First Aid, Chapter 4 Laboratory Tests, Cell Surface Markers and Receptors Flashcards
What are the roles of cell surface molecules?
Cell surface makers play a role in the following:
- Recognition
- Adhesion
- Signal transduction
- Cell recognition in research
What do cluster of differentiation markers do? What are their roles?
Cluster of differentiation (CD) markers signal the presence of cell surface proteins, which leads to the identification and characterization of leukocytes.
CD markers have multiple roles:
-Cell identification
-Antigen or cytokine receptors
What are other names for CD? Where are they expressed? What is the structure? What is its function?
Other names:
Expression:
Structure:
Function:
What are other names for CD1? Where are they expressed? What is the structure? What is its function?
Other names:
Five subsets CD1a– e CD1a (Leu6)
Expression: APCs
Structure: Member of Ig superfamily, binds to β2microglobuli
Function: Presents autologous and bacterial lipid antigen to T lymphocytes
What are other names for CD2? Where are they expressed? What is the structure? What is its function?
Other names: LFA2, E rosette receptor Expression: Early T and NK cells Structure: Ig superfamily Function: Binds LFA3 (CD58) on APC Activates T lymphocytes Induces cytokine production Mediates adhesion between T lymphocytes and APCs Inhibits apoptosis of activated T lymphocytes
Where are CD3 expressed? What is the structure? What is its function?
Expression: T lymphocytes (plasma cells, macrophage) Not found on NK cells
Structure: Ig superfamily δ, ε, γ, and ζ chains
Function: Required for TCR expression and signal transduction δ, ε, γ, and ζ defects causes T-B+NK+ SCID OKT3—monoclonal antibody clone, which recognizes human CD3 in the treatment of solid-organ transplant rejection and acute Tlymphocyte ALL. Leads to activation then apoptosis of T-cells causing immunosuppression
What are other names for CD14? Where are they expressed? What is the structure? What is its function?
Other names: LPS receptor
Expression: Macrophages and monocytes
Structure: Pattern recognition receptor
Function: Detects lipoteichoic acid on GPB, and LPS on GNB, mycobacteria, and fungi Mediates IL-12 and IFNγ production
What are other names for CD16 (the A receptor)? Where are they expressed? What is its function?
Other names: FcγRIIIA Low-affinity IgGR Expression: NK cells, granulocytes, and macrophages Function: ADCC
What are other names for CD16 (the B receptor)? Where are they expressed? What is the structure? What is its function?
Other names: FcγRIIIB Low-affinity IgGR
Expression: Neutrophils
Structure: Most common IgG FcR
Function: Phagocytosis
What are other names for CD18? Where are they expressed? What is the structure? What is its function?
Other names: B2 chain
Expression: Neutrophils, macrophages, monocytes, and NK cells
Structure: Combines with αL: LFA1, (CD11aCD18), αM: MAC-1 and CR3 (CD11bCD18), αX: p150,95 and CR4 (CD11cCD18)
Function:
Adhesion and signaling Defect in common β chain responsible for LAD1
Where are CD19 expressed? What is the structure? What is its function?
Expression: Pre B lymphocytes, B lymphocytes, and follicular dendritic cells
Structure: Coreceptor with CD21
Function: B-lymphocyte ontogeny and activation
What are other names for CD20? Where are they expressed? What is the structure? What is its function?
Other names: L26 MS4A1
Expression:
On B lymphocytes after CD19 expression Follicular dendritic cells
Structure: Transmembra ne phosphoprotei n—forms structure like ion channel— Ca influx
Function: B lymphocyte activation and signaling
What are other names for CD21? Where are they expressed? What is its function?
Other names: CR2 C3d receptor EBV receptor
Expression: Mature B lymphocytes and follicular dendritic cells
Function: Binds EBV, HHV8, C3d, and CD23 High levels of CD21lo B cells are associated with CVID class Ia
What are other names for CD22? Where are they expressed? What is its function?
