Immune cells like macrophages, neutrophils, natural killer cells, T cells, B cells, and cytokines in the tumor microenvironment can either promote or inhibit cancer progression. Adoptive cell immunotherapy uses tumor-infiltrating lymphocytes, cytotoxic T lymphocytes, or chimeric antigen receptor T/NK cells to target cancers. Clinical trials are exploring these immunotherapies for various solid tumors and hematological malignancies, though challenges remain for treating solid tumors due to the immunosuppressive tumor microenvironment.

1. ROLE OF IMMUNE CELLS IN CANCER AND
TARGETING IMMUNE CELLS FOR CANCER
THERAPY
SIVASWAROOP YARASI

2. CONTENTS
INTRODUCTION
ROLE OF DIFFERENT IMMUNE
CELLS IN CANCER
CANCER IMMUNOTHERAPY
CONCLUSION

3. INTRODUCTION

4. Cancer:
• Uncontrolled proliferation of cells
beyond their usual boundaries
that can invade adjoining parts of
the body and/or spread to other
organs.
Mechanism:
• Genetic alterations or infections or
due to environmental factors
which lead to:
• Increased oncogenes (gene
that has the potential to cause
cancer):
• RAS gene, MYC gene
Cyclins and cyclin
dependent kinases etc.
• Decreased tumor suppressor
genes:
• p53, PTEN, RB 1 etc.
Caner cells are characterized by:
Characteristics
Self-
sufficiency
in growth
signals
Insensitivit
y to anti-
growth
signals
Evading
apoptosis
Limitless
replicative
potential
Sustained
angiogenesis
Tissue
invasion
and metasta
sis

5. Immune system in
cancer
pathophysiology:
• Immune system and inflammation serve
as double edged sword in cancer.
• Overactivation of immune system results
in diverse immune cell infiltration into
tumor microenvironment (TME).
• And the dynamic tumor-immune cell
interplay gives rise to a rich milieu of
inflammatory cytokines and growth
factors which favour tumor-cell
proliferation, survival and metastasis.

6. Cancer cells
Cytokines and
chemokines which
attract immune cells.
Immune cell infiltrate
(macrophages,
neutrophils and
lymphocytes) into
TME
Produce cytotoxic
mediators, such as
ROS, and cytokines
(TNF-α, ILs and INFs)
Persistent activation
of immune system and
failure of
inflammatory
response to resolve
Leads to Chronic
inflammatory
microenvironment
Produce excessive
ROS (hydroxyl
radicals, superoxide)
& RNS (nitric oxide
and peroxynitrite)
Excess ROS & RNS
results in oxidative
stress
Causes DNA
mutations & nitration
of DNA bases
Failure of cell death
and repair programs
in chronically
inflamed tissues
leads to continuous
DNA replication
Cellular proliferation
and fosters tumor

7. ROLE OF DIFFERENT IMMUNE
CELLS IN CANCER

8. Macrophages:
• Macrophages are a prominent immune-cell population involved in diverse
aspects of immunity and immune homeostasis.
• Macrophages are most plastic cells of haematopoietic system.
• High levels of cellular plasticity and diversity allow macrophages to
change phenotype and polarize into different subsets in response to a wide
variety of environmental cues:
• M1 (classically activated)
• M2 (alternatively activated)

9. Environmental factors skewing macrophages to two different phenotypes

10. Neutrophils:
• Polymorphonuclear neutrophils are the most abundant circulating
leukocyte in humans.
• Innate immune cells of first line of defence and involved in
inflammatory response.
• Neutrophil migration is predominantly mediated by the chemokine
receptor CXCR2. TANs are attracted by CXCR2 ligands, such as
CXCL1, CXCL2 and CXCL5 produced in the TME.

11. Environmental factors skewing neutrophils to two different phenotypes

12. Natural Killer cells:
• NK cells are innate cells with cytotoxic capacity.
• NK lytic potential is mediated either through lytic
granule release or death signal expression.
• NK cells probe other cells with activating (which
identify stress-induced or foreign ligands) and inhibitory
(which identify self- MHC I molecules) receptors, which
either permit or restrain the killing capacity of NK cells,
respectively.

