2.4 Innate vs Adaptive Immune system Flashcards
Innate immunity (immediate 0 - 4 hours)
Infection -> recognition by performed, non-specific + broadly specific effectors -> removal if infectious agent
Early induced innate response (early 4 - 96 hours)
infection -> recognition of microbuial - associated molecular patterns -> inflammation recruitment + activation of effector cells -> removal of infectious agent
Adaptive immune response (late > 96 hours)
infection -> transport of antigen to lymphoid organs -> recognition by naive B + T Cells -> clonal expansion + differentiation to effector cells -> removal of infectious agent
Innate immune response
Inflammation, complement activation, phagocytosis + destruction of pathogen
- > minutes for response
- > response can occur for days
Adaptive immune response
Interaction between antigen-presenting dendritic cell + antigen-specific T cells; recognition of antigen, adhesion, co-stimulation, T-cell proliferation + differentiation
- > hours for response
- > response occurs for days
Activation of antigen-specific B cells
- > hours for response
- > response occurs for days
Formation of effector + memory T cells
- > days for response
- > response occurs for weeks
Interaction of T cells with B cells, formation of germinal centers, formation of effector B cells (plasma cells) + memory B cells. Production of antibody
- > days for response
- > response occurs for weeks
Emigaration of effector lymphocytes from peripheral lymphoid organs
- > a few days for response
- > response occurs for weeks
Effector cells + atibodies eliminate the pathogen
- > a few days for response
- > response occurs for weeks
Immunological memory
Maintenance of memory B cells + T cells + high serum or mucosal antibody levels. Protection against reinfection
- > days to weeks for response
- > response can be lifelong
Immune response
- > Bacteria trigger macrophages to release cytokines + chemokines
- > Vasolidation + increased vascular permeability cause redness, heat + swelling
- > inflammatory cells migrate into tissue, releasing inflammatory mediators that cause pain
Innate immunity
- > specificity inherited in the genome
- > expressed by all cells of a particular type (e.g. macrophage)
- > triggers immediate response
- > recognizes broad classes of pathogens
- > interacts with a range of molecular structures of a given type
Adaptive immunity
- > encoded in multiple gene segments
- > requires gene rearrangement
- > clonal distribution
- > able to discriminate between even closely related molecular structures
