-PSA, PAP, NY-ESO-1, MAGE-A1, MAGE-A3 and MAGE-A4. After 2 weeks of culture, the cells were stimulated with the peptides and T cell reactivity determined by externalization of CD107a. No TAAs-reactive effector T cells were detected in the patient's lymphocytes after their reconstitution. However, following their priming with the TAAs-derived peptides and 2-week culturing, the lymphocytes became enriched with polyclonal TAAs-reactive effector CD8+ T cells in 8 out of 14 BR and 5 out of 12 HR patients. No such reactive CD8+ T cells were detected in cultured lymphocytes without the peptide priming. Stimulation of the responding cultures with peptides derived from individual TAAs revealed a unique repertoire of the reactive CD8+ T cells. Our strategy revealed that the personalized multiple peptide-mediated ex vivo enrichment with multiple TAAs-reactive T cells in the PCa patient's lymphocytes is a viable approach for development of T cell immunotherapy of PCa.

• Klíčová slova
• CD107a externalization, Personalized T cell immunotherapy, Prostate cancer, Tumor-associated antigens,
• MeSH
• antigeny nádorové imunologie   MeSH
• CD8-pozitivní T-lymfocyty imunologie   MeSH
• imunoterapie metody   MeSH
• individualizovaná medicína metody   MeSH
• kalikreiny imunologie   MeSH
• kultivované buňky MeSH
• leukocyty mononukleární imunologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• melanomové antigeny imunologie   MeSH
• membránové proteiny imunologie   MeSH
• nádorové proteiny imunologie   MeSH
• nádory prostaty imunologie   patologie   MeSH
• peptidy imunologie   MeSH
• prostatický specifický antigen imunologie   MeSH
• senioři MeSH
• T-lymfocyty imunologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny nádorové MeSH
• CTAG1B protein, human MeSH Prohlížeč
• kalikreiny MeSH
• KLK3 protein, human MeSH Prohlížeč
• MAGEA1 protein, human MeSH Prohlížeč
• MAGEA3 protein, human MeSH Prohlížeč
• MAGEA4 protein, human MeSH Prohlížeč
• melanomové antigeny MeSH
• membránové proteiny MeSH
• nádorové proteiny MeSH
• peptidy MeSH
• prostatický specifický antigen MeSH

PURPOSE: We conducted an open-label, single-arm Phase I/II clinical trial in metastatic CRPC (mCRPC) patients eligible for docetaxel combined with treatment with autologous mature dendritic cells (DCs) pulsed with killed LNCaP prostate cancer cells (DCVAC/PCa). The primary and secondary endpoints were safety and immune responses, respectively. Overall survival (OS), followed as a part of the safety evaluation, was compared to the predicted OS according to the Halabi and MSKCC nomograms. EXPERIMENTAL DESIGN: Twenty-five patients with progressive mCRPC were enrolled. Treatment comprised of initial 7 days administration of metronomic cyclophosphamide 50 mg p.o. DCVAC/PCa treatment consisted of a median twelve doses of 1 × 107 dendritic cells per dose injected s.c. (Aldara creme was applied at the site of injection) during a one-year period. The initial 2 doses of DCVAC/PCa were administered at a 2-week interval, followed by the administration of docetaxel (75 mg/m2) and prednisone (5 mg twice daily) given every 3 weeks until toxicity or intolerance was observed. The DCVAC/PCa was then injected every 6 weeks up to the maximum number of doses manufactured from one leukapheresis. RESULTS: No serious DCVAC/PCa-related adverse events have been reported. The median OS was 19 months, whereas the predicted median OS was 11.8 months with the Halabi nomogram and 13 months with the MSKCC nomogram. Kaplan-Meier analyses showed that patients had a lower risk of death compared with both MSKCC (Hazard Ratio 0.26, 95% CI: 0.13-0.51) and Halabi (Hazard Ratio 0.33, 95% CI: 0.17-0.63) predictions. We observed a significant decrease in Tregs in the peripheral blood. The long-term administration of DCVAC/PCa led to the induction and maintenance of PSA specific T cells. We did not identify any immunological parameter that significantly correlated with better OS. CONCLUSIONS: In patients with mCRPC, the combined chemoimmunotherapy with DCVAC/PCa and docetaxel was safe and resulted in longer than expected survival. Concomitant chemotherapy did not preclude the induction of specific anti-tumor cytotoxic T cells.

