L2: T cell Therapy for Cancer (N. Hirano)

Question 1

2 Approaches for T cell therapy

Answer 1

TIL therapy (isolating TILs from tumor, expanding, putting back into patient)
CAR/TCR T therapy (T cell isolation, genetic modification, expansion, put back +IL-2 infusion)

Question 2

CAR design

Answer 2

targeting element (extracellular)
transmembrane domain (controls efficiency of signal transduction)
intracellular: costimulatory domain (improves in vivo persistence and effector functions) and CD3zeta

Question 3

prototypic CARs

Answer 3

1st gen: activation only
2nd gen: dual signaling
3rd gen: >=3 signaling

Question 4

prototypic 2nd gen 28z CD19 CARs

Answer 4

pre-clinical: less persistence, increased effector memory, less mitochondrial biogenesis (no difference in clinical)
long-term follow up: less overall survival compared to BBz

Question 4

prototypic 2nd gen BBz CD19 CARs

Answer 4

pre-clinical: increased persistance, central memory, metabolisms (no difference in clinical)
long-term follow up: 66% overall survival

Question 5

Limitations of CAR-T Cell Therapy

Answer 5

antigen escape
on target off tumor
CAR T cell trafficking and infiltration
immunosuppressive microenvironment
CAR T cell associated toxicities

Question 6

CAR T cell therapies to treat diseases beyond cancer

Answer 6

fibrosis, autoimmunity, senescence

Question 7

Minimum number of Ags required on target cells for TCR vs CAR

Answer 7

1-10 for TCR
10-100 for CAR

Question 8

NY-ESO-1

Answer 8

a cancer testis antigen expressed in various cancers

Question 9

3 signals for CAR T cell activation

Answer 9

1 - MHC2-TCR interaction
2 - CD80 - CD28 interaction
3- secretion of cytokines

Question 10

BITE

Answer 10

Bispecific T cell engager
antibody-based technology
for tumor antigen and CD3 T cell interaction

Question 11

TCR recognizes … complex

Answer 11

peptide/HLA
CD8 –> Class 1
CD4 –> Class 2 (ends open - longer peptide)

Question 12

how do we detect HLA-restricted antigen specific T cells

Answer 12

pHLA multimers
class 1 and 2 MHC tetramers differ, can detect using flow cytometry
pHLA multimers, also known as peptide-HLA multimers or pMHC multimers, are artificial complexes composed of a specific peptide antigen bound to major histocompatibility complex (MHC) molecules.

Question 13

issues of conventional pHLA multimers

Answer 13

difficult production for some alleles bc of poor in vitro refolding
multiple steps required for peptide exchange
poor staining of a subset of TCRs
commercially available only for frequently studied pHLA complexes
expensive

Question 14

what is KD

Answer 14

dissociation constant (the tendency that measures the
tendency of a species to separate into smaller components)
higher KD= interacting LESS, dissociate more

Question 15

what is the B*07:02 dimer

Answer 15

reactivity to tumors restricted by this allele

Question 16

HLA Class 2 binds weakly or strongly to CD4?

Answer 16

VERY weakly

Question 17

HLA-DP, DR, and DQ

Answer 17

different loci
DP: 2 mutation, DR: 4, DQ: 6

Question 18

which class of HLA is expressed by cancer cells

Answer 18

class 2

Question 19

MHC Class 1 vs 2

Answer 19

expression: 1- ubiquitous, 2-restricted
peptide binding: 1- allele specific
class1: closed end, class 2: open end

Question 20

HLA-agnostic TCR-like CAR therapy

Answer 20

targets c2 peptide promiscuously presented by diverse c2 molecules

Question 21

what signals should be included in a CAR T cell construct in order to optimally activate the T cell? What examples of each?

Answer 21

Optimal activation:
T cell receptor (TCR) engagement (signal 1)
Co-stimulation (signal 2)
Cytokine engagement (signal 3).

The CAR should encode:
the TCR signaling (CD3z) – signal 1
A co-stimulatory domain (CD28 or 41BB) – signal 2
A cytokine signalling domain (JAK-STAT) – signal 3