Characteristics of Innate Immunity
classes of external innate defense
internal innate immune defenses
•physiologic barriers (temp, O2, complement, IFNs)
sensors of innate immunity?
•TLR (toll-like receptor)
•NLR (Nod-like receptors)
NLRs and TLRs roles are (non)redundant.
TLRs are located in ___
• bound to cell membrane or endosomal vesicles
• sense bact components or viral NAs
NLRs are located in ___
• detect bact PG and viral RNA
NLR activation results in ...
production of inflam mediators
Characteristics of acquired immunity
• able to distinguish self from non-self
Two arms of acquired immunity
1. humoral (Ab-mediated, B cells, protect against circulating extracell. pathogens-bact, toxins, virus)
2. cell-mediated (T-mediated, Th/CTL, protects against intracell parasites- virus)
What determines which MHC presents an antigen?
•location in cell
•cytosol → MHC-I → CTLs
•endosome → MHC-II → Th...
Treg secretes which inhib cytokines
first line of defense against virus?
circulating ab or IFN
defense against virus p infx?
immunological memory refers to...
memory cells and ↑ IgG quant and affinity
pathogen immune evasion systems
• genetic variation
• gene rearr
minor gene mutation
gene exchange b/t pathogen and 2º host
A prime example of genetic variation as a mechanism for immune system evasion is...
• usu recognized by hemagglutinin, but can undergo antigenic drift or shift
Herpes virus family has various mechanisms to interfere with viral antigen presentation. These mechanisms are:
1. proteasome inhibition (no processing)
2. TAP transport disruption (HSV)
CMV can _____ MHC-I molecules in the ER, thereby evading antigenic presentation
Variations in polysaccharide coat of Strep. pneumonia is an example of _______, which helps the pathogen invade the host even after an effective response has been mounted about the first infx.
• genetic variation
• different genes exhibit different coats, so the host does not recognize new infx as being from the same type of organism
Besides Strep pneumoniae, another bug that uses genetic variation to evade immune response is _____.
Most inherited immunodeficiencies are recessive. What is a prime example of one that is DOMINANT?
• IFN-γ receptor deficiency
Antibody deficiencies (XLA) cause an inability to clear _____.
T cell defects lead to ____, such as agammaglobulinemia
• DiGeorge is also caused by a T cell defect
Chronic Granulomatous Dz is caused by a primary immunodeficiency of ____
HIV infects ___, ___, and ___ cells
CD4+, DCs, macros
HIV uses a chemokine co-receptor to infx hosts. Individuals with a genetic defect in what chemokine receptor seem to be resistant to HIV?
A healthy individual has >1000 CD4+ T cells/μL. At what point does HIV seem to be symptomatic? What is the threshold for full-blown AIDS?
Uncontrolled inflam @ systemic level can cause _____. It is triggered by SEB (endotoxin) stimulating large numbers of Th cells to rls cytokines and LPS from G- bact stim macros and monos to secrete inflam cytokines.
• septic shock
• SEB- strep enterotoxin B (superantigen)
SEB is called a "superantigen." This label is applied to antigens which are able to....
cause non-specific activation of T cells resulting in large number of cytokines
Under influence of LPS, macros secrete lots of the cytokine...
S. pyogenes is assoc c rheumatic fever and glomerulonephritis. This is because its M proteins express epitopes that are highly _______ with epitopes of cardiac myosin, tropomyosin, vimentin, laminin, and keratin
T cells that cross react b/t M protein and myosin may be involved in pathogenesis of _____
BCG and cholera vaccines are usually....
live, attenuated bact
Polio and rabies vaccines are usually...
live, attenuated viruses
TDaP vaccine is a ____ vaccine
H. influenzae and pneumococcus vaccines are ____ vaccines, because they use the pathogen-related antigen coupled on a carrier protein
Hepatitis vaccine is _____ vaccine, and they are good at inducing a B cell response
Viral vector vaccines induce a ____ response, but their major drawback is lack of specificity
Edible vaccines are
• painless and palatable
• being experimented c in hep and HIV