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Monoclonal Antibody Ihc-Leica® bond™ t Cell Activation

$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin)

Background: OX40 (TNFRSF4, CD134) is a member of the tumor necrosis factor (TNF) receptor superfamily that regulates T cell activity and immune responses. The OX40 protein contains four cysteine rich domains, a transmembrane domain, and a cytoplasmic tail containing a QEE motif (1,2). OX40 is primarily expressed on activated CD4+ and CD8+ T-cells, while the OX40 ligand (OX40L, TNFSF4, CD252) is predominantly expressed on activated antigen presenting cells (3-7). The engagement of OX40 with OX40L leads to the recruitment of TNF receptor-associated factors (TRAFs) and results in the formation of a TCR-independent signaling complex. One component of this complex, PKCθ, activates the NF-κB pathway (2,8). OX40 signaling through Akt can also enhance TCR signaling directly (9). Research studies indicate that the OX40L-OX40 pathway is associated with inflammation and autoimmune diseases (10). Additional research studies show that OX40 agonists augment anti-tumor immunity in several cancer types (11,12).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin)

Background: Forkhead box (Fox) proteins are a family of evolutionarily conserved transcription factors containing a sequence known as Forkhead box or winged helix DNA binding domain (1). The human genome contains 43 Fox proteins that are divided into subfamilies. The FoxP subfamily has four members, FoxP1 - FoxP4, which are broadly expressed and play important roles in organ development, immune response and cancer pathogenesis (2-4). The FoxP subfamily has several characteristics that are atypical among Fox proteins: their Forkhead domain is located at the carboxy-terminal region and they contain motifs that promote homo- and heterodimerization. FoxP proteins usually function as transcriptional repressors (4,5).FoxP3 is crucial for the development of T cells with regulatory properties (Treg) (6). Mutations in FoxP3 are associated with immune dysregulation, polyendocrinopathy, enteropathy, and X-linked syndrome (IPEX) (7), while overexpression in mice causes severe immunodeficiency (8). Research studies have shown that FoxP3 functions as a tumor suppressor in several types of cancer (9-11).

$129
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: B7 homolog 3 (B7-H3, CD276) is a member of the B7 family of cell surface ligands that regulate T cell activation and immune responses. B7-H3 protein contains two extracellular Ig-like V-type domains and two IgG-like C2-type domains, a transmembrane domain, and a short intracellular domain (1,2). Early research examining the biological process of B7-H3 suggested that B7-H3 is a positive regulator of T cell response (1). Subsequent research studies indicated that B7-H3 is a negative regulator of T cell response, and that the protein inhibits T cell proliferation (2,3). One possibility is that B7-H3 interacts with two distinct sets of receptors, resulting in seemingly opposite biological outcomes (2). B7-H3 is expressed by antigen presenting cells, activated T cells, and a few normal tissues, including placenta and prostate (1,4,5). Expression of B7-H3 is seen in several cancer types, including prostate, breast, colon, lung, and gastric cancers, and in endothelial cells from tumor associated vasculature (6-8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: CD47 is a five-pass transmembrane protein expressed on all normal cells. It binds to the SIRPa that is expressed on myeloid cells including macrophages, and neuronal cells in the central nervous system. Binding of CD47 to SIRPα promotes phosphorylation of tyrosine residues in the immunoreceptor tyrosine-based inhibitory motifs (ITIM) within theSIRPα cytoplasmic tail, inhibiting macrophage phagocytosis towards CD47-expressing cells. In this way, CD47 serves as "don't eat me" signal or a marker of "self", functioning as an innate immune checkpoint. Additionally, CD47 was reported to modulate lymphocyte cell activation and proliferation (1-3). CD47 is over-expressed in many types of cancer. The expression level of CD47 on cancer cells is negatively associated with the response to therapies, and low expression on tumor cells is associated with a better prognosis and survival. Reagents that can block CD47-SIRPα interaction are being actively pursued for therapeutic applications (4,5). In addition to SIRPα, other proteins have been reported to bind to CD47. Thrombospondin 1 (TSP1) competes with SIRPα to bind to CD47 in the extracellular region and activates signaling pathways downstream CD47 (6). CD47 can laterally associate with VEGFR2, FAS, and certain integrins in different contexts, and influences their downstream signaling (7-9). CD47 can be shed from the cell surface by proteolytic cleavage. In addition, CD47 is present on extracellular vesicles including exosomes, suggesting additional extracellular signaling potential (10).

