Lecture 12 - Effector responses against infectious agents (2) Flashcards
What do activated CD4+ T-cells become?
T-helper cells
What do activated CD8+ T-cells become?
Cytotoxic T-lymphocytes (CTLs)
How do CD8+ T-cells get activated?
- Recognition by naive T-cell
- Proliferation and differentiation of T-cell
- Active T-cells kill virus infected target cells
How do cytotoxic t-lymphocytes kill an infected cell?
Release granules upon cell-cell contact to induce apoptosis of the cell
What does the cytotoxic granules contain? [3]
- Granzymes
- Granulysin
- Perforin
True or False? All nucleated cells within the body can be targeted by CD8+ cells
True
What is the main way that T-help cells regulate immune responses?
Producing cytokines to regulated parts of the immune system
What is the main role of CD4+ Th1 cells?
Activates macrophages
How do CD4+ Th1 cells activate macrophages?
- Secrete Interferon-gamma
- CD40 ligand/CD40 interaction
What is the main role of CD4+ Th2 cells?
- They deal with large extracellular pathogens
- e.g. parasitic worms
What other functions do CD4+ Th2 cells have?
- Help B-cells produce antibody (IgE)
- Activating basophils, eosinophils, and mast cells
How do CD4+ Th17 cells regulate immune responses?
- Recruit neutrophils
- Stimulate macrophage and neutrophil production
- Induce antimicrobial peptide production
Where do antibodies come from?
B-cells
How do antibodies enhance the innate immune system? [6]
- Neutralisation
- Agglutination
- Opsinisation
- Antibody-dependent cell-mediated cytotoxicity
- Activation of complement
- Specialised resposnes
How does neutralisation work?
Antibody binds directly to the pathogen to prevent entry into a cell
