IMMUNITY• INNATE (present before birth,
“NATURAL”)
•ADAPTIVE (developed by exposure to pathogens, or in a broader sense, antigens)
INNATE IMMUNITY• BARRIERS• CELLS: LYMPHOCYTES, MACROPHAGES,
PLASMA CELLS, NK CELLS• CYTOKINES/CHEMOKINES• PLASMA PROTEINS: Complement,
Coagulation Factors• Toll-Like Receptors, TLR’s
ADAPTIVE IMMUNITY
•CELLULAR, i.e., direct cellular reactions to antigens•HUMORAL, i.e., antibodies
CELLS of the IMMUNE SYSTEM
• LYMPHOCYTES, T• LYMPHOCYTES, B• PLASMA CELLS (MODIFIED B CELLS)• MACROPHAGES, aka “HISTIOCYTES”, (APCs, i.e.,
Antigen Presenting Cells)• “DENDRITIC” CELLS (APCs, i.e., Antigen Presenting
Cells)
• NK (NATURAL KILLER) CELLS
GENERAL SCHEME ofCELLULAR EVENTS
• APCs (Macrophages, Dendritic Cells)• T-Cells (Control Everything)–CD4 “REGULATORS” (Helper)–CD8 “EFFECTORS”
• B-Cells Plasma Cells AB’s• NK Cells
The immune response
Immune response :It is a specific defense mechanism developing against particular types of irritants to overcome the irritant on subsequent exposure.
Hypersensitivity : Is the change in tissue reaction Following re- exposure to antigen
Def:Def:
IMMUNITY HYPERSENSITIVITY
When After first exposure Secondary exposure
Duration Take longer time Faster
Tissue damage No or minimal tissue damage
More tissue damage
LN More LN affection Less
Types InnateAdaptive
IIIIIIIV
Example
Type III(immune complex reaction)
Ag + Ab Immune complex with slight excess of Ag
Diffuse through the wall of blood vessels
Precipitate on the endothelial lining & outside blood vessels
Activation of complement Inflammatory reaction
With increase vascular permeability & exudation
Release of chemotactic factor PNL Phagocytose
complement & immune complex Proteolytic enzymes
Tissue destruction.
Types• @ Serum sickness• Oedema of the eye lid• Generalized lymphadenopathy• Urticaria• Fever & bone aches
• @ Arthus phenomenon• Repeated skin injection of the antigen (e.g. insulin)
tissue necrosis, hge. And ulceration
Systemic immune- complex disease
Acute serum sickness
Arthus reaction
1- Serum sickness2- Arthus reaction.3- Poly arteritis nodosa.4- Post streptococcal GN.5- SLE.
Examples
Serum sickness
Top Related