Novus Biologicals Blog

Lymphocyte activation gene 3 (LAG3): No lag time in immune response

October 23rd, 2014

The LAG3 protein belongs to the Ig superfamily and contains 4 extracellular Ig-like domains (D1-D4). This molecule plays an key role in the immune response through negative regulation of T-cell proliferation, function, and homeostasis. It is required for maximum natural and induced regulatory T-cell function. LAG3 is closely related to the T-cell co-receptor CD4, and like CD4, binds to MHC class II molecules – but with a significantly higher affinity. It is expressed exclusively in activated T- and natural killer (NK) lymphocytes.

Western Blot: Lymphocyte Activation Gene 3 Antibody

Western Blot: Lymphocyte Activation Gene 3 Antibody

Studies with the LAG3 antibody from Baixeras’ lab established LAG3 as a new human leukocyte antigen class II antigen ligand1.  More detailed characterization studies relied upon use of the LAG3 antibody to map critical functional domains within the various Ig-like areas2.  Follow-up studies out of the same lab employed yet again the LAG3 antibody to generate expression profiles of infiltrating T-lymphocytes (TILs)3. Their data suggests that TIL-expressed LAG3 is involved in class II engagement on antigen presenting cells (APCs), APC activation, and Th1/Tc1 cell commitment. Di Carlo’s group also compared the role of LAG3 versus IL12 in promoting intratumor recruitment, activation, and Th1 APC commitment using the LAG3 antibody4.  Some intriguing findings out of Triebel’s lab indicate that soluble LAG3 (sLAG3) could serve as a valuable prognostic marker for particular subsets of breast cancer, and emphasize the importance of Th1 response in adjuvant therapy response. Use of the LAG3 antibody allowed these researchers to carefully profile a cohort of 246 breast cancer patient seras with regards to their estrogen and progesterone receptor expression state5.

Novus Biologicals offers Lymphocyte activation gene 3 reagents for your research needs including:

PMIDs

  1. 1380059
  2. 9159144
  3. 11527700
  4. 15586367
  5. 15946792

TNF alpha (tumor necrosis factor alpha, cachectin, macrophage cytotoxic factor (MCF))

October 22nd, 2014

TNF alpha is a multifunctional proinflammatory cytokine that belongs to the tumor necrosis factor (TNF)-receptor superfamily. It is involved in the regulation of a wide spectrum of biological processes: cell proliferation, differentiation, apoptosis, inflammation, lipid metabolism, and coagulation. TNF alpha has been implicated in a variety of autoimmune diseases (rheumatoid arthritis, Crohn’s disease, multiple sclerosis, and psoriasis), insulin resistance, septic shock, and tumor metastases related to cancer. The major source of TNF alpha is activated macrophages but it is also secreted by T-cells, natural killer (NK) cells, and certain tumor cells. This cytokine received its designation because it causes tumor necrosis when injected into tumor-bearing mice.  TNF alpha exists as a multimer of two, three, or five noncovalently linked units and is closely related to tumor necrosis factor beta (TNF beta, or lymphotoxin), sharing the same receptors and cellular actions. TNF alpha binds to the TNFRSF1A/TNFR1 and TNFRSF1B/TNFBR receptors.

Immunocytochemistry/Immunofluorescence: TNF alpha Antibody

Immunocytochemistry/Immunofluorescence: TNF alpha Antibody

Binding of TNF alpha to its downstream receptors leads to apoptosis, differentiation, or proliferation depending on the specific receptor engaged (TNFRI has been identified as the major receptor). TNF alpha signals through major pathways such as NF-kB, JNK and MAPK. The targeted blockage of TNF alpha by powerful antibodies such as Remicade and Humira has been tremendously successful as therapeutic modalities for autoimmune diseases. Anti-aging researchers performed liver proteasome profiling studies with the TNF alpha antibody to better understand how the cell’s ability to handle stress and protein damage translates to a longer lifespan1. Roth et al relied upon the TNF alpha antibody for their work on eosinophil subpopulations in skin diseases2. With the help of the TNF alpha antibody, this group created different expression patterns across a wide range of diseases to better understand the role of distinct functional subtypes with respect to host defense, immunomodulation, fibrosis, and tumor development. Additionally, Bakers’ lab employed the TNF alpha antibody to investigate the in vitro and in vivo effects of coplanar polychlorinated biphenyls (PCBs) on glucose homeostasis in adipocytes, where PCBs naturally accumulate3. Furthermore, Piao et al used the TNF alpha antibody in their basal-like breast cancer research to uncover a novel NFkB-dependent pathway that can be inhibited by alpha-catenin4.

