MIMM 214 Lecture Notes - Lecture 11: T Helper 17 Cell, Cytokine, Mhc Class I
7 Jun 2018
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Lecture 11 – January 27, 2017
Once Ag encountered – long T cell/DC interaction
- Naïve CD4+ T cells arrest their movements after engaging Ag
- Image: T cells (red) bind to DC (green) and slow down their movement through the lymph node
- Kinetics of early encounters depends on quality, quantity and availability of Ag (and activation
state of DC)
- T cells become involved in committed, long term (8 hours or more) relationships with DCs
Some numbers in peripheral blood
- Leukocytes = 4.5-10 x109 cells/L og blood
o Polymorphonuclears
▪ Neutrophils = 50-70%
▪ Eosinophils = 0-3%
▪ Basophils = 0-1%
o Mononuclears
▪ Lymphocytes = 25-35%
• T cells = 60-85%
o CD4+ t cells = 35-70% of peripheral blood T cells
o CD8+ T cells = 25-40% of peripheral blood T cells
• B cells = 15-30%
▪ Monocytes= 4-6%
Summary
- DCs travel to lymph nodes
o Activated conventional DCs
o PRR singaling needed
o Increase in: receptors that targets to lymphoid tissue, antigen processing, MHC
expression, costimulatory molecule expression
o Enter via afferent ………..
APCs, MHC and T cells
- Most adaptive immune responses require activation of T cells, ie T cell dependant responses
- T cells can only recognize peptide fragments of the Ag bound to self molecules of the Major
Histocompatibility Complex (MHC) (MHC restriction)
- These Peptide-MHC complexes are expressed on the plasma membrane of the APC
CD4+ t cells recognize antigens on MHC II
CD8+ T cells recognize antigens on MHC I
T cells
- Types of lymphocytes
- Arisinf in the thymus from bone marrow progenitors
- Key role in adaptive immunity
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Once ag encountered long t cell/dc interaction. Na ve cd4+ t cells arrest their movements after engaging ag. Image: t cells (red) bind to dc (green) and slow down their movement through the lymph node. Kinetics of early encounters depends on quality, quantity and availability of ag (and activation state of dc) T cells become involved in committed, long term (8 hours or more) relationships with dcs. Leukocytes = 4. 5-10 x109 cells/l og blood: polymorphonuclears, neutrophils = 50-70, eosinophils = 0-3, basophils = 0-1, mononuclears. Lymphocytes = 25-35: t cells = 60-85, cd4+ t cells = 35-70% of peripheral blood t cells, cd8+ t cells = 25-40% of peripheral blood t cells, b cells = 15-30, monocytes= 4-6% Dcs travel to lymph nodes: activated conventional dcs, prr singaling needed. Increase in: receptors that targets to lymphoid tissue, antigen processing, mhc expression, costimulatory molecule expression: enter via afferent
