host defenses Flashcards
what in the alimentary tract can destroy viruses?
acid, proteolytic enzymes, bile
how does bile destroy enveloped viruses?
destroys the lipids of enveloped viruses
rhinovirus/adenovirus attack ____respiratory tract, influenza/RSV attack______respiratory tract
upper; lower
major innate immunity mechanisms against viruses (3)
- IFN alpha/beta
- NK cells
- macrophages
IFN alpha produced by?
leukocytes
IFN beta produced by?
fibroblasts, non-leukocytes
what is the 1st line of defense against virus infected cells?
NK cells
relationship of NK cells and IFN
NK cell activity enhanced by IFN
what cell type is capable of ADCC?
NK cells
what are the killing mechanisms of NK cells?
- apoptosis
2. perforin mediated osmotic death
how do macrophages interfere with virus replciation (2)?
production of:
- TNF alpha
- NO
what type of adaptive immuntiy is most important early in viral infxn?
humoral immunity
what type of adaptive immunity is important in established viral infxns?
CMI
are memory T cells of B cells quiescent until reactivated by Ag?
memory T cells
what is released by macrophages in response to intracellular bacteria?
IL12
what does IL12 stimulate?
stimualtes NK cells to release IFN-gamma
in granuloma response, what sort of response is triggered by release of IL-12?
TH1 immunity
tuberculoid leprosy is Th1 or TH2 mediated?
Th1 mediated
lepromatous leprosy is Th1 or TH2 mediated?
Th2 mediated
what type of leprosy: normal serum Ig levels, normal T cell responsiveness
tuberculoid leprosy
what type of leprosy: hypergammaglobinemia, low T cell responsiveness
lepromatous leprosy
which part of the body has no physical barriers?
- eye
2. GU tract
viruses localized to mucosal sites confer what type of immunity?
short-lived protective immunity
half life of serum Ig?
less than 3 weeks
