Biology subjects

Feils, A. S.

Publications and source records attributed to Feils, A. S..

5 recordsLinked to original sources

bioRxiv2025

Immune-mediated Engagement of T Regulatory Cells with Tumor Cells Results in Trogocytosis and Tumor Cell Killing.

Despite advances in treatment, >50% of patients with advanced melanoma are unresponsive to current therapies. Using the B78-D14 melanoma model (GD2+/MHC-I-/MHC-II+), we can cure mice with a regimen that includes radiation therapy (RT) in combination with immunocytokine (IC; anti-GD2 monoclonal antibody linked to IL-2) while establishing immunological memory. We interrogated the role of T cells in the antitumor and memory responses following RT+IC. We show a requirement for CD4, but not CD8 T cells, to achieve both the initial and memory responses. Upon IC-induced cell-cell contact, subsets of CD4 T cells, including Foxp3 T regulatory cells, trogocytose GD2 from tumor cells, acquire cytotoxic granules, and kill tumor cells. These results were confirmed using human tumor cell lines. These findings reveal that CD4 T regulatory cells, upon immunologically-induced binding to tumor cells, can trogocytose tumor antigens and directly kill tumor cells, redefining their potential role in antitumor immunity.

cancer biology↗

bioRxiv2025

Divergent role of CD8 T cells with distinct metabolic phenotypes during curative radio-immunotherapy in hot versus cold tumors

Immunotherapy has potential for impactful cancer cures by empowering patients own immune cells. We developed a radio-immunotherapy regimen that can cure large immunologically hot and cold murine tumors. Here, we explored the divergent role of CD8 T cells during this radio-immunotherapy in contrasting hot colon carcinoma versus cold melanoma. We introduced an immunocompetent mouse model with mCherry-expressing CD8 T cells to provide cell tracking in vivo. We investigated single-cell function, metabolism, and gene expression temporal changes using flow cytometry, in vivo multiphoton imaging, single-cell RNA sequencing, and multiplexed immunofluorescence to determine the underlying mechanisms. We found that in contrast to the hot colon carcinoma model, CD8 T cells from the cold melanoma model do not drive tumor cures, despite getting activated, possibly due to a static oxidative metabolism and exhausted phenotype plus down regulation of tumor MHC-I expression. These findings have implications for improving immunotherapy response in immunologically cold cancers.

immunology↗

bioRxiv2024

Bispecific GD2 x B7-H3 Antibody Improves Tumor Targeting and Reduces Toxicity while Maintaining Efficacy for Neuroblastoma

The current treatment for neuroblastoma involves an immunotherapy regimen that includes a monoclonal antibody that recognizes disialoganglioside (GD2), expressed at high levels on neuroblastoma. GD2 is not present on most normal tissues but is expressed on nerves. Thus, anti-GD2 treatment causes substantial, dose-limiting, neuropathic pain. B7-H3 is overexpressed on multiple tumor types, including neuroblastoma, with minimal normal cell expression and is absent on nerves. We designed a bispecific antibody (bsAb) that requires simultaneous binding of these two tumor antigens to achieve tight-binding of tumor cells. Our preclinical research shows that when compared to an anti-GD2 monospecific antibody, the GD2xB7-H3 bsAb has improved tumor specificity with similar efficacy and reduced toxicity. Since this bsAb does not bind to nerves, it may be possible to administer increased or additional doses beyond the tolerable dose of monospecific anti-GD2 antibodies, which could improve therapeutic efficacy and quality of life for patients with neuroblastoma.

cancer biology↗

bioRxiv2024

Targeting both GD2 and B7-H3 using bispecific antibody improves tumor selectivity for GD2-positive tumors

