Cancer and cancer immunotherapy Lanyi Arpad alanyi@dote.hu, X65246

The hallmarks of cancer Hanahan and Weinberg Cell, 2011 pp646-

Hanahan and Weinberg Cell, 2011 pp646- A tumor is a wound that never heals Hanahan and Weinberg Cell, 2011 pp646-

A tumor olyan mint egy szerv…Érhálózattal, különböző sejttípusokkal és őssejtekkel Olyanná alakítja a környezetét hogy az kedvez a tumor növekedésének és Progressziójának.

It seems that our immune system is able to destroy tumors If this response is specific Tumor-specific antigens must also exist!!

The immune response to tumors

Tumor-specific antigens and tumor associated antigens

Tumor-specific antigens Shown here are tumor antigens discovered in the course of studying the T-cell response to different types of cancer: five are peptide antigens containing a point mutation (in magenta), and three are peptides derived from the novel protein produced by the fusion of the BCR and ABL genes that characterizes chronic myelogenous leukemia. ABL is an oncogene and BCR encodes a kinase (not the B-cell receptor). The HLA molecule that presents each peptide antigen, and thus ‘restricts’ the immune response, is shown. These data are taken from the Cancer Immunity Peptide Database website [http://cancerimmunity.org/peptide/], which contains many more examples of mutant tumor antigens.

CT antigens Cancer/testis antigens are expressed almost entirely by cancerous cells, showing little or no expression in healthy tissue, with the exception of normal testis, embryonic ovaries and placenta. No MHC expression Many of them X-linked Over 100 in total --- Potential targets for immune therapy Thirty-eight different types of cancer/testis (CT) antigen have been defined and numbered in a CT series analogous to the CD series of differentiation antigens. Shown here are the first 10, and best-characterized, CT antigens, the number of genes that encode them, and the chromosomal location of the genes. Genes encoding 17 of the 38 CT antigens are on the X chromosome; the others are distributed between 11 autosomes, none of which has genes for more than three CT antigens. This information and more can be found on the Cancer Immunity CT Gene Database website [http://cancerimmunity.org/resources/ct-genedatabase/].

The tumor-specific immune responseI Induction of CD8+ T cell responses against tumors. CD8+ T cell responses to tumors may be induced by cross-priming (also called cross-presentation), in which the tumor cells or tumor antigens (or both) are taken up by dendritic cells, processed, and presented to T cells. In some cases, B7 costimulators expressed by these antigen-presenting cells (APCs) provide the second signals for the differentiation of the CD8+ T cells. The APCs may also stimulate CD4+ helper T cells, which may provide signals for CTL development (see Chapter 5 , Fig. 5–7 ). Differentiated CTLs kill tumor cells without a requirement for costimulation or T cell help. CTL, Cytotoxic T lymphocyte. Immune Responses against Tumors and Transplants : Immunity to Noninfectious Transformed and Foreign Cells Abbas, Abul K., MBBS, Basic Immunology: Functions and Disorders of the Immune System, Chapter 10, 189-205 Copyright © 2014 Copyright © 2014, 2011, 2009, 2006, 2004, 2001 by Saunders, an imprint of Elsevier Inc.

Activation of tumor-specific T-cells by DC Cross-presentation

Main stratrgies for cancer immunotherapy Sattwa S. Neelapu Mol. Oncol (2015 in press)

Cancer immunoediting Why are then tumors NOT eliminated?

Immune evasion mechanisms by tumors How tumors evade immune responses. Antitumor immunity develops when T cells recognize tumor antigens and are activated. Tumor cells may evade immune responses by losing expression of antigens or major histocompatibility complex (MHC) molecules or by producing immunosuppressive cytokines or ligands such as PD-L1 for inhibitory receptors on T cells. Immune Responses against Tumors and Transplants : Immunity to Noninfectious Transformed and Foreign Cells Abbas, Abul K., MBBS, Basic Immunology: Functions and Disorders of the Immune System, Chapter 10, 189-205 Copyright © 2014 Copyright © 2014, 2011, 2009, 2006, 2004, 2001 by Saunders, an imprint of Elsevier Inc.