Other names: B-lymphocyte cell adhesion molecule (BLCAM)
Expression: B lymphocytes
Function: Inhibits B signaling
What are other names for CD23? Where are they expressed? What is the structure? What is its function?
Other names: Low affinity IgE receptor FCeRII
Expression: activated, mature B lymphocytes and follicular dendritic cells
Structure: Type C lectin
Function: B-lymphocyte ontogeny and activation
Which cell marker of the following is not found on NK cells: CD3, CD16, CD56?
CD3
What are other names for CD25? Where are they expressed? What is its function?
Other names: IL-2 Ra chain
Expression: Activated B and T lymphocytes
Function: Suppress self-reactive T lymphocytes. prevent CTL cytolysis, and suppress NK cells. Elevated in HLH
What are other names for CD27? Where are they expressed? What is the structure? What is its function?
Other names: TNFRSF7
Expression: Memory B lymphocytes
Structure: TNF receptor superfamily
Function: B-lymphocyte activation and Ig production Memory B lymphocytes: CD27+ Memory T lymphocytes: CD27-
What are other names for CD31? Where are they expressed? What is the structure? What is its function?
Other names: PECAM-1
Expression: Endothelial cells, platelets, monocytes, and macrophage
Structure: Ig Superfamily
Function: Cell adhesion and bind CD38
What are other names for CD32? Where are they expressed? What is its function?
Other names: FcγRII (types a, b, and c)
Expression: WBCs
Function: Binds Fc of IgG immune complexes to remove foreign antigens Binding of FcγRIIb proposed mechanism of IVIG
Where is CD34 expressed? What is its function?
Expression: Adult hematopoietic stem cells
Function: Adhesion molecule and binds CD62L (L selectin)
What are other names for CD35? Where are they expressed? What is its function?
Other names: CR1 C3b and C4b receptor
Expression: WBCs
Function: Binds immune complexes coated with C3b and C4b Cofactor for factor Imediated cleavage
What are other names for CD40? Where are they expressed? What is its function?
Other names: TNFRSF5
Expression: APCs
Function: T–lymphocyte-dependent Ig switching Expressed on B cells Defective in HIGM3
Where is CD44 expressed? What is the structure of CD44? What is its function?
Expression: Activated B and T lymphocytes
Structure: Surface glycoprotein
Function: Cell adhesion
What are other names for CD45? Where are they expressed? What is the structure? What is its function?
Other names: Leukocyte common antigen (LCA)
Expression: CD45RA naïve T lymphocytes and CD45RO memory or activated T lymphocytes
Structure: Protein tyrosine phosphatase
Function:
Defective in T-B+NK- SCID
What are other names for CD46? Where are they expressed? What is its function?
Other names: Membrane cofactor protein (MCP)
Expression: All cells (no RBC)
Function: Cofactor for factor I-mediated cleavage Adenovirus receptor
What are other names for CD49? Where are they expressed? What is its function?
Other names: Very late antigen (VLA a–f)
Expression: WBCs
Function: Receptors for fibronectin, VCAM, and others in cell adhesion
What are other names for CD52? Where are they expressed? What is its function?
Other names: CAMPATH-1 antigen
Expression: Mature lymphocytes
Function: Target for alemtuzumab (Campath)—monoclonal antibody used in the treatment of CLL
What are other names for CD54? Where are they expressed? What is its function?
Other names: ICAM-1
Expression: WBCs
Function: Binds LFA-1 (CD50). Receptor for rhinovirus.
What are other names for CD55? Where are they expressed? What is its function?
Other names: Decayaccelerating factor (DAF)
Expression: Hematopoietic cells, epithelial cells, and cell matrix
Function: Binds C3bBb and C4b2a to accelerate decay of C3 convertase Deficient in paroxysmal nocturnal hemoglobinuria
What are other names for CD58? Where are they expressed? What is its function?
Other names: LFA-3
Expression: WBCs
Function: Binds CD2 and adhesion
What are other names for CD59? Where are they expressed? What is its function?
