Mitzi Nagarkatti, PhD Professor and Chair Dept. of Pathology, Microbiology and Immunology

1. Tumor Immunology Mitzi Nagarkatti, PhD Professor and Chair Dept. of Pathology, Microbiology and Immunology School of Medicine and Deputy Director, Basic and Translational Research University of South Carolina Cancer Center Tel. # (803)733-3275 E-mail: mnagark@uscmed.sc.edu

2. Objectives Introduction Ags expressed by cancer cells Nature of immune response How cancer evades immune system Immunotherapy

3. Cancer Introduction • Uncontrolled growth produces a tumor or neoplasm. • A tumor that grows indefinitely and often spreads (metastasis) is called malignant--also called cancer. • A tumor that is not capable of indefinite growth----benign. • Malignant---kills host. • Benign---does not kill host.

4. Cell Growth Control of cell growth Growth-restricting Tumor-suppressor genes Growth-promoting Proto-oncogenes

5. Molecular Basis of Cancer Radiation Chemical (Carcinogen) Virus Mutations Uncontrolled cell growth Proto-oncogenes Tumor-suppressor genes

6. Types of cancers based on etiologic agent • Chemically-induced tumors • Each tumor induced by a carcinogen (e.g. benzopyrene) injected at various sites expresses a unique Ag. • Thus difficult to develop vaccine. • Virus-induced tumors • Tumors induced by same virus express same tumor Ag. • Induce a strong immune response. e.g. Gardasil vaccine – Human Papilloma Virus (HPV) induced cervical cancer • UV-induced tumors • UV radiation--->melanomas • Highly tumorigenic

7. Virus-induced tumors e.g.SV40

8. Chemical-induced tumors e.g. methylcholanthrene

9. Types of Cancer based on the tissue affected • Carcinoma: Cancer of endo or ectoderm e.g. Skin or epithelial lining of organs • Sarcomas: Cancer of mesoderm e.g. bone • Leukemias and Lymphomas: Cancers of hematopoietic cells

10. Evidence for the role of immune system in tumor rejection • Spontaneous regression • Infiltration of tumors by lymphocytes and macrophages • Regression of metastases after removal of primary tumor • Regression after chemotherapy • Lymphocyte proliferation in draining lymph nodes • Higher incidence of cancer after immunosuppression/immunodeficiency (AIDS, neonates, aged, transplant patients)

11. Antigens expressed on tumor cells Major Histocompatability Complex antigens TSTA Tumor-specific transplantation Ag TATA Tumor-associated transplantation Ag TSTA: unique to a tumor Play an important role in tumor rejection. TATA: shared by normal and tumor cells Tumor-associated developmental Ag (TADA) Tumor-associated viral Ag (TAVA)

12. Tumor-Associated Developmental Ags • Found on cancer cells and on fetal cells. • Do not trigger anti-tumor immunity. • Used in diagnosis. • Alpha-fetoprotein(AFP) Cancers of liver • Carcinoembryonic Ag (CEA) colorectal cancer

13. Other Tumor associated antigens • Differentiation Ags: B cells produce surface Ig. B cell tumors have sIg Melanomas and melanocytes express MART-1 • Overexpression of Ag on tumors compared to normal cells e.g. In breast cancer, HER2/neu • Ags expressed on male germ cells and melanoma e.g. MAGE-1

14. Inbred: repeated brother-sister matings Tumor Growth Syngeneic (accepted) Mouse Outbred: normal population Allogeneic (rejected) Across Species Rat Xenogeneic (rejected)

15. Tumor How does a tumor escape immune surveillance? • Generation of Regulatory cells (CD4+CD25+ FoxP3+ T cells) or Myeloid-derived suppressor cells(Gr-1+ CD11b+) • Secrete immunosuppressive molecules Ex: Transforming growth factor beta (TGF-b), interleukin-10 (IL-10), etc. T regs CTL MDSC IL-10, etc

16. Macrophage/ Dendritic cell (Ag presenting Cell) tumor Ag tumor • Failure to process and present tumor Ag. B cell MHC Class II T helper (Th) cell MHC Class I Cytotoxic T lymphocyte (CTL) tumor tumor

17. tumor Class I MHC B7 CD28 tumor Ag CTL • Tumors may fail to express costimulatory molecules involved in T cell activation. Tumors escape the action of CTL by not expressing B7 which provides 2nd signal involved in T cell activation

18. Downregulation of MHC expression on tumor cell (CTL resistant but NK sensitive) NK cell Tumor cell

19. Tumor escape mechanisms: FasL Fas Tumor CTL FasL Fas Tumor CTL When tumor cells express Fas Ligand, they can kill Fas+ T cells, thereby escaping immune destruction.

