Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
168 Cards in this Set
- Front
- Back
|
What is the most studied animal for immunology?
|
Mice
|
|
|
What organ do birds have that mammals do not?
|
Bursa of Fabricius
|
|
|
Do B cells mature within different organs of different species?
|
Yes
|
|
|
Give one example of where a B cell matures that isn’t in the bone marrow?
|
Birds - Bursa of Fabricus. Ruminants and Bits = Intestinal lymphoid tissues
|
|
|
Where do B cells mature in rodents and primates?
|
Bone marrow
|
|
|
Where do T cells mature?
|
In the thymus which is true for all species of mammals and birds, reptiles, amphibians and fish
|
|
|
In humans, ruminant, pigs, horses and dogs - where is the peyer’s patches?
|
Ileum (last section of the small intestine)
|
|
|
What percentage of the ileum is peyer’s patches, in humans, ruminants, pigs, horses, and dogs]?
|
80-90%
|
|
|
In sheep what is the largest lymphoid tissues?
|
Peyers’s patches. - 1% body weight but disappear in adult sheep
|
|
|
In rabbits and rodents, where does the peyer’s patch span from?
|
Jejunum and Ileum. (Jejunum is the middle part of the small intestine)
|
|
|
What do birds have instead of the peyer’s patch?
|
GALT = Caecal tonsils (caecum - pouch connected to junction of small and large intestines)
|
|
|
What happens if you remove the bursa of fabricus?
|
They cannot generate an immune response
|
|
|
When lymphocytes are circulating, where to naive lymphocytes migrate to and where do primed lymphocytes go?
|
Lymph nodes (naive). Tissue fluid (Primed). Both circulate back to the heart
|
|
|
What is the difference between the porcine lymph node structure and the ‘classical’ mammalian lymph node structure?
|
Classical’ = Cortex then medulla, with afferent lymph vessels a the top of the lymph node. Porcine = Medulla then cortex, with afferent lymph vessels at the top and bottom of the lymph node
|
|
|
Do lymphocytes randomly migrate in porcine species?
|
No, accumulate preferentially in specific compartments of the lymph node
|
|
|
What adaptive immune cells prefer which compartments of the porcine lymph node?
|
B cells = Follicles. T cells = Paracortex/medulla
|
|
|
What are the three stages for T cells and B cells going through the porcine lymph node?
|
1 = Entry: Regulated by adhesion molecules on endothelial cells (HEV) and lymphocytes. 2 = Transit:through the parenchyma of the lymph node. 3 = Exit: Directly into blood vessels (or via efferent lymph)
|
|
|
Do porcine have a higher, lower, or similar amount of T cells found in the efferent lymph compared to other species?
|
Fewer
|
|
|
Due to the inverted structure of the porcine lymph node, what is thought about the migration of cells?
|
Do not migrate through the ocrtex to the main efferent duct, but rater re-enter the blood system via HEV. It is not clear whether distinct HEV are used for entry and exit
|
|
|
What is the key difference when comparing lymphocyte recirculation of pigs against other mammals?
|
Pigs flows through the efferent vein not the efferent lymphatic. Pigs also missing the thoracic duct.
|
|
|
Describe the basic flow diagram of lymphocyte recirculation in pigs against other mammals?
|
Other mammals = Bloodstream->High endothelial venules (HEV)->Lymph node paracortex->Efferent lymphatic->Thoracic duct->Bloodstream. Pigs = Bloodstream->HEV->Lymph nod paracortex->Efferent vein->Bloodstream
|
|
|
What is absent in most species of bird in regards to the structure of their lymph nodes?
|
Birds only have one lymphatic vessel, whereas mammals have the efferent and afferent lymphatic vessels.
|
|
|
In what taxonomic families will you fine the lymph heart?
|
Amphibians, Reptiles, and some fish and birds
|
|
|
What is are the morphological characteristics of the lymph heart, and what does it do?
|
Small, two-chambered muscular structures where lymph vessels empty into veins. Pump lymph into general circulation for filtration through spleen.
|
|
|
Where is the Gut-Associated Lymphoid Tissue (GALT) found in birds?
|
Caecal tonsils
|
|
|
What surveys the oculonasal region in birds?
|
Harderian gland
|
|
|
What MHC class do B cells present?
|
MCH Class 2
|
|
|
What MHC class to cytotoxic T cells express?
|
MHC class 1
|
|
|
What MHC class do T helper cells express?
