Combination gemcitabine and PD-L1xCD3 bispecific T cell engager (BiTE) enhances T lymphocyte cytotoxicity against cholangiocarcinoma cells

Abstract

Cholangiocarcinoma (CCA) is a lethal cancer with rapid progression and poor survival. Novel and more effective therapies than those currently available are, therefore, urgently needed. Our research group previously reported the combination of gemcitabine and cytotoxic T lymphocytes to be more effective than single-agent treatment for the elimination of CCA cells. However, gemcitabine treatment of CCA cells upregulates the expression of an immune checkpoint protein (programmed death-ligand 1 [PD-L1]) that consequently inhibits the cytotoxicity of T lymphocytes. To overcome this challenge and take advantage of PD-L1 upregulation upon gemcitabine treatment, we generated recombinant PD-L1xCD3 bispecific T cell engagers (BiTEs) to simultaneously block PD-1/PD-L1 signaling and recruit T lymphocytes to eliminate CCA cells. Two recombinant PD-L1xCD3 BiTEs (mBiTE and sBiTE contain anti-PD-L1 scFv region from atezolizumab and from a published sequence, respectively) were able to specifically bind to both CD3 on T lymphocytes, and to PD-L1 overexpressed after gemcitabine treatment on CCA (KKU213A, KKU055, and KKU100) cells. mBiTE and sBiTE significantly enhanced T lymphocyte cytotoxicity against CCA cells, especially after gemcitabine treatment, and their magnitudes of cytotoxicity were positively associated with the levels of PD-L1 expression. Our findings suggest combination gemcitabine and PD-L1xCD3 BiTE as a potential alternative therapy for CCA.

Genistein Sensitizes Human Cholangiocarcinoma Cell Lines to Be Susceptible to Natural Killer Cells

“…KKU055 cells were usually sensitive to the standard chemotherapeutic agents [ 41 ]. KKU100 cells exhibited resistance trait to 5-FU, and etoposide, but were sensitive to doxorubicin while KKU213A cells was the more sensitive to gemcitabine than KKU100 cells [ 41 , 42 ]. In line with the results studied by others, our result revealed the impact of cancer heterogeneity on the varied responses to genistein treatment, which suggests the benefit of drug response assessments and the point of the requirement of biological markers for prediction of drug response and evaluation of disease outcome.…”

Development of pharmacological immunoregulatory anti-cancer therapeutics: current mechanistic studies and clinical opportunities

“… 412 , 413 Furthermore, therapeutic DNA demethylation can alter the composition and behavior of immune cells; it can increase the expression of MHC molecules, alleviate T cell exhaustion and enhance T cell effector and memory potential, increase secretion of Th1-type cytokines, and reduce immunosuppressive myeloid and Treg cells. 412 , 413 DNA methylation status and demethylating agents can also directly affect the expression of multiple immune checkpoints, including PD-1, 414 , 415 PD-L1 , 414 , 416 , 417 , LAG3, 414 TIM-3 , 414 , 418 , 419 , CTLA-4, 414 , 420 and TIGIT, 421 , 422 by recruiting of proteins involved in gene repression or by inhibiting the binding of them.…”

Targeting tumor microenvironment for cholangiocarcinoma: Opportunities for precision medicine

“…The authors hypothesized that blocking PD-1/PD-L1 axis would prevent its inhibitory effect on T cells activated by binding CD3, whose activity is enhanced by gemcitabine. Authors observed an enhanced T cells activity, resulting in a CCA cells killing, and suggested that the association of PD-L1xCD3 bispecific T cell engager and gemcitabine could represent a potential therapeutic strategy [ 86 ]. In another recent study it has been showed that stimulation of DCs and TAMs, via a CD40 agonist, may improve response to anti-PD-1 therapy with an increased number of activated CD4+ and CD8+ T cells in CCA mice models [ 87 ].…”

“…[ 71 ] TAMs, MDSCs Animal model / Anti-Ly6G ab + anti-CSF1R + anti–PD-1 ab enhanced effect of anti- PD-1 therapy NCT04677504 PD-L1, VEGFR Phase II clinical trial Advanced CCA pts 1 st line Atezolizumab + bevacizuab + gemcitabine + cisplatin NA Wathikthinnakon et al. [ 86 ] CD3+ T lymphocytes, PD-L1 Cell culture PD-L1xCD3 BiTE Enhanced T cells activity against CCA cells Diggs L. P. CD40+ APCs, PD-1 Animal model CD40 agonist + PD-1 ab Increased number of activated CD4+ and CD8+ T cells with improved response to anti-PD-1 therapy NCT03203876 KIR, PD-1 Phase I clinical trial Advanced solid tumors Lirilumab + nivolumab +/- ipilimumab NA Pan et al. [ 88 ] PD-L1, CTLA4 Animal model / PD-L1-CTLA4 DNA vaccination Increased number of CD8+ T cells, reduced tumor growth Abbreviations CAFs: cancer associated fibroblasts; EGFR: epidermal growth factor receptor; IR: insulin receptor; IGF1R: insulin-like growth factor 1 receptor; IL-6: interleukin-6; IL-8: interleukin-8; CCA: cholangiocarcinoma; PD-L1: programmed cell death 1 ligand; TGF-β: Transforming growth factor beta; ORR: overall response rate; TAMs: tumor associated macrophages; MDSCs: myeloid-derived suppressor cells; PD-1: programmed cell death 1; ab: antibody; VEGFR: vascular endothelial growth factor receptor; pts: patients; NA: not available; APCs: antigen presenting cells; CSF1R: CSF1 receptor; BiTE: bispecific T cell engager; KIR: Inhibitory killer cell immunoglobulin-like receptor; CTLA4: cytotoxic T-lymphocyte-associated protein 4.…”