Changes

==Helper CD4⁺==

==Helper CD4⁺==

<p>These T cells express the marker CD4 and are categorised into two groups, Th1 and Th2, which are distinguished by the cytokines they produce. T helper cells recognise antigens bound to MHC II complexes.

<p>These T cells express the marker CD4 and are categorised into two groups, TH₁ and TH₂, which are distinguished by the cytokines they produce. T helper cells recognise antigens bound to MHC II complexes.

*Th1 cells produce Il-2, IFN-γ and TNF-α  

*TH₁ cells produce IL-2, IFN-γ and TNF-α  

*Th2 cells produce Il-4, Il-5, Il-10 and Il-13  

*TH₂ cells produce IL-4, IL-5, IL-10 and IL-13  

Th1 cells interact with CD8⁺, NK and dendritic cells and Th2 cells interact with B cells. Th1 cells are involved with the control of intracellular pathogens and Th2 cells extracellular pathogens. Il-2 produced by Th1 cells stimulates further proliferation of CD4⁺ cells.</p>

TH₁ cells interact with CD8⁺, NK and dendritic cells and TH₂ cells interact with B cells. TH₁ cells are involved with the control of intracellular pathogens and TH₂ cells extracellular pathogens. IL-2 produced by Th1 cells stimulates further proliferation of CD4⁺ cells.</p>

<p>Th0 populations are CD4⁺ cells that have yet to differentiate into Th1 or Th2 cells and they secrete Il-2, IL-4, Il-5, IFN-γ. In the presence of Il-4 they develop into Th2 cells while in the presence of Il-2 they develop into Th1 cells. In the abscence of Il-2 Th1 cells will change into Th2 cells.</p>

<p>TH₀ populations are CD4⁺ cells that have yet to differentiate into TH₁ or TH₂ cells and they secrete IL-2, IL-4, IL-5, IFN-γ. In the presence of IL-4 they develop into TH₂ cells while in the presence of IL-2 they develop into TH₁ cells. In the abscence of IL-2 TH₁ cells will change into TH₂ cells.</p>

<p>Th1 cells have two populations; one that secretes IFN-γ and is short lived, and the other that doesn’t secrete IFN-γ and is long lived. The cells that do not secrete IFN-γ are termed '''memory T cells'''</p>

<p>TH₁ cells have two populations; one that secretes IFN-γ and is short lived, and the other that doesn’t secrete IFN-γ and is long lived. The cells that do not secrete IFN-γ are termed '''memory T cells'''</p>

==Cytotoxic CD8⁺==

==Cytotoxic CD8⁺==