generation-of-human-chimeric-antigen-receptor-regulatory-t-cells

Generation of Human Chimeric Antigen Receptor Regulatory T Cells

Chimeric antigen receptor (CAR) T-cell therapy has reshaped the face of cancer treatment, leading to record remission rates in previously incurable ...

Medical University of South Carolina

The adaptive immune system exhibits exquisite specificity and memory and is involved in virtually every process in the human body. Redirecting adaptive immune cells, in particular T cells, to desired targets has the potential to lead to the creation of powerful cell-based therapies for a wide range of maladies. While conventional effector T cells (Teff) would be targeted towards cells to be eliminated, such as cancer cells, immunosuppressive regulatory T cells (Treg) would be directed towards tissues to be protected, such as transplanted organs. Chimeric antigen receptors (CARs) are designer molecules comprising an extracellular recognition domain and an intracellular signaling domain that drives full T cell activation directly downstream of target binding. Here, we describe procedures to generate and evaluate human CAR CD4 helper T cells, CD8 cytotoxic T cells, and CD4FOXP3 regulatory T cells.

Redirecting Human Conventional and Regulatory T Cells Using Chimeric Antigen Receptors.

Chimeric antigen receptor (CAR) T cell therapy has proven to be a successful treatment option for leukemias and lymphomas. These encouraging outcomes underscore the potential of adoptive cell therapy for other oncology applications, namely, solid tumors. However, CAR T cells are yet to succeed in treating solid tumors. Unlike liquid tumors, solid tumors create a hostile tumor microenvironment (TME). CAR T cells must traffic to the TME, survive, and retain their function to eradicate the tumor. Nevertheless, there is no universal preclinical model to systematically test candidate CARs and CAR targets for their capacity to infiltrate and eliminate human solid tumors in vivo. Here, we provide a detailed protocol to evaluate human CAR CD4 helper T cells and CD8 cytotoxic T cells in immunodeficient (NSG) mice bearing antigen-expressing human solid tumors.

How to Test Human CAR T Cells in Solid Tumors, the Next Frontier of CAR T Cell Therapy.

Regulatory T cells (Tregs) are promising cellular therapies to induce immune tolerance in organ transplantation and autoimmune disease. The success of chimeric antigen receptor (CAR) T-cell therapy for cancer has sparked interest in using CARs to generate antigen-specific Tregs. Here, we compared CAR with endogenous T cell receptor (TCR)/CD28 activation in human Tregs. Strikingly, CAR Tregs displayed increased cytotoxicity and diminished suppression of antigen-presenting cells and effector T (Teff) cells compared with TCR/CD28 activated Tregs. RNA sequencing revealed that CAR Tregs activate Teff cell gene programs. Indeed, CAR Tregs secreted high levels of inflammatory cytokines, with a subset of FOXP3 CAR Tregs uniquely acquiring CD40L surface expression and producing IFNγ. Interestingly, decreasing CAR antigen affinity reduced Teff cell gene expression and inflammatory cytokine production by CAR Tregs. Our findings showcase the impact of engineered receptor activation on Treg biology and support tailoring CAR constructs to Tregs for maximal therapeutic efficacy.

High affinity chimeric antigen receptor signaling induces an inflammatory program in human regulatory T cells.

Regulatory T cells (Tregs) are promising cellular therapies to induce immune tolerance in organ transplantation and autoimmune disease. The success of chimeric antigen receptor (CAR) T cell therapy for cancer has sparked interest in using CARs to generate antigen-specific Tregs. Here, we compared CAR with endogenous T cell receptor (TCR)/CD28 activation in human Tregs. Strikingly, CAR Tregs displayed increased cytotoxicity and diminished suppression of antigen-presenting cells and effector T (Teff) cells compared with TCR/CD28-activated Tregs. RNA sequencing revealed that CAR Tregs activate Teff cell gene programs. Indeed, CAR Tregs secreted high levels of inflammatory cytokines, with a subset of FOXP3 CAR Tregs uniquely acquiring CD40L surface expression and producing IFN-γ. Interestingly, decreasing CAR antigen affinity reduced Teff cell gene expression and inflammatory cytokine production by CAR Tregs. Our findings showcase the impact of engineered receptor activation on Treg biology and support tailoring CAR constructs to Tregs for maximal therapeutic efficacy.

Russell W. Cochrane

Department of Microbiology and Immunology,
Department of Regenerative Medicine and Cell Biology,
Hollings Cancer Center

Medical University of South Carolina

Generation of Human Chimeric Antigen Receptor Regulatory T Cells

Russell W. Cochrane

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Microbiology and Immunology,Department of Regenerative Medicine and Cell Biology,Hollings Cancer Center

Medical University of South Carolina

Generation of Human Chimeric Antigen Receptor Regulatory T Cells

Department of Microbiology and Immunology,
Department of Regenerative Medicine and Cell Biology,
Hollings Cancer Center