You searched for: Proteins and Peptides

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Interleukin 7 (IL-7) is a member of the type I cytokine family that is critical for T and B cell development and survival. It is produced by non-hematopoietic cells in the thymus, lymphoid organs, and by bone marrow stromal cells (Lundström et al.). IL-7 binds to a receptor composed of common gamma chain and IL-7Ra (CD127) and signals through the JAK/STAT and PI3K pathways. IL-7 regulates the survival of naïve and memory CD4+ and CD8+ T cells, γδ T cells, NK T cells, innate lymphoid cells, and T regulatory cells (Carrette and Surh), and provides signals to promote survival, proliferation, and differentiation during B cell development (Clark et al.; Corfe and Paige).

Supplier: STEMCELL Technologies

Transforming growth factor (TGF) beta 3 is a member of the TGF-β superfamily and regulates diverse cellular phenotypes. TGF-beta 3 binds to serine-threonine kinase type I and II receptors and activates signal transduction through SMAD2/3 proteins, thus regulating a variety of functions, including cell proliferation, differentiation, wound healing, apoptosis, and metabolism (Massagué; McDowell et al.). TGF-beta 3 enhances glycosaminoglycan production by mesenchymal stromal cells, stimulates scar-free healing, and improves glucose tolerance and phenotypic changes in adipocyte morphology (Hall et al.; Holton et al.). TGF-beta 3 induces proliferation of posterofrontal suture-derived mesenchymal stromal cells, and stimulates expression of fibroblast growth factors 2 and 18 (James et al.). This product is animal component-free.

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Interleukin 1 alpha (IL-1α) is a member of the IL-1 family and a dual-function cytokine. Both the unprocessed precursor and a processed IL-1α protein signal through IL-1 receptor type 1 (IL-1R1). Various cells, including keratinocytes, thymic epithelium, hepatocytes, endothelial cells, fibroblasts, and the epithelial cells of mucous membranes, have high levels of intracellular IL-1α precursor. The precursor is also expressed on the surface of monocytes and B lymphocytes (Netea et al.). IL-1α recruits infiltrating cells to a site of injury during necrosis and plays an important role during processes of sterile inflammation (Cohen et al.; Rider et al.). During hypoxia, IL-1α contributes to angiogenesis (Carmi et al.). Studies in mice show that IL-1α is produced by microglia-like cells after ischemic brain injury, which contributes to the inflammation (Luheshi et al.).

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Lipocalin-2 (LCN2) is a member of the lipocalin superfamily, which share a highly conserved fold containing an eight-stranded antiparallel beta barrel (Flower), and transport small hydrophobic molecules. Playing a role in innate immunity, Lipocalin-2 acts as a potent bacteriostatic reagent by sequestering iron-containing siderophores (Flo et al.). It is mainly expressed in activated neutrophils, but is also secreted by other immune cells in response to infection. Lipocalin-2 has been implicated in multiple cellular processes, such as differentiation (Yang et al.), migration (Du et al.), and apoptosis (Devireddy et al.). In vitro studies suggest that lipocalin-2 is a potential therapeutic target for certain cancers, including colorectal cancer (CRC; Zhang et al.) and chronic lymphocytic leukemia (Bauvois et al.). This protein product contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, lipocalin-2 from STEMCELL comes lyophilised with ≥94% purity, and endotoxin levels are verified to be ≤1.0 EU/μg protein.

Supplier: STEMCELL Technologies

Human Interleukin 4 (IL-4) is important for immune responses to helminth infection as well as in allergic responses (Olpihant et al.). The IL-4 receptor consists of a heterodimer of IL-4Ra and common gamma chain. IL-4 receptor engagement leads to the activation of JAK1/3 and the recruitment of STAT6 and IRS1/2 (Nelms et al.). IL-4 drives immunoglobulin class switching in B cells (to IgE, IgG4), mast cell hyperplasia, mucus production, and the differentiation of naïve T cells into Th2 cells, which produce IL-4, IL-5, IL-10, and IL-13 (Bao et al.; Nelms et al.; Olpihant et al.). In addition to Th2 cells, IL-4 is produced by CD4+ NK T cells, γ/δ T cells, activated basophils, eosinophils, and mast cells. Human IL-4 does not cross-react with mouse cells (Park et al.).

