Manipulating the Tumor Environment Vincenzo Bronte Verona University Hospital

vincenzo.bronte@univr.it

Escape from immune control can be viewed as one of the «Hallmarks of Cancer»

D. Hanahan and R. A. Weinberg, Cell, 2011

D. Hanahan , R. A. Weinberg, Cell, 2011

Cancer stroma comprises different immune cells

Meta-analysis of 124 published articles studying the impact of cytotoxic T cells, memory T cells, and T-helper subpopulations with regards to prognosis of patients with cancer

W. H. Fridman et al., Nat. Rev. Cancer, 2012 Courtesy of Jerome Galon

20 cancer types analyzed

A. J. Gentles et al., Nat. Med., 2015

Computational meta-analysis of expression signatures from 18,000 human tumors reveals positive and negative correlations between tumor-infiltrating leukocytes and patient survival

Myeloid cells of innate immunity

Dendritic cells

Mast cells

Neutrophils

Monocytes/Macrophages

Phagocytosis, inflammation, antimicrobial peptide production

Phagocytosis, inflammation, tissue repair

Eosinophils

Inflammation, vascular permeability

Defense against parasites

Activation of naïve T cells

Cell type Main function in immune response

M. G. Manz and S. Boettcher, Nat. Rev. Immunol., 2014

Steady-state hematopoyesis

Monocyte and macrophage developmental pathways (before birth and under steady-state condition)

F. Ginhoux and S. Jung, Nat Rev Immunol., 2014

Classic and alternative activation of macrophages

K. Abbas K, A. H. Lichtman. Cellular and Molecular Immunology, 7th Edition

Macrophage plasticity

J. P. Murray et al., Immunity, 2014

Metabolic and molecular pathways for TAM programming

Notch-Rbpj VEGF TGF

O. R. Colegio et al., Nature, 2014 V. Bronte, Immunology and Cell Biology , 2014

M. G. Manz and S. Boettcher, Nat. Rev. Immunol., 2014

Emergency granulopoiesis

c/EBP

V. Bronte et al., Nat. Comm., 2016

E. Timosenko et al., Immunotherapy, 2016

The metabolic control of T cell activation by myeloid cells

P. J. Murray, Nat. Immunol., 2016

Amino acid metabolizing enzymes with immuno regulatory activity

Enzyme Substrate Effects of enzymatic activity

Main cytokine controlling expression

Cell type

Indoleamine 2,3-dioxygenase

L-tryptophan L-tryptophan depletion and kinurenine

IFN- Plasmacitoid DC, MØ, DC subsets, some tumors

Arginase L-arginine L-arginine depletion, urea and polyamines

IL-4/IL-13 MDSC, MØ, some tumors

Nitric Oxide Synthase

L-arginine NO IFN- MDSC, MØ

Interleukin-4-induced gene 1

(oxidase)

L-phenylalanine H2O2 and

phenylpyruvate

IL-4/IL-13 DC, B lymphocytes

Amino acid metabolizing enzymes and control of immune response

D. H. Munn and A. L. Mellor, Trends Immunol., 2016

WTNosKOArgNosKO

E 7 s.c. injectionG

Day 0 Day 7 Day 50

0.5x10 OT-1 CTL or PBS i.v. injection

6

Tumor reached 2000 mm3

A

Mouse sacrifice

ARG1 genetic ablation favors immunotherapy

I. Marigo et al., Cancer Cell, 2016

Current clinical trials

Indoleamine 2 3-dioxygenase 1 (IDO1)

- About 24 clinical trials in cancers (mostly in

combination with checkpoint inhibitors or other

cancer therapies)

- 4 small molecule inhibitors and one vaccine

Arginase 1 (ARG1)

- 3 clinical trials, only one in cancer

- Small molecule inhibitor

Ornithine decarboxylase (ODC)

- About 34 clinical trials (Trypanosoma infections,

cancer prevention and treatment, alone or in

combination)

