Flashcards in Ch 2 Cells involved in Immune Responses Deck (60):
what are the pro B cell surface markers?
CD 43, CD19, CD20
what are the pre B cell surface markers?
CD 43, CD19, CD20, pre-BCR, cytoplasmic u chain
what are the surface markers for immature naive B cells?
CD19, CD20, IgM
what are the surface markers for a mature naive B cell?
CD19, CD20, IgM, IgD
what stage of B cell development does RAG and TdT perform their actions?
what stage of B cell development hosts heavy chain rearrangement? Light chain?
Pro; pre (k or lambda)
what chemokine is expressed on naive mature B cells and what attracts that to the lymph node?
CXCL5 on B cells; CXCL13 gradient created by follicular DC in lymph node follicles
where does class switching and somatic hypermutation take place?
germinal centers of lymph node follicles
what survival factor maintains plasma cells?
what survival factor maintains memory B cells?
what process determines if an Ig is membrane bound or secreted?
alternative splicing of primary mRNA transcript; transmembrane and cytoplasmic exons remain in for membrane-bound; spliced out for secreted
what are the survival signals for B cells in the periphery and their receptors?
BAFF, BLYSS, APRIL. Receptors: BR3, TACI (early on), BCMA (later)
what are B1 cells?
innate; T cell independent; produce natural antibodies of low affinity that respond to microbes and lipids; found in peritoneal cavity and fetus
what are marginal zone B cells?
T cell independent; first responders to polysaccharide antigens (develop by 2 years of age...why infants have poor polysaccharide responses)
what are B2 cells?
conventional or follicular B cells, including memory B cells and plasma cells; adaptive; T cell dependent; protein antigens
what is the name of the molecule that commits T cells to develop?
what chemokine is expressed by naive T cells and what is the chemokine gradient in nodes?
CCR7 directed by CCL19/21 in perifollicular T cell zone (produced by stromal cells in T cell zone); DC in T cell zone express CCL19 and CCL18 (binds to CCR3 on naive T cells)
what are markers of central memory T cells?
CD45RA-, CD27+, CCR7+, CD62L+; effector memory T cells lack all aforementioned markers and home to the peripheral sites
expression of what draws T cells out of lymph node and back into circulation?
SIP1 via sphingosine-1-phosphate concentration gradient; SIP1 is internalized if T cell binds cognate MHC
describe intrinsic pathway of lymphocyte apoptosis
intracellular stress-> Bim -> Bax/BAK-> cytochrome C-> caspase 9 -> caspase 3; Bcl-2 and Bcl-XL inhibits Bax/BAK
desribe extrinsic pathway of lymphocyte apoptosis
lethal ligands and/or repeated lymphocyte activation leads to binding FasL (CD178) to Fas (CD95) -> caspase 8 -> caspase 3
which cell is CD14++; CD16-
monocytes; CD14 is part of TLR4 and LPS receptor
what are chemokines that attract monocytes to lungs?
CCL2, 3, 4 & 5
what do macrophages typically express on their surface
CD14, CD16, CD11b/18 (Mac-1), CD33 and CD 36
highly expressed on monocytes and macrophages; part of TLR4; binds LPS and activates innate immune responses
what cytokine promotes granuloma formation and what cell secretes it?
TNFa; secreted by macrophages
what disease process leads to uncontrolled activation of macrophages?
hemophagocytic lymphohistiocytosis (HLH)
what are criteria for HLH?
fever, splenomegaly, elevated ferritin (>500), cytopenia of >2 cell lines, hypertriglyceridemia or hypofibrinogenemia, hemophagocytosis on smear/bone marow, hepatitis, low NK cells, soluble CD25 (IL2 R) >2400
what virus leads to fatal HLH? and in what immunodeficiency? What is the mutation?
EBV leads to fatal HLH in boys with XLP; mutation is SH2D1A-> encodes SAP protein
what are distinguishing markers for plasmacytoid DCs?
CD 123 (lack CD11c); conventional have CD11c, CD1, CD13, CD14; Langerhans and insterstitial dendritic cells also epxress CD11c
what is CD1? what chromosome is it mapped to?
