Novus Biologicals Blog

Factor VII – A Major Protein in Blood Coagulation

October 31st, 2014

Factor VII (coagulation factor VII) is a 50 kD multidomain single chain plasma glycoprotein synthesized in the liver. It is a vitamin K-dependent serine protease essential for the extrinsic pathway of hemostasis, or blood coagulation. Factor VII circulates in the blood in a zymogen form that is converted to an active form (via factor IXa, factor Xa, factor XIIa, or thrombin). Rare bleeding disorders (RBDs) are rare within the general community, but present both a diagnostic and effective treatment challenge due to the highly variable range in clinical presentation and cause. Defects in Factor VII cause coagulopathy and hemorrhagic disease, which range in severity from mild tolerable events to acutely severe and repeated hemarthroses and life-threatening intracerebral hemorrhages.

Immunohistochemistry-Paraffin: Factor VII Antibody

Immunohistochemistry-Paraffin: Factor VII Antibody

A review by James attempts to validate an adequate bleeding assessment tool, laboratory aspects, phenotyping, and optimal management of RBDs1.  Recent work using the Factor VII antibody from Favaloro’s group describes laboratory markers for hemostasis with regards to aging and age-related changes2. His review addresses changes in current measurable markers (Factors V, VII, and VIII, fibrinogen) and their implication for clinical and laboratory practice. Interesting work out of Unlu’s lab in the Netherlands used some Factor VII antibody experiments to correlate links between tumor-expressed coagulation factors and cancer progression and venous thrombosis3. Their publication reviews molecules such as tissue factor (TF), ectopic thrombin, and Factors VII and X on tumor growth and angiogenesis.

Novus Biologicals offers Factor VII reagents for your research needs including:

PMIDs

  1. 24762279
  2. 25099191
  3. 24862150

CRISPR-associated system 9 (CAS9)

October 30th, 2014

CAS9 is a novel DNA-cutting enzyme that is the main component of an intrinsic DNA editing system used by bacteria to kill attacking viruses. Clustered regularly interspaced short palindromic repeats (CRISPR) are distinct features of most bacterial genomes, and thought to be involved in resistance to bacteriophages. CRISPR is a primitive immune system of sorts that determines resistance specificity, as published by the Danisco Corporation in Science1. Because of CAS9’s ability to allow for parallel targeted DNA edits has huge implications in a wide range of applications, including gene therapy, agricultural advancements, and energy-producing microbes for biofuels. Deltcheva et al investigated mechanisms of CRISPR RNA maturation and identified a small trans-encoded RNA that appears to direct RNA-mediated immunity2.

Immunocytochemistry/Immunofluorescence: Cas9 Antibody

Immunocytochemistry/Immunofluorescence: Cas9 Antibody

Jinek et al were able to identify the CAS9 family members and demonstrate their utility in RNA-programmable genome editing in a 2012 Science paper3. Their results were complemented by another Science publication out of Mali’s lab; this paper established the CAS9 system as a facile, robust, and multiplexable tool for genome engineering in human cells4. A Methods in Molecular Biology chapter authored by Yang’s group at Harvard Medical School details the protocols for using the CRISPR system in human cells; in particular, design methods and construct generation, as well as optimized delivery protocols are shared5. Because of the ease of customization and synthesis compared to current brute sequence-specific endonucleases, the CAS9 system is an exciting and extremely versatile genome engineering breakthrough.

Novus Biologicals offers CAS9 antibodies for your research needs.

PMIDs

 

  1. 17379808
  2. 21455174
  3. 22745249
  4. 23287722
  5. 24557908

Scary Protein Names: Halloween Infographic Edition

October 29th, 2014

Check out some of the spooky protein names as we approach Halloween in our Scary Protein Name Infographic. Learn about their function, gene name, molecular weight and subcellular location. Featured proteins in this infographic include: SCARE1, DEAD Box Protein 60, Spo Spook, BAT3, BOO and GST. Happy Halloween!

Scary Protein Names

Novus Biologicals offers research reagents mentioned in this post including:

Download the PDF version of our Scary Protein Names Infographic.