|
MHC class 2
|
|
|
Where is MHC class one found?
|
On all nucleated cells
|
|
|
Are T cell receptors hetrodimers or monomers?
|
Hetrodimers composed of either alpha/beta or gamma/delta chains
|
|
|
What allows for the diversity of T cell receptors?
|
Gene rearrangement
|
|
|
If a cell is infected what MHC class will it present the antigenic peptide on?
|
MHC 1
|
|
|
In an antigen presenting cell, what MHC does it posses, and which does it present antigenic peptides on if it is infected, or alternatively, it wants to activate an adaptive immune response?
|
MHC class 1 for if the cell is infected. MHC 2 for if it wants to invoke an adaptive immune response thorough the use of T helper cells
|
|
|
In T cells, what are deleted during development? Also for B cells, what is deleted during development?
|
T cells specific for self-peptides. B cells specific for self-proteins.
|
|
|
At what loci are MHC class 1 expressed?
|
3 different loci, A, B and C
|
|
|
Are MHC highly polymOrphic?
|
Yes
|
|
|
How many loci are MHC 2 expressed at?
|
3 different loci, DP, DQ and DR
|
|
|
Are MHC 2 highly polymorphic?
|
Yes
|
|
|
Where is MHC 2 predominantly expressed?
|
On antigen presenting cells (Dendritic cells, monocytes/macrophages and B cells)
|
|
|
Do mammals posses MHC?
|
Yes, Class 1, 2 and 3
|
|
|
Where are MHC derived from?
|
A single ancestor (orthologous)
|
|
|
If MHC is derived from a single ancestor, are their differences between the MHC?
|
Yes in the number of MHC alleles and molecules expressed
|
|
|
Do mammals differ in the way they express their MHC class 2 molecules?
|
Yes
|
|
|
Give an example of how mammals differ in the way they express their MHC class 2 molecules?
|
Human or mouse T cells do not express MHC class 2 molecules, whereas they are expressed on nearly all activated T cells in pigs, dogs , cats and horses.
|
|
|
Are class 1 and 2 MHC molecules very polymorphic?
|
Yes
|
|
|
In terms of MHC, what is the advantage of heterozygous animals over homozygous?
|
Heterozygous able to bind a greater array of antigens
|
|
|
How is the polymorphic trait of MHC molecules maintained?
|
Through natural selection
|
|
|
Is avian MHC simpler and smaller than mammalian?
|
Yes
|
|
|
How many regions encode for avian MHC?
|
Two independent genomic regions (Beta and Gamma). Each containing class one and two loci
|
|
|
What MHC class do chickens have?
|
Only have MHC class 2 DM genes
|
|
|
In common chicken haplotypes, how many MHC classes are expressed?
|
Only a single Class 1 and Class 2 molecule are expressed
|
|
|
What does this expression of only a single Class 1 and 2 MHC molecule in inbreed chickens have implications for?
|
Major implications for disease resistance/susceptibility.
|
|
|
What are the three stages of diversification of immunoglobulin?
|
1 = Gene recombination during B cell development. 2 = Gene conversion. 3 = Somatic mutation after antigen exposure.
|
|
|
Is there a difference between species in V,D and J gene composition
|
Yes, significant difference
|
|
|
In what animals does somatic mutation after antigen exposure occur?
|
Birds and mammals
|
|
|
How do birds generate immunoglobulin diversity?
|
Gene conversion
|
|
|
Describe the process of gene conversion in birds to generate different immunoglobulin?
|
Single functional V region at the heavy and light chain immunoglobulin loci is continually alters, by the donation of sequences from an upstream array of pseudogenes. The continued iterations of gene conversion produces a virtually unlimited antibody repertoire of starting antibodies.
|
|
|
How many subclasses of IgG do camels and llamas have?
|
Three
|
|
|
What is different about the structure of IgG 2 and 3 in camels and llamas?
|
They have no light chains and just utilise a variable heavy chain (VHH) to bind antigen.
|
|
|
What is different about the structure of camel and llamas antigen binding site?
|
It is convex binding site so can bind concave active-sites of enzymes, which ‘ conventional’ Ig could not bind
|
|
|
What is the principle immunoglobulin in chicken serum called?
|
IgY
|
|
|
Is IgY is similar in structure to what other Ig molecule?
|
Mammalian IgG.
|
|
|
Whilst IgY is similar in structure to mammalian IgG, what are the differences between them?
