BIO 343 Lecture Notes - Lecture 8: Antigen, Lymph Node, Myeloid Tissue
Chapter 8A additional notes
• We have billions of Naïve T cells
o Can be differentiated based off co-receptors
o Whe there first reogized the do’t reogize the hole atige
o Cell undergoes clonal expansion and CD4 cells make decision what type of T cell they
want to be
o 5 subsets of Cd4 cells with distinct function
o production of memory cells
o in case pf cd8, clonal expansion occurs but only one kind of effector CD8 cell
• Chapter 8- T-cell mediated immunity
o Always understand t cell is dead in water unless it has become activated
o In case of t cell we cll this priming
o Billios of t ells i peripher are aïe eaig the hae’t see peptide so there
activated which triggers clonal expansion
o What were talking about is signal is sent through tCR and changes in transcription
occurs and cell undergoes division
o Effector T cells—official definition—terminally differentiated activated t cells
▪ Clonal expansion has ended and cells are now able to go out and deal with
infection
• In order for t cells to be activated we need to have antigen
▪ Meets in secondary lymphoid tissue like node
▪ Antigen Is likely collected by lymphatics and taken to draining lymph node and
here is where t cell will respond to antigen
▪ In blood, t cell in spleen react to antigen
▪ In respiratory tract, get to tonsils or BALT
• Not nicely formed like lymph node but same setup
▪ If Ag is i gastro trat… stiulates t ells i GALT or peers pathes
• Antigen capture in skin are carried by dendritic cells
o Myeloid dendritic cells are classic dendritic cells weve been talkingabout all semester
o These a preset for lass or lass ad are far superior to other PAC’s
o Migrate to place t cells located
o Macrophages are in lymph nodes
▪ May role is come in through afferent lymph and these prevent pathogens from
passing through and reaching the blood
▪ Not main APC to activate t cells
• Periphery nd skin
o All throughout connected tissues we have these dendritic cells
o In connective tissues these dendritic cells are actually very immature
o Take up antigens in many different ways and get into lymphatic system and migrate to t
cell area of lymph node
o Langerhans cells→ refers to those dendritic cells located somewhere in your skin
▪ As they migrate they further differentiate and mature
• Immature dendritic cells
o Have ability to take up antigens to process and they lose that ability
o Migrate to lymphoid tissues and as they mature they express increased amounts of
MHC molecules
• Mature dendritic cells are those that migrate there and are mature and expert in activating t
cells in the lymph nodes
find more resources at oneclass.com
find more resources at oneclass.com
