Immunology – studies physiological mechanisms that1.Protect our organism from pathogens2.Perform immunosurveillance against tumors

Immune system is essential for our survival!

Characteristics of immune response:1) universality (can be activated in response to almost any molecular structure)2) appropriateness (responses are focused on and tailored for the specific attacker)3) tolerance (responses against self are forbidden or at least limited)

Functions of immune systemrecognizes the presence of microbial invasorsprevents/limits their proliferation and spreadingeradicates infection from our organismIt returns to a state of equilibrium (homeostasis) and establishes a state of protection (immunity)

+slide

Pathogens comes in different forms, sizes etc-phagocytosed bacteria-parasites in blood = blood vessel-virus infected cell-bacteria on epithelium mucosal surface-bacteria in tissue-intracellular = body tissue -worm in gut = body cavities

The immune response is:-Specifically induced by pathogens entry-Specifically directed against pathogen-Auto limiting (homeostatic)-Capable of memory (long term protection)

+slides

Immune system is complex system consisting of:-cells-tissues-soluble mediators (which are interconnected and finely regulated)

Components of immune system1.Haeomopoietic cell types-differentiation-recognition-activation-effector functions

2.Soluble mediators-cytokines (regulatory function)-antibodies (effector function)-complement and mediators (effector/regulatory function)

+slides 2x

bone marrow and thymus are primary..

CDC-cluster designation / Cluster Differentiation

Receptors on haemopoietic cells (markers) are defined by a CD n and identified through reactivity with monoclonal antibodies

Expression of different CD depends on:-cell type-activation state-differentiation step

General properties of cytokines-cytokines regulate all aspects of the immune response-cytokines mediate communication among immune cells and between immune and tissue cells-both immune and tissue cells secrete cytokines-cytokine synthesis, secretion, half-life and bioavailability are finely regulated at multiple levels

Cytokines can exert different actions1.Autocrine action2.Paracrine action (nearby cell)3.Endocrine action (circulation distant cell)

Cytokines typically display pleiotropic activity (slide) +slide

Effector cells of innate immunity1.Phagocytes-monocytes (circulation) and macrophage (in tissues), neutrophil granulocyte2.NK cells (lymphocytes NK)

Soluble components of Innate immunity1.The complement system (slides)2.The acute phase response3.Anti-macrobial peptides

Antigen- any molecular structure recognized by T and B lymphocyte antigen receptors