- Small molecule inhibitor

Dendritic cells (DCs) in cancer immunity • Many tumors have few or immature DCs

• Conventional (c)DCs of are necessary for inducing and maintain

T-cell responses to cancer

• cDC1 type depend of BATF3 transcription factor and have enhanced ability to cross-present antigens

• Among cDC1, migratory CD103+ DCs in mice are capable of capturing tumor antigens and present them to CD8+ T cells in lymph nodes and within the tumor environment

• Sensing of damage-associated molecular pattern (DAMP) signals by receptor of innate immunity triggers release of type I interferon and fuel CD8+ T cell priming (example: STING, immunogenic cell death)

• Tumor-specific CD8+ T cells can stimulate inflammatory DCs derived from monocytes to help the destruction of cancer cells

An exemplified comparison of macrophage and DC ontology

M. Guilliams et al., Nat. Rev. Immunol., 2014

L. Corrales et al., Cell Research, 2017

Tumor-infiltrating DCs can activate CD8+ T cells

S. Spranger et al., Nature, 2015 S. Spranger and T. Gajewsky, Adv. Immunol., 2016 S. Spranger and T. Gajewsky, Oncoimmunology, 2015

Oncogenic landscape influences T cell infiltration (-catenin in melanoma)

Tumor-specific CD8+ T cells collaborate with Tip-DCs

I. Marigo et al., Cancer Cell, 2016 S. Pilon-Thomas and B. Ruffell, Cancer Cell, 2016

Intratumoral transfer of Nos2+ TipDCs is required for tumor rejection following ACT

I. Marigo et al., Cancer Cell, 2016

Cold and immune-evasive tumors: the micro-environment as target

• Cancer cell molecular programs -catenin

• Signaling and transcription factors in myeloid infiltrating cells

PI3K, c/EBP, miR142-3p

• Chemochines, cytokines and chemoattractants CCL2, CCL3, CCL4, CSF-1

Enzymes IDO1, Arginase 1

• Myeloid cell activation and biology Anti-CD47, TLR4 agonists, STING agonists, TLR9 agonists

V. Bronte and P. J. Murray. Nat. Med. 2015

Therapeutic interventions to improve cancer therapy

W. Zheng and J. W. Pollard, Cell Research, 2016 M. M. Kaneda et al., Nature, 2016 O. De Henau et al., Nature, 2016

Targeting PI3K in myeloid cells

gal CTLs

Ablation + mTERT CTLs

No Ablation + mTERT CTLs

C57BL/6 c/ebp; Tie2Cre

flox/+ c/ebp;

Tie2Cre

flox/flox

0

20

60

40

80

100

0 20 40 60 0 20 40 60 0 20 40 60

% s u

r v i v

a l

Days after adoptive transfer

+/+ +/- -/-

P<0.01

I. Marigo et al., Immunity, 2010

Targeting cEBP in myeloid cells

Among miRs down-regulated in tumor-infiltrating myeloid cells, miR-142-3p promotes the macrophage differentiation by controlling cEBP

N. Sonda et al., 2013, Immunity

Reprogramming the bone marrow by enforced miR-142-3p expression

N. Sonda et al., 2013, Immunity

Days

Ly6C+ Monocytes

M2 macrophages PMN-MDSCs

DCs M1 macrophages

Cancer

?

N. Sonda et al., 2013, Immunity

Reprogramming the bone marrow by enforced miR-142-3p expression

Conclusions

• Targeting myeloid cells is likely not going to be effective as single therapy but can enhance cancer immunotherapy. • Single or combinatorial approaches depleting macrophages for prolonged times might have secondary effects on tissues homeostasis. • Treatments that acts on cell plasticity might offer some advantages over simple depletion. • Intratumoral DC activation can promote a sustained T cell response. • Further characterization of tumor-infiltrating myeloid cells might provide better molecular targets for intervention.

Chemotherapy Radiotherapy

CD11b CSF1R CCL2

cEBP Gata6 PI3K miR-142-3p

Refining therapeutic strategies to alter myeloid compartment in cancer