|
IgY = Extra conserved common on heavy chain. Lack hing region - reduced flexibility.
|
|
|
What do some birds lack on their antibodies?
|
The Fc region.
|
|
|
Overall what do avian antibodies show when compared to mammaliann?
|
Restricted diversity and affinity maturation
|
|
|
The Treg lineage transcription factor forkhead box P3 (FOXP3) has been identified in the major mammalian veterinary species, but is absent in what species?
|
Birds
|
|
|
Do pigs have different amounts of Alpha/Beta T cells and Gamma/delta T cells compared to humans and mice?
|
Yes
|
|
|
What do most porcine T cells express?
|
Both CD4+ and CD8+
|
|
|
Porcine species lack the expression of CD 1 but express what other CD molecule in high amount?
|
CD5
|
|
|
What does the high expression of CD5 in porcine species suggest
|
That these cells were a mature reaction population
|
|
|
CD4+ CD8+ T cells account for more than half of the CD4 T cells in piglets by 6 months of age. But what is odd about this?
|
CD4+ and CD+ Cells are absent from the lymphoid tissues of neonatal piglets
|
|
|
How could CD4 CD8 T cells suddenly account for half of a pigs CD4 T cells by six moths of age, if they are not present at birth?
|
Appears CD4 T cells acquire CD8 expression upon exposure to their cognate antigen.
|
|
|
What are the three possible way’s CD4 obtains the ability to express CD8 as well in pigs?
|
CD4+ and CD8alpha -, are naive MHC Class 2 restricted CD4 T cells. CD4+CDalpha+ (CD8 alpha alpha homodimer) are antigen experienced (effector/memory) MHC class 2 restricted CD4 T cells. CD4-CD8alpha higher (CD8alphaBeta hetrodimer) T cells are MHC class 1 restricted CD8 T cells with cytotoxic capacity
|
|
|
What are the porcine T cell subsets?
|
CD4+ CD8alpha low T Cells (memory CD4). CD4-CD8alpha high (CD8 T cells). CD4+ CD8 alpha - T cells (naive CD4). CD8alpha +/- gamma delta T cells
|
|
|
What is the WC1 marker?
|
Surface marker on the peripheral blood T cells. Major co-receptor for gamma delta T cells not present in man/mouse
|
|
|
Where are gamma delta T cells found in their most abundance?
|
Epithelial rich tissues (e.g. Skin, reproductive, respiratory and intestinal tracts).
|
|
|
Do gamma delta T cells recognise antigen present through the use of MHC?
|
No
|
|
|
What type of antigen can they recognise?
|
Soluble antigen in a manner akin to B cells. Also share recognition features of NK cells recognising MHC-like molecules, expressed on the surface of stressed/infected cells
|
|
|
Where do gamma delta and alpha beta T cell arise from?
|
Common progenitor cell in the thymus
|
|
|
Many tissue-specific gamma delta T cells express different what?
|
Specific subsets of TCRs with little or no diversity.
|
|
|
Different subsets of Game delta T cells arise in the thymus at different stages of ontogenesis, give an example of when they arise?
|
Skin and respiratory tract gamma deltsa T cells are only generated in the early foetal thymus. Gut and SLO gamma delta T cells generated later and are continued to be produced in the thymus until adulthood
|
|
|
Gamma delta TCR also bind to microbial what?
|
PAMPs (pathogen-associated molecular pattern’s). Also DAMPs (Damage-associated molecular pattern’s) - host proteins associated with stress
|
|
|
Give an example of a PAMP Gamma delta TCR can recognise?
|
Pathogen-derived lipids, organic phosphoesters, nucleotide conjugates and other non-peptide ligands with no requirement for antigen processing/presentation by MHC molecules.
|
|
|
Give an example of a DAMP gamma delta TCR recognise and bind to?
|
Damages, transformed or infected cells (e.g. non-classical mHC molecules and heat-shock proteins)
|
|
|
Give a function of the gamma delta T cell in the innate immune response?
|
Production of IFN-gamma and Interlukin-17. Antigen presentation to alpha beta T cells
|
|
|
Gamma delta T cells have limited or wide range of TCR diversity in the innate immune system?
|
Limited
|
|
|
Give a function of gamma delta T cells in the adaptive immune response?
|
Production of Interferon-gamma or Interlukin-4. Immunoregulation
|
|
|
Gamma delta T cells have a lesser or greater range of TCR diversity in the adaptive immune system than in the innate?