$122
20 µl
$293
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Flow Cytometry, IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: FcγRIIB (CD32B) is a low affinity, IgG Fc-binding receptor expressed on B cells, monocytes, macrophages, and dendritic cells (DCs) (1-3). It is the inhibitory Fc receptor and signals through an immunoreceptor tyrosine-based inhibitory motif (ITIM) within its carboxy-terminal cytoplasmic tail (2). Binding of immune complexes to FcγRIIB results in tyrosine phosphorylation of the ITIM motif at Tyr292 and recruitment of the phosphatase SHIP, which mediates inhibitory effects on immune cell activation (2,4). In this way, FcγRIIB suppresses the effects of activating Fc-binding receptors (3). For example, mice deficient for FcγRIIB have greater T cell and DC responses following injection of immune complexes (5, 6). In addition, FcγRIIB plays a role in B cell affinity maturation (7). Signaling through FcγRIIB in the absence of signaling through the B cell receptor (BCR) is proapoptotic, while signaling through FcγRIIB and the BCR simultaneously attenuates the apoptotic signal and results in selection of B cells with higher antigen affinity (7).

$129
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: Lymphocyte activation gene 3 (LAG-3, CD223) is an immune checkpoint control protein that negatively regulates T cells and immune responses. A CD4-like member of the Ig superfamily, LAG3 contains an extracellular IgV and three IgC domains, a transmembrane domain, and a short cytoplasmic region (1). LAG3 is primarily expressed by activated CD4+ T cells, CD8+ T cells, Tregs and NK cells, where it's activated by MHC Class II molecules, its only known ligand. While it was initially shown to activate Treg cells (2), LAG3 can also inhibit CD8+ T cells (3,4). LAG3 is often co-expressed with PD-1 on the surface of tumor infiltrating lymphocytes, where the two proteins act independently to contribute to tumor-mediated immune suppression (4,5). Blockade of LAG3 is a promising strategy for neoplastic intervention (6).

$129
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: Cluster of Differentiation 8 (CD8) is a disulphide-linked heterodimer consisting of the unrelated α and β subunits. Each subunit is a glycoprotein composed of a single extracellular Ig-like domain, a polypeptide linker, a transmembrane part and a short cytoplasmic tail. On T cells, CD8 is the coreceptor for the T cell receptor (TCR), and these two distinct structures recognize the Antigen–Major Histocompatibility Complex (MHC). Specifically, the Ig-like domain of CD8α interacts with the α3-domain of the MHC class I molecule. CD8 ensures specificity of the TCR–antigen interaction, prolongs the contact between the T cell and the antigen presenting cell, and the α chain recruits the tyrosine kinase Lck, which is essential for T cell activation (1).