Novus Biologicals offers TNF alpha reagents for your research needs including:

PMIDs

  1. 22567116
  2. 21884530
  3. 23099484
  4. 24509793

EpCAM or CD326 – Take your pick

October 20th, 2014

The type I transmembrane glycoprotein EpCAM is a monomeric membrane glycoprotein that is expressed on most epithelial cell membranes as well as on a variety of epithelial carcinomas. It contains an extracellular domain with two epidermal growth factor-like extracellular domain repeats adjacent to a cysteine-poor region, along with a transmembrane domain, and a short cytoplasmic tail. EpCAM is a powerful tool for the detection of circulating and disseminated cancer cells (CTCs/DTCs) in blood and bone marrow, and it is the most commonly used epithelial marker to capture CTCs/DTCs. EpCAM expression appears to be down regulated during the epithelial-to-mesenchymal transition. Aleksic et al performed a western blot with the EpCAM antibody for their studies on the impact of insulin-like growth factor receptor (IGF-1R) and its nuclear import on downstream function1. Their data suggests that import may play a key role in identifying the efficacy of pathway-specific inhibitory drugs.

Immunohistochemistry-Paraffin: EpCAM/CD326 Antibody

Immunohistochemistry-Paraffin: EpCAM/CD326 Antibody

Further nuclear localization studies from Ralhan’s lab employed the EpCAM antibody to test nuclear EpCAM intracellular oncogenic domain (Ep-ICD) detection as a biomarker of aggressive thyroid cancer (TC)2.  Immunohistochemical and immunocytochemical experiments with the EpCAM antibody allowed Anagnostaki’s group to contrast staining patterns between normal bladder epithelium and transitional carcinomas3. Molecular therapeutics researchers examined the role of mesenchymal stem cells (MSCs) in breast cancer metastasis with the EpCAM antibody, and were able to raise valid concerns about the safe use of MSCs as transgene delivery systems4.  Flow cytometry employing the EpCAM antibody allowed Conaghan et al to monitor both in vitro and in vivo efficacy of unconjugated humanized anti-carcinoembryonic antigen (CEA) monoclonal antibodies targeted to colorectal cancers5.

Novus Biologicals offers EpCAM/CD326 reagents for your research needs including:

PMIDs

  1. 20710042
  2. 20579375
  3. 2200496
  4. 21763624
  5. 1834984

CD79b – A Signal Transduction Component of the B-cell Receptor

October 17th, 2014

The B-cell antigen receptor (BCR) is a complex multimeric aggregate that includes the following key noncovalently-bound components: antigen-specific surface immunoglobulin (Ig), CD79a (Ig-alpha), and CD79b (Ig-beta). BCR signaling is a pivotal pathway in tumorigenesis. The CD79 signaling subunits are essential for proper B-cell development, maintenance, and activation. Both are transmembrane proteins with extended cytoplasmic domains containing immunoreceptor tyrosine activation motives (ITAMs). Their expression (both alpha and beta) is restricted to B-lymphocytes and they are the first BCR components developmentally expressed.

Immunocytochemistry/Immunofluorescence: CD79b Antibody

Immunocytochemistry/Immunofluorescence: CD79b Antibody

The CD79b antibody, the underlying signaling mechanisms, coordinated regulation between both subunits, and direct coupling between to downstream BCR effector molecules (protein tyrosine kinases and SLP65) is discussed by Wienands et al1.  Using sophisticated genetic tools and the CD79b antibody, Conley’s group compares and contrasts the most common mutations – those affecting Btk, BCR lambda5, CD79a, and CD79b – that lead to primary B-cell immunodeficiencies2. Their studies were aimed at assessing clinical heterogeneity and trying to pinpoint the genetic and environmental factors influencing clinical phenotype and presentation. The role of BCR in B-cell malignancies is being carefully mapped, and because such cancers are highly sensitive to kinase inhibitors, there is an emerging class of potentially powerful targeted therapeutics – such as Ibrutinib and Idelalisib – as discussed in a review by Niemann’s group from the NIH3.

