Immunology 1 Flashcards
What is the most extreme immune system disorder? What causes it?
SCID- Sever combined immune deficiency Caused by lack of lymphocytes
What is the main characteristics of SCIDS?
Recurrent bacterial, viral or fungal infections which are more serious and less responsive to treatment
Can also have chronic diarrhoea
What is the treatment for SCID’S?
Bone marrow transplant to replace the immune system
Describe the stem cell pathway for B and T cell production? What type of immunity do these cells provide?
Pluripotent stem cell—-lymphoid stem cells— B and T cells
Provides adaptive immunity
Describe the stem cell pathway for the production of esiniohils, basophils, neutrophils, monocytes and megacaryocytes. What type of immunity do they provide?
Pluripotent stem cell—–myloblast—-
Esinophilic myleocyte- Esinophils
Basophilic myleocyte- Basophils
Monocyte progenitor- Monocytes
Granulocyte progenitor- Granulocytes
Megakaryocytes
They provide innate immunity
What does the activation of B cells and T cells lead them to produce?
B cells- Memory B cells and antibodies
T cells - CD8 cytotoxic
CD4 Helper
Where in the body are B cells and T cells made? What is the group name for these locations?
T cells- Thymus
B cells- Bone marrow
Together they are called primary lymphoid tissues
What are secondary lymphoid tissues? Name all 6 locations
where T cells and B cells interact with each other and nonlymphoid cells to generate immune responses to antigens
- Tonsisl
- Lymphatic vessels
- Liver
- Spleen
- Payers patch on small intestine
- Appendix
How does the immune system recognise pathogens?
Responds to non self componenets
Describe an antigen based on the immune system. What is the difference between a self and foreighn antigen?
Anything which causes an adaptive immune responce. Binds to specific receptors on immune cells.
Self antigen- immune system responds (attacks) to self
Foreign antigen- When atigen is not from self (external) sources
How do immune cells respond to foreign molecules?
They Use receptors
Describe and name the receptors located on T cells and B cells
They are both antigen specific (recognise fragments of antigens) and ignore self molecules. Thye first need to undergo cell division before taking effect
B cells- BcR receptors- The antigen receptor is an antibody
T cells- TcR receptors
What is an immunogen?
Anything that provokes an immune responce
What is an antigen?
Anything recognised by cells and molcules of the immne responce
What is a determinanat?
The part of an antigen recognised by the immune system
Describe the term specificity in terms of the immune system
Specificity refers to how well a receptor recognises its determinant (antigen)
A receptor is very specific when it requires a close fit to its determinant
What are pattern recognition receptors (PRR)? What do they recognise?
They are receptors located on antigen presenting cells (phagocytes, macrophages, dendritice cells).
They regonise PAMPS- pathogen assoctaited molecular patterns
They recognise DAMPS- damage associated molecular pattersn
What are Fc receptors? What do they mediate?
Recetors found on the surface of phagocytes which bind to the constant heavy chain region on antibodies.
They mediate opsonisation
When the skin is compromised what do skin macrophages and neutraphils do?
The resident skin macrophages recognise bacteria using toll like receptors. They make cytokines (TNFa and IL-1B) which act on edothelial cells lining the blood vessels making them for sticky.
This causes neutraphils to stick onto the blood vessels and migrate to the site of infection then phagocytose the bacteria.
During inflammation reactions, which white blood cells are first to act?
Neutrophils and resident macrohpages
Describe what PAMP’s are (pathogen associated molecular patterns). Which part of pathogens can be described as PAMPS?
Components of bacteria and viruses which the human cells don’t have, hence the body identifies them as foreign.
For bacteria is it features of the cell wall and bacteria DNA and plasmid
For viruses it is the caspid and envelope of viruses plus viral DNA and RNA
What are Toll like receptors? Where are the located?
Molecules on the surface of phagocytes (mammalian cells) which regonise PAMP’s for bacteria and viruses and alert the immune system of this
Located on all cells especially phagocytes and epithelial cells
What does TLR2 recognise?
Lipoproteins
Lipoarabinomannan
Lipopolysaccharides (Leptospira)
LPS (P. gingivalis)
Peptidoglycans (Gram-positive)
Zymosan (Yeast)
GPI anchor (T. cruzi)
What does TLR4 recognise?
LPS (Gram-negative)
F protein (RS virus)