Other names: Protectin Complement regulatory molecule
Expression: All cells
Function: Inhibits MAC formation by binding to C8 or C9
What are other names for CD62E? Where are they expressed? What is its function?
Other names: E selectin, ELAM1, SELE
Expression: Endothelium
Function: Ligand for CD15s, CD44, and CD162 Leukocyte rolling Defective in LAD2
What are other names for CD62L? Where are they expressed? What is its function?
Other names: LECAM-1, SELL, L Selectin
Expression: B and T lymphocytes, and NK cells
Function: Lymphocyte homing to HEV of LN Binds CD34, CD15s,and MAdCAM-1
What are other names for CD62P? Where are they expressed? What is its function?
Other names: PADGEM, SELP, P Selectin
Expression: Platelets Activated endothelial cells (membranes of Weibel-Palade bodies)
Function: Binds CD162, rolling on activated endothelial cells Defective in LAD2
What are other names for CD64? Where are they expressed? What is its function?
Other names: FcγRI High affinity IgG receptor
Expression: APC (macrophages, neutrophils, eos)
Function: ADCC
What are other names for CD95? Where are they expressed? What is its function?
Other names: Fas Apo-1 TNFRSF6
Expression: Activated B and T lymphocytes
Function: Apoptosis when ligated by FasL Defective in ALPS
What are other names for CD106? Where are they expressed? What is its function?
Other names: VCAM-1
Expression: Endothelium, fibroblasts, and respiratory epithelium
Function: VLA-4 (α4:β1) α4β7 (act-1, LPAM-1)
What are other names for CD154? Where are they expressed? What is its function?
Other names: CD40L TRAP
Expression: T lymphocytes
Function: Regulates B lymphocyte function Expressed on T-cells Defective in XHIGM (X-linked hyper-IgM)
What is the CD marker for FcγRII?
CD32
What is the CD marker for CD40L expressed on T-cells?
CD154
What are other names for CD158? Where are they expressed? What is its function?
Other names: KIR (KIR2DL, NKG2A, and others)
Expression: NK and T
Function: Binds HLA class I and inhibits NK or T cell cytotoxicity
What are other names for CD159? Where are they expressed? What is its function?
Other names: NKG2A
Expression: NK
Function: Modulates NK killing
What are other names for CD162? Where are they expressed? What is its function?
Other names: P-selectin glycoprotein ligand-1 (PSGL-1)
Expression: Myeloid cells, Activated T lymphocytes
Function: Adhesion with endothelial cells
What are other names for CD178? Where are they expressed? What is its function?
Other names: CD95 ligand, FasL
Expression: Activated cytotoxic T lymphocytes
Function: Apoptosis Fas-expressing cells
What are the other names for CD4?
OKT4, CD223
What cells is CD4 expressed on?
T Helper cells Monocytes Phagocytes Dendritic cells Langerhans cells Thymocytes
What is the % T-lymphocyte expression of CD4?
65%
What is the structure of CD4?
Ig Superfamily, Monomer
What is the domain-binding MHC of CD4?
beta-2
What are the function or biological properties of CD4?
- MHC-restricted antigen induced T-lymphocyte activation
- HIV receptor on T lymphocytes
- Downregulated by HIV nef protein during infection
What is another name for CD8?
OKT8
What is the cell expression of CD8?
Cytotoxic T lymphocytes Cortical thymocytes
NK cells
Dendritic cells
What is the % T-lymphocyte expression of CD8?
35%
What is the domain binding MHC of CD8?
alpha 3
What are the functions or biological properties of CD8?
MHC-restricted antigen-induced cytosis
Where is the CD28 receptor located?
T lymphocytes
What are the ligands for CD28? Where are they located? What is the function?
ligands: CD80 (B71), CD86 (B72)
Location: APCs (DC, macrophage, B lymphocytes)
Function: Costimulation or activation
Where is CTLA4 (CD152) located? What are its ligands? Where are the ligands located? What is its function?
