Tumor-specific cytotoxic T lymphocyte responses against chondrosarcoma with HLA haplotype loss restricted by the remaining HLA class I allele

Response to PD1 inhibition in conventional chondrosarcoma

Background

Chondrosarcoma is one of the most common malignant bone tumors in adults. Conventional chondrosarcoma represents around 85% of all chondrosarcomas and is notoriously difficult to treat with chemotherapy.

Case presentation

We describe a 67-year-old man with metastatic conventional chondrosarcoma who was treated with nivolumab. Treatment was discontinued after restaging showed increased tumor burden, which later proved to be pseudoprogression. The patient restarted nivolumab and continues to have a near complete response.

Conclusion

Conventional chondrosarcoma may be sensitive to checkpoint inhibitors. Further, this case demonstrates clearly the phenomenon of pseudo-progression in this disease, a factor that must be considered in the design of clinical trials and clinical care. This case supports additional study of immunomodulatory agents in this deadly disease.

NYESO-1/LAGE-1s and PRAME are targets for antigen specific T cells in chondrosarcoma following treatment with 5-Aza-2-deoxycitabine

BACKGROUND

Chondrosarcoma has no proven systemic option in the metastatic setting. The development of a non-cross-resistant strategy, such as cellular immunotherapy using antigen-specific T cells would be highly desirable. NY-ESO-1 and PRAME are members of the Cancer Testis Antigen (CTA) family that have been identified as promising targets for T cell therapy. LAGE-1 is a cancer testis antigen 90% homologous to NY-ESO-1, sharing the 157-165 A*0201 NY-ESO-1 epitope with its transcript variant, LAGE-1s. A number of CTA's have been induced using 5-Aza-2-Deoxycitabine (5-Aza-dC) in other cancers. We sought to evaluate the feasibility of targeting chondrosarcoma tumors using NY-ESO-1/LAGE-1s and PRAME specific T cells using 5-Aza-dC to induce antigen expression.

METHODS

We used 11 flash frozen tumors from the University of Washington tumor bank to test for the expression of NY-ESO-1, PRAME, LAGE-1s and LAGE-1L in chondrosarcoma tumors. Using four chondrosarcoma cell lines we tested the expression of these CTA's with and without 5-Aza-dC treatments. Finally, using NY-ESO-1/LAGE-1s and PRAME specific effectors that we generated from sarcoma patients, we evaluated the ability of these T cells to lyse A*0201 expressing chondrosarcoma cell lines in vitro both with and without 5-Aza-dC treatment.

RESULTS

A minority (36%) of chondrosarcoma tumors expressed either NY-ESO-1 or LAGE-1s at >10% of our reference value and none expressed PRAME at that level. However, in all four of the chondrosarcoma cell lines tested, NY-ESO-1 and PRAME expression could be induced following treatment with 5-Aza-dC including in cell lines where expression was absent or barely detectable. Furthermore, NY-ESO-1/LAGE-1s and PRAME specific CD8+ effector T cells were able to specifically recognize and lyse A*0201 expressing chondrosarcoma cell lines following 5-Aza-dC treatment.

CONCLUSION

These data suggest that adoptive immunotherapy in combination with 5-Aza-dC may be a potential strategy to treat unresectable or metastatic chondrosarcoma patients where no proven systemic therapies exist.

Dendritic cells based immunotherapy of patient with chondrosarcoma--case report

We present a case report of patient with intracranial chondrosarcoma and attempt to use vaccination of dendritic cells as the salvage therapy. To our knowledge, this is the first case report of DCs vaccination in the head and neck chondrosarcoma. Immunotherapy with allogeneic DCs stimulated with tumor cell lysates in this case was demonstrated to be feasible, safe and well tolerated. Unfortunately we did not observe any clinical or immune response during vaccination. CD4+ and CD8+ regulatory cells could be responsible for ineffectiveness of immunotherapy.

Cellular and functional characterization of immunoresistant human glioma cell clones selected with alloreactive cytotoxic T lymphocytes reveals their up-regulated synthesis of biologically active TGF-beta

Two immunoresistant (IR) glioma cell variants, 13-06-IR29 and 13-06-IR30, were cloned from 13-06-MG glioma cell populations after receiving continuous immunoselective pressure from multiple alloreactive cytotoxic T lymphocyte (aCTL) preparations. Reapplication of aCTL immunoselective pressure to the IR clones, displaying a partial regain in sensitivity to aCTL after removal of the selective pressure, restored the resistance. The IR variants exhibited cross-resistance to non-human leukocyte antigen (HLA)-restricted effector cells and gamma-irradiation, but not to carmustine. The IR clones were characterized for factors that might contribute to the immunoresistance. The aCTL adhesion to extracellular matrix extracts derived from either the IR clones or the parental cells was similar and not impaired. Furthermore, aCTL binding to parental cells and IR clones was equal. Down-regulation of the cell recognition molecules, class I HLA or intercellular adhesion molecule-1 (ICAM-1), that would inhibit their recognition by aCTL was not observed on the IR clones. The down-regulation of Fas by the IR clones correlated with their resistance to FasL-induced apoptosis. HLA-G or FasL that might provide an immunotolerant environment or provide a means of counterattack to aCTL, respectively, were not associated with the IR phenotype. The aCTL, coincubated with the IR clones and parental cells, displayed up-regulation of multiple secreted cytokines. A significant up-regulation of bioactive transforming growth factor (TGF)-beta was observed in the IR clones compared with the parental cells. These data suggest that increased secretion of bioactive TGF-beta may inhibit aCTL lysis of the IR clones. Disruption of the TGF-beta signaling pathway may circumvent the resistance.

