How Live Attenuated Vaccines stimulates immunity?

Attached to MHC class II antigens, The APCs recirculate and display fragments of the processed antigen on their cell surface. This complex of processed foreign antigen peptide and host MHC class II antigens form an area of the precise signal, with which APCs (along with the MHC peptide complex) triggers the activation of T-helper lymphocytes. Once they replicate within the host live, attenuated vaccines stimulate protective immune responses.

Digested by scavenger cells, the antigen-presenting cells (APCs) that circulate throughout the body, the host are released into the extracellular space surrounding the infected cells and the viral proteins produced within and are then acquired, internalized. B cells, which work together to expand immune response, these APCs include macrophages, dendritic cells.

These complexes together are recognized by a second class of T cells, in conjunction with other stimulation by APCs and production of cytokine-stimulated T cells, killer or cytotoxic cells. This recognition, responsible for the event of mature cytotoxic T cells (CTL) capable of destroying infected cells. As viral proteins are produced within the host cells, they're processed through proteasome degradation. Small parts of these processed intracellular proteins accompany cytosolic host cell MHC class I and display on the cell surface.

 As powerful activators of immune cells, activated T cells secrete molecules that act. The T-cell receptor complex (TCR), and thus the co-stimulatory receptors CD28/CTLA4 present on the T cell surface, both drive T-cell expansion and activation through interaction with their respective ligands. Which display on their cell surface co-stimulatory molecules in conjunction with MHC-antigen complexes, the second a neighbourhood of the activation signal comes from the APCs themselves.