Changes

==Adaptive Immunity==

==Adaptive Immunity==

Although the innate immune system provides an effective first line of defence, [[T cells|T cells]] are fundamental in the development of immunity, demonstrated using T-cell deprived mice that fail to resolve otherwise non-lethal infections of, for example, ''T. cruzi''.  

Although the innate immune system provides an effective first line of defence, '''[[T cells|T cells]]''' are fundamental in the development of immunity, demonstrated using T-cell deprived mice that fail to resolve otherwise non-lethal infections of, for example, ''T. cruzi''.  

*Both CD4⁺ and CD8⁺ cells are required for protection, e.g CD4⁺ cells protect against the blood stage of a Plasmodium infection (erythrocytes do not express MHC class I), while CD8⁺ cells are required to mediate immunity against the liver stage (hepatocytes do not express MHC class II).

*Both CD4⁺ and CD8⁺ cells are required for protection, e.g CD4⁺ cells protect against the blood stage of a Plasmodium infection (erythrocytes do not express MHC class I), while CD8⁺ cells are required to mediate immunity against the liver stage (hepatocytes do not express MHC class II).

*T_H1 cells are required to fight intracellular protozoa - the release of IFN-γ activates macrophages to kill the protozoa residing within them

*T_H1 cells are required to fight intracellular protozoa - the release of IFN-γ activates macrophages to kill the protozoa residing within them