Implication of chemo-resistant memory T cells for immune surveillance in patients with sarcoma receiving chemotherapy

Apoptosis: a Janus bifrons in T-cell immunotherapy

Immunotherapy has revolutionized the treatment of cancer. In particular, immune checkpoint blockade, bispecific antibodies, and adoptive T-cell transfer have yielded unprecedented clinical results in hematological malignancies and solid cancers. While T cell-based immunotherapies have multiple mechanisms of action, their ultimate goal is achieving apoptosis of cancer cells. Unsurprisingly, apoptosis evasion is a key feature of cancer biology. Therefore, enhancing cancer cells' sensitivity to apoptosis represents a key strategy to improve clinical outcomes in cancer immunotherapy. Indeed, cancer cells are characterized by several intrinsic mechanisms to resist apoptosis, in addition to features to promote apoptosis in T cells and evade therapy. However, apoptosis is double-faced: when it occurs in T cells, it represents a critical mechanism of failure for immunotherapies. This review will summarize the recent efforts to enhance T cell-based immunotherapies by increasing apoptosis susceptibility in cancer cells and discuss the role of apoptosis in modulating the survival of cytotoxic T lymphocytes in the tumor microenvironment and potential strategies to overcome this issue.

Chemosensitivity of Lung Metastatic High-Grade Synovial Sarcoma

Background: Synovial sarcoma is a relatively chemosensitive type of soft tissue sarcoma and it often metastasizes to the lung. We investigated the role of adjuvant chemotherapy in patients with high-grade synovial sarcoma at their first lung metastasectomy (LMTS). Methods: Forty-six HGSS patients had their first LMTS at our institute (Rizzoli Orthopedic Hospital, Bologna, Italy) between 2000 and 2020. We divided them into two groups: (1) those undergoing adjuvant chemotherapy (n = 24) and (2) those not receiving adjuvant chemotherapy (n = 22). The primary outcome was a median survival at 32.5 (IQR 18.0-82.7) median follow-up. The disease-free interval was calculated at time zero (DFI₀, interval between the diagnosis of the primary tumor and the first CT-diagnosed lung metastasis) and at any further lung relapse (DFI_1-3). T₀ was defined as the time at first LMTS and T₁-T₃ referred to the time of further metastasectomy. Results: Freedom from SS-specific mortality at 60 months was significantly higher in patients without chemotherapy (50.0% (33.0-76.0%) vs. 20.8% (9.55%-45.4%), p = 0.01). Chemotherapy was associated with a higher risk of SS-specific mortality at multivariable Cox regression (HR 2.8, p = 0.02). Furthermore, DFI₀ ≤ 6 months, female sex, age > 40 years, and primary tumor > 10 cm increased the risk of death by about four, six, >three, and >five times, respectively. Conclusions. Adjuvant chemotherapy did not show any advantage in terms of freedom from SS-specific mortality in HGSS patients. Further larger studies are necessary to confirm our findings.

Immune composition and its association with hematologic recovery after chemotherapeutic injury in acute myeloid leukemia

Chemotherapy-induced bone marrow (BM) injury is a significant cause of morbidity and mortality in acute myeloid leukemia (AML). Time to hematologic recovery after standard ("7 + 3") myeloablative chemotherapy can vary considerably among patients, but the factors that drive or predict BM recovery remain incompletely understood. Here, we assessed the composition of innate and adaptive immune subsets in the regenerating BM (day 17) after induction chemotherapy and related it to hematologic recovery in AML. T cells, and in particular the CD4 central memory (CD4CM) T-cell subset, were significantly enriched in the BM after chemotherapy, suggesting the relative chemoresistance of cells providing long-term memory for systemic pathogens. In contrast, B cells and other hematopoietic subsets were depleted. Higher frequencies of the CD4CM T-cell subset were associated with delayed hematopoietic recovery, whereas a high frequency of natural killer (NK) cells was related to faster recovery of neutrophil counts. The NK/CD4CM ratio in the BM after chemotherapy was significantly associated with the time to subsequent neutrophil recovery (Spearman's ρ = -0.723, p < 0.001, false discovery rate <0.01). The data provide novel insights into adaptive immune cell recovery after injury and identify the NK/CD4CM index as a putative predictor of hematopoietic recovery in AML.

Predictors of lung recurrence and disease-specific mortality after pulmonary metastasectomy for soft tissue sarcoma

BACKGROUND

We identified prognostic factors in a 30-year series of STS treated at a single Institution, using an advanced statistical approach.

METHODS

From June 1988 to July 2019, 164 patients were referred to Rizzoli Orthopedic Hospital, Bologna, Italy) for STS lung metastasectomy (LMTS). The endpoints were lung metastasis recurrence (LMR) and lung metastasis-specific mortality (LMSM). The analysis included directed acyclic graphs, cubic splines, and a competing risk model in order to minimize bias.

RESULTS

The 10- and 15- year LMR cumulative incidence were 0.77 (0.76-0.78) whereas 10- and 15- year freedom from LMSM were 0.60 [0.51-0.70] and 0.56 [0.47-0.67], respectively. The malignant peripheral nerve sheath tumor (MPNST) histotype (SHR 4.12 [2.05-8.27]), a disease-free interval (DFI) up to 68 months (HR from 2 [1.7-2.2] to 1.5 [1.1-1.9]) and a LM size ≥4 mm (3.1 [2.1-4.4]) predicted LMR. Myxofibrosarcoma (HR 2.52[1.64-3.86]), synovial sarcoma (2.53[1.22-5.23]), adjuvant chemotherapy (2.01[1.11-3.61]), DFI between 2 months and 20 months (HR from 1.5 [1.1-2.3] to 1.3 [1.1-1.7] and primary tumor size a primary tumor size comprised between 3.6 cm and 10 cm predicted LMSM. A sharp increase in LMSM was observed with a tumor size from ≥20 cm.

