Cell Mediated Immunity 2 Flashcards
Which of cytotoxic and helper T cells have CD8 and CD4?
Cytotoxic CD8
T Helper 1/2 CD4
What does PALS stand for?
Periarteriolar Lymphoid Sheath
What causes a follicular aggregation in the spleen?
An antigen specific response similar to germinal centre in lymph node
Which T cells are MHC class I restricted and class II restricted?
Cytotoxic Class I restricted
Helper Class II restricted
What is the functions of Cytotoxic, T helper 1 and 2 cells?
Cytotoxic- kills cells with intracellular pathogens
T helper 1- activate effectors ^ to kill intracellular pathogens (pro inflammatory)
T helper 2- Stimulate antibody production and switching (anti-inflammatory)
Why do intracellular infections require Cytotoxic T cells?
Antibodies cannot function as cannot penetrate cell membrane
What are cytokines?
Soluble proteins messengers of the immune system
What are the 3 ways cytokines are produced?
Autocrine- works on itself
Paracrine- works on neighbouring cell
Endocrine- system level
What factors dictate the type of cellular immune response?
Type of pathogen- intra/extra cellular leads to MHC I/II complex therefore CD4/8 restriction
The cytokine microenvironment
What is T-cell differentiation?
When bacteria viruses, fungi, helminths recognised by innate immune response and present antigen and produce cytokines
The different combination of infective agents causes rise of different types of t helper cells via different cytokines
What are some CD8 effectors?
IFN-gamma TNF-beta TNF-alpha Perforin Granzymes Fas ligand
What are TH1 effectors?
IFN-gamma GM-CSF TNF-alpha IL-3 IL-2 TNF-beta
What are the TH2 effector cells?
IL-4 IL-5 IL-13 IL-10 TGF-B GM-CSF CD40 ligand
How do TH1 and TH2 cells block each other?
TH1 produce IFN-gamma which blocks TH2
TH2 produces IL-4/13 which blocks TH1
What is clonal expansion?
A single T or B cell with specific antigen specificity proliferating after co-stimulation