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Interleukin 12 (IL-12p70) is a heterodimeric cytokine composed of p35 and p40 subunits. IL-12 is produced by monocytes, macrophages, dendritic cells, neutrophils and B cells in response to bacterial products and cytokines such as IFN-γ. The IL-12 receptor is expressed on T, NK, and dendritic cells. Upon binding, IL-12 initiates signaling via the JAK/STAT signaling pathway and stimulates NK, B, and T cells to produce IFN-γ (Watford et al.). It also regulates cytokine synthesis, proliferation of T and NK cells, and stimulates differentiation of CD4+ and CD8+ T cells (Germann and Rüde). Mice that are deficient in IL-12 are susceptible to many intracellular pathogens and have impaired IFN-γ secretion, Th1 differentiation and NK cytolytic activity; however, Th2 development and IL-4 production are enhanced (Watford et al.).

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Heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF) is a member of the EGF family (Nishi and Klagsbrun). HBEGF promotes blastocyst adhesion to the uterine wall (Iwamoto and Mekada). It also plays a role in smooth muscle cell hyperplasia and brain injury (Nishi and Klagsburn). HBEGF produced by CD4+ T cells promotes wound healing by stimulating migration and proliferation of keratinocytes, fibroblasts, and smooth muscle cells (Blotnick et al.). It binds to EGFR, ErbB4, ErbB2, and ErbB3, activating the PI3K/AKT signaling cascade (Iwamoto and Mekada). HBEGF is produced in a variety of cells, where it contributes to physiological and pathological processes. HBEGF is overexpressed in ovarian, breast, gastric, colorectal, pancreatic, and endometrial cancers, which likely contributes to pathogenesis (Miyata et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Vascular endothelial growth factor D (VEGF-D) is a member of the VEGF/platelet-derived growth factor (PDGF) family of proteins. VEGF-D is a potent angiogenic factor and promotes lymphangiogenesis, endothelial cell growth and survival, and can affect blood vessel permeability. VEGF-D is expressed in the lung, heart, small intestine, fetal lung, and at lower levels in the pancreas, colon, and skeletal muscle (Otrock et al.; Roy et al.; Stacker et al.; Yamada et al.). VEGF-D is a ligand for VEGF receptors 2 (Flk1) and 3 (Flt4) (Baldwin et al.). VEFGR-3 is highly expressed in lymphatic endothelial cells and is essential for their growth and differentiation (Otrock et al.; Roy et al.). Binding of VEGF-D to neuropilins contributes to VEGFR-3 signaling during lymphangiogenesis, whereas binding to integrin α9β1 promotes endothelial cell adhesion and migration (Roy et al.; Otrock et al.). During embryogenesis, VEGF-D also plays a role in the formation of the venous and lymphatic systems.

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Interleukin 3 (IL-3) is a species-specific pleiotropic cytokine that promotes the survival and proliferation of pluripotent hematopoietic stem cells and lineage-committed progenitor cells and their differentiation into mature cells of most lineages, including basophils, neutrophils, eosinophils, macrophages, dendritic cells, erythrocytes, and megakaryocytes (Yang et al.; Dorssers et al.; Broughton et al.). IL-3 is produced by activated T cells and has a physiological role in inflammation and allergies by promoting the secretion of inflammatory mediators such as histamine, IL-4, and IL-6 by basophils and eosinophils (Broughton et al.). The IL-3 receptor consists of a unique alpha subunit (CD123) and a beta common subunit (βc or CD131) that is shared with the receptors for IL-5 and GM-CSF, and is the principal signal transduction subunit for these cytokines. IL-3 binding to the heterodimeric receptor activates JAK/STAT, MAPK, and PI3K signaling pathways (Woodcock et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Interleukin 19 (IL-19) is a member of the IL-10 cytokine family and is produced by keratinocytes, B cells, and monocytes (Romer et al.; Wolk et al.). Expression of IL-19 can be induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) or lipopolysaccharide (LPS; Gallagher et al.). IL-19 is considered to be a proinflammatory cytokine, as it upregulates IL-6 and tumor necrosis factor alpha (TNF-α; Liao et al. 2002). IL-19 binds the IL-20 receptor complex (IL-20R) which comprises IL-20R alpha and IL-20R beta to activate the STAT3 pathway (Dumoutier et al.). IL-19 also induces T-helper cell differentiation towards a Th2 response, resulting in the production of IL-10 and additional IL-19 (Liao et al. 2002; Liao et al. 2004). IL-19 has been implicated in aging, vascular disease, Type I diabetes, and rheumatoid arthritis.