13. Schematic representation of
physiological NK cell functions
a) A balance of signals delivered by
activating and inhibitory receptors
regulates the recognition of healthy
cells by natural killer (NK) cells.
b) Tumour cells that downregulate major
histocompatibility complex (MHC) class
I molecules are detected as ‘missing
self’ and are lysed by NK cells.
c) Tumour cells can overexpress induced
stress ligands recognized by activating
NK cell receptors, which override the
inhibitory signals and elicit target cell
lysis.
d) Tumour antigen-specific antibodies
bind to CD16 and elicit antibody-
dependent NK cell-mediated
cytotoxicity.

14. Activating
immunological synapse
between NK cell and
tumour target
• NK cell encounter with a tumour
cell target generates an
immunological synapse at the point
of contact.
• If the ligand combination on the
tumour target engages NK cell
activating receptors sufficiently,
cytoskeletal rearrangements take
place resulting in granule
polarization and the eventual
release of cytotoxic granules on to
the target cell.

15. T cells:
• In the context of cancer, there are two antagonistic classes of T cells that have
important roles in the fight against cancer —
• Cytotoxic CD8+ T cells
• CD4+ regulatory T cells (i.e. Tregs).
• Cytotoxic CD8+ T cells:
• Cytotoxic CD8+ T cells are essential for direct killing of pathogens or
transformed cells.
• Under physiologic conditions, naïve CD8+ T cells circulate within the periphery.
Upon TCR-pMHC engagement, these naïve cells are rapidly activated,
proliferate and differentiate into cytotoxic T cells.
• These effector CD8+ T cells bind to antigen-expressing target cells and release
cytotoxins, such as perforin and granzyme B (GZMB), to induce target cell lysis.

17. Regulatory T cells:
• Tregs are immunosuppressive cells
with a central role in maintaining
self-tolerance and immune
homeostasis.
• Like CD8+ T cells, Tregs also
infiltrate the tumor stroma and a
low CD8+ T cells to Tregs ratio is a
poor indicator of disease outcome,
overall survival and treatment
outcomes.

18. B cells:
• B cells can have either tumor-promoting or tumor-suppressive
properties, depending on their subtypes.
• As the TME consists of a heterogeneous population of functionally
distinct immune cells, the balance of various cell-specific responses
indicates whether the B-cell population is poised for pro-
tumorigenic or anti-tumorigenic functions.

19. B cells as positive mediators
of the antitumor response
• The production of antibodies by plasma
cells has many roles:
• antitumor antibodies promote antibody-
and complement-mediated killing of the
tumor cells,
• Fc-mediated phagocytosis by
macrophages.
• ADCC by natural killer (NK) cells.
• Importantly, antibody-coated tumor cells
can also be taken up and processed by
dendritic cells, which present tumor
antigens to CD4+ T cells and cross-
present antigens to CD8+ T cells.
• If the tumor antigen contains an MHC-I
epitope, anti-tumor CD8+ T cells could be
activated; these effector CD8+ cytotoxic T
cells will then traffic to the site of the
tumor, killing the tumor cells.
• In some cases, B cells can also take up
and process tumor antigens, which can
then be presented to CD4+ T cells. .

20. B cell suppression of the
antitumor response
• B cells can produce lymphotoxin, which
induces angiogenesis and thus promotes
tumor growth.
• Tumor-derived extracellular vesicles (tEVs)
can activate B cells to produce antibodies,
which can bind antigen and form immune
complexes.
• These circulating immune complexes can
activate Fcγ receptors on myeloid cells,
inducing them to become MDSCs, which
suppress anti-tumor CD4+ and CD8+ T cell
responses.
• A subset of B cells called regulatory B cells
(Bregs) can also secrete immunoregulatory
cytokines, including TGFβ, which induces
CD4+ T cells to become Foxp3+ CD4+ T
regulatory cells (Tregs), and IL-10, which
suppresses CD4+ Th1 cells, natural killer
(NK) cells, and CD8+ cytotoxic T cells.

