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The adaptive and [[Innate Immune System|innate responses]] work together to destroy bacteria. The adaptive response ensures the [[Innate Immune System|innate response]] is carried out efficiently. There are two major branches of the adaptive immune response, humoral immunity and cell-mediated immunity.

The adaptive and [[Innate Immune System|innate responses]] work together to destroy bacteria. The adaptive response ensures the [[Innate Immune System|innate response]] is carried out efficiently. There are two major branches of the adaptive immune response, humoral immunity and cell-mediated immunity.

==Humoral==

==Humoral==

*[[Complement|Complement]] activation of the classical pathway

Humoral immunity includes [[Complement|complement]] activation of the classical pathway. It results in the production of [[Immunoglobulin M|IgM]] and [[Immunoglobulin G|IgG]] and makes the complement system more efficient.

**Production of [[Immunoglobulin M|IgM]] and [[Immunoglobulin G|IgG]] makes the complement system more efficient

'''Cell-Mediated'''

==Cell-Mediated==

*Help for macrophages

Cell-mediated immunity provides help for macrophages. It includes [[Immunoglobulin G|IgG]] production (through T-helper type II (T_H2) cell interaction with [[Lymphocytes#B Cells|B cells]]), which improves phagocytosis by opsonisation. Infected [[Macrophages|macrophages]] are rescued by T-helper type I (T_H1) cells when phagocytosis and digestion mechanisms fail to eliminate the pathogen.

**[[Immunoglobulin G|IgG]] production (T-helper type II cells and [[Lymphocytes#B Cells|B cells]]) which improves phagocytosis by opsonisation

**Infected [[Macrophages|macrophages]] are rescued by T-helper type I cells when phagocytosis and digestion mechanisms fail to eliminate the pathogen

'''Extracellular Infection'''

==Extracellular Infection==

*Complement and phagocytosis

The response to extracellular infection involves [[Complement|complement]] and phagocytosis; [[Lymphocytes#B Cells|B cell]] and T_H2 cell stimulation and the production of [[Immunoglobulin M|IgM]], which activates the classical cascade. T_H17 stimulation also enhances extravasation of [[Neutrophils|neutrophils]] to the area to clear the pathogen. There is also class switching of [[Immunoglobulin M|IgM]] to [[Immunoglobulin G|IgG]], which is a good opsonin and targets bacterial Fcγ receptor expressed by [[Macrophages|macrophages]] and [[Neutrophils|neutrophils]].

*Production of [[Immunoglobulin M|IgM]] which activates the classical cascade

During a vesicular infection, the infected [[Macrophages|macrophage]] secretes IL-12. IL-12 stimulates T-helper type I cells which release IFN-γ. IFN-γ then triggers the [[Macrophages|macrophages]] to kill the pathogens inside.

*Class switching of [[Immunoglobulin M|IgM]] to [[Immunoglobulin G|IgG]] which is a good opsonin and targets bacterial Fcγ receptor expressed by [[Macrophages|macrophages]] and [[Neutrophils|neutrophils]]

<big>'''Also see [[Immunity to Bacteria]]'''</big>

 

'''Vesicular Infection'''

*The infected [[Macrophages|macrophage]] secretes IL-12

[[File:Adaptive Immunity to Intracellular Bacteria.png|thumb|right|300px|Adaptive Immunity to Vesicular Bacteria - R.J.Francis, RVC 2012]]

 

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*IFN-γ triggers the [[Macrophages|macrophages]] to kill the pathogens inside

 

<big>'''Also see [[Immunity to Bacteria]]'''</big>

[[Category:Adaptive Immune System]]

[[Category:Adaptive Immune System]]