20. Traditional approaches to treat cancer Surgery Radiation Chemotherapy • Localized tumors Metastastic tumors Affects proliferating cells • (bone marrow, etc.) • Radiation/Drug-resistant tumors • Novel Mode:Immunotherapy

21. Immunotherapy • Active Immunization: The host actively elicits an immune response. • Specific • Vaccination with viral Ags: e.g. • Hepatitis B virus • Human Papilloma virus (HPV) - Gardasil

22. Normal Mf Tumor Tumor lysis Activated Mf • Nonspecific: • BCG (Bacillus Calmette-Guerin) Mycobacteria - melanoma, bladder carcinoma

23. IL-2R Anti-IL-2R IL-2 Passive Immunization: Preformed Abs or immune cells transferred Specific:Ab Therapy Abs against growth factor receptor e.g. IL-2R in HTLV-1 induced Adult T cell leukemia Abs specific for oncogene product e.g. Abs against HER2/neu (Herceptin or trastuzumab)

24. Monoclonal Abs used in Immunotherapy • Unlabelled Ab: e.g. Anti-CD20 Ab in non-Hodgkin’s lymphoma • Complement (C’) • Ab-dependent cell mediated cytotoxicity (ADCC) • Labelled Ab (Radioisotope/Toxin) • 131I (Iodine) • Internalization C’ B cell tumor CD20 FcR Mf/NK/ PMN

25. Tumor Ricin Anti-tumor Abs coupled to toxin, radioisotopes, drugs or enzymes: Immunotoxins: Ricin A/diphtheria/Pseudomonas toxin coupled to Abs. e.g. antiCD20-Pseudomonas toxin in B cell leukemia Internalized toxin inhibits protein synthesis. Cytocidal isotopes or anticancer drugs (adriamycin) coupled to Abs

26. Adoptive Immunotherapy 1. Lymphokine-activated killer cells (LAK): Peripheral Blood Lymphocyte (PBL) + high dose IL-2 NK/T LAK 2. Tumor-infiltrating lymphocytes (TIL): In and around solid tumors Activated NK and CTL

27. 1)Use of LAK cells + IL-2 to treat cancer IL-2 Isolate lymphocytes from blood lymphocytes melanoma +IL-2 for 3 days LAK cells

28. Treatment of Melanoma with LAK cells +IL-2 Before After

29. 2) Use of tumor-infiltrating lymphocytes + IL-2 to treat cancer IL-2 surgical removal of cancer nodule T cell tumor +IL-2 Successful treatment of melanoma and renal cell carcinoma

30. Treatment of Melanomas with TIL + IL-2 Before After

31. Dendritic Cells • Highly potent antigen processing and presenting cells • Prime an Immune Response • Pulse with tumor Ags or gene transfer Cl II Cl I

32. Autologous bone marrow (treated in vitro with Ab + C’) transplantation following irradiation/chemotherapy. • Allogeneic bone marrow transplantation (matched for HLA Ag) – Graft versus host reaction

33. Cytokine Therapy Inject cytokines. 1. Interleukin -2 (IL-2) high dose - Alone or with cells Melanoma and renal cell carcinoma Activates NK and CTL Toxic - fever, edema, shock 2. Tumor necrosis factor (TNF-a) - Carcinoma

34. 3. Interferon (IFN)-a : Activates NK activity Hairy B cell leukemia, renal cell carcinoma, melanoma, Kaposi sarcoma, hematologic cancers 4. IFN-g : Increases Cl II MHC expression. Ovarian carcinoma 5. Hematopoietic growth factors: Overcome neutropenia Granulocyte-macrophage colony stimulating factor (GM-CSF)

35. Gene therapy Introduce cytokine genes for IL-2, IL-4, IL-12, IFN-g orGM-CSF into tumor cells. IL-2 GM-CSF T cell tumor Mf

36. SUMMARY • Tumors should express TSTA. • Th cells and CTL are important in tumor rejection. • NK cells and macrophages also play an important role. • Tumors evade immune system in a number of ways. • Immunotherapy is promising.

37. Reading Immunology By Male, Brostoff, Roth and Roitt 7th Edition Pages 401-419