4 Flashcards
What B cells are there
B1
B2- gc B cells
Mz B cells
What are B1 cells involved in
Where are they found
Natural antibodies production ( early protection), express toll like receptors for common bacterial ligand and recognise self
Can also generate memory B cells during T cell indpendant immune response
Coelomic cavities lamina propria - milky spots FALC
At what point do mz B cells come from b2 cells
At the immature be cell stage
What are natural antibodies
Germ-line coded not affinity matured
Mostly igM some igG and igA
Can bind to proteins carbohydrates lipid and nucleic acids
Comparing b1 cells and classical B cells what are they both clustered around
B1 reticular networks of macrophages
Reticular networks of FCDS
What are MZ B cells for
Antigen independent hypermutarion to generate a predict raided set of B cells receptors
Rapid igM responses- especially to pathogens that don’t trigger classical t dependant responses
What are the two ig types that B cells can become
IgM - Unswitched, gc independent memory B cells
IgGa plasma cells
Which igs are in secretions
IgA igM
Which igs are in serum
IgG igA igM igD
Why is igE not normally found in circulation
Binds very tightly to fc region on basophils and mast cells or coats helminths
Which igs are produced first and by memory cells
IgM and igD
Which igs have to have been class switched to
IgG igA igE
How are long lived plasma cells displaced from their niches
New ones being formed
Where do most activate B cells reside
Adult gut mucosa
What are the two major general properties shared by newly generates T cells
I leave the thymus in a naive state
Can circulate through secondary lymphoid tissues - thymic development imprints the tissue tropism of T cell subsets
What is the difference between adaptive T cell and innate like T cells
Adaptive require T cell clonal expansion and are slow
Innate like can sense and respond to infections or stress quickly without need for expansion or differentiation
Which are the conventional T cells
Cd4 Cd8 Nkt Gem t MAIT
What are he two hypothesis for fate decision of CLPs
Default- all conventional some differentiate to non conventional
Exclusion- all unconventional, some switch off unconventional genes and differentiate
Thymic epithelial development is under the control of what
FoxN1 transcription factor
What makes the thymic connective tissue o
Mesoderm and neural crest
What is the general structure of the thymus
2-3 lobes
Capsule with septa/ trabeculae dived into lobules making a Cortes and continuous central core- medulla
What happened during involution of the thymus
Epithelial component atrophied - small scattered lymphocytes in abundance adipose
What it the cell population in the cortex of the thymus
What is special about this area
Thymocytes and comical epithelial cells
Has blood- thymus barrier and is isolated from self- antigens
What creates the the blood thymus barrier
Subcapsular epithelial cells lining trabeculae
Cortical blood vessels lined by cortical epithelial cells
Corticomedullary junction rich in antigen- capturing dendritic cells
Closed capillary type
