ABIO-0501

TALL-104 and NK-92MI-mediated cell killing assays were used to examine the immune resistance of UM cells...Notably, lactate secreted by IL-6-treated UM cells was crucial in influencing PD-L1 and HLA-E stability via the GPR81-cAMP-PKA signaling pathway. Our data reveal a novel mechanism by which UM cells acquire an immune-escape phenotype by metabolic reprogramming and reinforce the importance of the link between inflammation and immune escape.

Knockdown of VE-cad or the PD-L1 gene ablated the effects of YKL-40 and reinvigorated TALL-104 cell immunity against vessels. In summary, our study demonstrates a novel vascular immune escape mechanism by which mGBM promotes tumor vascularization and malignant transformation.

Fluorescently labeled wild-type HCT-116 colorectal cancer cells and TALL-104 T-cells were co-cultured and treated with GLPG-0187, a small molecule integrin inhibitor, at various doses. Probing for additional downstream markers of TGF-β and up-stream markers of PD-L1 will help to further elucidate this mechanism. Further co-culture experiments will also include anti-PD-L1 and anti-PD-1 therapy to investigate the viability of integrin inhibition as an adjuvant to immune checkpoint blockade.

GLPG-0187 promoted significant immune cell killing of the CRC cells by TALL-104 T lymphoblast cells and reduced phosphoSMAD2 in HCT116 p53-null cells either in the absence or presence of exogenous TGF-β. Our results suggest that TGF-β signaling inhibition by a general integrin receptor inhibitor may boost T-cell killing of MMR-deficient colorectal cancer cells and suggest that a combination of anti-GDF-15 in combination with TGF-β blockade be further investigated in the treatment of MMR-deficient mCRC. Our results support the development of a novel immune-based therapeutic strategy to treat colorectal cancer by targeting the TGF-β signaling pathway through integrin receptor blockade.

Phase 1 clinical trials are ongoing for treatment of primary liver cancer and uveal melanoma with liver metastases using pressure-enabled drug delivery of SD-101 in combination with systemic immune checkpoint inhibitors (ICIs). Combination PMD and ICI studies are needed to inform drug combinations and dosages in syngeneic murine models of primary liver cancer and CRCLM. Subcutaneous and orthotopic tumor models are expected to demonstrate the efficacy of local PMD treatment with systemic immunotherapy.

CRC and GBM cells were co-cultured with TALL-104 cells -/+ TMZ and -/+ ICI to measure TALL-104-mediated cell death. Our results indicate that TMZ sensitizes MSS, MGMT-expressing CRC cells to ipilimumab + nivolumab ICI. Importantly, this suggests that TMZ-mediated sensitization to ipilimumab + nivolumab is independent of MGMT status and the patient cohort that may benefit TMZ + ipilimumab + nivolumab may be expanded to CRC patients with MGMT-expressing, MSS tumors.

Additionally, both cancer cell lines as well as TALL-104 T-cells and NK-92 NK cells were treated with 0.5 μM 9-ING-41 for 24 hours and harvested for Luminex cytokine profiling. The treatment cohorts for these experiments include 9-ING-41 combined with either anti-PD-L1, anti-PD-1, or anti-CTLA-4 immune checkpoint inhibitors. Our results suggest a promising combination therapeutic strategy for patients with soft tissue and bone sarcomas and future work will strive to better elucidate the mechanisms of efficacy.

The standard treatment options are surgery, radiation therapy, and chemotherapy using temozolomide. Immune cell co-culture, comprising of GBM cell lines plus TALL104 human leukemia T cells, was used to determine the amount of tumor cell death with palbociclib, pembrolizumab and a combination at different time points in both normoxia and hypoxia conditions. Our results are providing insights into improving immune checkpoint therapy for GBM patients.

However, GLPG-0187 promoted significant immune cell killing of the CRC cells by TALL-104 T lymphoblast cells. Our results suggest that TGF- signaling inhibition by a general integrin receptor inhibitor may boost T-cell killing of MMR-deficient colorectal cancer cells, and suggest that a combination of anti-GDF-15 in combination with TGF- β blockade should be further investigated in the treatment of MMR-deficient mCRC. Our results support the development of a novel immune-based therapeutic strategy to treat colorectal cancer by targeting the TGF-β signaling pathway through integrin receptor blockade.

Applying this BsAb in a T cell-Tumor cell co-culture system showed that targeting both PD1 and AGR2 with this BsAb induces the attachment of TALL-104 (CD8 T-lymphocytes) cells onto co-cultured H460 AGR2 Lung tumor cells and significantly reduces migration of H460 cells...These effects are significantly reduced with AGR2 expression negative WI38 cells. Our results demonstrate that the AGR2xPD1 BsAb could be a potential therapeutic agent to provide better solid tumor targeting and synergetic efficacy for treating AGR2+ cancer by blocking AGR2 paracrine signaling to reduce tumor survival, and redirecting cytotoxic T-cells into AGR2+ cancer cells.

