Immunology Flashcards
What do mycobacteria infect?
They infect antigen presenting cells
Where are the blood tissue barriers and hence immune privileged tissues?
Blood-brain barrier
Blood-ocular barrier
Blood-testis barrier
What are warm antibodies?
IgG
What are cold antibodies?
IgM
Which antibodies form monomers?
IgG
IgE
IgD
Which antibodies form dimers?
IgA
Which antibodies form pentamers?
IgM
Which antibodies cannot cross the placenta?
IgM
Give examples of uses of passive immunity
Anti-venins
Pooled Ig for immune deficiencies
To prevent rhesus disease
What is caused by the measles vaccine?
SSPE
What is the marker for memory b cells?
CD27
What is the marker for memory T cells?
CD45
What are the 6 types of vaccine?
Killed whole pathogen Live attenuated Sub unit Synthetic Toxoid Conjugate
What is an attenuated pathogen?
Made unable to grow in the human body or grow slowly
What is the function of adjuvants?
Increase the immune response
What adjuvant is used in viral vaccines?
IL33
How does HIV enter T cells?
Gp120 on HIV binds CD4
What are the problems associated with a HIV infection?
Antibodies against gp120 can enhance infection in macrophages
Antigenic drift
Initial infection is transmitted by infected cell not by free virus
What are 5 types of immunodeficiencies?
X linked agammablobulinemia ADA SCID MHC deficiency Ig deficiency T cell deficiency
What are treatments for immunodeficiencies?
Prophylactic antibiotics PEGAylated ADA injections HSCT Gene therapy Pooled gamma globulin
What mutation is associated with x linked agammaglobulinemia?
Btk which causes mutational arrest of B cells
What are 3 contributory causes of MS?
Vitamin D
EBV infection
Genetics
What gene is associated with MS?
HLA-DRB1
What are the antigens in MS?
MBP
MOG
PLP
What is the pathophysiology of MS?
CD4 T cells are activated by APC, they express VLA4 so can cross the blood brain barrier. T cells cause inflammation with leads to demyelination. Increased levels of IgG and leukocytes are found in the cerebrospinal fluid
How does a decrease in vitamin D cause MS?
Increases inflammation. Less vitamin D = more Th1 response
What treatments are available for MS?
Interferon beta (inhibits IFN gamma)
Corticosteroids
Antibody therapies (rituximab against b cells and natalizumab against VLA4)
Methrotrexate
Cyclophosphamide (promotes Th2 response and is toxic to proliferating cells)
What does the classical complement system recognise?
Antibody:antigen complexes
What does the MBP/lectin system recognise?
Sugar residues
What does the alternative pathway recognise?
Pathogen surfaces
What is the result of all 3 pathways?
Production of C5 convertase and MAC
Why does complement have to be regulated?
To prevent it attacking host membranes
What regulates complement?
C1 disrupters
C3 convertase disrupters
MAC inhibitors
Common pathway
C3 + C3 convertase = C5 convertase
C5 convertase is cleaved to form C5a and C5b. C5b directs the MAC.