3-2 - B cell precursors associate with different stromal...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: B cell precursors associate with different stromal cells at different stages of maturation. Different stromal cells produce CXCL12 and IL-7. Pre-pro-B cells associate with CXCL12 + cells Pro-B cells associate with IL-7 + cells. Stromal cell Pre-pro-B cell CXCL12 CXCR4 4 integrin VCAM IL-7 is important for B and T cell maturation. B cell maturation in BM is blocked in the absence of IL-7. The number of B and T cells in spleen are reduced in the absence of IL-7. Signal transduction of IL-7/IL-7R IL7 IL-7R Jak Jak p p IL-7 induces dimerization of IL-7R and subunits. Activation of Jak (Janus family tyrosine kinase) p p Phosphorylation and dimerization of Stat. p p Stat activates transcription of target genes nucleus Stat translocates into the nucleus. IL-7 induces the expression of MCL-1, which promotes the survival of B and T cell precursors. IL-7 induces the expression of MCL-1 in T cells MCL-1-/- MCL-1 +/+ MCL-1 +/- Reduction of T and B cells in the spleen of MCL-1 deFcient mice MCL-1 +/- MCL-1-/- Reduction of B cell precursors in BM Bcl-2 family members regulate apoptosis. mitochondria Release of cytochrome c ATP Caspase-9 Apaf-1 Activation of Caspase-9 by autocleavage Caspase 3, 7 Degradation of cellular proteins (e.g. Lamins) Activation of CAD to degrade chromosomes Pro-apoptotic Pro-survival Bcl-2 Bcl-X L Mcl-1 BAX BAK Bid Bim Mcl-1 interacts with Bim. Immunoglobulin (Ig) genes are assembled from gene segments during B cell maturation. Immunoglobulin heavy chain (IgH) 65 V H 27 D H 6 J H 9 C H Variable Diversity Joining Constant region Ig locus in human 1 C 30 V Ig 4 J -C Ig 40 V 5 J Immunoglobulin light chain (IgL) The coding sequence for IgH variable region is assembled from V H , D H , J H gene segments by V(D)J recombination. D-J joining V-DJ joining V H gene segments D H gene segments J H gene segments C Germline conFguration Rearranged conFguration Intervening sequences deleted Intervening sequences deleted J H 1 J H 2 J H 3 Rearranged IgH gene Productive V(D)J recombination leads to the expression of...
View Full Document

Page1 / 26

3-2 - B cell precursors associate with different stromal...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online