immunio globulins Flashcards
what are the two responses of immune system
*Specific & Non Specific response
what are the exterior barriers of “Non Specific response”
Skin, Mucous membrane, Secretions
what does “non Specific response” involves and includes?
Involves myeloid leukocytes (including all phagocytic cells) such as macrophages
What will Participate in the inflammatory response to injury or disease.
Macrophages and Mast cell
what are cytokines
Proteins signal between cells,
what are the specs of Specific response
*Antigen-antibody relationship (acquired immunity).
*Vaccinations depend on this
*Involves lymphocytes (B, T and plasma cells)
what are the components of immune system?
A) Cellular
B) molecular
what is the role of B-lymphocytes in cellular immune system
it is responsible for humoral response (plasma immunoglobulins; humoral antibodies).
what is the role of T-lymphocytes in cellular immune system
it is responsible for cellular response (Cytotoxic killer T cells & Helper cells).
Macrophages.
Mature B cells are produce by ?
Molecular immunoglobulins
what are immunoglobulin and made for ??
Immunoglobulin is a glycoprotein that is made in response to an antigen
what globulin is immunoglobulins are
immunoglobulin are GAMMA globulin
immunoglobulin are synthesized by ?
plasma cell
what is the Constitute of total serum proteins in immunoglobulin
25-30%
where does antibodies of immunoglobulin present in ??
serum, tissue fluids & mucosal surfaces.
what is the different between antibodies and immunoglobulin
All antibodies are immunoglobulins, but all immunoglobulins may not be antibodies.
basic structure of immunoglobulin
Composed of 4 polypeptide chains.
2 identical light & 2 identical heavy chains.
Linked by disulphide bonds.
Light chains similar in all immunoglobulins.
Light chains occur in 2 varieties kappa & lambda
light and heavy chains of immunoglobulin subdivides into ?
variable & constant region.
what does Each heavy & light chain contains ?
amino terminal & carboxy terminal
what are heavy chain?
Heavy chains are structurally & antigenically distinct for each class.
how does loops form
Each immunoglobulin peptide chain has intra chain disulphide bonds
what is domain
Each loop is compactly folded to form a globular structure
what is light chain immunoglobulin contain
Light chain contains a single variable domain (VL) & a single constant domain (CL).
what does heavy chain immunoglobulin contain
Heavy chain contains one variable domain (VH) & 3 constant domains (CH1, CH2, CH3).
what is hinge region
the segment in heavy chain –between CH1, CH2.
what is papain enzyme?
Peptide bonds in the hinge region are broken.
Produces 3 fragments.
2 identical fragments called Fab (functional antigen binding) fragments; antigen binding activity.
The other fragment called Fc fragment (Fraction crystallizable).
what is pepsin digestion produce
Produce a single fragment composed of 2 Fab like subunits F(ab); 2 binds antigen.
Is “Fc fragment” is recovered in proteolytic enzyme
Fc fragment is not recovered; digested to small numerous peptides
what is Fc region composed of?
is composed of two heavy chains that contribute two or three constant domains depending on the class of the antibody
classification of immunoglobulin
classified as 5 types
Ig G - (gamma)
Ig A - (alpha)
Ig M - (mu)
Ig D - (delta)
Ig E - (epsilon)
what is the most abundant immunoglobulin in serum ?
Immunoglobulin G (igG)
what is the constitution of igG and where it is present?
75-80% total Ig and present in blood, plasma & tissue fluids.
life time of IgG
It has a half life of 23 days: the longest of all of the Ig isotypes
what does IgG do at the period of birth and to the fetus ?
Crosses placenta & provide natural immunity to fetus & neonate at birth
what does IgG do to toxin?
it neutralize the toxin
what does it will do to the virus?
It opsonizing; increase the susceptibility of (bacteria) to ingestion by phagocytes.
What are the sub classes of IgG?
Ig G1, Ig G2, Ig G3, Ig G4.
Biological Functions of IgG Subclasses
IgG1, IgG3, IgG4 – cross placenta & protect fetus
IgG1 & IgG3 binds to Fc receptor on phagocytic cells, monocytes & macrophages and mediate opsonizations (susceptibility of (bacteria) to ingestion by phagocytes)
how many percentage does IgA constitute and where does it present?
Constitutes 10-15 % of total Ig.
Present in milk, saliva, tears, mucous of respiratory, digestive & genitourinary tracts.
in serum IgA exist as?
monomers
in external secretion IgA exist as? and what is has? life time ?
In external secretions, exist as dimer called secretory Ig.
Has ‘J’ chain & secretory piece.
Half life: 6-8 days
Formation of Secretory Ig A
Dimeric Ig A binds to the receptor on the surface of the epithelial cells – endocytosed & transported across the cell to the luminal surface
what happened to
IgA after reaching to surface
the poly-Ig receptor is cleaved.
what will happen to the remaining portion of the receptors in IgA
It will remains attached to the Ig A dimer as a secretory component.
what will the secretory do in IgA ?
It will protects Ig A from digestive enzymes & denaturation by bacterial proteases
Functions of Ig A
Provides local immunity.
