Key facts Flashcards
xthrough what does the spleen receive lymphocytes and antigen?
splenic artery
*no afferent lymphatic supply
Which Tregs express FOXp3?
natural T regs
(NOT induced Treg1 or 3)
what is Bruton’s tyrosine kinases required for? what do its defects lead to?
pro to pre-B cell > B cell maturation
XLA
pre B cell receptor chains and main signal
u heavy chain with surrogate light-chain (gamma5 + VpreB)
signals B cells to stop heavy chain gene rearrangement
VDJ recombination results in __ diversity
Addition of nucleotides by TdT (terminal
deoxynucleotidyl transferase) and removal of endonuclease results in __ diversity (greatest variability for diversity)
combinatorial
junctional
most common form of T-B-NK+ SCID mutation in _, which affects _
RAG1 or 2
several proteins involved in VDJ recombination
what chemokines attract neutrophils to tissue
IL8 (CXCL8)
LTB4
defects in types of LAD
Type 1 LAD: defective CD18 integrin *Defective adhesion
Type 2 LAD: absent sialyl lewisX *defective rolling
Type 3 LAD: defective kindlin-3 which activates integrin *defective adhesion
Which cells secrete cytokines that activate neutrophils>
Th17
neutrophil granules in chediak-higashi syndrome vs specific granule deficiency
CHS - 1* granules enlarged
specific granule deficiency - 2* granules absent
what is FCepisolonRI expressed on?
mast cells
basophils
NOT EOS
what is KIT
receptor for cytokine stem cell factor
critical growth factor of mast cells and target of imatinib
encoded by photo-oncogene c-KIT
how does IgE bind to FCepisilonRI
main proteins in mast cell signaling
binds via alpha chain
proteins: lyn, fyn, syk
where does Xolair bind?
CH3/Fc (heavy chain) domain of free IgE, at FCepisilonRI binding site
Cepisilon3
do basophils produce tryptase, chimase, carboxypeptidase, heparin, PGD2, and LTB4?
NO
major basic protein
from EOS -> MC and basophils degranulate -> histamine release
can be used to detect recent presence of EOS in tissue
1 cause of marked eosinophilia in US vs worldwide
US: drug reactions
world: parasitic infection
CD14
highly expressed receptor on monocytes and macrophages
binds LPS and activates immune response
component of TLR4
mutation in what gene cause X linked lymphoproliferative syndrome
SH2D1A (encodes SAP protein)
*susceptible to HLH from EBV
langerhans cell histiocytosis
rare malignancy of langerhans cells
s/s: eczema, seborrhea, lytic bone lesions, mutlisystem involvement
dx: biopsy with positive staining for CD1a and CD207 (IDs langerhans cells)
do intestinal epithelial cells present Ag from gut lumen via MHCI or II
MHCII
IL4 and IL13 suppress __, contributing to pathogenesis of AD?
beta defensins
cathelicidin
stem cell factor (SCF)
aka kit ligand
signals through c-kit receptor (CD117)
what do platelets from patients with asthma release?
CCL5
IL33