Week 1 Flashcards
What cell line are antigens derived from?
B-Cell immunity
What cell line are antibodies derived from? Include direct cell they come from.
B-Cell immunity - Lymphoblasts - Plasma cells
Phagocytes, dendritic cells, NK cells and compliment are part of what immunity system?
Innate immunity
B lymphocytes, antibodies, T lymphocytes, effector T cells are part of what immune system?
Adaptive
Consider the following regarding innate immunity. Activity Response Potency Specificity Memory
Activity- Always ON Response - Immediate (minutes) Potency - Low Specificity - NOT specific i.e. general Memory Nil
Consider the following regarding adaptive immunity. Activity Response Potency Specificity Process Memory
Activity - Normally OFF Response - Slow (days) Potency - Higher Specificity - Ag specific Process - Slow Memory - Yes and subsequent response is faster & stronger
Antigens are also known as _______
immunogens
Foreign molecules that bind specifically to an antibody (Ab) or a T-cell receptor
antigen
Non-self substance capable of triggering an immune response
antigen
Parts/sites of the Ag that are recognised and bound by a particular Ab or T-cell receptor
Epitope of antigenic determinant
List 5 factors that contribute to immunogenicity of Ag
- Degree of foreignness
- Mass (> 10,000 Da)
- Dosage (no. of cells) and antigen density on cells
- Chemical composition and complexity
(Proteins > Carbohydrates > Lipids (inert)) - Route of Administration affects immunogenicity
(Intravenous (IV) & intraperitoneal (IP)
List the three regions on a basic antibody. (make sure you can label a drawing
Fab - Fragment antigen binding
FV - Fragment Variable
FC - Fragment Constant
IgG is referred to as a __________ and IgM is referred to as a ________
Monomer, Pentamer
Which is bigger IgG or IgM?
IgM
How many binding sights does a IgG and a IgM have?
IgG - 2
IgM - 10
Is this describing IgG or IgM - long-term immunity, memory antibodies, neutralizes toxins, opsonizes, fixes complement
IgG
Is this describing IgG or IgM - produces at first response to antigen, can serve a B-cell receptor
IgM
Can IgG and IgM both cross the placenta?
Only IgG due to it’s size
Which has a higher serum concentration percentage?
IgG 75% compared to IgM 10%
What is the optimum reaction temp for IgG and IgM?
IgM - 2-24C | IgG 37C
Cells or tissues from a genetically different individual is referred to as __________
allogeneic
cells or tissues from self is referred to as _________
Autologous
What are the three major biological activities of
the complement system?
- opsonization (prepare for eating),
- lysis of target cells, and
- stimulation of inflammatory
mediators
The alternate pathway is initiated by what?
The alternative pathway is initiated by the membrane
property of a microorganism.
The classical pathway is initiated by what?
The classical pathway is initiated by an antigen-antibody reaction.
Stages of in vitro Ag-Ab reactions
Stage 1 – Sensitisation
Describe
Ab attach to antigens on RBC membrane
but is random & NOT visible
Stage 2 – Agglutination
Describe
Formation of bridges between sensitised red cells
Forms lattice that can be visualised
What factors influence - Stage 1 Sensitisation (5)
o Serum to cell ratio o Reaction temperature o Incubation Time o pH o Ionic strength
What factors influence - Stage 2 Agglutination
o Distance b/w cells
o Concentration of Ag to Ab
o Centrifugation
In the PROzone what is in excess to cause small complexes ?
Ab
Which zone has large complexes (ratio of serum to cell)
Zone of Equivalence
Zeta potential - _______ charge on surface of red cell
Cloud of _______ charged ions surround
Negative, positively
Zeta potential keeps red cells approx _____ nm apart
18-20nm
What are 3 things that can decrease the Zeta potential to enhance IgG reaction?
- Add protein to solution
- Reduce ionic strength of solution
- Proteolytic enzymes
These antibodies will react with human antibody and
complement on red cells or in serum
Antihuman globulin (AHG)
Detects IgG Ab and complement proteins attached to RBC
Antihuman globulin (AHG)
What test is conducted to determine if RBC have been sensitised in vivo (i.e. Ab “already” bound to RBC).
Direct Antiglobulin Test (DAT)
Immune haemolysis leads to a Positive DAT. What are 3 possible causes?
Transfusion reaction, Autoimmune haemolytic anemia, haemolytic disease of the newborn
What test is conducted for compatibility testing to determine if the patient haw any IgG antibody in their sample?
Indirect Antiglobulin Test (IAT)
Cards with microcolumns filled with matrix (gel or glass) is called what?
Column Agglutination Test/Technology (CAT)
What is the principle of Cards with microcolumns filled with matrix test.
Agglutinated cells are larger thus cannot pass thru matrix and stay on top.
Non agglutinated cells can pass thru matrix & fall to bottom of colum
Specific location of gene on chromosome is called what?
Genetic loci
Different forms of a gene at specific locus is referred to as what?
Allele = E.g. ABO has 3 alleles – A, B & O
Only one form of allele req. to express ie. always expressed
Dominant allele
Only expressed when inherited from both parents i.e. double (homozygous) dose
Recessive allele
Gene that does not produce any detectable trait/chracteristic/expression Eg. O gene
Silent amorph
Expressed even when single gene is present
Equal expression of 2 different inherited alleles
Codominant alleles