Location: Activated T lymphocytes
Ligands: CD80 (B71), CD86 (B72)
Location of ligands: APCs (DC, macrophage, B lymphocyte)
Function: costimulation or inhibition
Where is ICOS located? What is the ligand? Where is the ligand located? What is its function?
Location: T lymphocytes
B-7 family ligand: ICOS-L
Location of ligand: APCs (DC, macrophage, B lymphocytes)
Function: costiumation
Where are the B7-H1 (PD-L1) and B7-DC receptor located? What is its B-7 Family ligand? What is the location of the ligand? What is its function?
Location: DCs, macrophages, B lymphocytes
B-7 Family ligand: PD1
Location of ligand: B lymph, T lymph
Function: Inhibition
What are the other names of CD16? What cells is it found on? What is the function? What is the ligand?
Other name (1): FcyRIIIA
Cell: NK cells
Function: ADCC
Ligand: IgG low affinity
Other name (2): FcyRIIIB
Cell: Neutrophils
Function: Phagocytosis
Ligand: IgG low affinity
What are the other names of CD32? What cells is it found on? What is the function? What is the ligand?
Other name (1): FcyRIIB
Cell: B lymphocytes, dendritic cells, macrophages
Function:
Feedback inhibition of B cells, dendritic cells, macrophages
Ligand: IgG low affinity
Other name (2): FcyRIIA
Cell: Macrophage Neutrophils Eosinophils Platelets
Function: Phagocytosis
Ligand: IgG low affinity
What are the other names of CD64? What cells is it found on? What is the function? What is the ligand?
Other name: FcyRI
Cell: macrophages, neutrophils, eosinophils
Function: phagocytosis
Ligand: High affinity IgG (IgG1, IgG3 and monomeric IgG)
What cells is FceRI located on? What is its function? What is its ligand?
Cells: Mast cells, basophils, eosinophils, dendritic cells
Function: Degranulation, antigen uptake
Ligand: Monomeric IgE high affinity
What cells is FceRII (CD23) located on? What is its function? What is its ligand?
Cells: B lymphocytes, eosinophils
Function: unknown
Ligand: IgE, low affinity
Where is the TNF R1/p55 receptor found? What is its function? What is the ligand?
Cell: most cells
Function: apoptosis
Ligand: TNF (membrane bound and trimeric soluble forms)
Where is the TNFR2/p75 receptor found? What is the ligand?
Cell: immune cells
Ligand: TNF (membrane-bound homotrimer form)
Where is the LT-BR receptor found? What is its function? What is the ligand?
Cell: Epithelial cell Myeloid cells (Not B and T lymphocytes)
Function: apoptosis, IL-8 release
Ligand: TRAF, lymphotoxin
Where is the Fas receptor found? What is its function? What is the ligand?
Cells: Activated B and T lymphocytes
Function: Apoptosis
Ligand: FasL
Where is the CD40/CD134 receptor found? What is its function? What is the ligand?
Cell: activated T lymphocytes
Function: Second signal
Ligand: CD40L, TRAF
Where is the OX40 ligand found? What is its function? What is the ligand?
Cell: Activate T lymphocytes
Function: Implicated in cytokine storm of H1N1
Ligand: TRAF
Where is RANK found? What is its function? What is the ligand?
Cell: Osteoclasts, dendritic cells, some macrophages
Function: activation of osteoclasts
Ligand: RANK ligand, TRAF
Which PID is associated with defective CD40 and which is associated with defective CD40L?
Defective CD40 = HIGM3 and defective CD40L = XHIGM
What does the activating mutation of CXCR4 cause?
Phagocytic defect, WHIM (or wart, hypogammaglobulinemi a, infection, and myelokathexis) syndrome.
What are the HIV coreceptors?
CCR5 adn CXCR4
How does complement bridge innate and cell-mediated immunity?
Innate responses generate complement components, which bind to receptors on WBCs. Ligand-receptor interaction leads to signaling pathways, cytokine release, and engagement of cell-mediated immunity.