21. Tumor cell immune evasion:
Davies M. New modalities of cancer treatment for NSCLC: focus on immunotherapy. Cancer management and
research. 2014;6:63.

22. CANCER
IMMUNOTHERAPY

23. Adoptive cell
immunotherapy:
• Adoptive cell transfer (ACT) is one of several
immunotherapeutic approaches which involves
infusing either autologous or allogenic cells
into patients.
• Tumor-specific immune cells make the perfect
“live drug” for cancer therapy.
• Strategies used in ACT:
• By isolating naturally occurring Tumor
Infiltrating Lymphocytes (TIL) from a resected
tumor.
• By generating cytotoxic T lymphocytes (CTLs)
ex vivo.
• By engineering autologous T cells to express a
tumor-specific chimeric antigen receptor (CAR).

24. • The T cells obtained from fresh
resected tumor sections are
expanded ex vivo to obtain number
of autologous cells with a large T
cell repertoire and infused back
into the patient.
• Multiple TIL cultures can be
derived from a single excised tumor
biopsy and more importantly, each
independent culture comprises a
diverse phenotype (CD4+/CD8+
frequency) with antigenic
specificities.
Tumor-infiltrating T
cells:
Restifo NP, Dudley ME, Rosenberg SA. Adoptive immunotherapy for cancer: harnessing
the T cell response. Nature Reviews Immunology. 2012 Apr;12(4):269.

25. • ACT of TILs in metastatic melanoma showed 55% cancer
regression overall.
• But only 1 of 20 patients (5%) achieved complete regression.
• Other cancers, such as renal cell carcinoma and breast cancer
which generate fewer TILs and achieved a lower success rate.
• A major challenge in using TILs is generating sufficient numbers
of tumor-specific T cells that retain their killing capacity in vivo.
• by using agonistic anti-4-1BB/CD137 during the early stages
of ex vivo T cell expansion could overcome this challenge.
• Achieved enhanced T cell yield (by 20%), activation signal
(CD28) expression and anti-tumor activity

26. Cytotoxic T
lymphocytes
(CTLs):
• CTLs are generated by stimulating
autologous peripheral blood-derived
CD8+ T cells with autologous
Dendritic Cells pulsed with known
tumor antigens.
• These CTLs produce an anti-tumor
response characterized by IFNγ
secretion and exhibit antigen-specific
killing of target cells.
June CH, Blazar BR, Riley JL. Engineering lymphocyte subsets: tools, trials and tribulations. Nature Reviews Immunology. 2009
Oct;9(10):704.

27. • Patients with progressive refractory metastatic melanoma
showed an improved clinical response with better survival (11
months versus 4 months) after MART1/gp-100 specific CTL
infusion.
• But adoptive transfer of gp100-specific CTLs into melanoma
tumor bearing mice induces massive infiltration of myeloid-
derived suppressor cells (MDSCs) into the tumor, which
suppresses anti-tumor responses over the long term.
• This may negate the anti-tumor activity of T cells.

28. CAR T/NK cells:
• By this approach, NK/T cells from
either patient or donor, are
collected and then genetically
modified to express chimeric
receptors specific to a tumor
antigen, along with a CD3ξ
signaling domain and co-
stimulatory molecules.
• NK cell lines, such as NK-92, are
favored over primary human NK
cells as they have almost no
expression of inhibitory killer cell
immunoglobulin-like receptors
and yet display cytotoxicity that is
equivalent to activated NK cells
even upon irradiation.
Fan M, Li M, Gao L, Geng S, Wang J, Wang Y, Yan Z, Yu L. Chimeric antigen receptors for adoptive T cell therapy
in acute myeloid leukemia. Journal of hematology & oncology. 2017 Dec;10(1):151.

