Cell-mediated hypersensitivity/ Delayed type of hypersensitivity
Principle
Type I
Type II
Type III
Type IV
Antibody-mediated degranulation of granulocytes leading to the destruction of cells.
Antibody-mediated destruction of healthy cells.
Antigen-antibody complex-mediated destruction of cells.
T lymphocytes mediated the destruction of cells.
Primary Mediator
Type I
Type II
Type III
Type IV
IgE
IgG/IgM
IgG/IgM
Specific subsets of CD4+ helper T cells or CD8+ cytotoxic T cells.
Other components as mediators
Type I
Type II
Type III
Type IV
Mast cells, Basophils, histamine & other pharmacological agents
Complement, Neutrophils
Complement, phagocytes and K cells
Dendritic cells, macrophages, and cytokines
Reaction time
Type I
Type II
Type III
Type IV
Immediate or within a few hours
5-8 hours
2-8 hours
After 24 hours only, mostly 48-72 hours after contact
Antigen
Type I
Type II
Type III
Type IV
Free in circulation (Soluble)
Fixed on cells
Free in circulation ( Soluble)
Soluble or cell-bound
Antigen origin
Type I
Type II
Type III
Type IV
Exogenous
Endogenous or exogenous
Exogenous or endogenous
Exogenous or endogenous
Antibody
Type I
Type II
Type III
Type IV
Fixed on mast cells and basophils
Free in circulation
Free in circulation
Not applicable
Mechanism
Type I
Type II
Type III
Type IV
Allergen-specific IgE antibodies bind to mast cells via their Fc receptor. When the specific allergen binds to the IgE, cross-linking of IgE induces degranulation of mast cells.
IgG or IgM antibody binds to a cellular antigen, leading to complement activation and cell lysis. IgG can also mediate ADCC with cytotoxic T cells, natural killer cells, macrophages, and neutrophils.
Antigen-antibody complexes are deposited in tissues. Complement activation provides inflammatory mediators and recruits neutrophils. Enzymes released from neutrophils damage tissue.
Th2 cells secrete cytokines, which activate macrophages and cytotoxic T cells.
Complement activation
Type I
Type II
Type III
Type IV
No
Yes
Yes
No
Appearance
Type I
Type II
Type III
Type IV
Weal & flare
Lysis & necrosis
Erythema & edema
Erythema & induration
Transfer with serum
Type I
Type II
Type III
Type IV
Passive transfer possible with serum
Passive transfer
Passive transfer
Cannot be transferred with serum; but possible with T cells transfer
please upload this in description mode
Hello, we have Hypersensitivity notes in detail as below-
https://microbenotes.com/type-1-anaphylactic-hypersensitivity-reaction/
https://microbenotes.com/type-ii-cytotoxic-hypersensitivity-mechanism-and-examples/
https://microbenotes.com/type-iii-immune-complex-hypersensitivity-mechanism-and-examples/
https://microbenotes.com/type-iv-cell-mediated-hypersensitivity-mechanism-and-examples/