What is the most potent complement receptor? What does it bind? What does deficiency of the complement that binds to this receptor lead to?
CR3 is the most potent complement receptor and binds iC3b, which is an opsonin like Ig. A hereditary deficiency of C3 will lead to defective phagocytosis of encapsulated bacteria and will present with autoimmune disease and repeated infections.
What is the other name for CR1? What cells is it found on? What is its function? What is its ligand?
Other names: CD35
Cells: Monocytes Neutrophils T and B lymphocytes Eosinophils RBCs
Function: Phagocytosis
Ligands: C3b, C4b, iC3b
What is the other name for CR2? What cells is it found on? What is its function? What is its ligand?
Other names: CD21
Cells: B lymphocytes, FDC
Function: B-lymphocytes activation, EBV receptor
Ligand: C3d, iC3b, c3dg
What is the other name for CR3? What cells is it found on? What is its function? What is its ligand?
Other names: Mac-1, CD11b/CD18
Cells: Monocytes, Neutrophils, NK cells
Function: Phagocytosis, adhesion
Ligand: iC3b, ICAM-1, bacteria
What is the other name for CR4? What cells is it found on? What is its function? What is its ligand?
Other names: p150.95, Cd11c/CD18
Cells: Monocytes, Neutrophils, NK cells
Function: Phagocytosis
Ligand: iC3b, ICAM-3
What is the other name for CRIg? What cells is it found on? What is its function? What is its ligand?
Other names: Complement receptor of the immunoglobulin family
Cells: Macrophage in liver (kupffer cells)
Function: Phagocytosis
Ligand: C3b, iC3b, inhibits alternatie pathway convertases
What cells is CCR3 found on? What is its function? What is its ligand?
Cells: Macrophage Eosinophils Basophils Th1 Th2 Airway epithelial cells
Function: Implicated in allergic disease
Ligand: CCL11 (eotaxin-1) CCL5 (RANTES) CCL7 (MCP-3) CCL8 (MCP2) CCL13 (MCP4) CCL26 (eotaxin-3)
What cells is CCR4 found on? What is its function? What is its ligand?
Cells:
CD4 T lymphocytes DCs Basophil Macrophage Platelets
Function: T-lymphocyte trafficking
Ligands: CCL17 (TARC) CCL22 (MDC)
What cells is CCR5 found on? What is its function? What is its ligand?
Cells: T lymphocytes Monocytes
Function: Cell trafficking. HIV coreceptor
Ligand: CCL3 (MIP 1α) CCL4 (MIP 1β) CCL5 (RANTES) CCL11 (eotaxin-1) CCL14 (HHC-1) CCL16 (HHC-4)
What cells is CCR7 found on? What is its function? What is its ligand?
Cells: T lymphocytes, DCs (EBV-infected B lymphocytes)
Function: Naive T lymphocyte and DC trafficking to LN
Ligand: CCL19 (MIP-3B/ELC) CCL21 (SLC)
What cells is CXCR4 found on? What is its function? What is its ligand?
Cells: Mature blood cells, blood progenitor cells, epithelial cells
Function: B lymphocyte development HIV co-receptor
Ligand: CXCL12 (SDF-1)
What cells is CXCR5 found on? What is its function? What is its ligand?
Cells: B lymphocytes
Function: Home to B-T junction in LN
Ligand: CXCL13 (BCA-1)
What is the function of XCR1? What is its ligand?
Function: T and NK cells recruitment
Ligand: XCL1 (Lymphotactin)
What is the function of CX3CRI? What is its ligand?
Function: Recruits T, NK, and macrophages. Activates CTL and NK.
Ligand: CX3CL1 (factalkine)
What do NK cells lack expression of?
CD3 and TCR
Which complement receptor is also known as CD11c/CD18?
CR4
What lymphocyte cell surface marker is present on memory B cells and absent on memory T cells?
CD27
Which cells express MHC1?