MHC-like molecules that present non-peptide antigens (lipids) to T cells; maps to MHC locus on chromosome 15
what immunohistochemical staining would identify Langerhans histiocytosis?
True or False: FCeR1 is expressed on mast cells, basophils and eosinophils?
False; not expressed on eos
which cell produces PGD2 when activated? and what is the function?
mast cells (not basos or eos); bronchocontriction; vasodilation and increased permeability; LTB4 is also unique to mast cells and is a neutrophil and T cell chemoattractant
which cell produces PGE2 when activated?
eos (not basos or mast cells); opposite effect of PGD2; inhibits 5 lipoxygenase activation
what lipid mediators are common to mast cells, basos and eos?
LTC4, LTD4, LTE4; also PAF; thromboxane is made by mast cells and eos, but not basos
what is c-kit? what is its receptor? what is a pharmacologic target for this?
c-kit is a proto-oncogene; binds kit receptor; imatinib targets
what are the mast cell preformed mediators
histamine, tryptase, chymase, carboxypeptidase, cathepsin G
where can you find MCtc?
think connective tissue; skin, intestinal and respiratory SUBmucosa, conjunctiva, blood vessels, synovium
where can you find MCt?
alveolar and GI mucosa
what is the low-affinity IgE receptor?
FcERII; CD 23
what allergen has been shown to cleave CD23?
Der-p-1; cleaves from cell surface which serves to increase the production of allergen specific IgE
what % reduction is needed in IgE to see clinical efficacy with omalizumab? What is omalizumab?
96% reduction (may take many months; IgG to IgE
describe the FCeRI complex?
Can exist as tetramer (a (binds the Fc portion of IgE), b and 2 y chains (main signaling component) or trimer (a and 2 y chains)
what is a key receptor that distinguishes MCtc from MCt?
C5a receptor (CD88)
what is an important growth factor for basophils?
IL-3 (binds to IL-3R aka CD123)
what are the markers measured for basophil activation test?
CD203c; CD 63
what is the transcription factor for eos development and what brings them to tissue?
GATA1; CCL-5 (Rantes) and CCL11 (eotaxin1) and CCL24 (eotaxin2)
what factors are known to suppress eosinophilia?
bacterial and viral infections (except HIV), fever and steroids
what are neutrophil attractants?
CXCL8 (IL8) and LTB4 (also T cell chemotaxis)
which granules are enlarged in Chediak Higashi?
primary (azurophilic); contain MPO, defensins, cathelidins, cathepsin
what aspect of platelets are targeted by antibodies in ITP? TTP?
what are the layers of the epidermis?
Basale, Spinosum, Granulosum, Lucidum, Corneum; Mnemonic: Before Signing Get Legal Counsel
what are key cytokines secreted by epithelial cells?
TSLP, IL33, GM-CSF, IL-25
what is the target antigen for pemphigus vulgaris? pemphigus foliaceous? Location?
IgG and IgM targeting Desmoglein 3; IgG to desmoglein 1; located in desmosome
what is the target antigen for bullous pemphigoid, including pemphigoid gestationis?
IgG (linear at BMZ) to BP 230 or BP180; located in hemidesmosome
what is the target antigen for dermatitis herpetiformis? what disease process?
granular IgA to transglutaminase; celiac (linear IgA is seen in IgA bullous dermatoses)
what is the CD nomenclature, adhesion molecule location, ligand and ligand location for E-, P- and L-selectin?
CD62E (endothelium), P (endothelium), L (leukocytes); Ligand for E and P = sialyl lewis x on leukocytes; L selectin binds Sialyl Lewis X on GlyCam1/MadCam1 on HEVs
what are the 3 key integrins for transmigration of leukocytes? what do they bind and where?
Integrins are all expressed on leukocytes; LFA1 (CD11aCD18) binds to ICAMs in endothelium; VLA4 binds to VCAMs in endothelium; A4b7 binds to MadCam1 in Gut epithelium