Immunology Flashcards
How can we split the immune response?
What makes up each of these categories?
Innate
- Physical barriers
- Physiological barriers
- Commensal bacteria
- Mucous
- Sebaceous secretions
Adaptive
- Humoral B cells
- Cell-mediated T cells
Compare innate and adaptive immunity in terms of…
Time?
Specificity?
How it works?
Memory?
Rapid (minutes and hours) vs. slow (days and weeks)
No memory vs. immunological memory (from memory B cells)
Non-specific vs. specific for each type of antigen
PAMPS + PRR vs. antigens and antibodies
What does a high neutrophil count mean?
Are neutrophils long or short lived?
- raised neutrophils = ACUTE inflam
- short-lived
Dendritic cells
- describe their role in immunology
Antigen presenting cells (APC) - present antigens from phagocytosis via MCH class II to CD4 cells
Bridge gap between innate and adaptive
Mast cells
Allergic response
Release histamine and heparin = kill by degranulation
Define opsonisation
Coating of pathogens by soluble factors to enhance phagocytosis
E.g. C3b and Ig
Draw Complement system
What is C3 and MBL an example of? What of these is used prognostically?
Compare to diagram in onenote
Acute phase protein - CRP is used to measure acute inflam (v. short half life so disappears v quickly after inflam dies down)
What 3 ways can complement system be activated?
- Classical pathway e.g. IgM + IgG
- MBL pathway (mannose binding lectin)
- Alternative pathway (C3b causing feedback loop)
Where do B cells mature?
Bone marrow
B = bone
What is primary lymphoid tissue?
Blood and lymph
What is secondary lymphoid tissue?
What happens here? What 2 things are required for this to take place?
lymph nodes
spleen
MALT
B cells become activated
Antigens and T helper cell signals must be present for ^^ to occur
Where do antigens bind to on antibodies?
What part of antibody binds to cells?
What antibody can act as a powerful opsonin as phagocytic cells have receptors for this class of antibodies heavy chain?
Variable region sites of antibody
Heavy chain body of cells
IgG (makes it more efficient than IgM)
Define aggulatination
clumping of antigens together to enhance phagocytosis
What antibody is found in blood as a pentameric shape? It is also the largest antibody-type
IgM
5 point on M
What is the 1st antibody produced?
IgM
What antibody can be transferred by mother to foetus via placenta?
IgG
Why is IgA important?
Neonatal immunity (transferred from mother to foetus in breast milk and colostrum)
What antibody levels drop 6 months post birth and what one starts to rise?
IgG drops
IgA rises
GA GA
G first in womb
A through breast milk
Where do T cells mature?
Thymus
T = thymus
What are the 3 types of T cells?
CD4+ helper
CD8+ killer
Regulatory
How do T cells work?
recognise peptide antigens presented to the TCR (T cell receptors) found on T cells
Antigens are presented by MHC molecules
What is the role of MHC?
Only needed by T cells
Display peptide antigens to TCR (T cell receptors) on T cells
What are the 2 types of MHC and on what cells do you find each type?
What CD cell does each bind to?
MHC I
- present on all nucleated cells
MHC II
- present on APCs (MACROPHAGES AND DENDRITIC CELLS)
MCH I -> CD8+
MCH II -> CD4+
Types of hypersensitivity
Give an example of each type, name cells involved and explain the MOA of each type of reaction
Give time frame for each type of reaction
Remember as A B C D
I - Antibody e.g. Allergy
- IgE
- mast cells and eosinophils
- seconds
II - antiBody e.g. breakdown of RBC in mismatch blood transfusions
- IgG + IgM
- NK cells
- seconds - hrs
III - immune Complex e.g acute hypersensitivity pneumonitis
- IgG
- neutrophils
- hrs - days
IV - Delayed e.g. TB, sarcoidosis, chronic hypersensitivity pneumonitis
- macrophages and T cells
- days
What is the most abundant antibody-type?
IgG
What antibody-type is secreted in breastmilk, saliva and tears?
IgA - (link to IgA importance in neonatal immunity)
What regulates the adaptive response?
Regulatory T cells
Explain what PAMPs and PRRs are
Think of a weaker antigen and antibody
PAMPs (pathogen assoc. molecular patterns)
- found on pathogens
- (think of as a lesser antigen)
PRRs (pathogen recognition receptors)
- found on cells on innate system
- (think of as a lesser antiobody)
PAMPs and PRRs bind together
When does a monocyte become a macrophage?
When it leaves the bloodstream and enters the affected tissue
Describe the difference in appearance between basophils and eosinophils
BOTH bi-lobed
Basophil - blue granules
Eosinophil - red granules
List leukocytes from most to least common
Neutrophils Lymphocytes Eosinophils Monocytes/macrophages Basophils
Newton Licks Elliots Massive Balls
For the following cells of the innate system state identifying feature macroscopically, method of killing and if they produce any cytokine:
Neutrophils Lymphocyte Eosinophil Monocyte/macrophage Basophil NK cells Mast cells
Neutrophil
- multi-lobed
- NETS, degranulation and phagocytosis
Lymphocyte
Eosinophil
- bilobed, red granules
- think ALLERGY
Monocyte/macrophage
- kidney bean shaped nucleus
- Phagocytosis
- TNF-alpha
Basophil
- bilobed, blue granules
- effector in allergic reactions
NK cells
- granular
- degranulation of perforin -> induce apoptosis
- INF-gamma
Mast cells
- ..
- degranulation of histamine + heparin etc.
What cell travels across the endothelium via transendothelial migration?
What do the cells bind to on the vascular endo?
Neutrophils
Adhesion molecules (selectins and ICAM-1)
(travel across via diapedesis)
What 3 cells are associated with allergic response?
What antibody is associated?
Eosinophils
Basophils
Mast cells
IgE
What are the 5 effects of acute inflam?
What system is responsible for acute inflam?
Tumour - swelling Dolor - pain Calor - heat Rubor - redness Functio laesa - loss of function
Innate
What antibody is present in secretions such as breast milk and colostrum (first secretion from mammary glands post birth)?
IgA
What antibody is most abundant in body?
IgG
For each of the following immune-deficency disorders describe their pathology:
X-linked agammaglobulinaemia DiGeorge Syndrome Kostmann syndrome Reticular dysgenesis (most severe form of SCID) SCID (severe combined immunodeficiency)
X-linked agammaglobulinaemia - no B cells
DiGeorge Syndrome - no T cells
Kostmann syndrome - neutropenia
Reticular dysgenesis - failure to produce WBC
SCID - no B and T cells
What T helper cells help macrophages and what ones help B cells?
TH1 - macrophages
TFH - B cells
Which WBC is most likely to deal with large parasites that cannot be phagocytosed?
Mast cells
What do B cells do?
Produce antibodies
B cells = antiBodies
Name the 3 soluble mediators of the innate response?
Complement
CRP
Cytokines
What is measured in anaphylaxis - measure of mast cell degranulation?
Serum tryptase
Antibody producing cells. Fully differeniated
Plasma cells
