Immunology Flashcards
Why don’t anti-hep C envelope antibodies confer lasting immunity?
Because there is a huge amount of antigenic variation amongst hep c envelope proteins. They are prone to mutation and there is no 3-5 exonuclease activity. Also multiple subspecies can infect at once. This is why there is no vaccine for hep c
Why do we give Rh- mothers Anti RhD IgG antibodies if their baby is Rh positive?
Because they will cross the placenta and neutralize a number of rh+ RBCs. This will prevent a maternal immune response. This doesn’t kill the baby because the amount of IgG adminstered is so much less than if there were an actual immune response.
How is MHC I presented?
Antigen loaded in RAR, taken to membrane via TAP
How is MHC II presented?
Antigen is loaded following the release of the invariant chain in acidified lysosome
Interferon alpha and beta?
Produced as a defense against viral infections. Released by virally infected cells to prime cells around them should they become infected. Primed cells respond to viral dna by degrading viral mRNA and inhibiting protein synthesis. Then apoptosis occurs
What cells produce interferon gamma?
NK cells and macrophages to increase MHC class II, increase TH1 cells, and cause killing of viral cells
What is secreted by TH1 Cells?
IFN gamma, Il2
What is secreted by TH2 cells?
IL4 (ige and igg), Il5 (iga and eosinophil activation), Il10 (stops TH1)
Tryptase
Released by mast cells in addition ot histamine during anaphylaxis
CD19+ Cells
Only B cells that remain in Brutons X-linked agammaglobulinemia.
Marker of NK cells?
CD16 and CD56
How to tell if a patient has combined immunodeficiency?
They have bacterial, viral and fungal infections
Cells involved in type IV HSR
Macrophages, CD4, CD8, NK cells
How does fas cause apoptosis
FAS binds FASL and creates FADD binding site. Which activates caspases
How to toddlers present with hepatitis A
Usually an anicteric viral illness
Hemolytic disease of the newborn
If mom has O blood, and baby as A, B, AB, mom has anti a anti B IgG. Cross placenta and cause hemolysis. If mom has a or b, she has IgM antibodies which do not cross
What do sarcoid granulomas produce?
1,25 OH D and ACE
Lysozyme
Oxygen independent killing in neutrophils. Hydrolyzes peptidoglycan cell walls. Found in tears and saliva.
Why can neisseria infections recur?
Have high degree of antigenic variation.
CD14
Is a marker of monocytes and macrophages
Leukocyte adhesion deficiency
Decrease in CD18+, which is a neutrophil integrin. No pus, delayed separation of the umbilical cord, poor wound healing.
Acute hemolytic transfusion reaction
Causes fever, chills, chest pain, back pain, hemoglobinuria. Is a type II HSR against Blood cells.
Acute nonhemolytic transfusion reaction has fever and chills. Due to type II HSR against foreign proteins.