Summary: IgA Fc receptor, binds IgA and eliminates IgA coated targets
Induces phagocytosis, degranulation, respiratory burst and killing of microorganisms
Positive staining (normal): granulocyte lineage, monocyte lineage, activated eosinophils, alveolar and splenic macrophages
CD90
Summary: May mediate differentiation of hemaoietic stem cells and synaptogenesis in the CNS
Aka Thy-1
CD34+CD90+ cells include hemaoietic stem cells that serve as autologous grafts to replace the bone marrow in patients with malignancies
Positive staining (normal): hemaoietic stem cells, neurons, connective tissue
CD91
Summary: low density lipoprotein receptor-related protein 1; aka alpha-2-macroglobulin receptor
Binds to apoE-containing lipoproteins and mediates chylomicron remnant clearance from the plasma
Also a cell surface receptor for heat shock proteins, Archives 2003;127:178
Positive staining (normal): fibroblasts, dendritic cells, macrophages; liver, brain, lung
Micro images: psoriasis
CDw92
May regulate dendritic cell function
Positive staining (normal): leukocytes, endothelial cells
CD93
Positive staining (normal): granulocytes, monocytes, endothelial cells
Positive staining (disease): AML blasts
CD94
Inhibits NK cell function
Positive staining (normal): NK cells, gamma/delta and alpha/beta T cells
CD95
Summary: activates apoptosis when bound by Fas ligand (FasL, CD178)
Aka FAS, APO-1
Receptor for FasL; when activated, FADD (Fas-associated death domain, a separate protein from Fas) recruits caspase-8 to the receptor; resulting “death-inducing signaling complex” performs caspase-8 proteolytic activation; activated caspase-8 initiates a subsequent cascade of caspases mediating apoptosis
Fas-FasL system mediates extra-thymic self-tolerance (FasL+ cells induce apoptosis in infiltrating Fas+ lymphocytes), T cell mediated cytotoxicity, halting of immune response
Mutations cause loss of regulation of B lymphocytes, predisposing to systemic autoimmunity (SLE); Fas mutant mice develop lymphadenopathy and systemic autoimmune disease
Downregulation may cause reduction in CD4+ T cells in HIV, Archives 2002;126:28
Positive staining (normal): activated B cells, activated T cells (initially extra but nonfunctional Fas), resting T cells (low levels), breast, vaginal, endometrial and ovarian epithelium
Positive staining (disease): thyroid epithelial cells in Hashimoto’s thyroiditis, Reed-Sternberg cells in classic Hodgkin’s lymphoma, AJSP 2001;25:388, Barrett’s esophagus, esophageal adenocarcinoma
Negative staining: normal gastric mucosa
References: GeneCards
Images: Apoptosis pathway chart, Fas expression in lymph nodes of HIV patients
Micro images (Hum Path subscribers): benign tamoxifen-exposed postmenopausal endometrium
CD96
Aka T cell activated increased late expression (TACTILE)
May be involved in adhesion of activated T and NK cells late in immune response
Positive staining (normal): activated T cells
CD97
Binds to CD55 and G protein-coupled receptors
May be involved in cell adhesion and signaling processes early after leukocyte activation
Highly expressed at sites of inflammation in skin, lung and rheumatoid arthritis.
Positive staining (normal): activated T > B cells, monocytes/macrophages, dendritic cells, granulocytes
Positive staining (tumors): thyroid carcinomas, GI adenocarcinomas
Negative staining: microglia
CD98
Amino acid transporter, aka SLC3A2
Associated with function of pancreatic islet cells, thyroid C cells and parathyroid cells
Also involved in normal and neoplastic cell growth
Upregulated on leukocytes in inflammatory lesions, strongly expressed by neoplastic cells.
