Principles of Immunology T Cell-Mediated Immunity 3/28/06 - PowerPoint PPT Presentation

About This Presentation
Title:

Principles of Immunology T Cell-Mediated Immunity 3/28/06

Description:

'Each of us needs to be the change we wish to see in the world' Ghandi. Word/Terms List ... Principal function-Response to intracellular pathogens and cells ... – PowerPoint PPT presentation

Number of Views:84
Avg rating:3.0/5.0
Slides: 24
Provided by: uvmaff
Learn more at: https://www.uvm.edu
Category:

less

Transcript and Presenter's Notes

Title: Principles of Immunology T Cell-Mediated Immunity 3/28/06


1
Principles of ImmunologyT Cell-Mediated
Immunity3/28/06
  • Each of us needs to be the change we wish to see
    in the world
  • Ghandi

2
Word/Terms List
  • ADCC
  • Effector cells
  • GVH reaction
  • Perforin

3
T Cell-mediated Immunity
  • Principal function-Response to intracellular
    pathogens and cells expressing foreign antigens
  • Recirculation-Naïve T cells circulate between
    the blood stream and the lymphatic system
  • Antigen presentation-Naïve T cell cells only
    respond to APCs

4
Priming of T Cells
  • Three types of effector T cells
  • CD8 (TC)
  • CD4 (TH1)
  • CD4 (TH2)
  • Each type
  • Responds to different types of Ags
  • Activated by different Ag presentation
  • Has different effector function

5
T Cell Effector Types
  • CD8
  • Viruses and intracellular bacteria
  • MHC I
  • Cytotoxic effector cells
  • CD4 TH1
  • Bacteria and parasites in APCs
  • MHC II
  • Effectors activate macrophages, CTLs and induce B
    cells to produce opsonins
  • CD4 TH2
  • Extracellular bacteria and toxin producers
  • MHC II
  • Activate B cells to produce multiple antibody
    classes

6
T Cell Adhesion
  • T cells pass through endothelial cells
    (extravasation)
  • Endothelial cells and T cells both have cell
    adhesion molecules (CAMs)
  • Various CAMs

7
Cell Adhesion Molecules
  • Selectins
  • Mucins
  • Integrins
  • Immunoglobulin superfamily

8
APCs
  • Dendritic cells
  • Macrophages
  • B cells

9
Dendritic Cells
  • Antigen presentation is sole function
  • Antigenic uptake is followed by migration to
    lymph nodes
  • Expression of MHC I, MHC II and B7
  • Loses phagocytic property
  • Secretes chemokines

10
Macrophages
  • Involved in both innate and adaptive immunity
  • May destroy pathogens or present Ag to T cells
  • Expression of MHC I, MHC II and B7
  • Scavenges dead cells

11
B Cells
  • Binds soluble antigens
  • Constitutively expresses MHC II
  • Induced to express B7

12
NK Cells
  • 5 of lymphocytes
  • Nonspecific cytotoxicity
  • No TCR/CD3
  • Not MHC restricted
  • No memory

13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
CTL Cytotoxicity
  • Conjugate formation
  • Membrane attack
  • Dissociation
  • Target cell death

17
Conjugate Formation
  • Cell adhesion
  • Recognition of MHC IAg on target cell

18
Membrane Attack
  • Granules in CTLs
  • Perforin
  • Granzymes
  • Exocytosis of granule contents
  • Perforin action similar to C9
  • Granzymes act as nucleases
  • Fas ligand to Fas triggers target cell death

19
Dissociation and Target Cell Death
  • CTL interacts for about five minutes
  • Dissociates and can conjugate with other target
    cells
  • Target dies after several hours

20
(No Transcript)
21
Antibody-Dependent Cell-Mediated Cytotoxicity
  • NK cells, macrophages, neutrophils
  • Bind to Fc region of Ab
  • Multiple cytotoxic mechanisms

22
(No Transcript)
23
Graft vs. Host Reaction
  • Immunocompromised recipient
  • Lymphocytes of donor attack allogeneic antigens
    of recipient
  • Splenomegaly
Write a Comment
User Comments (0)
About PowerShow.com