Lecture 1 Flashcards
what are the primary lymphoid organs
-bone marrow
-thymus
what are the secondary lymphoid organs
-lymph nodes
-spleen
-peyers patches
what are the 3 signals for activation and differentiation
Activation: when it sees its antigen and starts proliferating
Signal 1: present antigen with MHC
Signal 2: co-stimutary molecules ex: cd28 in T cells and B7 in dendritic cells
Differentiation: starts to produce cytokines for T cell. When you start doing stuff
Signal 3: polarizing cytokines. Polarizing: specializes t cells one way or another.
You are polarizing cells to induce gene expression patters that will induce it and then stimulate certain cytokine production by those cells
If a dendritic cell produces IL-12 that is a TH1 polirizing = will start making INFgamma
Why are the lymph nodes the sites for the activation of T cells?
-Gathering places where there are lots of opportunity for everyone to show what they are presenting. It is packed with B and T cells and dendritic cells
-They are everywhere in the body, it is close to all barrier tissues. They are at strategic barrier sites like mouth, feet, gut, brain
how do non lymphoid orgrans communicate with lymphoid organs
through non resident cells like dendritic cells
what are tissue resident cells vs non resident
-Tissue resident immune cells: dendritic cells(these can move and neutrophils too), macrophages and neutrophils that are not circulating through the blood/lymph nodes. It is auto-replenishing within the tissue, they don’t really need to be activated
-non resident they travel all throughout the body
how do leukocytes travel
Extensive lymphatic system is the reason why these cells can migrate to the lymph nodes and the tissues and enter the blood circulation
Tissues residents vs circulating leukocytes: what do we need both?
-Tissue residents are super fast responders and they are able to sense incoming assaults and communicate with dendritic cells;
-Tissue residents are also very important for the recruitment of other cells and to recognize the antigens and sometimes they don’t even need to to see the antigen to become activated in response to damage signals.
-Because tissue residents are secreting these cytokines to recruit othe cells
true or false: we have more traveling immune cells than resident cells
false:
We have more more resident cells than traveling to provide early source of protection
true or false: neutrophils are resident cells
false there are evidence that they are able to traverse the non lymphoid barrier
what did Ilya Mehcnikov do?
-He was the first to demonstrate phagocytosis and the usefulness of inflammation
-He was studying translucent starfish larvae and stuck a mango thorn in it
-He saw all these cells wrapping all around the mango thorn inside the larvae: these cells are not responsible for causing disease: they protect
-He saw that inflammation was responsible to contain the infection: host defense properties
Neutrophils swarm was then showed 100 years later with the leishmania mouse that was taken to a microscope directly after the infection what can we see with the neutrophils
-These neutrophils will swarm at the infected tissues: initial inflammatory step to kill these parasites
-The macrophage come in and eat the neutrophils to stop the inflammation
Why are phagocytes are attacking the infection?
-To identify self and non-self to decide whether attack
-If they recognize non self they will attackkkk
what is janeway’s litte secret?
-Janeways little secret: adjuvants
-He therorized that innate immune cells must recognize components that are shared across various types of microbes: bacteria, viruses, fungi. Self vs non-self
Ilya was the father of
innate immunity
Janeway’s receptors
-He called the receptors on macrophages, neutrophils and dendritic cells pattern recognition receptors: PRR ex: Toll like receptors: recognizes some pamps, nods: to recognize bacterial species and the microbial components pathogen associated molecular patterns : PAMPS ex: LPS expressed by gram - bacteria. To recognize gram + lipoteichoic acid
-This treaty also applies how adjuvants work: they contain some pamps that cells recognize through PRRs
What is a TOLL discovery?
-The development of the fruit flies uses this toll pathway to grow: used in adulthood for protection against pathogens: the TOLL receptors
-This also applies to humans: janeway proved that we have TOL like receptors too
-The start of how the immune system senses pathogens
What is a limitation of Janeway hypotheses?
the mango thorn is not a pathogen
Matzinger’s danger theory
Pamp theory is not enough
She theorized that innate immune cells not only recognize microbial patterns but also sense other forms of danger including indicators or cell stress/dysfunction/death
damps def
Coined the term danger associated patterns : DAMPS: include both microbial and non-microbial inflammatory triggers
danger associated molecular pattersn
Sterile inflammation def and ex
-Sterile inflammation:when you have tissue damage in the absence of any microbial agents and the absence of overt infection
-Sterile inflammatory events: obesity because damage response without any microbials, bruising: tissue damage