lecture 16- immunity to microbes Flashcards
what can surface lipopolysaccharide activate
alternative or mannose-binding lectin pathways
what are the receptors that C3a and C5a located on
resident ast cells
what does mast cell degranulation enhance
blood flow
what class is early antibacterial Ab production
IgM
what are the 2 principal mechanisms that infections are caused by pathogenic extracellular bacteria
tissue damage is caused by inflammation at the site of infection or bacteria produce toxins which have diverse pathologic effects
what is endotoxin (LPS) a potent activator of
macrophages, DCs and endothelial cells
what does diphtheria toxin do
shuts down protein synthesis in infected cells
what does tetanus toxin do
inhibits neuromuscular transmission
what are some examples of bacteria that resist phagocytosis
pneumococcus, neisseria meningitidis
what is an example of a bacteria that uses scavenging of reactive oxygen species
catalase-positive staphylococci
what are the principal injurious consequences of host responses to extracellular bacteria
inflammation and septic shock
define septic shock
severe pathologic consequence of disseminated bacterial infection by some gram negative and gram positive bacteria
what is septic shock syndrome characterized by
circulatory collapse and disseminated intravascular coagulation
what is the global suppressor of macrophages function
IL-10
what super antigens are known for food poisoning
staphylococcal SAgs
what is streptococcal TSS caused by
S. pyogenes
what is toxic shock syndrome caused by
S. aureus
where are viral peptides expressed
in the MHC class I peptide-binding groove
how do TH1 cells recruit and stimulate virus-specific CTLs
by providing IL-2 for proliferation of CD8+ T cells
how do Th cells and CTLs leave the LN
via the draining lymphatics and ultimately enter the blood
when do virus-infected cells secrete viral proteins
after their death
what is the innate immune response to intracellular bacteria mediated mainly by
phagocytes and NK cells
what do DCs and macrophages produce that activates NK cells
IL-12 and IL-15
describe the endogenous pathway
proteins from intracellular pathogens are degraded by the proteasome and then resulting peptides are shuttled to the ER by TAP proteins