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Interleukin 2 (IL-2) is a monomeric cytokine that was originally identified as a T cell growth factor (Gaffen and Liu). It binds to heterotrimeric receptors consisting of CD25, CD122, and CD132. Upon binding, it activates JAK3-, STAT5-, and AKT-dependent signaling pathways, which results in cellular proliferation and survival (Ma et al.). The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, although B cells and dendritic cells were found to produce IL-2 in small amounts. IL-2 downregulates immune responses to prevent autoimmunity during thymic development, influences the development of CD4+CD25+ regulatory T cells, and affects development of follicular helper T cells. IL-2 also controls inflammation by inhibiting Th17 differentiation (Banchereau et al.). High IL-2 levels in serum are associated with progression of scleroderma, rheumatoid arthritis, and gastric and non-small cell lung cancer, though no known disease can be directly attributed to the lack or excess of IL-2 (Gaffen and Liu).

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Granulocyte colony-stimulating factor (G-CSF) is a member of the CSF family of glycoproteins that regulate hematopoietic cell proliferation, differentiation, and function. It is a key cytokine involved in the production of neutrophils and the stimulation of granulocyte colony formation from hematopoietic progenitor cells (Metcalf andamp; Nicola). G-CSF causes a range of effects including a transient reduction of SDF-1 expression (Petit et al.), the activation of metalloproteases that cleave VCAM-1 (Levesque et al.), and the release of norepinephrine from the sympathetic nervous system (Katayama et al.), leading to the release or mobilisation of hematopoietic stem cells from the bone marrow into the periphery. The G-CSF receptor is expressed on a variety of hematopoietic cells, including myeloid-committed progenitor cells, neutrophils, granulocytes, and monocytes. In addition to hematopoietic cells, G-CSF is also expressed in cardiomyocytes, neuronal cells, mesothelial cells, and endothelial cells. Binding of G-CSF to its receptor leads to activation of the JAK/STAT, MAPK, PI3K, and AKT signal transduction pathways.

Supplier: STEMCELL Technologies

Granulocyte colony-stimulating factor (G-CSF) is a member of the CSF family of glycoproteins that regulate hematopoietic cell proliferation, differentiation, and function. It is a key cytokine involved in the production of neutrophils and the stimulation of granulocyte colony formation from hematopoietic progenitor cells (Metcalf and Nicola). G-CSF causes a range of effects including a transient reduction of SDF-1 expression (Petit et al.), the activation of metalloproteases that cleave VCAM-1 (Levesque et al.), and the release of norepinephrine from the sympathetic nervous system (Katayama et al.), leading to the release or mobilisation of hematopoietic stem cells from the bone marrow into the periphery. The G-CSF receptor is expressed on a variety of hematopoietic cells, including myeloid-committed progenitor cells, neutrophils, granulocytes, and monocytes. In addition to hematopoietic cells, G-CSF is also expressed in cardiomyocytes, neuronal cells, mesothelial cells, and endothelial cells. Binding of G-CSF to its receptor leads to activation of the JAK/STAT, MAPK, PI3K, and AKT signal transduction pathways. This product is animal component-free.

Supplier: STEMCELL Technologies

Interleukin 31 (IL-31), a four-helix bundle inflammatory cytokine, belongs to the IL-6 cytokine family which includes IL-6, oncostatin M, leukemia inhibitory factor (LIF), and cardiotrophin-1 ( Dillon et al.). IL-31 signals through a heterodimer composed of IL-31RA (also known as gp130-like receptor or GPL) and the oncostatin-M receptor (OSMR), both of which are expressed on monocytes (Diveu et al.; Ghilardi et al.), epithelial cells (Ip et al.), and keratinocytes (Kato et al.). Signaling through the GPL/OSMR complex activates the JAK/STAT, RAS/ERK, and PI3K/AKT signaling pathways, resulting in the downstream activation of STAT1, STAT3, and STAT5 transcription factors (Cornelissen et al.; Dambacher et al.; Dillon et al.; Ip et al.). IL-31 responses have been associated with allergic responses and inflammatory skin diseases including atopic dermatitis (Cornelissen et al.; Gangemi et al.).

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Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes the proliferation and differentiation of hematopoietic progenitor cells and the generation of neutrophils, eosinophils, and macrophages. In synergy with other cytokines such as stem cell factor, IL-3, erythropoietin, and thrombopoietin, it also stimulates erythroid and megakaryocyte progenitor cells (Barreda et al.). GM-CSF is produced by multiple cell types, including stromal cells, Paneth cells, macrophages, dendritic cells (DCs), endothelial cells, smooth muscle cells, fibroblasts, chondrocytes, and Th1 and Th17 cells (Francisco-Cruz et al.). The receptor for GM-CSF (GM-CSFR) is composed of two subunits: the cytokine-specific α subunit (GMRα; CD116) and the common subunit βc (CD131) shared with IL-3 and IL-5 receptors (Broughton et al.). GM-CSFR is expressed on hematopoietic cells, including progenitor cells and immune cells, as well as non-hematopoietic cells. GM-CSF is able to stimulate the development of DCs that ingest, process, and present antigens to the immune system (Francisco-Cruz et al.).

