Human HLA-A*02:01/CHM1+ allo-restricted T cell receptor transgenic CD8+ T Cells specifically inhibit Ewing sarcoma growthin vitroandin vivo

Abstract

The endochondral bone protein Chondromodulin-I (CHM1) provides oncogene addiction in Ewing sarcoma (ES). We pre-clinically tested the targetability of CHM1 by TCR transgenic, allo-restricted, peptide specific T cells to treat ES. We previously generated allo-restricted wildtype CD8+ T cells directed against the ES specific antigen CHM1319 causing specific responses against ES. However, utilization of these cells in current therapy protocols is hampered due to high complexity in production, relatively low cell numbers, and rapid T cell exhaustion.In order to provide off-the-shelf products in the future, we successfully generated HLA-A*02:01-restricted T cell receptor (TCR) transgenic T cells directed against CHM1319 by retroviral transduction.After short-term expansion a 100% purified CHM1319-TCR-transgenic T cell population expressed a CD62L+/CD45RO and CD62L+/CD45RA+ phenotype. These cells displayed specific in vitro IFNg and granzyme B release in co-culture with HLA-A*02:01+ ES cell lines expressing CHM1. When co-injected with ES cells in Rag2−/−ɣc−/− mice, CHM1-specific TCR-transgenic T cells significantly inhibited the formation of lung and liver metastases in contrast to control mice. Lungs and livers of representative mice displayed CD8+ T cell infiltration in the presence (control group treated with unspecific T cells) and in the absence (study group) of metastatic disease, respectively. Furthermore, mice receiving unspecific T cells showed signs of graft-versus-host-disease in contrast to all mice, receiving CHM1319-TCR-transgenic T cells.CHM1319 specific TCR-transgenic T cells were successfully generated causing anti-ES responses in vitro and in vivo. In the future, CHM1319-TCR-transgenic T cells may control minimal residual disease rendering donor lymphocyte infusions more efficacious and less toxic.

Ewing sarcoma partial regression without GvHD by chondromodulin-I/HLA-A*02:01-specific allorestricted T cell receptor transgenic T cells

“…23 For efficacious T cell therapy, both, the identification of proteins essential for cancer survival and TCR reactivity have to be addressed. 2,14,17,19,24 Utilization of TCRs from the allogeneic repertoire, exploiting a naturally occurring mechanism of self-defense, may circumvent both the requirement for affinity enhancement and anergy of T cells to tumor self-antigens. 15,25 Attempts to translate recent achievements of cellular therapy with e.g., chimeric antigen receptor T cells into the treatment of solid tumors, in particular pediatric sarcomas, has had limited success so far.…”

“…Differences in phenotypes were most likely due to varying expansion protocols. 14,17,19 T cells of patients #1, #2, and #3 were 29.2%, 99.7%, and 45.1% positive for the CHM1 319 -specific multimer, respectively, and 63.5% positive for the EZH2 666 multimer in patient #1 (Fig. S3).…”

“…by major histocompatibility complex (MHC) disparate stem cell transplantation plus treatment with donor-derived T cells. 14,15 Allorepertoire-derived T cells were used for the identification of T cell receptors (TCR) recognizing ES-derived peptides in the context of (human leukocyte antigen) HLA-A Ã 02:01; these cells are termed allorestricted peptide-specific T cells. We have described previously tumor control without side effects with allorestricted T cells directed against ESassociated peptides CHM1 319 and EZH2 666 .…”

“…We have described previously tumor control without side effects with allorestricted T cells directed against ESassociated peptides CHM1 319 and EZH2 666 . 14,16 Here, we report on the first clinical use of both HLA-A Ã 02:01/CHM1 319 TCR transgenic and HLA-A Ã 02:01/CHM1 319 -peptide directed allorestricted wild-type CD8 C T cells in patients with refractory ES.…”

Systematic identification of cancer-specific MHC-binding peptides with RAVEN

“…6,7 This restricted expression pattern increases the likelihood of circulating lymphocytes directed against immunogenic peptides encoded by these CSGs, 7 which can be exploited clinically. In neuroblastoma and Ewing sarcoma, which are aggressive and oligo-mutated pediatric cancers, 8,9 adoptive T cell therapy targeting CSGs has been successfully applied in humanized mouse models 10–13 and patients. 14 Screening for additional CSGs could be enabled by comprehensive and already available transcriptome datasets of cancer and normal tissues, 15 However, due to the lack of specific algorithms and user-friendly tools, the identification of CSGs and derivative peptides with high affinity to MHCs continues to be laborious and slow.…”