Development of Lymphocytes Flashcards
stem cells migrate, from where and to where?
Pluripotent stem cells in the fetal liver migrate to the thymus and bone marrow, which are referred to as the primary lymphoid organs
Primary Lymphoid organs include the
bone and thymus
T cells and B cells do what in primary lymphoid tissue?
they proliferate, differentiate, and mature
What kind of receptors are localized on the surface of T and B cells?
Ag-specific receptors
Naive lymphocytes have a shelf life of
1-3 months if they do not recognize an Ag
What defines a “resting lymphocyte” ?
it’s a naive lymphocyte that is not dividing, nor are they performing effector functions
What morphologically distinguishes a naive B and T cell?
they can’t be
naive lymphocytes receive a name when they are observed in blood smears. what?
small lymphocytes
resting lymphocytes occupy what stage in the cell cycle?
Go
they go on to enter G1 when stimulated before going on to divide
What functional difference is there between a large and small lymphocyte?
Larger lymphocytes are activated: their diameter is a little wider. They are called lymphocytes or lymphoblasts.
Survival of naive lymphocytes relies on signals produced by
Ag receptors and cytokines
Ag receptors of B cells =
BCR
Ag receptors of T cells =
TCR
A theory of B cell survival states that
BCRs stimulate survival signals even in the absence of Ag
How do naive T lymphocytes survive?
Naive T lymphocytes recognize Self Ag weakly: this generates survival signals but without triggering clonal expansion and differentiation into effector cells