Exam 3: Dr. Pinchuk Fetal and Neonatal Immunology Flashcards
When is the immune system fully formed?
At birth. All acquired immune response in the newborn are primary responses
What do newborn mammals obtain immunoglobulins from?
Their mother either by direct transfer across the placenta or by ingestion Ig-reach colostrum immediately after birth
What may the failure of the passive transfer result in?
The newborn suffering from overwhelming infections
What does milk provide?
A constant supply of Ig (mostly IgA), which helps protect the newborn against intestinal infections
What do mothers provide?
Protective antibodies to their young both before and after birth
What does IgG come through?
Placenta
How is IgA transported to the newborn?
By poly-Ig-receptor
What does the receptor FcRn do?
Transports IgG from the blood stream into the extracellular spaces
What happens to the level of IgG during the first year of life?
Transient decrease
What is the most critical period in life? Why?
6 months, there is no maternal IgG
What is pregnancy the one natural situation for?
The production of anti-MHC antibodies
What do paternal HLA isoforms that differ from the mother’s HLA type have the potential to do?
Stimulate an alloreactive immune response
What is immune complex-mediated inhibition of naive B cells used to do?
Prevent hemolytic anemia of the newborn
What does a primary immune response produce?
Naive and memory B cells
What does a secondary immune response?
Inhibit naive B cells and activate memory B cells
When should you be very careful about vaccinations?
Passive immunity
When does the thymus develop?
41 days
What are the different type of placenta?
Hemochorial (humans, primates)
Endotheliochorial (dogs, cats)
Syndesmochorial (ruminant)
Epitheliochorial (horses, pigs)
How does the passive transfer of immunity occur with hemochorial and endotheliochorial placentas?
IgG levels in infant are comparable to those of its mother
5-10% of IgG may be transferred
How does the passive transfer of immunity occur with syndesmochorial and epitheliochorial placentas?
Passage of IgG is totally prevented
Newborns are entirely dependent on antibodies received through the colostrum
What happens if there are more layers of a placenta?
There is more restricted the movement of blood between mother and fetus
What antibody class is a majority of ruminant milk?
IgG
2nd is IgA
3rd is IgM
What antibody class is a majority of nonruminant milk?
IgA
2nd is IgG
3rd is IgM
What do maternal antibodies inhibit?
Vaccination
What may maternal antibodies do?
Bind to injected antigens or pathogens and accelerate their clearance or they may bind the critical epitopes and prevent activation of B cells and antibody production
What do maternal antibodies form? What do they do?
Complexes
Inhibit activation of B cells
Look at birth of a PI calf
Look at birth of a PI calf
How can hemolytic anemia of the newborn be prevented?
If in the first and subsequent pregnancies the mother is passively infused with purified human anti-Rh antibodies before she has made her own response