The role of the immunosupressive stroma Why are then tumors NOT eliminated? The role of the immunosupressive stroma

Modulation of DC-function by the tumor TSLP-induced DCs recruit Th2 and Treg cells

Antibody-based immunotherapy

Humanized monoclonal antibodies used in the treatment of patients with cancer. Naked antibodies rituximab----- Trastuzumab Immunotoxins Yttrium 90 Denileukin IL2+diphteria tox. (cutaneous T-cell lymphoma) ADCC--- NK and Macrophage complement

Many therapeutic anticancer monoclonal antibodies work by delivering the tumor cells to NK cell-mediated ADCC. Antibodies bind to a cell-surface antigen of the tumor cells, for example CD20. The Fc regions of the antibodies engage FcγRIII on an NK cell, which then becomes activated to kill the tumor cell.

Néhány a rák-terápiában engedélyezett monoklonális ellenanyag Brentuximab Anti CD30 (Hodhkin lymphoma) Anti-CD52 monoclonal Alemtuzumab (marketed as Campath), Used in chronic lymphocytic leukemia (CLL), cutaneous T-cell lymphoma (CTCL) and T-cell lymphoma.

Adoptive T-cell transfer

T-cell responses to tumors can be improved with chimeric antigen receptors (CARs) Low affinity of TCR (compared to virus spec. T cells) MHC restriction prevents use in the entire population problem solved by Fv Variable fragment of the heavy and light chains of a Tumor-specific antibody made a single chain Fusion of FV to an intra cell. domain cont. CD28, CD137 and zeta-chain sequences Generates strong signal in the absence of costimulation Structure of a chimeric antigen receptor. These artificial and engineered T-cell receptors are designed to have the binding strength and specificity of immunoglobulins. The chimeric antigen receptor is a single polypeptide that contains domains derived from several different immune-system proteins. The extracellular binding site consists of one immunoglobulin light-chain variable region (VL) and one immunoglobulin heavy-chain variable region (VH). This is connected via a transmembrane region to three signaling domains. One is derived from CD28, a second is derived from CD137, and the third is derived from the ζ chain of the CD3 complex. Thus the chimeric antigen receptor is capable of transducing all the signals needed to activate the T cell.

B cell tumors can be targeted by CARs specific to CD19 Mechanism of action of an anti-CD19 chimeric antigen receptor. In exploring the potential of chimeric antigen receptors (CARs) in cancer immunotherapy, B-cell tumors have been the major target. Many of the CARs are specific for the CD19 component of the B-cell co-receptor. T cells isolated from a patient’s blood are engineered to express the CAR and are then infused back into the patient. The CAR on the T cells binds tightly to CD19 on the tumor cell and provides strong signals that activate the T cell’s effector functions. Shown here is a T cell that has a tumor-specific T-cell receptor, which will be augmented by the activity of the CAR. T cells that are not specific for the tumor will also be targeted at the tumor by the CAR (not shown). As CD19 is present on normal B cells the CAR T-cell needs an inducible Suicide gene (i.e. caspase 9 etc)

Treatment of B‑cell tumors using anti-CD19 CAR T cells.

Activaton of the immune system used in the treatment of patients with cancer. Therapeutic cancer vaccines Sipuleucel_T autologous CD54+ leukocytes activated by a fusion protein GM-CSF some clinical benefit in advanced prostatecancer patients Therapeutic vaccination: peptide vaccines , melanoma Shown here are antibodies that function purely as antibodies, not as delivery systems for chemotherapy or radiation therapy. "Year approved" refers to their approval for medical use in the United States by the US Food and Drug Administration.

Vaccination of melanoma patients may cause their tumor to regress Rec. virus Synthetic peptide vaccine A patient with metastatic melanoma was vaccinated with an antigenic peptide from the MAGEA3 protein that is presented by the patient’s HLA-A1 allotype. The first four immunizations used a recombinant viral vaccine (open arrowheads); the last seven immunizations (black arrowheads) were with synthetic peptides. The red line shows the percentage of total CD8 T cells in the peripheral blood that were specific for the peptide. The status of the cancer’s growth is indicated in the blue box above the graph. Data courtesy of Pierre Coulie. It is not yet clear when the vaccine would work. Spectrum from remission to no response.