Novus Biologicals offers CD79b reagents for your research needs including:

PMIDs

  1. 11913945
  2. 19302039
  3. 24060900

Major Histocompatibility Complex (MHC) Class I

October 16th, 2014

The products of MHC genes are antigen-presenting molecules (APMs) designed for antigen fragment (peptide) presentation to the T-cell receptor. In particular, MHC Class I molecules play a key role in the immune system by presenting endogenously synthesized peptides derived from the endoplasmic reticulum (ER) lumen to CD8+ T-lymphocytes, which are usually cytotoxic T-cells. MHC Class I antigens are heterodimers consisting of one 44kD highly polymorphic alpha chain non-covalently complexed with an invariant 11.5kD beta2-microglobulin subunit. The MHC Class I antigen is expressed on all somatic cells at varying levels – mostly on nucleated cells. Fibroblasts or neurons show only low levels of MHC Class I.

Immunohistochemistry: MHC Class I Antibody

Immunohistochemistry: MHC Class I Antibody

Early studies with the MHC Class I antibody from Bukovsky’s lab analyzed and characterized cell surface antigens present on lymphoid cells during early pregnancy1.  Related immunology studies from Fujikawa et al relied upon use of the MHC Class I antibody to characterize the in vitro response of class II antigens in the retinal vascular endothelium2. Additionally, a German group performed immunohistochemical experiments with the MHC Class I antibody to monitor abatement of alopecia areata-like hair loss in a mouse model in response to treatment with the topical immunosuppressant FK506 (Tacrolimus)3. The induced hair regrowth appears to be via suppression of a T-cell mediated immune response. As published in Virology, rat CMV infection depletes and down regulates MHC Class II through a novel mechanism that does not involve the conventionally-identified HCMV proteins such as US2, US3, UL83, and UL111a4.  The MHC Class I antibody allowed Stettner et al to implicate the pro-inflammatory interleukin-17 (IL-17) cytokine as a myelin-suppressive mediator in the peripheral nerve, where it was shown to inhibit Schwann cell-mediated myleination5.

Novus Biologicals offers MHC Class I reagents for your research needs including:

PMIDs

  1. 6146566
  2. 2783579
  3. 11525945
  4. 19349057
  5. 24678820

Multifunctional CD38

October 15th, 2014

CD38 is a 42 kD type II transmembrane glycoprotein that uses nicotinamide adenine dinucleotide (NAD) as a substrate to form cyclic adenosine diphosphate ribose (cADPR). This novel multifunctional ectoenzyme has both cyclase and hydrolase enzymatic activity, and is expressed on the surface of most white blood cells (CD4+, CD8+, B-lymphocytes and natural killer (NK) cells).  It is also expressed at high levels in normal tissues and organs like the pancreas, liver, and kidney as well as in malignant lymphoma and neuroblastoma. In addition to having a key role in lymphocyte activation and differentiation, CD38 is also involved in cell adhesion, signal transduction, insulin secretion, and calcium signaling.

Immunohistochemistry-Paraffin: CD38 Antibody

Immunohistochemistry-Paraffin: CD38 Antibody

A very recent review by Chilemi et al examines the role of CD38 in shaping the bone marrow microenvironment by incorporating both old and new models1.  This review focuses specifically on myeloma and chronic lymphocytic leukemia (CLL) and suggests that CD38 status may strongly impact and guide antibody-mediate immunotherapy. Wei’s group details the CD38 signaling pathway in a recent paper that summarizes the pathway modules and highlights recent advances with respect to Ca2+ mobilization2. Use of CD38 as an independent negative prognostic marker for CLL is detailed in a review by Vaisitti’s group3. They share the evolution of CD38 from a marker to a disease modifier to a potential therapeutic marker.