CONCLUSIONS

Our analysis corrected by potential confounders allowed us to identify specific histotypes and DFI intervals as predictors of both LMR and LMSM. Tumor size adjuvant chemotherapy adversely affected LM-related survival. Our findings need to be confirmed by larger randomized studies.

The potentiality of immunotherapy for sarcomas: a summary of potential predictive biomarkers

Sarcomas are rare and heterogeneous malignant tumors of mesenchymal origin. A total of 25-50% of patients treated with initial curative intent will develop as recurrent and metastatic disease. In the recurrent and metastatic setting, effect of chemotherapy is limited; therefore, more effective therapies are urgently desired. As a brake for activation of T cell, PD-1/PD-L1 plays a crucial role in the progression of tumor by altering status of immune surveillance. Some success has been acquired recently in the use of PD-1/PD-L1 inhibitors for the treatment of several solid tumors, for examples, non-small-cell lung cancer and melanoma. Immunotherapeutic strategies based on PD-1/PD-L1 for sarcomas have also been explored these years. As in other cancers, major challenges are identification of biomarkers to predict response for immunotherapy, optimization of patient's benefit and minimization of side effects. Therefore, we focused on potential biomarkers of immunotherapy for treatment of sarcomas in this review.

Phosphorylated vimentin as an immunotherapeutic target against metastatic colorectal cancer

Colorectal cancer (CRC) patients with metastatic lesions have low 5-year survival rates. During metastasis, cancer cells often obtain unique characteristics such as epithelial-mesenchymal transition (EMT). Vimentin a biomarker contributes to EMT by changing cell shape and motility. Since abnormal phosphorylation is a hallmark of malignancy, targeting phosphorylated vimentin is a feasible approach for the treatment of metastatic tumors while sparing non-tumor cells. Recent evidence has revealed that both CD8 cytotoxic T lymphocytes (CTLs) and also CD4 helper T lymphocytes (HTLs) can distinguish post-translationally modified antigens from normal antigens. Here, we showed that the expression of phosphorylated vimentin was upregulated in metastatic sites of CRC. We also showed that a chemotherapeutic reagent augmented the expression of phosphorylated vimentin. The novel phosphorylated helper peptide epitopes from vimentin could elicit a sufficient T cell response. Notably, precursor lymphocytes that specifically reacted to these phosphorylated vimentin-derived peptides were detected in CRC patients. These results suggest that immunotherapy targeting phosphorylated vimentin could be promising for metastatic CRC patients.

Peptide vaccinations elicited strong immune responses that were reboosted by anti-PD1 therapy in a patient with myxofibrosarcoma

Peptide-based immunotherapy does not usually elicit strong immunological and clinical responses in patients with end-stage cancer, including sarcoma. Here we report a myxofibrosarcoma patient who showed a strong clinical response to peptide vaccinations and whose immune responses were reboosted by anti-PD1 therapy combined with peptide vaccinations. The 46-year-old man showed a strong response to the peptide vaccinations (papillomavirus binding factor peptide, survivin-2B peptide, incomplete Freund's adjuvant, and polyethylene glycol-conjugated interferon-alpha 2a) and subsequent wide necrosis and massive infiltration of CD8+ T cells in a recurrent tumor. The patient's immune responses weakened after surgical resection; however, they were reboosted following the administration of nivolumab combined with peptide vaccinations. Thus, anti-PD1 therapy combined with peptide vaccinations might be beneficial, as suggested by the observations in this sarcoma patient.

Implication of chemo-resistant memory T cells for immune surveillance in patients with sarcoma receiving chemotherapy

Chemotherapy has improved the prognosis of patients with sarcomas. However, it may suppress anti‐tumor immunity. Recently, we reported a novel CD8⁺ memory T cell population with a chemo‐resistance property, “young memory” T (T_YM) cells. In this study, we investigated the proportion and function of T_YM cells in peripheral blood of healthy donors and sarcoma patients who received chemotherapy and those who did not. The proportion of T_YM cells was significantly decreased in patients compared with that in healthy donors. In healthy donors, anti‐EBV CTLs were induced using mixed lymphocyte peptide culture, from not only T_YM cells but also T_CM and T_EM cells. No CTLs directed to tumor‐associated antigens were induced. In sarcoma patients who did not receive chemotherapy, in addition to anti‐EBV CTLs, CTLs directed to the tumor‐associated antigen PBF were induced from T_YM, T_CM and T_EM cells. In sarcoma patients who received chemotherapy, EBV‐specific CTLs were induced from T_YM cells but were hardly induced from T_EM cells. Interestingly, CTLs directed to the anti‐tumor‐associated antigen PBF were induced from T_YM cells but not from the T_CM and T_EM cells in sarcoma patients who received chemotherapy. The findings suggest that T_YM cells are resistant to chemotherapy and can firstly recover from the nadir. T_YM cells might be important for immunological memory, especially in sarcoma patients receiving chemotherapy.