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The platelet-derived growth factor (PDGF) family has five heparin-binding members that assemble into four homodimers (PDGF-AA, PDGF-BB, PDGF-CC, and PDGF-DD) and one heterodimer (PDGF-AB; Fretto et al.; Li and Eriksson). PDGF signals through the receptor tyrosine kinases PDGFRα and PDGFRβ. It has been shown that PDGF-induced migration involves signaling pathways involving MEK/ERK, EGFR, Src, and PI3K/AKT (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin, such as fibroblasts, glial cells, and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). PDGF-DD promotes growth and survival of renal artery smooth muscle cells and lens epithelial cells, and can act as a macrophage chemoattractant (Changsirikulchai et al.; Lokker et al.; Ray et al.; Uutela et al.).

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Stem cell factor (SCF) is an early-acting cytokine that plays a pivotal role in the regulation of embryonic and adult hematopoiesis. SCF promotes cell survival, proliferation, differentiation, adhesion, and functional activation of cells at multiple levels of the hematopoietic hierarchy. Together with other cytokines such as thrombopoietin and Flt3/Flk-2 Ligand, SCF is commonly used to promote expansion of primitive hematopoietic stem cells and multi-potent progenitor cells in culture (Martin et al.; Kent et al.). In synergy with various growth factors, including IL-2, IL-3, IL-6, IL-7, G-CSF, and erythropoietin, SCF increases proliferation and differentiation of myeloid and erythroid progenitor cells and a subset of lymphoid progenitor cells (Broudy). SCF is also a primary growth and activation factor for mast cells and eosinophils. SCF exists in two biologically active splice forms: a soluble and a transmembrane isoform. Upon binding to its receptor (c-Kit tyrosine kinase receptor; CD117), it activates PI3K, JAK/STAT, and MAPK pathways. SCF and signaling from c-Kit have also been reported to play an important role in pigmentation, fertility, vasculogenesis, motility of the gut via c-Kit positive interstitial cells of Cajal, and in the migration of neuronal stem and progenitor cells to sites of injury in the brain. This product is animal component-free.

Supplier: STEMCELL Technologies

Vascular endothelial growth factor (VEGF) is a heparin-binding homodimeric glycoprotein involved in vasculogenesis and angiogenesis. VEGF binds to FLT1 (VEGFR-1) and KDR (VEGFR-2), and activates Raf/MEK/ERK and PI3K/AKT pathways (Ferrara et al.). VEGF exists in multiple isoforms that result from alternative splicing of VEGF mRNA in the terminal exon. Proximal splice-site selection in exon 8 results in pro-angiogenic VEGFxxx isoforms (xxx is the number of amino acids), whereas distal splice-site selection results in anti-angiogenic VEGFxxxb isoforms (Nowak et al.). VEGF plays an important role in neurogenesis both in vitro and in vivo (Storkebaum et al.). It has neurotrophic effects on neurons of the central nervous system, and it promotes growth and survival of dopaminergic neurons and astrocytes. VEGF also promotes growth and survival of vascular endothelial cells, monocyte chemotaxis, and colony formation by granulocyte-macrophage progenitor cells (Ferrara et al.). Various splice variants of VEGF exist, with different functions. For example, it has been shown that VEGF isoform VEGF-164(165) and not VEGF-120(121) induces inflammation, stimulates intracellular adhesion molecule (ICAM)-1 expression on endothelial cells, and induces chemotaxis of monocytes (Usui et al.).