$269
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: CD40, also known as tumor necrosis factor receptor superfamily member 5 (TNFRSF5), is a type I transmembrane protein expressed on the surface of B cells and professional antigen-presenting cells of the immune system, as well as on several non-hematopoietic cell types and cancers (1-4). CD40 interacts with CD40 ligand (CD40L/TNFSF5), which is expressed primarily on activated T cells but has also been reported on blood platelets, mast cells, basophils, NK cells, and B cells (5). Upon engagement with CD40L, CD40 signals through TNF receptor associated factors and MAP kinase signaling pathways, resulting in a wide variety of immune and inflammatory responses, including dendritic cell activation and cross-presentation, T cell-dependent immunoglobulin class switching, memory B cell development, and germinal center formation (6-8). The CD40/CD40L axis is essential for the initiation and progression of cellular and humoral adaptive immunity, and is an important area of interest in the study of tumor immunology, neurodegenerative diseases, vascular diseases, and inflammatory disorders (9-12).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: CRACC/SLAMF7/CD319 (also known as CS1) is a member of the signaling lymphocytic activation molecule (SLAM) family. It is a single-pass type l transmembrane glycoprotein expressed on NK cells, subsets of mature dendritic cells, activated B and T lymphocytes, but not in promyelocytic B or T cell lines. Expression of this protein has been detected in the spleen, lymph node, peripheral blood leukocytes, bone marrow, small intestine, stomach, appendix, lung, and trachea (1-6). Homophilic interactions of CRACC/SLAMF7/CD319 modulate the activity and differentiation of immune cells. CRACC/SLAMF7/CD319 may function as an inhibitory or activating receptor in immune cells depending on cellular context and availability of adapter proteins, SH2D1A/SAP and/or SH2D1B/EAT-2 (5-9). In the presence of SH2D1B/EAT-2, CRACC/SLAMF7/CD319 activates NK cells and B cells (5-7). T cells lack SH2D1B/EAT-2 expression, and therefore CRACC/SLAMF7/CD319 acts as an inhibitory receptor (8). In LPS-activated monocytes, CRACC/SLAMF7/CD319 negatively regulates production of proinflammatory cytokines (9). CRACC/SLAMF7/CD319 is upregulated in multiple myeloma and is implicated in the uncontrolled proliferation of these cells, and thus has become the target for therapeutic intervention (10, 11). Seven isoforms of CRACC/SLAMF7/CD319 produced by alternative splicing have been identified.

$129
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: B7 homolog 4 (B7-H4, VTCN1) is a member of the B7 family of cell surface ligands that regulate T cell activation and immune responses (1-3). B7-H4 protein contains two extracellular Ig-like V-type domains, a transmembrane domain, and a short, two amino acid intracellular domain (3). The B7-H4 protein is shown to inhibit T cell activation, proliferation, and cytokine production (1,4,5). Although B7-H4 mRNA is widely expressed, B7-H4 protein is restricted to antigen presenting cells and B cells (1). The B7-H4 protein is also found in several tumor types, including ovarian cancer and breast cancer (6). Research studies indicate that B7-H4 protein is present on the surface of ovarian tumor cells, and that targeted inhibition of B7-H4 using recombinant antibodies restores T cell activation pathways. These studies suggest some potential therapeutic value in blocking B7-H4 function and restoring T cell function in cancer patients (7,8).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: Major histocompatibility complex class II (MHC class II) molecules are heterodimeric, transmembrane glycoproteins expressed on the surface of antigen-presenting cells such as macrophages, dendritic cells, and B cells. Expression can also be induced on other cell types through interferon-γ signaling (1). Prior to being displayed on the cell membrane, MHC class II molecules are loaded with exogenous peptide antigens approximately 15-24 amino acids in length that were derived from endocytosed extracellular proteins digested in the lysosome (2). Antigen-presentation through MHC class II is required for T cell activation during the immune response to extracellular pathogens (2). In humans, the MHC class II protein complex is encoded by the human leukocyte antigen gene complex (HLA). HLAs corresponding to MHC class II are HLA-DP, HLA-DM, HLA-DOA, HLA-DOB, HLA-DQ, and HLA-DR (3).

$115
20 µl
$269
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: Cluster of Differentiation 4 (CD4) is a glycoprotein composed of an amino-terminal extracellular domain (four domains: D1-D4 with Ig-like structures), a transmembrane part and a short cytoplasmic tail. CD4 is expressed on the surface of T helper cells, regulatory T cells, monocytes, macrophages and dendritic cells, and plays an important role in the development and activation of T cells. On T cells, CD4 is the co-receptor for the T cell receptor (TCR), and these two distinct structures recognize the Antigen–Major Histocompatibility Complex (MHC). Specifically, the D1 domain of CD4 interacts with the β2-domain of the MHC class II molecule. CD4 ensures specificity of the TCR–antigen interaction, prolongs the contact between the T cell and the antigen presenting cell and recruits the tyrosine kinase Lck, which is essential for T cell activation (1).

