08/02/59. Tumor Immunotherapy. Development of Tumor Vaccines. Types of Tumor Vaccines. Immunotherapy w/ Cytokine Gene-Transfected Tumor Cells

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1 Tumor Immunotherapy Autologous virus Inactivation Inactivated virus Lymphopheresis Culture? Monocyte s Dendritic cells Immunization Autologous vaccine Development of Tumor Vaccines Types of Tumor Vaccines Strategies for enhancing immune responses to tumors Immunotherapy w/ Cytokine Gene-Transfected Tumor Cells 1

2 Systemic Cytokine Therapy for Tumors Adoptive Cellular Therapy Ex vivo activate CTLs or NK cells CAR-T-cell Immunotherapy 2

3 13 Chimeric antigen receptors (CARs) ocars are engineered receptors on immune effect cell S gee/files/2014/11/discovery_medicine_no_fhtml?id=2 attachment_5 Chimeric antigen receptor (CAR) enhance antigen recognition and cellular activation Engineered NK cells with Chimeric antigen receptors (CAR) Antigen binding component Expressed on outside of cell; This can be part of an antibody, or other molecule usually binds HIV envelope on infected cells HLA independent; Signaling Component Sends signal into the cell Directs the cell to kill HIV infected target Binds Viral protein CD3 NK cell CD4 CAR HIV Env HIV-infected cells 16 Chimeric antigen receptors (CARs) o Adoptive T cells therapy genetically modified for targeted cytotoxic cell killing holds considerable promise and for treatment of tumor cells or chronic viral infections. Targeted cell killing strategies to achieved by adoptive transfer of autologous CD8 T cells genetically modified to express a CAR recognizing an intact surface antigen preferentially expressed on the surface of target cells. 17 Overview: Adoptive T cell therapy 1. Isolation of TILs or tumor specific T-cells from blood 2. Expand and activate T-cells ex vivo 3. Infuse the "boosted" T-cells into the patient. Target therapy with Tumor specific T cells Cancer: Melanoma Autologous tumor infiltrating lymphocytes (TILs); Live drug Advantages High response rate (>50%), Long-term remission, Less toxic & gentler to the patient Limitation: Extraction of TILs, Cell manufacturing Possible alternate T cell Engineering (CAR-T cells) Rosenberg SA & Dudley ME 2009 Current Opinion of Immunology 3

4 Adoptive T cell therapy: CAR-T cells CAR-T cells (Chimeric antigen receptor-t cells0 T cells transduced with tumor-specific CAR CAR: Single fusion molecule with antigen specificity plus signaling domain Three types of CAR: First/second/generations Based on co-stimulatory receptors Cancer: Solid tumor & hematological malignancies Live drug Advantages of CAR T cells Tumor recognition independent of HLA (no HLA typing needed) Multiple antitumor immunomodulators can be engineered Target variety of antigens (protein, carbohydrate, glycolipid) Antigen specific domain Maus M V et al. Blood 2014;123: Clinical significance of CAR-T cells Target CAR Cancer Objective response CD19 CAR:CD28-CD3 Lymphoma and CLL CD20 N=7: 1CR, 5 PR & 1SD CAR:CD137-CD3 ALL 2CR CAR:CD28-CD3 ALL 5CR CAR:CD137-CD28- NHL N=3: 1PR, 2NED CD3 CEA CAR-CD3 (1 st gen) Colorectal & breast GD2 CAR-CD3 (1 st gen) Neuroblastom a ERBB2 CAR:CD28-CD137- CD3 Colorectal cancer N=7: minor responses in two patients N=19: 3CR N=1, patient died Kershaw et. al Nature Reviews cancer CAR-T cells T cells transduced with tumor-specific Chimeric Antigen Receptor (CAR) Tumor recognition independent of HLA (no HLA typing needed) Target: variety of tumor antigens (protein, carbohydrate, glycolipid) High response rate (up to 88%): pre- clinical and clinical findings Summary Limitation of CAR-T cells Toxicities On target/off tumor toxicities Cytokine syndrome Tumor microenvironment Presence of MDSCs & Treg in tumor Immunosuppressive agents

5 25 26 CAR-T FOR HIV APPLICATION HIV 1 Envelope glycoprotein (ENV) 27 Bispecific CD4 based CAR Constructs 28 o The human immunodeficiency virus type 1 envelope glycoprotein is synthesized as a precursor glycoprotein (gp160), and is then processed into gp120 and gp41by the protease. oa novel bispecific CAR in which a CD4 is linked by Gly4Ser repeats to a scfv 17b human Mab, the 17b Mab recognizing a highly conserved CD4 induced epitope on gp120 involved in co receptor binding. (Dey B, et al. 2003, Lagenaur LA, et al. 2010) o Moreover, the polypeptide linker between the CD4 and 17b is designed to sufficiently long (CD b CAR) versus too short (CD b). to permit simultaneous binding of the two moieties to a single gp120 subunit. Experiment 5 29 To study suppression of spreading HIV 1 infection in PBMCs by CD4 based CARs. Experiment 5: Suppression of primary spreading HIV 1 infection by CAR T cells. For comparisons of the relative CAR activities using cells from three different donors 30 various HIV 1 R5 isolates (p24 titer of 50 to 150 ng/ml) collect supernatant to analyze p24 levels by ELISA kit PBMCs (5x10 6 cells per well) Co culture Incubate 37 C, O/N at 37 C, for 8 days infected PBMCs (target cells) at various ratios of T:E (1:0.008, 1:0.04, 1:0.2, 1:1) CD4 based CARs can suppress the primary spreading HIV 1 infection The results demonstrate various levels of suppressive activities by For analysis of relative CAR activities using different HIV 1 isolates (single donor PBMCs) the three CD4 based CARs [CD b > CD4 > CD b], The control 139 CAR was ineffective FIG5: (A) BX08 data show the average level of infection of PBMCs, and the p24 levels are expressed relative to cocultures with control 139 CAR at the lowest E:T ratio(defined as 100). (B) CD4 based CARs were tested against the indicated HIV 1 isolates 5

6 Conclusion 31 ips cells Technology 32 o CD4 based CARs displayed specific functional activities against HIV 1 Env expressing target cells. o The superior potency of CD b CAR over CD b CAR The greater potential ti for efficient i T cell activation The ability of two CD b molecules to simultaneously bind a single gp120 subunit. Avoidance of the undesired rendering of the genetically modified CD8 T cells susceptible to HIV infection. 6