Targeting Multiple Tumors Using T-Cells Engineered to Express a Natural Cytotoxicity Receptor 2-Based Chimeric Receptor

Abstract

Recent developments in cancer treatment are demonstrating the increasing and powerful potential of immunotherapeutic strategies. In this regard, the adoptive transfer of tumor-specific T-lymphocytes approaches can lead to tumor regression in cancer patients. More recently, the use of T-cells genetically engineered to express cancer-specific receptors such as the anti-CD19 chimeric antigen receptor (CAR) continues to show promise for the treatment of hematological malignancies. Still, there is a crucial need to develop efficient CAR-T cell approaches for the treatment of solid tumors. It has been shown that other lymphocytes such as natural killer (NK) cells can demonstrate potent antitumor function—nonetheless, their use in immunotherapy is rather limited due to difficulties in expanding these cells to therapeutically relevant numbers and to suppression by endogenous inhibitory mechanisms. Cancer recognition by NK cells is partly mediated by molecules termed natural cytotoxicity receptors (NCRs). In the present study, we hypothesize that it is possible to endow T-cells with an NK recognition pattern, providing them with a mean to recognize tumor cells, in a non-MHC restricted way. To test this, we genetically modified human T-cells with different chimeric receptors based on the human NCR2 molecule and then assessed their antitumor activity in vitro and in vivo. Our results show that expression in primary lymphocytes of an NCR2-derived CAR, termed s4428z, confers T-cells with the ability to specifically recognize heterogeneous tumors and to mediate tumor cytotoxicity in a mouse model. This study demonstrates the benefit of combining tumor recognition capability of NK cells with T cell effectiveness to improve cancer immunotherapy.

T-cells “à la CAR-T(e)” – Genetically engineering T-cell response against cancer

“…Although usage of NK-based immunotherapies is currently limited by poor expansion and endogenous inhibitory mechanisms [198], one way to combine the tumor recognition capability of NK cells with T cell effectiveness and flexibility is to design CARs based on the EC domain of NCRs. Thus, we and others showed that NCR1 [199], NCR2 [105] and NCR3 [200] based chimeric receptors can mediate the recognition of several types of tumors (e.g. pancreatic, lung, cervical cancers) both in vitro and in vivo.…”

“…It has been shown that its nature may influence CAR function [105,106]. For example, to reach antigens that are short and proximal to the target cell membrane, one should use lengthier hinges [107].…”

“…It was suggested the role in CAR signal transduction via TM domain that comes into interaction with different membrane co-receptors [114]. We also recently showed that CD28 TM domain maybe superior to the native one in certain types of chimeric receptors [105,115]. Still, more research is required to obtain a more reliable understanding of TM domain impact on CAR stability and function [116].…”

Targeting glycosylated antigens on cancer cells using siglec‐7/9‐based CAR T‐cells

“…Of all the tested constructs, CAR that incorporated the TM region of CD28 performed optimally (Figure 2). This strengthens the need to examine CAR function empirically 19,36‐38 . Closer examination of the critical Ig‐domains in the extracellular siglec‐7 moiety showed that the main functional domains for tumor recognition were 1 and 3.…”

Engineering of chimeric natural killer cell receptors to develop precision adoptive immunotherapies for cancer

“…Similarly to NKp46, a single study has been undertaken which evaluated three NKp44-based CARs. These comprised a fusion of the NKp44 extracellular domain to the transmembrane and endodomain of CD28 followed by that of CD3ζ (s4428z), an identical construct further incorporating a CD28 hinge/spacer to increase the distance between the targeting domain and the plasma membrane (h4428z), and finally a CAR, whereby the extracellular and transmembrane domain of NKp44 were joined to a fused CD28-CD3ζ endodomain (44tm28z) [124] (Fig. 3c).…”