9. imunitas terhadap patogen intraseluler
DESCRIPTION
jTRANSCRIPT
Immune Response
to Intracellular Pathogens
Hera [email protected]. of Microbiology
Fac. of Medicine Universitas Gadjah Mada
Outline
• Two types of immune response to intracellular pathogens:
• Innate Response:
• Phagocytic cells
• IFN
• NK cells
• Adaptive Response:
• T cells
• B cells
Pathogens can be found in various compartments of the body, where they must be combated by different host defense mechanism
Immune Response to Pathogens
Innate Response to Intracellular pathogens
Infections and the responses to them can be divided into a series of stages
Mechanism of phagocytosis
Important cytokines and chemokines secreted by dendritic cells and macrophages in response to bacterial products include IL-1β, IL-6, CXCL8, IL-12 and TNFα
10
Interferons are antiviral proteins produced by cells in response to viral infection
Killing by NK cells depends on the balance between activating and inhibitory signals
Adaptive Response to Intracellular
pathogens
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MHC class I molecules present antigen derived from proteins in the cytosol
CD8 cytotoxic T cells are specialized to kill cells infected with intracellular pathogens
Cytotoxic T cells kill target cells bearing specific antigen while sparing neighboring uninfected cells
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The humoral immune response is initiated when B cells that bind antigen are signaled by helper T cells
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The immune response to intracellular bacteria is coordinated by activated Th1 cells
Mycobacterium tuberculosis
The inner layer is composted of peptidoglycan which is covalently linked to arabinogalactan layer. The outer membrane contains mycolic acids, glycolipids
like (mannose-capped) lipomannan, and mannoglyco- proteins.
PIM: phosphatidyinositol mannosides
Figure 11-15
Granulomas from when an intracellular pathogen or its constituents cannot be eliminated completely
Immune response to M.tuberculosis
Human Immunodeficiency Virus (HIV)
Figure 11-23
Figure 11-25
Immune response to HIV
Figure 11-20
Figure 11-29
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Innate & Adaptive Immune Responses Against Viruses
Immunity against viruses functions to prevent infection and to eradicate established infection. Innate immunity is mediated by type I IFNs, which prevent infection, and NK cells, which eliminate infected cells. Adaptive
immunity is mediated by anti bodies and CTLs, which also block infection and kill infected cells, respectively.
The innate immune response to intracellular bacteria consists of phagocytes and NK cells,interactions among which are mediated by cytokines (IL-12 and IFN-γ). The typical adaptive immune response to these microbes is cell-mediated immunity, in which T cells activate phagocytes to eliminate the microbes.
Innate and adaptive immunity to intracellular bacteria.
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