Positive staining (normal): broad
Positive staining (tumors): transformed cells
CD99
Summary: relatively non-specific marker for Ewing’s sarcoma and T cell lymphoma
Aka MIC2, O13
Associated with EWS-FLI1 fusion transcript, t(11;22)(q24;q12), causing FLI-1 protein overexpression
Interpretation: distinct membranous staining for Ewings/PNET; cylasmic for other tumors
Positive staining (normal): ovarian granulosa cells, pancreatic islets, infant thymus, Sertoli cells
Positive staining (tumors): T cell acute lymphoblastic lymphoma, calcifying aponeurotic fibroma, Ewing's sarcoma/PNET (95% sensitive), gastrointestinal stromal tumor, intraabdominal desmoplastic small round cell tumor (23-35%), leukemia cutis, nuchal fibromas, perineuroma (myxoid sclerosing type), rhabdomyosarcoma (membranous staining, AJSP 2002;26:1175), sinonasal undifferentiated carcinoma (rare, AJSP 2001;25:156), small cell carcinomas of lung (rare), solitary fibrous tumor, synovial sarcoma (poorly differentiated, monophasic and myxoid types), Wilm’s tumors (some), endometrial stromal tumors with sex cord differentiation
Negative staining: adult neuroblastoma
Micro images: GIST vs. solitary fibrous tumor
Micro images (AJSP subscribers): PNET of pancreas (figure B), Ewings sarcoma/PNET of kidney#1, #2, sinonasal undifferentiated carcinoma
Micro images (Hum Path subscribers): Ewings sarcoma of esophagus
Micro images (Mod Path subscribers): PNET of dura (figure C)
Reference: Archives 2002;126:1189, AJSP 2002;26:1040, Mod Path 2002;15:673
CD100
Increases CD45 induced T cell adhesion; down-regulates B cell expression of CD23
Positive staining (normal): most hemopoietic cells, increased expression after T cell activation
Negative staining: immature bone marrow cells
CD101
Positive staining (normal): monocytes, granulocytes, dendritic cells, activated T lymphocytes
CD102
Aka ICAM-2
Provides costimulatory signal in immune response; important in lymphocyte recirculation
Positive staining (normal): resting lymphocytes, monocytes, platelets, vascular endothelial cells
Positive staining (tumors): some lymphomas
Negative staining: neutrophils
CD103
Aka human mucosal lymphocyte antigen 1, integrin alphaE chain
Useful marker for intraepithelial lymphocytes (normal or tumoral), although also expressed by activated lymphocytes
Positive staining (normal): intraepithelial lymphocytes, some lamina propria T lymphocytes in the intestine
Positive staining (tumors): hairy cell leukemia; AML (many), enteropathy-associated T cell lymphomas, adult HTLV-1 associated T cell leukemia
CD104
Aka integrin beta 4 chain
Positive staining (normal): thymocytes
CD105
Aka endoglin
Regulatory component of TGF-beta receptor complex; mediates cellular response to TGF-beta 1
Target gene for Hereditary Hemorrhagic Telangiectasia type I; each affected family has a different mutation
Positive staining (normal): activated monocytes, endothelial cells; erythroid precursors in marrow; syncytiotrophoblasts, cytotrophoblasts in first trimester (transient expression)
CD106
Aka VCAM-1; alpha 4 beta 1 ligand
Adhesion molecular found in stimulated endothelium that plays a role in migration of white bloo--
CD107a
Also called lysosome-associated membrane protein 1 (LAMP-1)
Enclodes a membrane glycoprotein that provides selectins with carbohydrate ligands
May play a role in tumor metastasis, as highly metastatic tumor cells express more lamp molecules on their cell surface
Present in lysosomes, degranulated platelets, activated neutrophils, T cells and endothelium
References: (OMIM) - 153330
CD107b
Also called lysosome-associated membrane protein 2 (LAMP-2)
Enclodes a membrane glycoprotein that provides selectins with carbohydrate ligands
May play a role in tumor metastasis, as highly metastatic tumor cells express more lamp molecules on their cell surface
May protect or maintain lysosomes
Defects cause various glycogen storage diseases
Present in lysosomes, degranulated platelets, weakly in activated neutrophils and endothelium
References: (OMIM) - 309060
CD108
Also called SEMA7A, John-Milton-Hagen (JMH) human blood group antigen
A semaphorin
Potent stimulator of cytokine production, chemotaxis and superoxide release in monocytes; may have adhesion function; may modulate immune response
Autoantibodies are common, and associated with loss of JMH antigen expression
Deficiency may be associated with a rare form of congenital dyserythropoietic anemia
Expressed on erythrocytes, lymphoblasts, lymphocytes (low levels)