Secretory IgA binds to surface antigens of microorganism & prevent its attachment
invasion of the mucosal surfaces of respiratory & digestive tract and immune elimination.
invasion of the mucosal surfaces of respiratory & digestive tract and immune elimination.
what does secretory IgA provides?
It provides important line of defense against salmonella, Vibrio cholerae, N. gonorrhoeae, influenza virus and poliovirus.
Functions of Ig A
Secretory IgA present in breast milk protects newborn during first months of life.
Promotes phagocytosis & intracellular killing of microorganisms.
what is the amount of protein in IgM
for 5-10% of total immunoglobulin proteins.
how many monomeric units are there in IgM
Polymer of five monomeric units (pentamer).
with what is IgM is held ?
Held together by disulfide bonds & ‘J’ chain.
what is the molecular weight and life time of IgM
Mol. Wt. of 900,000- 1,000,000 (millionaire molecule).
Half life: 5 days.
Functions Of Ig M
It agglutinates bacteria.
Causes opsonization & immune hemolysis.
Believed to be responsible for protection against blood invasion by microorganisms.
what is the First Ig to be produced in primary response to antigen.
immunoglobulin M (IgM)
what is the life time of IgM
Relatively short-lived hence its demonstration in the serum indicates recent infection.
where does Monomeric IgM appears?
and how it act?
Monomeric IgM appears on the surface of unstimulated B lymphocytes & act as receptors for antigens.
how many percentage IgM contain and where it present?
Most of IgM (80%) present intravascularly.
And in low concentration in intercellular tissue fluids
what infection does IgM antibodies indicates
Presence of IgM antibody in serum of newborn indicate congenital infection
does IgM can cross placenta
No it Cannot cross placenta.
Earliest immunoglobulin to be synthesized by fetus at?
20 weeks
structure and region of domains of IgE
Structure is similar to IgG.
Has 4 constant region domains
what is the molecular weight and life time of IgE
Mol. Wt. 1,90,000.
Half life: 2 days.
what is Normal serum concentration
0.3 ug/ml
where does IgE present
Mostly present extra cellularly.
what is the Heat labile
of IgE and does it cross placenta ?
Heat labile (inactivated at 560C in 1 hour).
Does not cross placenta.
where does IgE produced and binds
Produced in the lining of respiratory & intestinal tract.
Binds to the Fragment, crystallizable (Fc)receptors on the membranes of blood basophils & tissue mast cells.
Functions of Immunoglobulin E (Ig E)
Mediates immediate hypersensitivity reaction.
Responsible for symptoms of anaphylactic shock, hay fever & asthma.
Play a role in immunity against helminthic parasites.
where does IgE binds
IgE binds to Fc receptors on the membrane of blood basophils & tissue mast cells.
what will happen to IgE while binding with same antigen?
cells degranulates; release histamine & pharmacological mediators of anaphylaxis from cell.
Physical role of IgE
The physiological role of IgE appears to be protection against pathogens by mast cell degranulation & release of inflammatory mediators.
structure and concentration of IgD
Structure is similar to IgG.
Serum concentration 30 ug/ ml.
total percentage of constitute ig and life time
Constitutes 0.2% of total Ig.
Half life: 3 days
what will happened IgD together with IgM
IgD together with IgM is major membrane bound Ig on unstimulated B lymphocytes and it acts as recognition receptors for antigens.
Role of different immunoglobulin classes
Ig G: Protects the body fluids
Ig A: Protects the body surfaces
Ig M: Protects the blood stream
Ig E: Mediates type I hypersensitivity
Ig D: Role not known
what is multiple myeloma (MM)
MM is a group of diseases characterized by proliferation of single plasma cell clone (myeloma cell)
what will multiple myeloma (MM) cause
it cause overproduction of monoclonal immunoglobulin molecules known as paraprotein (myeloma M-protein).
What is the origin of M-protein? in patients(percentage)
55% - IgG
23% - IgA
20% - Ig light chains
2 % - IgD, IgM
Where are myeloma cells & paraproteins localized?
Myeloma cells
Bone marrow
Blood
Paraprotein
Blood
Urine (light chain -Bence- Jones protein)
What is Biochemical Profile of Multiple Myeloma?
Plasma cell > 10%
Serum electrophoresis: M- band (sharp peak in the gamma-globin fraction).
Hypercalciemia
Normal ALP.
20% of patients with light chain paraprotein do not detect it in serum but show presence of Bence-Jones protein in the urine.
What are Bence-Jones proteins?
Bence-Jones protein is Ig light chain.
The presence of specific protein in the urine of patient with Multiple Myeloma (MM)
How are they detected by heating test?
ppt at 40-500C but dissolve on further urine heating to boiling point.
what is Bone disease – lytic lesions of
bone ?
Activation of osteoclasts (increase resorption).
Inhibition of osteoblasts (decrease formation).
Pain, deformation.
what is impaired renal function?
Overflow proteinuria.
what causes renal tubular amyloidosis ?
Multiple myeloma may cause renal tubular amyloidosis
what is amyloidosis and where it present
Amyloidosis,a buildup of abnormal protein, called amyloid, in the tissues and organs
Obstruction of lumen of nephrons by
paraproteins.
what is anemia
Bone marrow erythropoietic cell are replaced by the plasma cells, resulting in anemia.