|
Greater
|
|
|
Alpha beta T cells and gamma delta T cells, recognise what form of antigen?
|
Alpha beta = MHC and peptide. Gamma delta = MHC-like molecules, and non-protein ligands.
|
|
|
What is a ligand?
|
A molecule which binds to another
|
|
|
What is the function of Alpha beta T cells and gamma delta T cells?
|
Alpha beta = Help for activation of other leukocytes. Immunoregulation. Cytotoxic Killing. Gamma delta = Help immunoregulation and Cytotoxicity
|
|
|
Gamma delta T cells are a major population in what type of animal?
|
Artiodactyls (cloven-hooved ungulates). Also significant population in chickens
|
|
|
Where are the highest proportions of gamma delta T cells found in artiodactyls?
|
Young animals
|
|
|
What percentage of of lymphocytes circulating in porcine’s are gamma delta T cells?
|
15-35%
|
|
|
With 15-35% of the lymphocytes in porcine species being Gamma Delta T cells, what do a minority of these cells express?
|
CD2 and CD8
|
|
|
Where are gamma delta T cells found in lower number in porcine species?
|
Lymphoid tissue compared to blood and spleen
|
|
|
Whilst there is no systemic or systematic analysis for porcine gamma delta cells in tissues, where do they appear to be primarily coming from?
|
Appear to be blood borne, being recruited to skin and mucosal sites by inflammatory processes (differs from other species)
|
|
|
Are antigens recognised by porcine gamma delta T cells well defined?
|
No. Do not recognise the HMB-PP phosphoantigen. Selectively activated by an extract of Allantospermum hispidium.
|
|
|
Porcine gamma delta T cells do not express what?
|
Perforin (may be cytotoxic through other mechanisms e.g. the Fas-L death receptor pathway)
|
|
|
What sort of cytokines are porcine gamma delta T cells able to produce?
|
Inflammatory and anti-inflammatory cytokines.
|
|
|
Emergency vaccines for Foot and Mouth Disease (FMD) protects pigs after how many days?
|
4 days, which precedes the appearance of antibodies
|
|
|
Which T cells are the major cell population that proliferates when stimulated with FMDV vaccine in vitro?
|
Gamma delta T cells.
|
|
|
What do gamma delta T cells produce when porcine species are exposed to FMDV vaccine?
|
Proinflamm cytokines
|
|
|
A proportion of porcine gamma delta T cells express surface molecules usually associated with what immune cell function?
|
Antigen presenting cells (MHC class2)
|
|
|
Whilst some porcine gamma delta T cells express surface molecules usually associated with professional antigen presenting cells, they do not express surface markers for what?
|
Monocytes, Macrophages or Dendritic cells
|
|
|
Porcine gamma delta T cells appear to have the capacity to take up antigen and preset it with what molecules?
|
MHC 2 to CD 4 T cells.
|
|
|
How was the presentation of antigen via MHC 2 to CD4 T cells demonstrated?
|
In vitro with the model antigen ovalbumin and with African swine fever virus.
|
|
|
It appears that gamma delta T cells express a range of genes normally associated with what cells?
|
Myeloid and B cells
|
|
|
Bovine gamma delta T cells represent up to what percentage of circulating T cells, and is it calves or adults which have the greatest number of them?
|
60% and calves
|
|
|
Cattle express a greatly expanded number of TCR what?
|
Delta variable gene segments
|
|
|
The majority of bovine Gamma delta T cells express what phenotypes?
|
WC1+, CD2, CD4, CD8-
|
|
|
What is Workshop Cluster 1 (WC1)?
|
A transmembrane glycoprotein belonging to the scavenger receptor cystenine rich (SRCR) family.
|
|
|
Bovine gamma delta T cells were originally defined by what?
|
Membrane antibodies to this co-receptor
|
|
|
How many subsets of WC1+ and WC1 - gamma delta bovine T cells are there, and name one?
|
Three subsets - WC1.1. WC1.2. WC.3.
|
|
|
Is it known whether WC1 expression defines functional subsets and if so how?
|
Unclear
|
|
|
Give some bovine gamma delta T cell activating ligands?
|
Viral, bacterial or protozoan PAMPs. Phosphate antigens from Mycobacterium bovid. Peptide antigen from the bacterium Anaplasma marginale. Stree-inducible molecules. Cytokines.