29. CAR design:
• Chimeric antigen receptors (CARs) are composed of an extracellular domain, a transmembrane domain and an
intracellular signaling domain.
• First generation CARs only have a CD3z signalling domain.
• Second generation CARs have a costimulatory signalling domain to enhance the signal function of the CD3z signalling
domain.
• In third generation CARs, two costimulatory signalling domains are added to amplify anti-tumor effect of second
generation CARs.
• In the fourth generation CARs (TRUCKs), cytokine genes are added.

30. • Success of CAR T therapy is evident in hematologic malignancies with the eminent FDA
approval of:
• Kymriah™ (Tisagenenlecleucel, Novartis, USA) for acute lymphoblastic leukemia
(for patients up to 25-years old) and diffuse large B-cell lymphoma.
• Yescarta™ (Axicabtagene Ciloleucel, Kite Pharma, US) for large B-cell lymphoma.
• Both has side effects like cytokine release syndrome and neurotoxicity.
• Challenges for CAR T therapy is that it encountered hurdles in the treatment of solid
tumors due to the added complexity of the TME.
• CAR T treatment on solid tumors encounters safety concerns such as “on-target, off-
tumor” toxicity where CAR T cells target normal cells that express tumor-associated
antigens.
• “on-target, off-tumor” toxicity was tackled with designing:
• Dual-antigen specific CAR T cells
• Switchable CAR T cells
• CAR designing also overcomes the immunosuppressive TME by 4th generation CARs –
TRUCKS cells re-directed for universal cytokine mediated killing.
• TRUCKs release pro-inflammatory upon CAR engagement with a cognate tumor antigen.
• Which further activates effectors T cells with sustained cytotoxic function, preventing T cell
exhaustion.

31. Trial Description
NCT03585764 MOv19-BBz CAR T Cells in aFR Expressing Recurrent High Grade Serous Ovarian, Fallopian
Tube, or Primary Peritoneal Cancer
NCT03873805 PSCA-CAR T Cells in Treating Patients With PSCA+ Metastatic Castration Resistant
Prostate Cancer
NCT03907527 Modified Immune Cells (Autologous CAR T Cells) in Treating Patients With Advanced,
Recurrent Platinum Resistant Ovarian, Fallopian Tube or Primary Peritoneal Cancer
NCT02932956 Glypican 3-specific Chimeric Antigen Receptor Expressed in T Cells for Patients With Pediatric
Solid Tumors (GAP) (GAP)
NCT03330834 CAR-T Cell Immunotherapy for Advanced Lung Cancer
NCT03356795 Intervention of CAR-T Against Cervical Cancer
NCT03851146 A Study of Anti-Lewis Y Chimeric Antigen Receptor-T Cells (LeY-CAR-T) in Patients With
Solid Tumours (LeY-CAR-T)

32. • CAR Designing of NK cells along with tumor-
targeted GrB derivatives:
• NK cells can be modified to express targeted
cytotoxic chimeras such as the pro-apoptotic
serine protease granzyme B (GrB) fused to a
tumor cell-specific ligand or antibody fragment.
• Such molecules are stored together with
endogenous granzymes and perforin in cytotoxic
granules.
• Upon the activation of endogenous NK-cell
receptors through CAR, tumor-targeted GrB is
released together with perforin and granzyme B
(GrB) fused to a tumor cell-specific ligand or
antibody fragment.

33. • NK cell lines, such as NK-92 are used to design CAR NK cells.
• From these NK-92 cells further different cell lines are derived to overcome
some hurdles
• NK-92MI cell are designed to ease reliance on IL-2 for expansion.
• Modified NK-92MI cells to express the Fcγ receptors CD16 or CD64.
• Murine studies reported that NK-92MI cells expressing these Fcγ
receptors selectively killed CD20- expressing tumor cells in the
presence of anti-CD20.
• Genetically modified NK-92 cells expressing NKG2D, a key activation
receptor of NK cells, have higher anti-tumor activity and CD107
expression (marker for degranulation) than NK-92 cells expressing a
CAR T construct (CD28−CD28−CD137-CD3ξ).

