CIS 2 Flashcards
How are infants resistance to infectious diseases during the first months of their life?
The first level of resistance depends development of phagocytes, which develops slowly.
So most resistance is due to immunoglobin-based immunity of mom. Before pregnancy, it is recommended that expecting mommies get boosters on immunization.
. Immunizations of pregnant moms with tetanus toxoid protect the infant from
umbilical tetanus neonatorum.
Immunoglobulin IgG is able to pass the PLACENTAL BARRIER.
Levels of lgG in an infant are a reflection of the maternal IgG levels. IgG is considered the MOST PROTECTIVE ANTIBODY for several reasons.
- Present in higher amounts
- Binds avidly with the antigen, so it doesnt leave and cause more damage
- Activate the compliment system
- V good at opsinizing
- Bc small MW, easy to penetrate tissues
Neonatal FcR belongs to the MHC family. Unlike them, however it cannot do what?
Present antigens.
They are not diverse
MATERNAL IgG is internalized by ______ and encounters FcRn in the early endosome.
This allows active FcRn‐mediated transport of IgG across the cell and its subsequent release on the opposite, extracellular side
endocytosis
At what age do infants develop the ability to synthesize antibodies?
Fetuses can make their own IgM from middle of the second trimester– birth.
After birth, IgG production stats and reach 80% of IgG levels during the 1st year.
At 6 months old, the mothers Ab disappear from the newborn and they start to rely on their own.
If a bby has an immune deficiency, how it is manifested as
recurring infections
Which antibodies are formed earliest by infants?
In utero–> IgM
After birth–> titers of all Ig increase as they are exposed to antigens. By the time of puberty, they have the adult levels of Ab.
Ig A is secreted out of moms milk and breastfed infants have the benefit of this antibody for protection of their ____________________ and __________ against infection.
Upper respiratory
Intestinal tracts
Only _____ immune responses create memory
Active
Masha was immunized with polysaccharide antigens of Hemophilus influenzae repeatedly. Why did she get the sickness?
If repreated or large doses are given, it can cause immunotolerance.
Also, if she received a purified capsular vaccine, it could not have been immunogenic before 2 yo.
Immunological tolerance is the inability of an antigen to create an expexted immune response. This can be due to a failure of B or T cells.
B cell tolerance is noted to develop after _____ doses of antigens are given.
LARGE
Anergy in T-cells
Causes by lower doses of antigens and is of longer duration.
Allergens
induce potent IgE by very low doses, causing the development of allergy in susceptible people
Polysaccharide antigens are T-cell ________ antigens.
The lgM response to these antigens fades quickly due to the short half-life of lgM.
Covalently coupling them to protein carriers converts these antigens to T-CELL ______ antigens, a favoring lgG response.
independent
dependent