|
|
|
What are the functions of Bovine gamma delta T cells?
|
Anti-microbial effectors and immune activation.
|
|
|
Give an example of bovine gamma delta T cell anti-microbial effectors?
|
Secrete IFN-Gamma. Cytotoxicity, express both granulysin and perforin; however this killer phenotype is predominantly observed in young animals and diminishes with time.
|
|
|
Do bovine gamma delta T cells have memory?
|
Evidence that they do, with enhanced proliferation and IFN-gamma secretion (dependent upon antigen-specific CD4 T cells)
|
|
|
Give an example of bovine gamma delta T cell immune activation?
|
Evidence for reciprocal activating signals between gamma delta T cells and Dendritic cells. Capable of acting as antigen-presenting cells and stimulation results in the expression of MHC 2 and CD80 on a small proportion of cells
|
|
|
In most species the expression of the transcription factor forkhead box P3 (FOXP3) is by what CD molecule, and confers what?
|
CD4 T cells and confers a regulatory phenotype
|
|
|
Where do FOXP3+ CD4+ T cells exist?
|
In cattle but they do not exhibit anergic or suppressive properties in vitro.
|
|
|
Whilst FOXP3+CD4+ T cells do not exhibit anergic or soppressive properties, what molecules do?
|
FOXP3-WC1+ gamma delta T cells
|
|
|
Gamma delta T cells in Bovine species spontaneously secret what and proliferate a response to what?
|
IL-10 and proliferate a response to iL-10, TGF-beta and contact with APCs
|
|
|
What do IL-10 expressing gamma delta T cells inhibit in Bovine species?
|
Antigen specific and nonspecific responses to CD4+ and CD8+ T cells in vitro.
|
|
|
Due to IL-10 expressing Gamma delta T cells inhibiting Antigen-specific and nonspecific responses of CD4+ and CD8+ T cells, it is proposed that gamma delta T cells are a major what in cattle?
|
Regulatory T cell population in cattle
|
|
|
Marsupials are characterised by giving birth to relatively what type of young?
|
Undeveloped
|
|
|
Why do marsupials give birth to relatively undeveloped young?
|
They lack a complex placenta to protect the embryo from tis mothers immune system
|
|
|
At birth, the tissues of the marsupial immune system are what?
|
Underdeveloped and not immunocompetent
|
|
|
Due to marsupial young having an underdeveloped and non immunocompetent immune system, what is their survival in a microbially rich environment dependent on?
|
Maternal strategies, including immunoglobulin transfer via milk and, in some species, prenatally via the yolk sac placenta. Also likely that pouch secretions play a role.
|
|
|
What does the placenta act as in mammalian species?
|
Functions as an immunological barrier between the mother and the foetus, creating an immunologically privileged site
|
|
|
What does the placenta secrete?
|
Immunosuppressive enzymes
|
|
|
What cells does the placenta contain high proportions of?
|
Suppressor cells e.g. Tregs
|
|
|
What in the placenta lack MHC class 1 molecules, and what do they express instead?
|
Placental trophoblast lack classical MHC class 1. Express atypical molecules to prevent attack by CTL and NK cells.
|
|
|
Why does the placenta form a syncytium, and what is a syncytium?
|
A syncytium is a multinucleate mass of cytoplasm that is not separated into cells. Forms without any extracellular spaces between cells in order to limit the exchange of migratory immune cells between the developing embryo and the body of the mother
|
|
|
The increased immune tolerance pregnancy for mammals can cause what?
|
An increased susceptibility to and severity of some infectious disease
|
|
|
In some mammalian species the placenta does not block what Ig antibody?
|
IgG. This passes through the placenta, providing immune protection to the foetus against infectious diseases
|
|
|
In dogs and cats, the chronic epithelium is in contact with what, enabling what to be transferred?
|
Maternal endothelium capillaries. Allowing the transfer of 5-10% of IgG
|
|
|
In ruminant, pigs and horses. The chorionic epithelium is in contact with the what, preventing the transfer of what?
|
Chorionic epithelium is in direct contact with uterine tissues/epithelium. Prevents the transfer of IgG, meaning they are totally reliant on obtaining Ig from the mother’s colostrum
|
|
|
In humans and rodents what is in direct contact with the chorionic epithelial, and enables what to occur?