• Klíčová slova
• castration-resistant prostate cancer, dendritic cell, immunotherapy, overall survival, prostate cancer,
• MeSH
• adenokarcinom imunologie   mortalita   sekundární   terapie   MeSH
• adjuvantní chemoterapie MeSH
• alkylační protinádorové látky aplikace a dávkování   MeSH
• časové faktory MeSH
• cyklofosfamid aplikace a dávkování   MeSH
• dendritické buňky imunologie   transplantace   MeSH
• docetaxel MeSH
• imunoterapie škodlivé účinky   metody   mortalita   MeSH
• Kaplanův-Meierův odhad MeSH
• lidé středního věku MeSH
• lidé MeSH
• metronomické podávání léků MeSH
• nádory prostaty rezistentní na kastraci farmakoterapie   imunologie   mortalita   patologie   MeSH
• nomogramy MeSH
• prednison aplikace a dávkování   MeSH
• proporcionální rizikové modely MeSH
• protokoly protinádorové kombinované chemoterapie aplikace a dávkování   škodlivé účinky   MeSH
• rizikové faktory MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• T-lymfocyty - podskupiny imunologie   MeSH
• taxoidy aplikace a dávkování   MeSH
• tumor infiltrující lymfocyty imunologie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze I MeSH
• klinické zkoušky, fáze II MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alkylační protinádorové látky MeSH
• cyklofosfamid MeSH
• docetaxel MeSH
• prednison MeSH
• taxoidy MeSH

The concept of immunogenic cancer cell death (ICD), as originally observed during the treatment with several chemotherapeutics or ionizing irradiation, has revolutionized the view on the development of new anticancer therapies. ICD is defined by endoplasmic reticulum (ER) stress response, reactive oxygen species (ROS) generation, emission of danger-associated molecular patterns and induction of antitumor immunity. Here we describe known and emerging cancer cell death-inducing physical modalities, such as ionizing irradiation, ultraviolet C light, Photodynamic Therapy (PDT) with Hypericin, high hydrostatic pressure (HHP) and hyperthermia (HT), which have been shown to elicit effective antitumor immunity. We discuss the evidence of ICD induced by these modalities in cancer patients together with their applicability in immunotherapeutic protocols and anticancer vaccine development.

• Klíčová slova
• ATP, Adenosine triphosphate, CRT, calreticulin, DAMPs, danger-associated molecular patterns, DC, dendritic cells, EGFR, endothelial growth factor receptor, ER, endoplasmic reticulum, HHP, high hydrostatic pressure, HMGB1, high-mobility group box 1, HSP, heat shock protein, HT, hyperthermia, Hyp-PDT, Hypericin-based Photodynamic therapy, ICD, immunogenic cell death, IFNγ, interferon-γ, NDV, Newcastle Disease Virus, ROS, reactive oxygen species, RT, radiotherapy, TLR, Toll-like receptor, UVC, ultraviolet C light, cancer immunotherapy, eIF2α, eukaryotic translation initiation factor 2α, high hydrostatic pressure, hyperthermia, immunogenic cell death, ionizing irradiation, photodynamic therapy with hypericin,
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

BACKGROUND: For clinical applications, dendritic cells (DCs) need to be generated using GMP-approved reagents. In this study, we tested the characteristics of DCs generated in two clinical grade culture media and activated by three maturation stimuli, Poly I: C, LPS and the mixture of proinflammatory cytokines in order to identify the optimal combination of culture media and activation stimulus for the clinical use. METHOD: We tested DCs generation using two GMP-certified culture media, CellGro and RPMI+5% human AB serum and evaluated DCs morphology, viability and capapability to mature. We tested three maturation stimuli, PolyI:C, LPS and the mixture of proinflammatory cytokines consisting of IL-1, IL-6, TNF and prostaglandin E2. We evaluated the capacity of activated DCs to induce antigen-specific T cells and regulatory T lymphocytes. RESULTS: Cell culture in CellGro resulted in a higher yield of immature DCs resulting from increased number of adherent monocytes. DCs that were generated in CellGro and activated using Poly I:C were the most efficient in expanding antigen-specific T cells compared to the DCs that were generated in other media and activated using LPS or the cocktail of proinflammatory cytokines. A comparison of all tested combinations revealed that DCs that were generated in CellGro and activated using Poly I:C induced low numbers of regulatory T cells. CONCLUSION: In this study, we identified monocyte-derived DCs that were generated in CellGro and activated using Poly I:C as the most potent clinical-grade DCs for the induction of antigen-specific T cells.

• MeSH
• buněčná diferenciace účinky léků   MeSH
• dendritické buňky cytologie   účinky léků   MeSH
• epitopy imunologie   MeSH
• fenotyp MeSH
• imunoterapie metody   MeSH
• klinické zkoušky jako téma MeSH
• kultivační média farmakologie   MeSH
• lidé MeSH
• nádory imunologie   terapie   MeSH
• poly I-C farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• regulační T-lymfocyty cytologie   účinky léků   imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• epitopy MeSH
• kultivační média MeSH
• poly I-C MeSH