Functional CD8+ T cells infiltrate into nonsmall cell lung carcinoma

Infiltration of CD3(+)CD8(+) cytotoxic T cells was analyzed by multiparameter confocal laser microscopy in a panel of 16 randomly selected stage I nonsmall cell lung carcinomas. T-cell infiltration was observed in the stroma (range 57-2,093 T cells/mm(2)) but also in the tumor epithelium (range 21-892 T cells/mm(2)) and showed wide variation between individual tumors. Interestingly, a significantly higher percentage of CD3(+)CD8(+) T cells was detected in the tumor epithelium compared to the stroma illustrating that cytotoxic T cells may preferentially migrate into tumor epithelium. Aberrant HLA class I antigen expression was observed in 69% of the nonsmall-cell lung carcinoma (NSCLC) tumors. One tumor of a squamous cell lung carcinoma patient with the highest number of tumor infiltrating CD3(+) and CD3(+)CD8(+) cells was studied in detail and the majority (90%) of these cells were shown to be functionally activated granzyme B-positive cytotoxic T cells. DNA oligotyping of a lung carcinoma cell line established from this tumor revealed loss of one HLA haplotype corresponding with a translocation involving chromosome 6, as observed by COBRA-FISH. HLA class I-restricted tumor specific T cells could be isolated from PBMC. One further characterized cytotoxic CD8(+) T cell clone, that released TNF-alpha, IFN-gamma, and granzyme B upon co-incubation with the autologous tumor cells, was shown to be restricted by the remaining HLA-A11 allele, which was also shown to be expressed in the tumor tissue. Our data indicate that, despite HLA-haplotype loss a vigorous antitumor immune response mediated by CD8(+ )T-cells can be present in NSCLC offering possibilities for specific immunotherapy.

Lysis of human chondrosarcoma cells by cytolytic T lymphocytes recognizing a MAGE-A3 antigen presented by HLA-A1 molecules

Treatment of chondrosarcomas is limited to resection because these tumors are unresponsive to standard adjuvant treatments, such as chemotherapy and radiation. We have previously shown that high-grade chondrosarcomas express unspecified members of the Melanoma Antigen (MAGE) gene family. We show here that FS human chondrosarcoma (FS) cells express MAGE-A3 gene and HLA-A1 molecules. In vitro assays show that a cytolytic T-lymphocyte clone (CTL) specific for a MAGE-A3 peptide presented by HLA-A1 specifically lysed FS chondrosarcoma cells. Addition of antigenic peptide did not increase the susceptibility of FS cells to CTL mediated lysis, suggesting that HLA-A1 expression by the chondrosarcoma cells limited their susceptibility to lysis by the anti-MAGE-A3 CTL clone. Incubation of FS cells with 50 U/mL interferon-gamma increased surface expression of HLA class-I molecules, increased their susceptibility to lysis, and had no effect on MAGE-A3 gene expression. These results suggest that immunotherapy targeted against chondrosarcoma cells is possible.

Loss or down-regulation of HLA class I expression at the allelic level in freshly isolated leukemic blasts

Loss or down-regulation of human leukocyte antigen (HLA) class I expression has been demonstrated in a variety of solid tumors. To date, such altered HLA expression has not been studied extensively in freshly isolated leukemic blasts. If it occurs, leukemic cells could escape T-cell surveillance as a consequence. Genotypes of nine leukemic cell lines were determined using a polymerase chain reaction for HLA classes I and II. Cells were also examined for HLA beta2-microglobulin, and allele-specific HLA protein expression using flow cytometry. Next, 44 samples of freshly isolated leukemic blasts from 43 patients with malignant hematological diseases were examined for allele-specific HLA expression using flow cytometry. Microsatellite analysis was performed to determine heterozygosity in the HLA region on chromosome 6. Genotype analysis for HLA class I together with microsatellite analysis demonstrated loss of HLA haplotype in HL-60 cells. No loss of HLA haplotype was observed in 44 samples of freshly isolated leukemic blasts. As reported previously, flow cytometric analysis rarely demonstrated loss or down-regulation of HLA expression at initial diagnosis (3/39; 7.7%); however, this was evident in two of five cases in relapse (40.0%), which contrasts with previous reports. In one patient with acute leukemia, HLA-A2 cell surface expression was present at initial diagnosis, lost at relapse, and completely restored after 48 h of culture in the presence of interferon-gamma. These results suggest loss of allele-specific HLA expression may be involved in the pathogenesis of relapse in patients with leukemia. The findings should be valuable in designing new strategies for clinical immunotherapy.