|
Blood is in direct contact with the chorionic epithelial cells, allowing for the transfer of IgG - amounts of IgG are comparable to serum
|
|
|
Describe the process of the development of the mammalian immune system for bovine species?
|
Thymus. at about 60 days bone marrow, then lymph nodes. At about 90 days complement. Around 130 days Serum IgG, 140 days serum IgM. Around 170 days Peyer’s patches.
|
|
|
Where does leukocyte development commence for bovine species?
|
In the yolk sac, progresses to foetal liver and then to the bone marrow
|
|
|
Around 80-100 days after conception for bovine species, what do foetal T cells respond to?
|
Mitogen
|
|
|
At around 100-130 days after conception for bovine species, what can be detected in the foetus?
|
It’s antibody response to virus infection
|
|
|
Name a pestivirus which infects either Porcien, bovine or ovine species?
|
Classical swine fever virus. Bovine virus/Diarrhoea virus. Border disease virus (ovine)
|
|
|
What can Classical swine fever virus, Bovine virus, and border virus cause?
|
Crosses placenta causing either - Congenital damage/abortion. Persistent infection. No effect
|
|
|
If infected with a pestivirus, at what point of the pregnancy is an abortion most likely to occur?
|
First trimester
|
|
|
What happens if infected with a pestivirus during the second trimester?
|
Production of persistently infected animals. Developing immune system sees virus as ‘self’ and non immune response is mounted.
|
|
|
What happens if infected with a pestivirus during the third trimester?
|
Can still cause abortion but most commonly produce a normal but seropositive calf due to the immunocompetency of the foetus.
|
|
|
Can maternal antibodies protect against pestivirus?
|
No, no protection form material IgG.
|
|
|
Foetal development of neonates occurs in what sort of environment?
|
Sterile environment of the uterus and then neonates are born into a microbe-rich environment
|
|
|
Are neonate immunocompetent?
|
Yes capable of mounting both innate and acquired immune responses
|
|
|
Acquired responses are what?
|
Primary response with a prolonged lag period and low concentrations of antibodies
|
|
|
Why are neonate immune responses skewed toward Th2 rather than Th1?
|
Result of homonal influences in utero to prevent IFN-gamma mediated placental damage.
|
|
|
Due to neonates immune response being skewed towards Th2 instead of Th1, what sort of infection are they more susceptible to?
|
Intracellular pathogens
|
|
|
What does the proper development of the newborn immune system depend largely on exposure to?
|
Exposure to intestinal microflora (‘germ-free’ animal may fail to develop GALT)
|
|
|
Colostrum and milk Ig levels are particularity important in what?
|
Ungulates due to the lack of IgG transfer in utero
|
|
|
What is an ungulate?
|
Hoofed animal
|
|
|
Colostrum in mammals is rich in which Ig antibodies?
|
IgG, IgA, but also contains some IgM and IgE.
|
|
|
As lactation progresses and colostrum changes to milk differences amount the species emerge. Give some examples of these differences?
|
Primate - IgA predominates in both colostrum and milk. Pigs and horses - IgG predominates in colostrum and IgA in milk. Ruminants - IgG predominates in both
|
|
|
Colostrum is not only rich in Ig antibodies but what else?
|
Cytokines which may promote the development of the neonates immune system. Also Lymphocytes
|
|
|
Colostrum is absorbed across which organ?
|
Intestine, which is highly permeable immediately following birth but species differ on selectivity and duration.
|
|
|
What Ig antibodies are selectively absorbed by horse/pigs and Ruminant. Also what is the difference in their duration of absorption?
|
Horse/Pigs = IgM and IgG. (IgA remains in the intestine). Ruminants - absorption is unselective, all classes are taken up although IgA is then gradually excreted back. Ruminants and horses = decline in absorption after 6 hours. Pigs = retained for up to four days in pigs, if milk products are withheld
|
|
|
Maternal antibodies inhibit neonatal what?
|
Ig synthesis
|
|
|
What does the impairment of Ig synthesis in by maternal antibodies in neonates do with regards to vaccines?
|
Impairs the induction of primary immune responses to vaccination. Also they may just mop-up/mask vaccine antigens preventing the induction of antigen-specific immune responses
|
|
|
What dictates when you should vaccinate young animals?
|
Dependent on the amount of Ig transferred and the half-life of Ig involved
|
|
|
How is immunity passed from hen to chick?
|
IgA in albumen ingested by chick protects the investing. IgY in the yolk is absorbed into the blood stream
|
