8. Inflammatory Cells And Their Functions Flashcards
Neutrophils
Phagocyte anddestory forgein antigens and microbial organisms
Main solders
Contain antimicrobial functions
Eosinophils
When stimulated release inflammatory factors which destroy parasites and trigger a histamine release from mast cells
Allergic reactions
Basophils
Role in allergic response, protective immunity in skin, eradication of parasites
High affinity for IgE
Mast cells
Source of mediators of immediate hypersensitivity
Have many receptors for IgE
Release mediators of allergic disease: histamine and prostaglandins
Monocytes/macrophages
In blood - in tissue become macrophages
Big eaters of immune system
ORIGIN: in adults hematopoietic stem cells in bone marrow
In fetus: hematopoietic stem cells in bone marrow and yolk sac, differentiate into a variety of organs
Three steps of Phagocytosis
Recognition and attachment
Engulfment
killing by ROS, NO or degraded by lysosome
Reactive Oxygen Species
Oxygen-derived free radicals (including H2O2 and hydroxyl radical) are released from a variety of inflammatory cells once activated
EFFECTS: endothelial cell damage cause it increased vascular permeability, injury through oxidative stress
Role of mediators of inflammation
Initiate and regulate inflammation
Secreted by cells or made from plasma proteins
Active mediators produced in response to stimuli
Short-lived
One mediator can stimulate release of other mediators
Principle mediators of inflammation
Histamine Prostaglandin Leukotrienes Cytokines (TNF, IL-1) Chemokines Complement system
Histamine
Source: mast cells
Action: vasodilation, increase vascular permeability
Prostaglandins
Source: Cell membrane phospholipid
Action: vasodilation, pain, fever
Leukotrienes
Source: cell membrane phospholipid
Action: increase vascular permeability
Cytokines (TNF, IL-1)
Source: macrophages, helper T cells
Action: Local- endothelial activation
Systemic- fever
Chemokines
Source: leukocytes, activated macrophages
Action: chemotaxis
Complement system
Source: plasma (produced in liver)
Action: direct target killing MAC
