Changes

*'''Lipopolysaccharide recognition''' (LPS)- this is a component of some Gram-negative bacterial cell walls and its recognition is thought to be an ancient mechanism that evolved before the acquired immune system. When released by bacteria, LPS can bind to soluble CD14, which causes the release of TNF-alpha and IL-1 (both lead to systemic phagocyte activation), or to lipoprotein particles, which neutralize it

*'''Lipopolysaccharide recognition''' (LPS)- this is a component of some Gram-negative bacterial cell walls and its recognition is thought to be an ancient mechanism that evolved before the acquired immune system. When released by bacteria, LPS can bind to soluble CD14, which causes the release of TNF-alpha and IL-1 (both lead to systemic phagocyte activation), or to lipoprotein particles, which neutralize it

*'''Complement'''- some bacteria, particularly those with an outer lipid bilayer (i.e. Gram-negative), are susceptible to complement activated via the alternative pathway (the lytic complex: C5b-9).  

*'''Complement'''- some bacteria, particularly those with an outer lipid bilayer (i.e. Gram-negative), are susceptible to complement activated via the alternative pathway (the lytic complex: C5b-9).  

**The release of C3a and C5a lead to histamine release, and attracts and activates [[Neutrophils - WikiBlood|neutrophils]]

**The release of C3a and C5a lead to histamine release, and attracts and activates [[Neutrophils|neutrophils]]

**Components of C3 aid opsonisation of the bacteria

**Components of C3 aid opsonisation of the bacteria

*'''Phagocytosis'''- most bacteria are killed this way

*'''Phagocytosis'''- most bacteria are killed this way