Novus Biologicals offers CD38 reagents for your research needs including:

PMIDs

  1. 24389178
  2. 24600514
  3. 24171772

Cytokeratin 18 – A Intermediate Filament Cyotskeletal Component

October 14th, 2014

Keratins, also called cytokeratins, are a family of filamentous structural proteins that form the intermediate filaments within epithelial cells. Keratins are differentially expressed depending on both the epithelial cell origin and degree of differentiation. An antibody to any given keratin is useful either as a stand-alone or part of an antibody panel to help identify or clarify tissue origin. Cytokeratin 18 (CK18) is a 45 kD normal constituent of the hepatocyte cytoskeleton and is expressed in combination with cytokeratin 8.  The cytokeratins 18 and 8 are the major keratin pair most commonly expressed intermediate filaments in single layer or simple epithelial tissues. CK18 is used as a tumor marker, not only because it is often persistently expressed in tumor cells derived from simple epithelia, but also because keratin expression patterns enable valuable sub-typing of tumors. Studies with the cytokeratin 18 antibody from a Georgetown lab indicate that PPARgamma surprisingly plays a role in mammary lineage specification and estrogen receptor (ER)+ tumor formation1.

Immunohistochemistry: Cytokeratin 18 Antibody

Immunohistochemistry: Cytokeratin 18 Antibody

Terada’s group relied upon use of the cytokeratin 18 antibody in their pathological assessments of an oral tumor mass and adjacent areas to make a diagnosis of an extremely rare occurrence of angiosarcoma – this diagnosis then directed subsequent course of action and surgery2. Immunohistochemical studies out of Yoon’s lab employed the cytokeratin 18 antibody to conduct a much-needed evaluation, profile, and comparison ameloblastoma and amyeloblastic carcinoma specimens3. Their work provided much insight into the use of CK18, parenchymal MMP-2, stromal MMP-9, and Ki67 as differentiation markers. Kaenel’s group in Switzerland examined the role of ephrin-B2 through use of the cytokeratin 18 antibody, which allowed them to demonstrate ephrin-B2’s role in stem cell niche regulation and differentiation4.  Furthermore, the cytokeratin 18 antibody allowed a group at UCLA’s Medical Center to carefully monitor progenitor populations (hematopoietic, mesenchymal, and epithelial) in the peripheral blood of patients undergoing extracorporeal membrane oxygenation (ECMO)5.

Novus Biologicals offers Cytokeratin 18 reagents for your research needs including:

PMIDs

  1. 19147585
  2. 20924728
  3. 22014999
  4. 22020958
  5. 19875689

Ki67 – A Crucial Cellular Proliferation Marker

October 13th, 2014

The Ki67 antigen is a prototypic cell cycle-related protein expressed by proliferating cells in all phases of the active cell cycle (G1, S, G2 and M). It is a non-histone nuclear protein originally identified in a Hodgkin’s lymphoma-derived cell line. Ki67 interacts with KIF15 and MKI67IP, and is approximately 395 kD. It exhibits a complex nuclear localization pattern that is cell cycle-dependent – expression peaks during late G1, S, G2, and M phases, but is undetectable in G0. Ki67 is phosphorylated and dephosphorylated during mitosis, and appears to be susceptible to proteolytic regulation. Due to its cell cycle association, Ki67 is routinely used as cell cycling and proliferation marker. Additionally, Ki67 antibodies are useful in establishing the cell growing fraction in solid tumors and certain hematological malignancies.

Immunohistochemistry-Paraffin: Ki67 Antibody

Immunohistochemistry-Paraffin: Ki67 Antibody

Original immunobiochemical characterization of the Ki67 antibody validated its exclusive expression in proliferating, but not quiescent, cell cohorts1. Molecular labeling studies from Zambon‘s lab at UCSD introduced a novel and dynamic real-time visualization cell cycle entry detection method with the Ki67 antibody2.  This genetic-based reporter method can be done with live cells in intact complex 3D cellular aggregates and has unique advantages over conventional methods. Swartling’s group used the Ki67 antibody to profile the role of MYCN in malignant childhood medulloblastoma (MB) and found that it has a wide reaching and pleiotropic role in the initiation, progression, and maintenance of the tumor3.  Jakate et al from the University of Toronto undertook a comprehensive and intricately detailed classification of endometrial sarcomas with regards to morphology, immunohistochemistry, and cytogenetics. Their study required immunohistochemistry with the Ki67 antibody and they concluded that there are distinct profiles indicative of the undifferentiated versus low-grade sarcomas4.  Recently, He’s group used the Ki67 antibody in immunoblotting to assess the efficacy of folate-linked lipoplexes targeting claudin3 (CLDN3) in ovarian cancer gene therapy5.