All nucleated cells
What cells express MHCI and MHCII?
B lymphocytes
What cells express MHC II?
CD4 T cells
What surface marker do switched memory B lymphocytes lose expression of?
Surface IgD
What surface marker mediates homing to skin?
CLA-1 on T lymphocytes mediates homing to skin
What surface marker mediates homing in on colonic tissue? How?
Α4β7 on T lymphocytes mediate homing in on colonic tissue by binding to MAdCAM-1.
Where do naive lymphocytes home to? Where do activate lymphocytes home to?
Naïve lymphocytes home in preferentially on secondary lymphoid organs such as lymph nodes, spleen, and Peyer’s patches. This ensures a maximal probability of a diverse TCR repertoire coming in contact with unique antigens. Once activated, lymphocytes enter the circulation, whereby they encounter antigen residing in different tissues to elicit a strong memory response.
What are the cell surface markers on naive B lymphocytes?
IgM/IgD
CXCR5
What are the cell surface markers on naive T lymphocytes?
L selectin
CCR7
CD45Ra
What are the cell surface markers on naive NK cells?
CD2
What are the cell surface markers on activated B lymphocytes?
IgA
IgE
IgG
CD27
What are the cell surface markers on activated T lymphocytes?
CD40L (CD154) CD28 CTLA4 CD 25 CD44 CD45RO CXCR3 CCR5 HLADR
What are the cell surface markers on memory B lymphocytes?
IgG
IgA
IgE
CD27+
What are the cell surface markers on memory B lymphocytes?
CCR7 L-Selectin (CD62L) IL-7R IL-15 (CD8 only) CD44 CD45RO MHCI CD27-
What is the inhibitory cell surface receptor for B lymphocytes?
CD22
What are the activating cell surface receptors for T lymphocytes?
IL-12 Rβ
IL-18 R
What are the inhibitory receptors for NK cells?
NKG2A (CD94)
ILT-2
KIR
What are the activating receptors for NK cells?
CD16 NCR KIR2DS CD92/NKG2C NKG2D
What is the cell surface marker for monocytes or macrophages?
FcyR
What is the cell surface marker for endothelial cells?
Selectins (CD62E)
What is the cell surface marker for NKT cells?
Vα24-Jα18
Vβ11
What is the cell surface marker for mast cells?
CD117 (c-KIT)
What are dendritic cells divided into? What are the roles?
-Conventional dendritic cells (myeloid, lymphoid)
o Act as antigen-presenting cells
-Plasmacytoid dendritic cells
o Produce IFNα
Why are cell surface markers so important? How does pathogenesis occur from defects?
Cell surface markers play an important role in cell function and survival. Clinical disease results as a defect in expression or in function, or by opportunistic use by a pathogenic organism.
Are CD1a-3, CD11c, and CD11b present on conventional dendritic cells? plasmacytoid dendritic cells?
CD1a-3: high levels on conventional dendritic cells, negative on plasmacytoid dendritic cells
CD11c: high levels on conventional dendritic cells, negative on plasmacytoid dendritic cells
CD11b: variable levels on conventional dendritic cells, negative on plasmacytoid dendritic cells
Which TLRs are present on conventional vs. plasmacytoid dendritic cells?
Conventional: TLR4, 5, 8
Plasmacytoid: TLR 7
Is CD80/CD86 present on conventional dendritic cells?
Inducible
Is IL T7 (CD85g) present on convetional dendritic cells? Plasmacytoid dendritic cells?
Conventional DCs: Negative
Plasmacytoid: High
Is CD33 (Siglec-3) present on conventional dendritic cells?
High
Is CD209 (DC sign) present on conventional dendritic cells?
High
Is CMKLR1 present on convetional and plasmacytoid DCs?
Conventional DCs: high
Plasmacytoid DCs: in vitro expression
Is TCL1 present on conventional DCs? Plasmacytoid DCs?
Conventional DCs: negative
Plasmacytoid DCs: high