Flashcards in IMI4: Integration of innate and adaptive branches of the immune system Deck (66)
Name the cell types from the myeloid lineage
- Mast Cell
- Dendritic cell
Name the cell types from the lymphoid lineage
Natural killer cell
What do phagocytes detect? With what?
- Pathogen Associated Molecular Patterns (PAMPs) using pattern recognition receptors e.g. TLRs
- Complements using complement receptors (CR)
- Antibodies using Fc receptors
What are PAMPs?
Molecular structures that are present in microorganisms but not on vertebrates
What enables the immune system to attack pathogens but not self-cells?
Different TLR expression patterns
What 3 components do Basophils release? To what effect?
- Histamine, a vasodilator that increases blood vessel permeability and smooth muscle contraction and which is responsible for many symptoms during allergic reactions;
- Serotonin, which stimulates monocytes and lymphocytes thereby modulating which cytokines get produced during a given immune response;
- Heparin an anti-coagulant that prevents blood clotting too quickly.
What do granuloctyes release and what does this do?
cannot perform phagocytosis. Instead, they are granulocytes that ﬁght parasites, particularly helminths, by releasing contents in their granules.
What are NK cells able to identify? - To what effect?
cells that have started to behave abnormally, rather than detecting pathogens directly. This triggers the NK cell to kill the misbehaving cell
How many proteins are there in the compliment system?
What can the compliment system do?
Can NK cells express TLR?
Yes they do
Do mice express TLRs?
Name all the phagocytic cells, and thus eliminate pathogens directly
What is the role of Cb3?
Tagging pathogens - promoting opsonisation
Where do B and T lymphocytes mature?
B - Bone marrow
T - Thymus
Briefly describe humoral immunity
Involves antibodies that circulate in the plasma, lymph and tissue ﬂuids, and it can protect us against extracellular bacteria and foreign molecules (danger signals)
Briefly describe cell-mediated immunity
Mediated by antigen-speciﬁc T cells, and it can protects us against intracellular pathogens, cancer and non-self cells
Cell-mediated immunity is a type of immunity directed against what type of pathogens?
1. have evaded the innate immune responses and
2. are replicating inside cells, away from antibodies, which circulate in the blood or are found in extracellular spaces
What are the two main players of cellular immunity?
- Cytotoxic T cells (TC), which generally express CD8 on their cell surface
- Helper T cells (TH), which generally display CD4 on their cell surface
What is an antigen?
a molecule capable of stimulating an immune response.
When can T-cells only recognise pathogens' antigens?
If they are presented to them in association with proteins known as the Major Histocompatibility Complex (MHC)
What is Major Histocompatibility Complex also known as in humans?
Human Leukocyte Antigen (HLA) system
What are the two signals required to activate the T-cell?
Which proteins do Cytotoxic T Cells recognise?
Recognise antigens presented on MHC Class I complexes, which are present on all nucleated cells. But they also require interaction of CD8 (On T-cell surface)
What three things can helper T cells do?
- Stimulate B cells to secrete antibodies to attack extracellular pathogens
- Activate macrophages to destroy ingested microbes
- Trigger cytotoxic T cells to kill infected target cells
What proteins do helper T cells recognise?
Antigens presented on MHC II complexes, that are found on antigen-presenting cells (APCs) such as dendritic cells, macrophages and B cells
T cells express what protein on their cell surface?
When activated for the ﬁrst time, the helper T cells can differentiate into what?
helper T cells 1 (TH1) or helper T cells 2 (TH2)
What are helper T cells 1 (TH1)?
TH1 cells primarily activate macrophages and cytotoxic T (TC) cells (cell mediate response)