Notes 3: CAR-T and CAR-NK Cells

Chimeric Antigen Receptor.

Chimeric Antigen Receptor (CAR) T Cell Therapy

• CAR stands for ________ _________ ______

variable fragment, linker, transmembrane, CD3zeta

• A CAR is an engineered molecule consisting of:

  • The most external component: the ________ ___ (FV) of an antibody's heavy chain or light chain.

  • A ___ sequence of peptides.

  • A ____ domain.

  • The intracellular domain of ______, which is part of the T cell receptor complex.

antigen

CAR T cells

• CD3 zeta is responsible for triggering signals inside T cells upon binding with an ____, leading to T cell activation.

activation

CAR T Cells

• T Cell _____ includes clonal expansion, cytokine secretion, and promotion of expansion in other T cells and cells.

cancer

• CAR T cell therapy harnesses this mechanism to target specific antigens on __ cells and activate T cell responses against them.

functionality

• CAR (Chimeric Antigen Receptor) designs are constantly evolving to enhance their _______.

• Various generations of CARs exist, each with additional components to potentiate their function.

cancer

• The core function of a CAR is to recognize a specific antigen expressed on ___ cells.

single chain variable fragment, linker, hinge, transmembrane, CD3zeta

• The first generation of CARs typically consists of:

  • _______ ______ ______ ______ (SCFV) to recognize the antigen.

  • _____ and ______ regions.

  • __________ domain to anchor the CAR in the cell membrane.

  • Intracellular domain of ______, responsible for triggering T cell activation upon antigen binding.

CAR

• Improvements in ___ design aim to enhance specificity, potency, and safety of CAR T cell therapy for cancer treatment.

co-stimulatory

• Second generation CARs include an _____-____ molecule, such as CD28, to enhance T cell activation.

co-stimulatory

• Third generation CARs further augment T cell activation by adding another ____-_____ molecule, such as CD27.

NFAT

• Fourth generation CARs incorporate a domain from ___, a transcription factor, to promote transcription of pro-inflammatory cytokines.

interleukin-2 receptor beta

• Fifth generation CARs include a domain from the ___-_ ______ ____ , which interacts with JAK/STAT signaling, amplifying the immune response.

engineered

• CAR T cells are ______ in the lab and then introduced into the patient's T cells to express the chimeric antigen receptor.

blood, transduced, CAR, amplified, infused

• CAR T cell therapy begins by isolating T cells from the patient's ___.

• In the lab, these T cells are ___ with an artificial gene encoding the chimeric antigen receptor (CAR).

• Transduction is often used for gene delivery due to its high efficiency.

• The CAR gene is introduced into the T cells, allowing them to express the ___ protein on their surface.

• The engineered T cells are then ____ in vitro, producing millions of CAR-expressing cells.

• These potentiated CAR T cells are ___ back into the patient.

tumor

• The CAR T cells recognize and target cancer cells expressing specific antigens, as determined by ___ biopsy or analysis.

coding sequence

• The artificial gene introduced into the T cells typically consists of the ______ ________ for the CAR, ready for transcription and translation upon integration into the T cell genome.

donor

CAR T-cell therapy typically utilizes the patient's own T cells rather than cells from a ___ to avoid complications such as graft-versus-host disease (GVHD) and host-versus-graft disease.

Graft-versus-host disease

• ____-____-__ ______ (GVHD) occurs when donor T cells recognize the recipient's cells as foreign and attack them. This can lead to severe complications, as the donor T cells are potent and may cause significant tissue damage.

Host-versus-graft disease

• ____-_____-______ _____ (HVGD) is the opposite scenario, where the recipient's immune system rejects the donor cells, leading to rejection of the transplanted cells or tissues.

immunosuppressive

• Both GVHD and HVGD can result in serious complications and require __________ therapy to manage.

allogeneic

• While using _____ (donor) T cells is a potential option, it carries a higher risk of immune reactions and may require extensive immunosuppression to prevent GVHD or HVGD.

hematologic

FDA-approved CAR T cell therapies primarily target _________ tumors, particularly those derived from B cells, due to the presence of specific antigens like CD19 and BCMA:

CD19

FDA-approved CAR T cell therapies

• ____ is a brilliant target antigen as it is primarily expressed in developing B cells and B cell-derived cancers. This specificity minimizes off-target effects and reduces the risk of immunocompromise in patients.

B

FDA-approved CAR T cell therapies

• CAR T cell therapies targeting CD19 have shown remarkable efficacy in treating __ cell malignancies such as acute lymphoblastic leukemia (ALL) and certain types of non-Hodgkin lymphoma.

B-cell maturation antigen

FDA-approved CAR T cell therapies

• BCMA (_-_____ ________ _____) is another promising target antigen expressed almost exclusively in multiple myeloma, a type of cancer affecting plasma cells in the bone marrow.

hematologic

FDA-approved CAR T cell therapies

• While CAR T cell therapies have demonstrated significant success in treating _______ (blood) malignancies, their efficacy against solid tumors has been limited.

soild

• ___ tumors present challenges such as heterogeneous antigen expression, immunosuppressive tumor microenvironments, and difficulties in trafficking CAR T cells to tumor sites.

antigens, off-target

CAR T cell therapy for solid tumors faces challenges due to the lack of tumor-specific _____ and potential __-_ effects:

normal

• Many solid tumors express antigens such as EGFR, HER2, and GPC3, which are also present in ___ tissues. Targeting these antigens with CAR T cells may result in off-target effects and toxicity.

on-target, off-tumor

On-target, off-tumor toxicity refers to a common type of adverse effect seen in CAR T cell therapy and other immunotherapies:

• __-__" refers to the intended target of the therapy, such as the EGFR receptor in cancer cells.

• "__-__" refers to healthy cells or tissues expressing the same target antigen as the cancer cells.

NK

CAR-__ cells offer a promising alternative to CAR-T cells, potentially providing greater efficiency and reduced toxicity:

graft-versus-host disease

• Natural Killer (NK) cells, unlike T cells, do not cause ___-___-___ ___ (GVHD) as they do not require specific antigen recognition via the major histocompatibility complex (MHC).

stress

NK cells possess inherent cytotoxic activity against infected or cancerous cells, mediated by activating receptors that recognize ___-induced ligands on target cells.

donors

CAR-NK cells are engineered to express chimeric antigen receptors (CARs) that enhance their targeting and killing capabilities against cancer cells.

• Unlike CAR-T cells, which require patient-derived T cells, NK cells can be obtained from multiple ____, expanded ex vivo, and banked for future use, eliminating the need for personalized cell therapy production.

NK

The CAR constructs used in CAR-NK cells may differ from those used in CAR-T cells, incorporating co-stimulatory molecules tailored to activate __ cells effectively, such as 2B4, DAP10, and DAP12, in addition to 41BB.