Exam 2 Review Flashcards
Adjuvant
A substance that when administered with an antigen (vaccine), provide local inflammation, drawing immune system cells triggering maturation of dendritic cells
Herd immunity (community immunity)
If a significant portion of the population is immunized (85%) it is protective against outbreaks
Basic reproductive number (Ro)
How many secondary cases generated by a primary case in a susceptible population
Conjugate vaccine
Capsular polysaccharide atttached to protein antigen (such as toxin), B cell and T cell response, get memory
Virus vectored vaccine
COVID 19 J and J vaccine, spike protein gene in adenovirus vector
mRNA vaccines
mRNA for spike protein into muscle/dendritic cell, get robust B and T cell response
Immunological tolerance
-Unresponsiveness of the adaptive immune system to antigens, results in the inactivation or death of antigen specific lymphocytes
Homeostasis
Decline in Ag-specific effector lymphocytes
Control mechanisms of T cells (3)
FasL/FAs on T cells
CTLA/PD-1 on T cells
Tregs
Deficiencies result in autoimmunity
Central tolerance
Deletion of self-reactive lymphocytes during development Neg selection in both B and T cells
Peripheral tolerance mechanisms (3)
Tregs (CD4+, CD25+ T cells) producing IL-10 and TGFB
Lack of Costimulation (No second signal B7-CD28)
Repeated stimulation
T regulatory cells
CD4+, CD25+ T cells that secrete IL-10 ad TGFB which inhibits other T cells
Anergy
happens as a result of lack of second signal, just floats around until it dies
Apoptosis
Repeated stimulation leads to self Fas FasL apoptosis
Autograft
Recipient and donor are the same person
Isograft (syngraft)
Recipient and donor are genetically identical
Allograft
Recipient and donor are genetically different
Xenograft
Recipient and donor are different species
Types of rejection (3)
Hyperacute
Acute
Chronic rejection
Hyperacute rejection
Happens in minutes and hours due to preformed antibodies in the recipient
Preformed antibody in transplantation methods (3)
- Childbirth
- Previous blood transfusion
- Previous organ transplant rejection
Acute rejection
Happens in 10-14 days, mediated by CD8+ T cells
Chronic rejection
Happens in months to years, Mediated by CD4+ T cells (chronic inflammation), antibodies and NK cells
Preventing hyperacute rejection (2)
- Match for blood group compatibility
- Test for pre formed abs (cross match)