FA 196 Dendritic cell activating T cells

[anbuitachi]

---

Members do not see this ad.

First aid says dendritic cell is the only APC that can activate naive T cell.. U world says macrophages can do so too, with IL-1.

On the bottom of the page it says macropahge lymphocyte interaction. activated lymphocyte release IFN-gamma, and macropahges release IL-1, TNF-alpha to stimulate each other. Does anyone know what this means? What happens when they stimulate each other?? [since the lymphocyte is already activated..]

 

[coolforschool]

First aid says dendritic cell is the only APC that can activate naive T cell.. U world says macrophages can do so too, with IL-1.

On the bottom of the page it says macropahge lymphocyte interaction. activated lymphocyte release IFN-gamma, and macropahges release IL-1, TNF-alpha to stimulate each other. Does anyone know what this means? What happens when they stimulate each other?? [since the lymphocyte is already activated..]

I would go with UW. Macrophages phagocytose antigen, express it on MHC Class II, and then present it to naive T-cells while secreting IL-12 to turn the T-cells into the TH1 subset (IL-1 can also do this, but to be safe, associate IL-1 with fever/inflammation and IL-12 with T-cell activation).

The TH1 cells now secrete IFN-gamma to activate the macrophages, which in turn increases the macrophages' killing ability (upregulation of some genes). Macrophages also secrete IL-1 and TNF-alpha, but generally you should associate these with the inflammatory response and not T-cell activation. The TH1 cells also secrete IL-2, which is an autocrine that promotes the growth and sustenance of other CD4+/CD8+/NK cells.

You mainly associate IL-12 with T-cell activation because in IL-12 receptor deficiency, you can't activate the T-cells, and therefore your macrophages won't get activated (no IFN-gamma) and you get increased susceptibility of infections from organisms like M. tuberculosis. Treatment is administration of IFN-gamma.

 

[anbuitachi]

thanks!!