BMS1058 - Immunology Flashcards
(41 cards)
What is the function of the immune system? What does it interlink closely with?
To protect the body against ‘foregin’ attack, limit replication of invading microorganisms and to promote healing.
Interlinks closely with physiological and hormonal systems.
What are the 2 main types of immune response? What are the differences?
Adaptive and Innate - work best in combination
INNATE:
- present from birth
- fast acting
- broad specificity
- same each time - no memory
ADAPTIVE:
- is learnt and develops throughout lifespan
- slower to develop (4-7 days)
- highly specific
- memory and strength improve with time
What are the innate and adaptive immune response’s main players/mechanisms?
INNATE:
- bacteria killing substances
- physical barriers e.g. skin
- protection of all mucosal surfaces - e.g. tonsils, GI, respiratory tracts
- firsrt attack in tissues by Myeloid cells (neutrophils, macrophages, eosinophils etc) and Natural Killer cells
ADAPTIVE:
- B cells make antibodies against foregin pathogen
- T cells attack infected cells in tissues
Stem cells in bone marrow differentiate under the influence of _______ factors into pluripotent stem cells and then progenitor cells which form which distrinct lineages? This is known as _________.
growth factors
2 main lineages: Myeloid and Lymphoid
Haematopoiesis
What cells come under the category of granulocytes (granular leukocytes)? Which lineage are these from? They are poly-morpho-nuclear. What does this mean?
Neutrophils
Eosinophils
Basophils
Mast cells
From myeloid lineage/stem cells.
Poly-morpho-nuclear = nucleus varies in shapes and sizes. often have 2 or 3 lobes.
What are neutrophils? What do they secrete?
Most important white blood cell in bacterial infections.
Have cytoplasmic granules containing enzymes - e.g. lysozyme
Highly phagocytitic - recognise and take up and kills foregin substances/microbes
Secrete NETs (neutorphils extracellular traps) –> cells burst and release DNA which sticks to bacteria).
[Hans Solo - goes in and shoots everything on mass that shouldn’t be there, releases a huge arsenal of weaponry]
What are Eosinopils?
Specialsied white blood cells.
Have cytoplasmic granules that release toxic chemicals and proteins to attack and kill harmful cells or germs. Protect body from parasites, allergens and bacteria.
When situmualted, release mediators which promote inflammation.
Phagocytic (although this is not the major function).
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What are basophils?
White blood cells, mostly in tissues during inflammation. Very few in the body.
On stimulation release substances that promote inflammation.
Important in allergy.
Not phagocytic
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What are Mast cells?
Stem cells migrate into tissues and mature into mast cells.
Improtant in allergy.
Release mediators (such as histamine) very rapidly when stimulated.
Can be phagocytic.
[background character]
What are monocytes and macrophages?
Myeloid white blood cells (leukocytes)
Monocytes:
- remain in blood 1-2 days
- mono-nuclear
- phagocytic
Monocytes differentiate into macrophages.
Macrophages:
- up to 10x larger than monoctyes
- characteristics depend on tissues. Can live for years.
- very phagocytic
- release a wide range of molecules that induce innate reponses
- present antigens to T cells (innate and adaptive response overlap)
[Chewbacka - Similar to neutrophils, release arsenal on mass to destroy everything that shouldn’t be there, just has bigger guns and muscles. Ability to survive longer.]
What are dendritic cells?
Myeloid leukocytes.
Irreguarly-shaped cells in most tissues.
Phagocytic.
When imature, cells ‘capture’ antigen and migrate to lymphoid tissues where they mature and present antigen to T cells.
[R2-D2 - processes a lot of info (taking up antigens) very quickly and communicate back out to the community who can deal with it ]
What cells does the lymphoid lineage give rise to? What do adaptive lymphocytes look like?
What do they become when stimulated by foreign molecules/antigens?
Lymphocytes (lymphoid leukocytes)- around 30-40% WBCs, including T cells, B cells which are adaptive.
Have large nuclei and small halo of cytoplasm.
All upon stimulation by foreign molecules/antigens become effector or memory cells.
There are also innate lymphocytes.
Describe B lymphocytes.
Differentiate and ‘taught’ not to recognise ‘self’ molecules in bone marrow.
Make hundreds of copies of identical antibodies. Have B cell receptors, which are highly specific and bind to foreign molecules.
Each B cell recognises only one Antigen.
When activated, B cells differentiate into plasma cells and secrete Antibody or memory cells.
[Like commander who directs and sends out spaceships to fight the enemy (antibodies)
B cells recognise _____ ______, but still need help from Helper T cells to become effector _____ cells and make _______ OR remain as memory B cells.
whole antigens
plasma cells
antibodies
What do antibodies do?
Coat antigens for recognition.
Agglutinate cells for clearance
neutralise toxins
Can block movement/attachment of microbes
Activate inflammation
Describe T lymphocytes. Name the 3 main types of T cells.
Move from the bone marrow to be ‘taught’ not to recognise ‘self’ mocleules in the thymus.
Have many identical highly speicific T cell receptors on surface which bind to foreign antigens. Don’t produce antibodies.
[young luke skywalker - going to be able to fight the bad guys, just doesn’t know how to do it yet]
Different types:
- Helper T cells
- Cytotoxic T cells
- Regulatory T cells
T cells have to be shown ______ and not whole antigens. APCs do this. e.g….
Once activated they becomes ________ cells that carry out functions, or _________ cells.
peptides
APCs: MCs, Dendritic cells, B cells
effector
memory
What do Helper T cells do?
CD4
help all aspects of the immune response, particuarly adaptive responses, usually through secretion of mediators (cytokines).
[Princess Leia - doesn’t kill anything but is very good at organising cells to kill things]
What do Cytotoxic T cells do?
CD8
kill infected target cells and cancer cells.
[Jedi fighter - oB1Kanobi - highly specialised in kill]
What do Regulatory T cells do?
CD4 or CD8
Help to regulate immune responses.
Natural Killer T cells, Natural Killer Cells and Innate Lymphoid cells. What do they do? What do they look like?
Kill certain tumour and virally infected cells and/or have ‘helper’ roles in innate immune responses at skin/mucosal surfaces.
Lymphocyte-like but larger, granular cytoplasm.
[Jedi Master - highly skilled cells to destroy things that shouldn’t be there - virally infected and tumour cells]
List cells that are only in the innate immune system.
Basophils
Neutrophils
Eosinophils
Mast cells
Monocytes
List cells that are only in the Adaptive immune system.
B cells
T cells - helper, cytotoxic and Regulatory
List cells which are part of both the innate and adaptive immune system.
Macrophages
Dendritic cells
Natural killer cells, NKT, ILCs