Anti-tumor immunotherapy AZ AKTÍV TUMOR-SPECIFIKUS IMMUNTERÁPIA LEHETŐSÉGEI A tumor antigének beviteli módja Anti-tumor immunotherapy Tumor protein-derived peptide Anti-idiotipe Ab Tumor protein Vírus-tumor genome Plasmid DNA Modified tumor cell Modified DC Irradiated tumor cell Tumor cell lysate Loaded DC Heat shock protein Mocellin S et al. Lancet Oncology 2004

Oncolitic viruses in cancer therapy

Alternative immunne adjuvant therapies almond mushroom, edible, imune stimulator. Because Agaricus sub-rufescens contains a high level of beta glucans, compounds known for stimulating the immune system, the fungus is used in oncological therapy in Japan and Brazil.

Checkpoint therapies Blocking negative receptors used by Tregs Targeting stimulatory co-receptors with agonistic antibodies

Blocking the inhibitory effects of CTLA4 with a human monoclonal antibody. (Ipilimumab etc) PD programmed death 2 year survival is over 24% but quite some complications. Blocking the PD1/PDL1 interaction with a human monoclonal antibody also works.

Blocking PD-1/PD-L1 interaction with a human monoclonal antibodies significantly improves therapy. After Tcell activation, Tcells express immune checkpoints such as CTLA-4 and PD-1. A biopsy of tumors taken from patients before treatment with immune checkpoint therapy (so prior to infiltration of activated Tcells into tumor tissues) may indicate lack of PD-L1 expression. However, upon T cell activation, T cells can traffic to tumors, up-regulate expression of immune checkpoints such as CTLA-4 and PD-1, and produce cytokines such as IFN-γ, which leads to expression of PD-L1 on tumor cells and other cells, including T cells, within the tumor tissues. Works well for melanoma, but it is in trial for many less immunogenic tumors Padmanee Sharma1,2 and James P. Allison SCIENCE 2015 Vol. 348 pp56

Combinational therapies may help when tumors are not immunogenic Potential characteristics of immunogenic and nonimmunogenic tumors. (A) Tumor tissue depiction indicating tumor cells and an invasive margin (dotted line), which may delineate separation of tumor cells from stromal components. Evaluation of tumor tissues may reveal an immunogenic tumor microenvironment consisting of many immunologic markers, including CD8 Tcells, CD4 Tcells, PD-L1, granzyme B, and CD45RO, which may be effectively treated with immune checkpoint therapy to elicit clinical benefit. (B) Tumor tissues that lack expression of many immunologic markers may indicate a nonimmunogenic tumor microenvironment, which may require combination therapies consisting of an agent to create an immunogenic tumor microenvironment plus an immune checkpoint agent to further enhance the immune response for clinical benefit.

PDL1/PD1 interakciógátló szignálokat indukál T-sejtekben. Konstitutív vagy indukált PDL1 expresszió tumor sejteken

Dendritic cell-based therapy

TARGETING DENDRITIC CELLS CTLA-4 CTLA-4 promotes nuclear localization of Foxo3 transcription factor, which suppresses expression of genes encoding IL-6 and TNF. IDO (indoleamine-2,3-dioxygenase) induction is also CTLA-4 dependent. IDO catalyses the degradation of the essential amino acid L-triptophan to N- formylkynurenine, the initial, rate-limiting step of tryptophan catabolism. Effector T-cells starved of tryptophan are unable to proliferate and go into G1 cell cycle arrest. Metabolites of tryptophan including kynurenine, quinolinic acid, and picolinic acid are toxic to CD8+ and CD4+ Th1 cells. TNF Blocking Downregulation Transendocytosis TNF

IDO inhibitors move center stage in immuno-oncology

Terápiás ellenanyagok (2012)