Development of Lymphocytes Flashcards
What 8 cell types make up the innate immune system?
โ neutrophils โ macrophages โ monocytes โ NK โ dendritic cells โ eosinophils โ basophils
What 3 cell types make up the adaptive immune system?
โ B cells
โ T cells
โ plasma cells
What are 2 conditions and 1 drug that can affect B cells?
โ Congenital agammaglobulinaemia
โ common variable immunodeficiency (CVID)
โ rituximab
What are 2 conditions and 3 acquired reasons that can affect T cells?
โ SCID
โ DiGeorge syndrome
โ HIV/chemotherapy/novel biologics
What are the 8 ways that a lymphocyte can be classified?
โ Morphology โ lineage โ function โ phenotype โ specificity โ type of receptor โ differentiation โ their products
What are the two key features of adaptive immunity?
โ Specificity and memory
Describe the basic tenet of adaptive immunity?
โ one cell has one specificity โ one B cell has one Ig โ one T cell has one TCR โ selection and expansion of the clone โ retention in memory of clonal progeny
How much time does the primary response take to peak?
โ A couple of weeks
What is the difference between the primary and secondary response?
โ it is quicker and peaks at a higher level
What precursor do B and T cells come from?
โ Common lymphoid precursor
What happens to T cells after they are made from the lymphoid precursor?
โ They are programmed in the thymus
โ They are distributed among lymphoid organs
What is the defining feature of a lymphocyte?
โ The receptor
Describe the receptor on an alpha beta T cell?
โ alpha chain and a beta chain
โ the top region is highly variable
What adds to the diversity of the lymphocyte receptors?
โ genetic reshuffling
What are the 4 ways the immune system recognises pathogens?
โ It looks like a pathogen
โ their presence is associated with damage
โ the pathogens have been seen before
โ it is not โselfโ
What are DAMPs?
โ damage associated molecular patterns
How does the immune system set up a system to recognise things it has not seen before?
โ It has so many different combinations that one of them has to be the right one
What is the issue with having such a vast array of possible receptors for detecting pathogens?
โ The precursor frequency of the right cell will be low
โ you can start recognising โselfโ by chance
Which MHC binds to CD8 T cells?
โ MHC I
Which MHC binds to CD4 T cells?
โ MHC II
What does every cell in the body express?
โ MHC-I
What is the function of MHC-I ?
โ peptides that the cell is producing are presented on MHC-I to show T cells that the proteins produced are normal and not viral
What do viruses do to MHC-I and how is this overcome by the immune system?
โ They downregulate MHC-I
โ CD8 cells recognise the lack of MHC and kill the cells
What are the three issues with the massive possibility approach?
โ You can recognise self by accident
โ you can recognise everything as being foreign
โ you can be underactive
