Week 5- Lymphocytes Flashcards
What cells are involved in the adaptive immune response?
Haemopoeitic stem cells, lymphoid progenitor cells, B/T cells
What does the adaptive immune response do?
Creates memory for protection against future infection and specificity to clear the infection. Is localized to the infected cells/organism responsible, helps improve efficacy of the innate immune response
How does immunological memory arise?
It is a consequence of colonial selection, antigen specific B/T cells are the basis and can confer life long immunity
What are the 2 different types of adaptive memory?
Humoral: B cells that produce antigens
Cell mediated: T cells produce cytokines and kill cells
What is an epitope?
The variable region of an antigen where the antibody binds
What type of epitope do T cells recognize?
Linear epitopes: strings of amino acids
What type of epitope do antibodies recognize?
Structural epitopes: 3 dimensional shapes
How is variety achieved with B/T cells?
By gene recombination and the V and J regions being able to bind in different combinations
What are the 2 main types of T cells?
CD8 & CD4
How are CD4 T cells activated and what is their function?
They are activated when they meet an APC, they divide to form clones and can assist in repair (by producing cytokines that activate T cells, helping the immune response be appropriate), immune memory and causing allergic reactions
How are CD8 T cells activated and what is their function?
They are activated when they meet an APC and are cytotoxic (they kill infected cells and pathogens by apoptosis) and form memory cells
Describe the T cell receptor
The variable region is made by gene reassortment, they recognize antigen fragments that are presented to them by other cells
What is the major histocompatibility complex?
It is a complex that defines wether cells are self or non self
What gene encodes for the major histocompatibility complex?
HLA gene
What types of major histocompatibility complex exist and which cells display what types?
All cells present MHC I but only APCs present MHC II