24 - Immune Flashcards
cardinal signs of inflammatory response
redness/rubor. pain/dolor. heat/calor. swelling/tumor
inflammatory response involves
release of inflammatory mediators like cytokines, prostaglandins, bradykinin. attracts phagocytes like macrophages/neutrophils. promotes tissue healing. can be reinforced by B + T lymphocytes
LPS lipopolysaccharide: what? composed of? binds to?
cell wall constitutent of gram -ve bacteria; glycolipid, antigenic oligosaccharaide chains. binds toll like receptor 4 = induces immune response
LPS as a research tool?
because it stimulates production of pro inflammatory cytokines
what are cytokines? examples? secreted by?
hormone like peptides that regulate immune response: TNF, ILs, IFNs. secreted by many cell types: endothelial, immune, glial and neuronal cells
classic view of cytokines + CNS?
not produced centrally; thought to be excluded from brain by BBB
cytokines: brain signalling evidence? (5)
receptors found on neurons/glia. ICV admin of cytokines = illness symptoms. block receptors = relieve symptoms. alters NT release in brain. cytokines can promote/inhibit apoptosis.
cytokine to brain signalling: what is unlikely? what then?
passive diffusion unlikely; carrier mediated transport
some cytokine roles in brain
mediate vascular endothelial cell production of NO + prostaglandins. activation of afferent nerve fibers
source of CNS cytokines
glial cells are major source. also neurons themselves.
4 stympcoms of illness + functions
body temp change = accelerates enzymatic reactions, enhances prolif of immune cells, slows pathogen replication. increased slow wave sleep = restorative. decreased activity = conserve energy. hyperalgesia = recuperative behaviours.
lymphoid tissues? innervated by? CNS regulation of cytokine purpose? involves?
spleen, lymph nodes, bone marrow + thymus. innervated by SNS. suppress release of pro inflamm cytokines. involes: HPA axis, SNS and PSNS
HPA-A axis + immune interactions
pro inflamm cytokines activate HPAA = secretion of glucocorticoids = suppress cytokine production
sympathetic: what brainstem areas monitor inflamm signals? send signals via? effect?
locus coeruleus and rostral ventrolateral medulla. efferent signals via NE and EPI –> bind b-adrenergic receptors = suppress cytokine formation
PSNS: cytokines do what? part of brain? effect?
cytokines stimulate afferent vagus nerve –> NTS, DMN, AP –> secretion of ACh = suppress cytokines
neuro-immune communication allows for? communication also occurs b/w?
bi-directional communication = avoid systemic inflamm response, promote local tissue healing. b/w PSNS, SNS and HPAA
blunted HPA axis = ?
hyperactive immune system = allergies, autoimmune, fatigue states
eczema: aka? hyperactive HPA axis = ?
atopic dermatitis, hyperactive = immunosuppression
chronic stress causes?
imbalances in HPA-axis; impairs wound healing
maternal deprivation: effects?
increased vulnerability to stress related illness. increased CRh release + HPA activity. increased activation of monoaminergic systems
depression and circadian rhythms
decreased AVP release from SCN = more activation of pituitary/adrenal = increased cortisol
HPA-A and depression: AVP effect? light therapy?
AVP neurons of SCN exert inhibitory influence on CRH neurons in PVN = more cortisol = depression. light therapy = activates SCN = more AVP = inhibit CRH neurons
