Pharmacological targeting of immune checkpoint A2aR improves function of anti-CD19 CAR T cells in vitro.

In spite of impressive results in the treatment of acute lymphoblastic B cell leukemia (B-ALL) with chimeric antigen receptor (CAR) T cells, the clinical outcome of some hematological cancers like follicular lymphoma (FL) and chronic lymphocytic leukemia (CLL) has not been very promising likely due to immunosuppressive networks within tumor microenvironment. Hypoxia in the microenvironment of hematological malignancies and consequently generation of adenosine molecule is appeared to be correlated with immunosuppression, tumor progression, and relapse. Herein, we hypothesized that whether pharmacological targeting of adenosine 2a receptor (A2aR) can enhance antitumor activity of anti-CD19 CAR T cells in vitro. Prior to functional assays, A2aR expression was assessed in CAR-expressing T cells. Our results showed that A2aR was not only up-regulated in the fully human anti-CD19 CAR T cells (hereafter referred to as huCAR19 T cells) but also was further overexpressed following re-stimulation with target cells. Although pharmacological inhibition of A2aR could significantly increase proliferation capacity and cytokine production of huCAR19 T cells following treatment with an adenosine analog, cytotoxic activity of huCAR19 T cells was not significantly improved. Considering A2aR overexpression in huCAR19 T cells in the tumor microenvironment, our results indicated that pharmacological targeting of A2aR could not only improve huCAR19 T cells functionality in a hostile tumor microenvironment but also could have a therapeutic advantage, and sought to assess the possibility in a pre-clinical setting.

Fallah-Mehrjardi K ，Mirzaei HR ，Masoumi E ，Jafarzadeh L ，Rostamian H ，Khakpoor-Koosheh M ，Alishah K ，Noorbakhsh F ，Hadjati J ... -  《-》

Genetic and pharmacological targeting of A2a receptor improves function of anti-mesothelin CAR T cells.

Masoumi E ，Jafarzadeh L ，Mirzaei HR ，Alishah K ，Fallah-Mehrjardi K ，Rostamian H ，Khakpoor-Koosheh M ，Meshkani R ，Noorbakhsh F ，Hadjati J ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Disruption of adenosine 2A receptor improves the anti-tumor function of anti-mesothelin CAR T cells both in vitro and in vivo.

Chimeric antigen receptor (CAR) T cells have been successfully used for the treatment of hematological malignancies including acute and chronic lymphoblastic leukemia. However, results of CAR T cell projects in solid tumors have been less impressive to date, partly because of immunosuppressive tumor microenvironment (TME). It is widely known that high adenosine production is an important factor causing tumor-induced immunosuppression in TME, and adenosine mediates the suppression of anti-tumor T cell responses via binding and signaling through adenosine 2a receptor (A2aR). Previous studies have shown that adenosine generated by cancer cells significantly inhibits T cell anti-tumor activity through binding and then activating adenosine 2A receptors (A2aRs) of T cells. Based on the previous work, in our study, we evaluated whether A2aR disruption by shRNA could enhance the anti-tumor function of anti-mesothelin (MSLN) CAR T cells both in vitro and in vivo. For this goal above, we used MSLN-positive human ovarian serous carcinoma cells (SKOV3) and human colon cancer cells (HCT116) as target cancer cells while MSLN-negative human ovarian cancer cells (ES2) as non-target cancer cells. We observed that targeting cell-intrinsic A2aR through shRNA overexpression caused significant A2aR disruption in CAR T cells and profoundly increased CAR T cell efficacy in both CAR T cell cytokine production and cytotoxicity towards MSLN-positive cancer cells in vitro. More importantly, in SKOV3 xenograft mouse models, anti-MSLN CAR-T cells significantly reduced the tumor burden compared with non-transduced T cells, and the anti-tumor activity of A2aR-disrupted anti-MSLN CAR-T cells was stronger than that of wild-type anti-MSLN CAR-T cells. Altogether, our study showed enhanced anti-tumor efficacy caused by shRNA-mediated A2aR disruption in anti-MSLN CAR T cells both in vitro and in vivo, which proved that shRNA-mediated modification of gene expression might be an excellent strategy for improving CAR T cell function in immunosuppressive tumor microenvironment (TME) and could potentially improve the outcome of treatment in clinical trials.

Liu G ，Zhang Q ，Liu G ，Li D ，Zhang L ，Gu Z ，Tian H ，Zhang Y ，Tian X ... -  《-》

Targeting the adenosine 2A receptor enhances chimeric antigen receptor T cell efficacy.

Beavis PA ，Henderson MA ，Giuffrida L ，Mills JK ，Sek K ，Cross RS ，Davenport AJ ，John LB ，Mardiana S ，Slaney CY ，Johnstone RW ，Trapani JA ，Stagg J ，Loi S ，Kats L ，Gyorki D ，Kershaw MH ，Darcy PK ... -  《-》

Simultaneous targeting of Tim3 and A2a receptors modulates MSLN-CAR T cell antitumor function in a human cervical tumor xenograft model.

Chimeric antigen receptor (CAR) T cell therapy has transformed the treatment of hematological malignancies. However, its efficacy in solid tumors is limited by the immunosuppressive tumor microenvironment that compromises CAR T cell antitumor function in clinical settings. To overcome this challenge, researchers have investigated the potential of inhibiting specific immune checkpoint receptors, including A2aR (Adenosine A2 Receptor) and Tim3 (T cell immunoglobulin and mucin domain-containing protein 3), to enhance CAR T cell function. In this study, we evaluated the impact of genetic targeting of Tim3 and A2a receptors on the antitumor function of human mesothelin-specific CAR T cells (MSLN-CAR) in vitro and in vivo. Second-generation anti-mesothelin CAR T cells were produced using standard cellular and molecular techniques. A2aR-knockdown and/or Tim3- knockdown anti-mesothelin-CAR T cells were generated using shRNA-mediated gene silencing. The antitumor function of CAR T cells was evaluated by measuring cytokine production, proliferation, and cytotoxicity in vitro through coculture with cervical cancer cells (HeLa cell line). To evaluate in vivo antitumor efficacy of manufactured CAR T cells, tumor growth and mouse survival were monitored in a human cervical cancer xenograft model. In vitro experiments demonstrated that knockdown of A2aR alone or in combination with Tim3 significantly improved CAR T cell proliferation, cytokine production, and cytotoxicity in presence of tumor cells in an antigen-specific manner. Furthermore, in the humanized xenograft model, both double knockdown CAR T cells and control CAR T cells could effectively control tumor growth. However, single knockdown CAR T cells were associated with reduced survival in mice. These findings highlight the potential of concomitant genetic targeting of Tim3 and A2a receptors to augment the efficacy of CAR T cell therapy in solid tumors. Nevertheless, caution should be exercised in light of our observation of decreased survival in mice treated with single knockdown MSLN-CAR T cells, emphasizing the need for careful efficacy considerations.

Soltantoyeh T ，Akbari B ，Shahosseini Z ，Mirzaei HR ，Hadjati J ... -  《Frontiers in Immunology》