T Cells provide cell mediated immunity Two types

T Cells provide cell mediated immunity Two types of T cells 1. Cytotoxic T cells (killer T cells)- effectors of the cell mediated response; they directly kill cells infected with pathogens 2. Helper T cells - do not directly kill infected cells but, instead, stimulate other immune cells. – required in the stimulation of B cells to produce antibodies and of cytotoxic T cells to kill infected cells

Nobel Prize in Medicine 2018 Immunotherapy James P. Allison and Tasuku Honjo win Nobel for their foundational work on cancer immunotherapy. The University of Texas MD Anderson Cancer Center and Kyoto University Checkpoint inhibitor drugs: prevent T cells from being switched off

FDA approves CAR T cell therapy for advanced lymphoma Chimeric antigen receptor (CAR) T-cell therapy 1. Isolate T cells 2. Insert the CAR gene into the T cell 3. Grow these CAR T cells 4. Inject CAR T cells into patients where it can attack the cancer cells Advantages - Using own immune cells Disadvantages - Hyperactivation of T cells - High costs

Interleukin 2 (IL-2) therapy • IL-2 is a drug (protein) approved by FDA for kidney cancer • Made by genetically engineered bacteria • Immunotherapy for cancer cells

Body’s Defenses - present at birth - specific - non specific Produced by cells called Type of immunity Secrete Type of immunity Killer T cells

Immune system disorders 1. Autoimmune diseases: Rheumatoid arthritis, type I diabetes, Multiple sclerosis (MS) 2. Immunodeficient disease: AIDS 3. Allergies 4. Cancer • HPV: Human Papilloma Virus causes cervical cancer • Hepatitis virus: increases risk of liver cancer

Autoimmune diseases Type 1 diabetes is an autoimmune disorder in which cytotoxic T cells destroy one’s own pancreatic cells. Multiple sclerosis: Immune cells destroy the Myelin sheath surrounding the nerve cell Rheumatoid arthritis: cartilage cells are destroyed in joints Healthy pancreatic cells Cytotoxic T cells

IMMUNE SYSTEM DEFICIENCY: HIV AIDS Without helper T cells, B cells and cytotoxic T cells cannot be activated. B cell Helper T cell Cytotoxic T cell HIV selectively targets Helper T cells; when too many helper T cells are lost, killer T cells and B cells are less active. This Makes one susceptible results in weak immune system to common pathogens

Allergies Allergens are _____ that causes an allergic response