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Interleukin-8 (IL-8) is a member of the CXC subfamily of chemokines and is produced by leukocytic cells (monocytes, T cells, neutrophils, and natural killer cells) and non-leukocytic somatic cells (endothelial cells, fibroblasts, and epithelial cells), with the most prominent source being monocytes and macrophages. Its production is induced by inflammatory stimuli, such as IL-1. IL-8, also known as CXCL8, activates neutrophils inducing chemotaxis, exocytosis, and the respiratory burst (Baggiolini and Clark-Lewis; Mukaida). IL-8 is considered one of the most potent neutrophil chemoattractants in inflammation and binds to two different chemokine receptors on leukocytes: the G protein-coupled receptors CXCR1 and CXCR2 (Hoffmann et al.; de Oliveira et al.). IL-8 has angiogenic effects on human intestinal microvascular endothelial cells in vitro that are mediated by CXCR2 (Heidemann et al.). IL-8 is reported to promote breast cancer progression by increasing cell invasion, angiogenesis, and metastasis and has been reported to be involved in regulating breast cancer stem-like cells (Singh et al.). IL-8 also has proangiogenic properties in inflammatory diseases of the conjunctiva, cornea, iris, retina, and orbit (Ghasemi et al.). It was also shown that a major T cell effector function in human newborns is IL-8 production, which has the potential to activate antimicrobial neutrophils and gamma/delta T cells (Gibbons et al.). A variety of human pathogens, such as HIV and Mycobacterium tuberculosis, have been shown to induce IL-8 production by monocytes and macrophages (Friedland et al.; Meddows-Taylor et al.).

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Platelet-derived growth factor (PDGF) is a dimeric glycoprotein consisting of two disulfide bridge-stabilized polypeptide chains, A and B, which are assembled as heterodimers (PDGF-AB) or homodimers (PDGF-AA and PDGF-BB) (Fretto et al.; Westermark and Heldin). PDGF signals through the receptor tyrosine kinases PDGFRalpha and PDGFRbeta. It has been shown that PDGF-induced migration involves signaling pathways involving MEK/ERK, EGFR, Src, and PI3K/AKT (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin, such as fibroblasts, glial cells, and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). It has been suggested that PDGF-AA is an important autocrine regulator of vascular endothelial growth factor (VEGF) expression in non-small cell lung carcinomas (Shikada et al.). PDGF-AA also mediates proliferation of oligodendrocyte progenitor cells and oligodendrocyte lineage differentiation through the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) (Hu et al.). PDGF-AA is commonly used to differentiate human pluripotent stem cell (hPSC)-derived neural progenitor cells into oligodendrocyte precursor cells (Piao et al.).

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Pepstatin A

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Bovine aprotinin (from Lung)

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Bovine serum albumin (BSA)

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Bovine serum albumin (BSA), Fraction V

Supplier: Roth Carl

Bovine serum albumin (BSA), Fraction V

Supplier: Roth Carl

Bovine serum albumin (BSA), Fraction V

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A cellular protein for detection of apoptotic cells, FITC-conjugated.

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Stimulating T cells with EBV (HLA Class I Control) peptide pool releases downstream cytokines and upregulates activation markers, enabling antigen-specific T cells to be detected or isolated for analysis. EBV (HLA Class I Control) Peptide Pool is a lyophilised mixture of 26 peptides from Epstein-Barr virus (EBV), and consists of defined HLA class I-restricted T cell epitopes. Viral peptide pools are useful for a broad range of applications, including vaccine development, immunological research, and diagnostic assay development. For consistency and reproducibility across your applications, CMV peptide pool from STEMCELL has a purity ≥95%.

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Stimulating T cells with HHV1 (gD) Peptide pool releases downstream cytokines and upregulates activation markers, enabling antigen-specific T cells to be detected or isolated for analysis. HHV1 (gD) Peptide pool is a lyophilised mixture of 96 peptides from envelope glycoprotein D of human herpesvirus 1 (HHV1; strain Patton), and consists of 15-mer peptides with 11-amino-acid overlaps that cover amino acids 1 to 394 on gD. gD is required at the first stage of virus-induced membrane fusion (Subramanian and Geraghty), which likely occurs via binding to receptors such as nectin-1 (Giovine et al.) and HVEM (Connolly et al.) on cell surfaces. Viral peptide pools are useful for a broad range of applications, including vaccine development, immunological research, and diagnostic assay development.

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Stimulating T cells with EBV (EBNA-3B) peptide pool releases downstream cytokines and upregulates activation markers, enabling antigen-specific T cells to be detected or isolated for analysis. EBV (EBNA-3B) Peptide Pool is a lyophilised mixture of 234 peptides from Epstein-Barr nuclear antigen 3B (EBNA-3B) of Epstein-Barr virus (EBV; strain AG876) and consists of 15-mer peptides with 11-amino-acid overlaps that cover amino acids 1 to 946 on EBNA-3B. EBNA-3B is considered non-essential for B cell growth transformation (Chen et al., 2005; Tomkinson and Kieff), but has been shown to regulate the expression of cellular genes in EBV-infected cells (Chen at al., 2006). Viral peptide pools are useful for a broad range of applications, including vaccine development, immunological research, and diagnostic assay development.