Initiating an Immune Response
The T lymphocyte activation pathway is triggered when a T cell encounters its cognate antigen, coupled to a MHC molecule, on the surface of an infected cell or a phagocyte. T cells contribute to immune defenses in two major ways: some direct and regulate immune responses; others directly attack infected or cancerous cells
The T lymphocyte activation pathway is triggered when a T cell encounters its cognate antigen, coupled to a MHC molecule, on the surface of an infected cell or a phagocyte. T cells contribute to immune defenses in two major ways: some direct and regulate immune responses; others directly attack infected or cancerous cells

Once in the lymphnodes the DCs use secretions such as cytokines to activate and differentiate (process by which a cell becomes a more specialized cell type) naive T-cells into specialised T-cells

Immature DCs have alot of endocytosic capablities (they can capture many antigens) but cannot activate any T cell response. Meanwhile mature DCs have high T-cell activation and secreting potential but can no longer capture invading pathogen.
Once a dendritic cell has matured into antigen presenting cells and migrate to lymph nodes it begins to activate the correct immune response. The T-cells then activate other appropriate cells and return via the lymphatic system to the site of infection. Once there, some T-cells attract other cells to help fight the invasion while others attack it directly.
To learn more about T-cells, B-cells or the Cytokines produced by Dendritic cells, click here.


DCs use specific peptide-MHCs to activate different immune cells;
  • polypeptides for B-Cells,
  • peptides for T-Cells,
  • glycopeptides and glycolipids to activate and differentiate both T-cells and NKT.



















video: (time 0.43-1.43 relevant) The Immune Response










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