$115
20 µl
$269
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Flow Cytometry, IHC-Leica® Bond™, Immunofluorescence (Frozen), Immunohistochemistry (Paraffin)

Background: Forkhead box (Fox) proteins are a family of evolutionarily conserved transcription factors containing a sequence known as Forkhead box or winged helix DNA binding domain (1). The human genome contains 43 Fox proteins that are divided into subfamilies. The FoxP subfamily has four members, FoxP1 - FoxP4, which are broadly expressed and play important roles in organ development, immune response and cancer pathogenesis (2-4). The FoxP subfamily has several characteristics that are atypical among Fox proteins: their Forkhead domain is located at the carboxy-terminal region and they contain motifs that promote homo- and heterodimerization. FoxP proteins usually function as transcriptional repressors (4,5).FoxP3 is crucial for the development of T cells with regulatory properties (Treg) (6). Mutations in FoxP3 are associated with immune dysregulation, polyendocrinopathy, enteropathy, and X-linked syndrome (IPEX) (7), while overexpression in mice causes severe immunodeficiency (8). Research studies have shown that FoxP3 functions as a tumor suppressor in several types of cancer (9-11).

$115
20 µl
$269
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: When T cells encounter antigens via the T cell receptor (TCR), information about the quantity and quality of antigens is relayed to the intracellular signal transduction machinery (1). This activation process depends mainly on CD3 (Cluster of Differentiation 3), a multiunit protein complex that directly associates with the TCR. CD3 is composed of four polypeptides: ζ, γ, ε and δ. Each of these polypeptides contains at least one immunoreceptor tyrosine-based activation motif (ITAM) (2). Engagement of TCR complex with foreign antigens induces tyrosine phosphorylation in the ITAM motifs and phosphorylated ITAMs function as docking sites for signaling molecules such as ZAP-70 and p85 subunit of PI-3 kinase (3,4). TCR ligation also induces a conformational change in CD3ε, such that a proline region is exposed and then associates with the adaptor protein Nck (5).

$129
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: Intercellular cell adhesion molecule-1 (CD54 or ICAM-1) is a cell surface glycoprotein that belongs to the immunoglobulin superfamily (IgSF) of adhesion molecules. CD54 is expressed at low levels in diverse cell types, and is induced by cytokines (TNF-α, interleukin-1) and bacterial lipopolysaccharide (1). Apical localization of CD54 on endothelial cells (or basolateral localization on epithelial cells) is a prerequisite for leukocyte trafficking through the endothelial (or epithelial) barrier (1). Apical expression of CD54 on epithelial cells mediates pathogen invasion as well as host defense, a pattern also observed in tumors (1). CD54 also functions as a co-stimulator on antigen presenting cells, binding to its receptor LFA-1 (leukocyte function-associated antigen-1) on the surface of T cells during antigen presentation (2). Cross-linking of CD54 or binding to its ligand triggers activation of Src family kinases and the Rho/ROCK pathway (3-7). Phosphorylation on Tyr485 of CD54 is required for its association with SHP-2 (5). SHP-2 seems essential for CD54-induced Src activation (7).

$269
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Flow Cytometry, IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: Bruton's tyrosine kinase (Btk) is a member of the Btk/Tec family of cytoplasmic tyrosine kinases. Like other Btk family members, it contains a pleckstrin homology (PH) domain and Src homology SH3 and SH2 domains. Btk plays an important role in B cell development (1,2). Activation of B cells by various ligands is accompanied by Btk membrane translocation mediated by its PH domain binding to phosphatidylinositol-3,4,5-trisphosphate (3-5). The membrane-localized Btk is active and associated with transient phosphorylation of two tyrosine residues, Tyr551 and Tyr223. Tyr551 in the activation loop is transphosphorylated by the Src family tyrosine kinases, leading to autophosphorylation at Tyr223 within the SH3 domain, which is necessary for full activation (6,7). The activation of Btk is negatively regulated by PKCβ through phosphorylation of Btk at Ser180, which results in reduced membrane recruitment, transphosphorylation, and subsequent activation (8). The PKC inhibitory signal is likely to be a key determinant of the B cell receptor signaling threshold to maintain optimal Btk activity (8).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunofluorescence (Immunocytochemistry), Immunohistochemistry (Paraffin), Western Blotting