Jurkat T lymphocytes, TALL-104 cytotoxic T cells and primary human and mouse CD3-positive T lymphocytes were employed for immune evasion studies...As such, personalised targeted immunotherapy could be adapted. Further investigations required to map the immune evasion machinery for each type of cancer and design the best targets for personalised immunotherapy of human malignancies.

Material and Methods We used human Jurkat T cells, TALL-104 cytotoxic T lymphocytes, THP-1 acute myeloid leukaemia (AML), MCF-7 breast cancer, WT3ab Wilms tumour cells, HaCaT keratinocytes, K562 chronic myelogenous leukaemia cells...We demonstrated the differential biochemical control of VISTA expression in human T cells and various types of rapidly proliferating cells, including cancer and foetal cells as well as keratinocytes. We hypothesized that this phenomenon is most likely determined by differential nuclear compartmentalisation of VSIG containing loci.

Senescence was induced in CRC cell lines by low-dose-etoposide treatment and confirmed by Senescence-associated β-galactosidase (SA-β-GAL) staining and fluorescence activated cell sorting (FACS) analysis...In vitro, NK-92 cells (mimicking natural killer T cells) or TALL-104 cells (mimicking both cytotoxic T cells and natural killer T cells) led to dose-dependent specific cytotoxicity in >75 % of the senescent CRC cells but <20 % of the proliferating control CRC cells...Absence as well as exceeding expression of senescence markers are associated with bad prognosis in CRC. The antitumorigenic potential of senescence induction is determined by tumor micromilieu and immune cell-mediated elimination of senescent cells.

We developed a phenotypic assay to screen for small molecules that interfere with this pathway using TALL-104 human leukemic cytotoxic T lymphocytes pretreated with prostaglandin E2 to elevate cAMP...Z' was higher using percent positive cells than mean fluorescence because the relationship between the two measures saturates, but using percent positive could make it harder to find hits in some assays. Second, variance was higher in positive controls than in negative controls in this assay, which degrades assay performance less than if variance was higher in negative controls.

We recently reported a humanized mouse model of hyperprogression using mismatch repair deficient (MMR-d) p53-/- HCT-116 colorectal cancer cells implanted subcutaneously into athymic mice humanized with human CD8+ T-cell line TALL-104 and treated with anti-PD-1 Pembrolizumab. We are conducting RNA sequencing to identify any changes in the RNAome of the HPD model, and immunoperoxidase analysis of resected tumor tissue for cytokine expression and cell death markers that may provide clues for accelerated growth within the HPD tumor microenvironment. Future studies will also focus on the interplay between Pembrolizumab and Panitumumab observed preliminarily to exacerbate the HPD with more comprehensive in vivo studies including of patient-derived xenotransplants.

A plant lectin with similar glycan-binding specificity, Wisteria floribunda agglutinin (WFA) showed less selective toxicity and induced cell death in Jurkat, Tall-104, and Hut-87 cell lines...However, the blockade of CD45 phosphatase activity failed to block either CNL-induced homotypic agglutination or cell death. Overall, our results indicate that CNL triggers atypical cell death selectively on Jurkat cells, suggesting the potential applicability of CNL in novel strategies for treating and/or detecting acute T cell leukemia.

Immunotherapy is an established treatment modality in oncology. This represents a novel humanized HPD mouse model with a link to deficiency of the p53 pathway of tumor suppression in the setting of MMR-d. Our novel humanized preclinical TALL-104/p53-null HCT116 mouse model implicates p53-deficiency in an MMR-d tumor as a possible contributor to HPD/HP and may help with evaluating therapeutic strategies in cancer immunotherapy to extend clinical benefits of ICB's in a broader patient population.

Co-culture experiments were conducted with GFP+ SW480 colorectal cancer cells and either NK-92 natural killer cells or TALL-104 T cells at various effector/target ratios in a 48-well plate, in the presence or absence of 9-ING-41. We hypothesize that a 9-ING-41-mediated decrease of VEGF in conjunction with a 9-ING-41-mediated increase of BRAK secreted by the tumor cells may increase the capacity of NK- and T cell-mediated killing of the tumor cells. Utilizing a compound such as 9-ING-41 could be a way to increase the host’s anti-tumor immune response to decrease tumor burden in conjunction with other therapeutic agents.

Design: Senescence was induced in CRC cell lines by low-dose etoposide treatment... Addition of immune cell lines NK92 or TALL104 to Caco-2 colon cancer cells leads to dose-dependent cell death in >75% of senescent Caco-2 cells but less than 20% of proliferating control cells... Senescence-associated molecules have significant prognostic value in CRC. Absence as well as high expression of these biomarkers are associated with a poor prognosis. Arresting the cell cycle of impaired cells imposes a barrier on tumorigenesis.

Both T-ALL cell lines (Jurkat and TALL-104) were treated with CHL...Consistent with in vitro studies, CHL significantly suppressed the growth and metastasis of tumor in vivo. Our finding uncovers the antitumorigenic effect of CHL in T-ALL progression through upregulating the expression of miR-9 and suppressing PD-L1 expression, which may provide a new potential strategy for T-ALL clinical treatment.