Novus Biologicals offers Ki67 reagents for your research needs including:

PMIDs

  1. 2012175
  2. 20235278
  3. 20478998
  4. 22918161
  5. 24144916

Podoplanin (OST8, Glycoprotein (Gp) 36 or 38, Lung Type I Cell Membrane Associated Glycoprotein)

October 10th, 2014

Podoplanin is a mucin-type 1 transmembrane glycoprotein found in a wide range of tissues. It appears to be differentially expressed in endothelial cells of lymphatic but not blood vessel origin. In normal skin and kidney, podoplanin co-localizes with VEGFR3/FLT4, another marker for lymphatic endothelial cells. It appears to be involved in lymphangioigenesis and cell migration and is regulated by the lymphatic-specific homeobox gene Prox1. Podoplanin has also been found to be expressed on a wide variety of tumors. Immunohistochemical studies with the podoplanin antibody from Schacht’s lab is a crucial player in directing the processes of cell adhesion, migration, and tube formation for lymphatic vasculature formation1.

Immunohistochemistry-Paraffin: Podoplanin Antibody

Immunohistochemistry-Paraffin: Podoplanin Antibody

A research group from the University of Basel relied upon the podoplanin antibody to validate their NCAM-deficient transgenic mice as a model system for endogenous tumor lymphangioigenesis and lymph node metastasis2.  Findings from Steele et al used the podoplanin antibody in flow cytometry coupled with a protein-based screening strategy to identify a novel beta1 integrin-dependent mechanism of matrix metalloproteinase-10 (MMP10) in lymphatic vessel remodeling3. Recently, the podoplanin antibody allowed researchers at Wayne State University to study the effects of the small molecular inhibitor CARP-1 functional mimetics (CFMs) on malignant pleural mesothelioma (MPM)4.  Related gene array studies by the same group also used the podoplanin antibody to investigate the FDA-approved compound for alcoholism treatment disulfiram (DSF) which also has other interesting properties – those of anti-tumor and chemosensitizing5. DSF appears to suppress mesothelioma growth by inducing apoptosis through NFkB- and stress activated protein kinase (SAPK)-dependent signaling pathways.

Novus Biologicals offers Podoplanin reagents for your research needs including:

PMIDs

  1. 12853470
  2. 15574770
  3. 21406228
  4. 24598827
  5. 24690739

SOX9 – Be careful, I can reverse your gender!

October 8th, 2014

SOX9 is a member of the SOX family of HMG DNA-binding domain transcription factors. The protein encoded by this gene recognizes the sequence CCTTGAG along with other members of the HMG-box class DNA-binding proteins. cAMP and protein kinase A (PKA) stimulation appear to induce SOX-9 nuclear translocation through its nuclear import upon phosphorylation at two particular serine residues.   It is required for the development and differentiation of multiple cell lineages and is expressed in primary and recurrent prostate cancers. In prostate basal cells, SOX9 supports the development and maintenance of the luminal epithelium. Most likely a subset of prostate cancer cells subverts normal basal cell requirements through unregulated SOX9 expression.

Immunohistochemistry-Paraffin: SOX9 Antibody

Immunohistochemistry-Paraffin: SOX9 Antibody

Along with steroidogenic factor 1, SOX9 acts during chondrocyte differentiation to regulate transcription of the anti-Muellerian hormone (AMH) gene. Signaling deficiencies in this particular signaling network lead to the skeletal malformation syndrome campomelic dysplasia, frequently with sex reversal. Studies with the SOX9 antibody from Sharma’s lab indicate that the helix-loop–helix protein inhibitor of differentiation 4 (Id4) regulates normal prostate development by regulating androgen receptor binding to transcriptional response elements1.   Hodgin et al at Columbia relied upon the SOX9 antibody to generate a detailed molecular profile of focal segmental glomerulosclerosis (FSGS) from archived formalin-fixed paraffin-embedded (FFPE) renal biopsies2. Their gene expression microarray analyses revealed novel insights into the pathology of renal injury and structural degeneration.  Vestentoft’s group employed the SOX9 antibody to develop protocols for novel and sophisticated 3D visualizations and reconstructions of bile duct, vessels, and protein expression during liver development and disease3.

Novus Biologicals offers SOX9 reagents for your research needs including:

PMIDs

  1. 23786676
  2. 20847290
  3. 21943389