Background: CD80 (B7-1, BB1) and CD86 (B7-2, B70) are members of the B7 family of cell surface ligands that regulate T cell activation and immune responses. CD80 is expressed on activated antigen presenting cells, including dendritic cells, B cells, monocytes, and macrophages. CD86 is expressed on resting monocytes, dendritic cells, activated B lymphocytes, and can be further upregulated in the presence of inflammation (1-3). CD80 and CD86 are ligands for CD28, which functions as a T cell costimulatory receptor. Interaction of CD28 with CD80 or CD86 provides the second signal required for naïve T cell activation, T cell proliferation, and acquisition of effector functions (3-7). Alternatively, CD80 and CD86 also act as ligands to CTLA-4, which results in the downregulation of T cell activity (3,7-9).

$115
20 µl
$281
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin)

Background: Programmed cell death 1 ligand 1 (PD-L1, B7-H1, CD274) is a member of the B7 family of cell surface ligands that regulate T cell activation and immune responses. The PD-L1 ligand binds the PD-1 transmembrane receptor and inhibits T cell activation. PD-L1 was discovered following a search for novel B7 protein homologs and was later shown to be expressed by antigen presenting cells, activated T cells, and tissues including placenta, heart, and lung (1-3). Similar in structure to related B7 family members, PD-L1 protein contains extracellular IgV and IgC domains and a short, cytoplasmic region. Research studies demonstrate that PD-L1 is expressed in several tumor types, including melanoma, ovary, colon, lung, breast, and renal cell carcinomas (4-6). Expression of PD-L1 in cancer is associated with tumor infiltrating lymphocytes, which mediate PD-L1 expression through the release of interferon gamma (7). Additional research links PD-L1 expression to cancers associated with viral infections (8,9).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin)

Background: S100A8 and S100A9 are calcium-binding proteins that form a noncovalent heterodimer present in monocytes, neutrophils, macrophages, and some epithelial cells (1, 2). S100A8 and S100A9 are secreted by a tubulin-dependent mechanism during inflammatory conditions and have antimicrobial and chemotactic functions (3-5). Extracellular S100A8/S100A9 also induces an inflammatory response in endothelial cells, including induction of proinflammatory chemokines and adhesion molecules and increased vascular permeability (6). S100A8/S100A9 induces and recruits myeloid-derived suppressor cells (MDSC) in tumor-bearing mice (7). MDSC produce additional S100A8/S100A9 themselves, resulting in a positive feedback mechanism that sustains MDSC accumulation (7). S100A8/S100A9 is also highly expressed in psoriatic skin, where it directly upregulates transcription of complement protein C3, which contributes to disease (8). In addition, tumor-infiltrating myeloid cells induce expression of S100A8 and S100A9 in cancer cells, which increases invasiveness and metastasis (9).

$129
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: Type 1 collagen is the most abundant collagen in many human tissues, including bone, skin, and tendons. It is a trimeric complex comprised of two molecules of COL1A1 (alpha-1 type 1 collagen) and one molecule of COL1A2 (alpha-2 type 1 collagen) (1-3). The expression levels of COL1A1 are regulated by multiple mechanisms, including mRNA stability, translation, and posttranslational modification (3-5). Overexpression of COL1A1 has been positively associated with tissue fibrosis disorders, including systemic sclerosis (6), while loss-of-function mutations in the COL1A1 gene are a major causative factor for osteogenesis imperfecta (brittle bone disease) (7). Notably, COL1A1 expression levels have also been associated with tumor development in gastric, lung, thyroid, and breast cancers. Research studies suggest that upregulation of COL1A1 can generate a modified extracellular matrix environment that promotes cancer cell survival, proliferation, metastasis, and invasion (8-11).