34. Trial Description
NCT00328861 Natural Killer Cells Plus IL-2 Following Chemotherapy to Treat Advanced Melanoma or
Kidney Cancer
NCT01181258 Pentostatin, Rituximab and Ontak and Allogeneic Natural Killer (NK) Cells for Refractory
Lymphoid Malignancies
NCT01385423 Haploidentical Donor Natural Killer Cell Infusion With IL-15 in Acute Myelogenous Leukemia
(AML)
NCT01875601 NK White Blood Cells and Interleukin in Children and Young Adults With Advanced Solid
Tumors
NCT01212341 Allogeneic Natural Killer (NK) Cell Therapy in Patients With Lymphoma or Solid Tumor
NCT03415100 Pilot Study of NKG2D-Ligand Targeted CAR-NK Cells in PatientsWith Metastatic Solid
Tumours
NCT03940820 Clinical Research of ROBO1 Specific CAR-NK Cells on PatientsWith Solid Tumors

35. ADVANTAGES:
• Engineer tumor specific T/NK cells
• Does not require presence of TILs.
• Independent of MHC expression.
• Less “on-target, off-tumor toxicity
DISADVANTAGES:
• Limited by appropriate tumor antigens.

36. IMMUNE CHECKPOINT
BLOCKADE (IBD)
• Immune checkpoints collectively
refer to:
• Co-stimulatory such as CD28,
• Co-inhibitory, namely CTLA-4,
PD-1, TIM-3 and LAG- 3.
• A balance between these signals
allows for self-tolerance under
normal physiological conditions
and protects the host from tissue
damage during an immune
response against a foreign antigen.
• In the event of malignancy,
immune checkpoint molecules are
co-opted, preventing effector T
cells from mounting an effective
anti-tumor response.
Darvin P, Toor SM, Nair VS, Elkord E. Immune checkpoint inhibitors: recent progress and
potential biomarkers. Experimental & molecular medicine. 2018 Dec 13;50(12):1-1.

37. RECENT DEVELOPMENTS IN
NANOPARTICLE (NP) –
MEDIATED IMMUNOTHERAPY

38. Gun SY, Lee SW, Sieow JL, Wong SC. Targeting immune cells for cancer therapy. Redox biology. 2019 Mar 20:101174.
Interaction of NPs with immune cells depend
on the NP’s biological identity as defined by
the protein corona, and its physicochemical
properties.
Cell mediated delivery of therapeutic
cargo: Cargo of nanoparticles are taken
by macrophages and monocytes to TME.
CAR genes

39. REFERENCES:
• Gun SY, Lee SW, Sieow JL, Wong SC. Targeting immune cells for cancer therapy. Redox
biology. 2019 Mar 20:101174.
• Darvin P, Toor SM, Nair VS, Elkord E. Immune checkpoint inhibitors: recent progress
and potential biomarkers. Experimental & molecular medicine. 2018 Dec 13;50(12):1-1.
• Fan M, Li M, Gao L, Geng S, Wang J, Wang Y, Yan Z, Yu L. Chimeric antigen receptors
for adoptive T cell therapy in acute myeloid leukemia. Journal of hematology & oncology.
2017 Dec;10(1):151.
• Davies M. New modalities of cancer treatment for NSCLC: focus on immunotherapy.
Cancer management and research. 2014;6:63.
• Oberoi P, Wels WS. Arming NK cells with enhanced antitumor activity: CARs and
beyond. Oncoimmunology. 2013 Aug 1;2(8):e25220.
• Restifo NP, Dudley ME, Rosenberg SA. Adoptive immunotherapy for cancer: harnessing
the T cell response. Nature Reviews Immunology. 2012 Apr;12(4):269.
• June CH, Blazar BR, Riley JL. Engineering lymphocyte subsets: tools, trials and
tribulations. Nature Reviews Immunology. 2009 Oct;9(10):704.

40. THANK YOU