Anti-mucin 1 chimeric antigen receptor T cells for adoptive T cell
therapy of cholangiocarcinoma
Abstract
Current treatments for cholangiocarcinoma (CCA) are largely unsuccessful
due to late diagnosis at advanced stage, leading to high mortality rate.
Consequently, improved therapeutic approaches are urgently needed. A
newly potential therapy – chimeric antigen receptor (CAR) T cell
therapy utilizes genetically modified T cells that specifically
recognize surface antigen on cancer cells without restriction by major
histocompatibility complex (MHC). Mucin 1 (MUC1) is an attractive
candidate antigen due to its high expression in CCA cells, and its
association with poor prognosis and survival. Since anti-MUC1-CAR T
cells have not previously been tested for activity in models of CCA, we
set forth to test their utility in this setting. A fourth generation
anti-MUC1-CAR construct was engineered to contain anti-MUC1-single-chain
variable fragment (scFv) and three co-stimulatory domains (CD28, CD137,
and CD27) linked to CD3ζ. Cultures of anti-MUC1-CAR T cells consisted
primarily of cytotoxic (CD8+) T cells (75.13±11.65%,
p<0.001). Anti-MUC1-CAR T cells produced increased levels of
IFN-γ when exposed to MUC1-positive KKU-100 and KKU-213A CCA cells
(31.33±6.02% and 46.5±8.82%, respectively; both p<0.05).
Moreover, anti-MUC1-CAR T cells demonstrated specific killing activity
against KKU-100 (45.88±7.45%, p<0.05) and KKU-213A cells
(66.03±3.14%, p<0.001) at an effector to target ratio of 5:1,
but demonstrated negligible cytolytic activity against control immortal
cholangiocytes (MMNK-1 cells). These activities of anti-MUC1-CAR T cells
supports the development of this approach as an adoptive T cell
therapeutic strategy for CCA.