BIOL 3120 Lecture Notes - Lecture 10: Thymocyte, Immunoglobulin M, Central Tolerance
Document Summary
Igm is mostly made in the beginning by alternative splicing, as cell matures it will have more igd, can be used to track stages of development. In spleen in t1, there is more negative selection. These areas are limited not enough signal to keep all 10% Drop to 1-3: marginal zone b cells: they develop in the spleen and stay there, appear more like b-1 cells, they can replicate (self renewing). Memory cells should not be igm, but in some infections we see igm, they are may be made by mz cells. Beta re(cid:272)o(cid:373)(cid:271)i(cid:374)atio(cid:374) happe(cid:374)s. ga(cid:373)(cid:373)a delta t (cid:272)ells do(cid:374)"t go through the sa(cid:373)e sele(cid:272)tio(cid:374) steps as the alpha beta t cells. As soon as a gamma delta tcr is made by rearrangement, it leaves the thymus. At this point it can still become a gamma delta cell, but as soon as alpha rearranges no more alpha (more likely: dn4: alpha rearrangement begins (after beta selection not clearly defined).