ObjectivesDisialoganglioside 2 (GD2), overexpressed by cancers such as melanoma and neuroblastoma, is a tumor antigen for targeted therapy. The delivery of conventional IgG antibody technologies targeting GD2 is limited clinically by its co-expression on nerves that contributes to toxicity presenting as severe neuropathic pain. To improve the tumor selectivity of current GD2-targeting approaches, a next-generation bispecific antibody targeting GD2 and B7-H3 (CD276) was generated. MethodsDifferential expression of human B7-H3 (hB7-H3) was transduced into GD2+ B78 murine melanoma cells and confirmed by flow cytometry. We assessed the avidity and selectivity of our GD2-B7-H3 targeting bispecific antibodies (INV34-6, INV33-2, and INV36-6) towards GD2+/hB7-H3- B78 cells relative to GD2+/hB7-H3+ B78 cells using flow cytometry and competition binding assays, comparing results an anti-GD2 antibody (dinutuximab, DINU). The bispecific antibodies, DINU, and a non-targeted bispecific control (bsAb CTRL) were conjugated with deferoxamine for radiolabeling with Zr-89 (t1/2 = 78.4 h). Using positron emission tomography (PET) studies, we evaluated the in vivo avidity and selectivity of the GD2-B7-H3 targeting bispecific compared to bsAb CTRL and DINU using GD2+/hB7-H3+ and GD2+/hB7-H3- B78 tumor models. ResultsFlow cytometry and competition binding assays showed that INV34-6 bound with high avidity to GD2+/hB7-H3+ B78 cells with high avidity but not GD2+/hB7-H3+ B78 cells. In comparison, no selectivity between cell types was observed for DINU. PET in mice bearing the GD2+/hB7-H3- and GD2+/hB7-H3+ B78 murine tumor showed similar biodistribution in normal tissues for [89Zr]Zr-Df-INV34-6, [89Zr]Zr-Df-bsAb CTRL, and [89Zr]Zr-Df-DINU. Importantly, [89Zr]Zr-Df-INV34-6 tumor uptake was selective to GD2+/hB7-H3+ B78 over GD2+/hB7-H3- B78 tumors, and substantially higher to GD2+/hB7-H3+ B78 than the non-targeted [89Zr]Zr-Df-bsAb CTRL control. [89Zr]Zr-Df-DINU displayed similar uptake in both GD2+ tumor models, with uptake comparable to [89Zr]Zr-Df-INV34-6 in the GD2+/hB7-H3+ B78 model. ConclusionThe GD2-B7-H3 targeting bispecific antibodies successfully improved selectivity to cells expressing both antigens. This approach should address the severe toxicities associated with GD2-targeting therapies by reducing off-tumor GD2 binding in nerves. Continued improvements in bispecific antibody technologies will continue to transform the therapeutic biologics landscape. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=114 SRC="FIGDIR/small/595624v2_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@11afee9org.highwire.dtl.DTLVardef@1558607org.highwire.dtl.DTLVardef@1d23d6eorg.highwire.dtl.DTLVardef@1bf1d63_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2019

CXCR4 allows T cell acute lymphoblastic leukemia to escape from JAK1/2 and BCL2 inhibition through CNS infiltration

Targeting the JAK/STAT and BCL2 pathways in patients with relapsed/refractory T cell acute lymphoblastic leukemia (T-ALL) may provide an alternative approach to achieve clinical remissions. Ruxolitinib and venetoclax show a dose-dependent effect on T-ALL individually, but combination treatment reduces survival and proliferation of T-ALL in vitro. Using a xenograft model, the combination treatment fails to improve survival, with death from hind limb paralysis. Despite on-target inhibition by the drugs, histopathology demonstrates increased leukemic infiltration into the central nervous system (CNS) as compared to liver or bone marrow. Liquid chromatography-tandem mass spectroscopy shows that ruxolitinib and venetoclax insufficiently cross into the CNS. The addition of the CXCR4 inhibitor plerixafor with ruxolitinib and venetoclax reduces clinical scores and enhances survival. While combination therapy with ruxolitinib and venetoclax shows promise for treating T-ALL, additional inhibition of the CXCR4-CXCL12 axis may be needed to maximize the possibility of complete remission.

cancer biology↗