Humoral and Cellular Immunity Kaynak: Abbas 2003, Male 2006, Le Bien Blood 2008 Dr. Yıldıran

Presentation Plan Basics of immune response Lymphocyte types Primary and secondary lymphoid tissues Development of B lymphocyte B lymphocyte functions Development of T lymphocytes Receptors of lymphocytes and activation Dr. Yıldıran

Objectives of this lecture You can tell: Development of B lymphocytes Functions of B lymphocytes Development of T lymphocytes Functions of T lymphocytes You can explain: Humoral immunity Cellular immunity Differencies between both of them Dr. Yıldıran

Dr. Yıldıran

Specific immunity (Adapttive) Non-specific immunity (Innate) Immune System Specific immunity (Adapttive) Non-specific immunity (Innate) Phagocytes NK cells Complement system T and B lymphocytes MEMORY! Dr. Yıldıran

Pathogen Immune System Extracellular Intracellular Toxin Microbiome Lactobacillus Flora Dr. Yıldıran

Antigen presenting cell Immune Response Antigen presenting cell Dr. Yıldıran Abbas, 2003

Adaptive immunity Dr. Yıldıran

Specific Immunity CD19 CD3 CD4 CD3CD8 Dr. Yıldıran Abbas, 2003

Maturation of Lymphocytes B lymphocytes in bone marrow T lymphocytes in thymus Then they include circulation as naive lymphocytes IL-7 is essential in this process. If naive lymphocytes don’t encounter to any foreign antigen they go to apopitosis (programmed death). Dr. Yıldıran

Antigens are catched and processed here Primary Lymphoid Tissues Thymus  Development of T lymphocytes Fetal liver and postnatal bone marrow  Development of B lymphocytes Secondary Lymphoid Tissues Spleen Lymph nodes MALT (mucosa associated lymphoid tissue) Antigens are catched and processed here Dr. Yıldıran

B lymphocyte development Early Pre-B cell LAte Pre-B cell Stem cell Pro-B cell Pre-BCR Fetal Liver Antigen independent Bone marrow Immatüre B cell Mature B cell Plasma cell Antigen dependent

Markers CD10+ Conley 2003

Genetic defects of B cell development

Class (isotype) switching (CSR): B cell produce firstly IgM, then switch this molecule to other Ig’s. Somatic hypermutation involves a programmed process of mutation affecting the variable regions of immunglobulin genes  immune repertoire Dr. Yıldıran

Antigen specific receptor Somatic recombination provides this with RAG (Recombination activating gene) ensyme If this gene disrupted, the result is severe combined immunodeficiency (SCID). Dr. Yıldıran

Immunglobulin Molecule Antigen binding site (Fab) Fc receptor and complement binding site Disulphit links Carbohydrate Heavy chain Light chain Ig domains Dr. Yıldıran

Functions of antibodies Complement activation Neutrolastion of microorganisms and toxins Antibodies B lymph Opsonisation and phagoctosis Microorganism Lysis Phagocytosis of opsonised microorganism by complement Complement activation Inflammation IgG Surface antigen FcRIII Antibody dependent cellular cytotoxicity Dr. Yıldıran NK cell

Maturation of T lymphocyte CD4+ T hücresi (Thelper=Th) CD8+ T cell Cytotoxic T cell Dr. Yıldıran

Selection of T lymphocyte DP DN Zone 1-4 SP AIRE Dr. Yıldıran

Receptors CTLA-4=CD152 Inhibitor Dr. Yıldıran

Activation Dr. Yıldıran

Activated Lymphocytes Activation markers CD25 and CD69 Effector molecules CD40L (=CD154) activates B lymphocytes, dendritic cells, endothelial cells Fas (CD95)  apopitosis Dr. Yıldıran

Peptide Antigen catch Dr. Yıldıran

Antigen processing CD4  IL-2, IFNG CD8  Perforin, granzym Antigen Presentig Cell ER: Endoplasmic Reticulum Dr. Yıldıran

Signaling IL-2, IL-4, IL-5, IFN secreted Dr. Yıldıran

Functions of T Lymphocytes Defense to intracellular microorganisms Th cytokine secretion, stimulation of macrophages Activation of B lymphocytes and phagocytes Th Killing of infected cells Ts Memory Dr. Yıldıran

memory T TCR specifity and diversity, recognize 107-109 different antigens.

Flowcytometry