3 - The Selection of Lymphocytes Flashcards
Why is there a risk to produce self reactive BCR in bone marrow?
They are rearrange without Ag exposure ▶️ could have affinity for normal body components
Which HLA molecule works as molecular chaperone to promote proper peptide loading?
HLA-DM
Function of B2-microglobulin, where is encode?
Part of MHC class I ▶️ transport of them to cell surface B2M gene at chromosome 15
Markers for immature B cells?
CD19, CD20, MHC II positive, IgM surface (+). Tdt, CD34 negative
What is the CD34 marker? Where do you find it?
Marker for early lymphohematopoeitic stem and progenitor cells
Cell-cell adhesion molecule
Mature B-cell markers
IgM, IgD (+) surface, CD19, CD20, CD21, CD40 (+). CD34, Tdt (-)
Markers for Pro-B cells
Tdt, CD19, CD20, CD34, MHC II (+).
Markers for Pre-B cells
CD34, CD19, CD20, MHC II (+), cytoplasmic u heavy chain (+). Also CD10 (+). Tdt (-).
Common acute lymphoblastic leukemia antigen (CALLA). Function.
CD10 ▶️ metalloendopeptidase
Best markers for identification of B lymphocytes?
CD19, CD20, CD21
Role of CD19 and CD20
*Ig-alfa, Ig-Beta
They are part of signal transduction complex of BCR during B-cell activation
*Others members of signal transduction complex of B cell.
In addition to be part of signal transduction complex what is the other role of CD20?
Receptor for C3d component of complement and EBV
What is CD56 used?
Marker for Natural Killer cells. Function unknown.
Where do you expect to find both CD4 and CD8 expression at the same time normally on T- cells? What case could be pathological and where do you find those cells?
Thymic cortex
T-cell lymphoblastic lymphoma ▶️ double positive (periphery)
*really it is a forming mediastinal mass and T-cell differentiation of the ALL
Function and where can you find CD2?
Also LFA-2 ▶️ adhesion molecule (Ig family genes). In T cells.
Ligand: LFA-3 on other lymphocytes and APC