Resources:

  1. http://www.uniprot.org/uniprot/P78380
  2. http://www.uniprot.org/uniprot/Q8IY21
  3. http://www.uniprot.org/uniprot/Q9VRM7
  4. http://www.uniprot.org/uniprot/P46379
  5. http://www.uniprot.org/uniprot/Q9HD36
  6. http://www.uniprot.org/uniprot/P09488

 

Ready, set, activate: (IL2RA/CD25)

October 27th, 2014

The Interleukin 2 Receptor alpha and beta chains, along with the common gamma chain, comprise the high affinity IL2 receptor(IL2R) that is present on both mature activated T- and B-cells, as well as early progenitors of T- and B-cells (thymocytes, pre B-cells, and T-regulatory cells). Formation of homodimeric alpha chains (IL2RA) results in a low affinity receptor, while homodimeric beta chains (IL2RB) produce a medium affinity receptor. IL2RA is normally an integral membrane protein, but a soluble IL2 Receptor alpha has been isolated and appears as the result of extracellular proteolysis. IL2RA plays a key role in lymphocyte differentiation, activation, and proliferation.

Immunohistochemistry-Paraffin: IL2RA/CD25 Antibody

Immunohistochemistry-Paraffin: IL2RA/CD25 Antibody

A standard processing and staining procedure to combat the known heterogeneity of human pancreatic islets was established using the IL2RA/CD25 antibody1. This rigorous method allowed for an extensive cross sectional analysis of pancreatic regions with respect to exocrine, ductular, and endocrine components. Resulting data was then curated into an online database collection for type 1 diabetes researchers. The IL2RA/CD25 antibody was also used in magnetic resonance (MR) scanning of dendritic cell (DC) migration in mice lymph nodes2. Joo’s group used a clinical MR scanner to noninvasively and dynamically follow prostaglandin E2 (PGE2)-induced DC migration to help reduce the costs of predictive DC therapy. Additionally, Crohn’s researchers employed the IL2RA/CD25 antibody to methodically evaluate and profile early pre-clinical disease in hopes of using early intervention to minimize disease severity3. Immunohistochemistry of various cell types and cytokines was performed in hopes of shedding etiological and pathogenesis data on early disease state and correlations between inflammation and other hallmarks.

Novus Biologicals offers IL2RA/CD25 reagents for your research needs including:

PMIDs

  1. 22665223
  2. 22009917
  3. 24411923

CD8 alpha – Marker for cytotoxic T lymphocytes

October 24th, 2014

The T-cell co-receptor CD8 is a cell-surface glycoprotein that bridges the lipid bilayer by interacting externally with ligands, such as major histocompatibility complex (MHC) class I, as well as internally with signaling molecules such as tyrosine kinase p56 lck. CD8 associates with lck through a zinc clasp structure and down regulates major Th2-type cytokine production. It is expressed on thymocyte subsets and cytotoxic T-cells and exists as either as a disulfide-linked homodimer or as a heterodimer of CD8 alpha and CD8 beta.  CD8 plays an important role in T-cell development in the thymus and T-cell activation in the periphery.

Immunohistochemistry: CD8 alpha Antibody

Immunohistochemistry: CD8 alpha Antibody

Early studies with the CD8 alpha antibody from Cambridge established different types of tolerance (reversible versus permanent) induced in peripheral T-cells in response to a wide range of antigens1.  Related tolerance studies from the same group relied upon the CD8 alpha antibody to demonstrate that a transplantation tolerance can be established using a simple, non-toxic anti-CD4 and anti-CD8 monoclonal antibody therapy2. Additional CD4 and CD8 studies out of  Takahashi’s lab employed the CD8 alpha antibody to map signaling molecules involved in mediating interleukin 2 (IL-2) downstream effects in T-cells3. Bankoti et al examined the effects of dioxin (TCDD) using the CD8 alpha antibody immunoblotting, which allowed them to monitor dendritic cell (DC) homeostasis and identify a splenic DC subpopulation highly responsive to dioxin4.  CD8 alpha antibody immunohistochemistry allowed bioengineers at Taiwan’s National Tsing Hua University to assess immune responses occurring during femoral bone defect healing5. These researchers found that baculovirus-engineered adipose-derived stem cells stimulated bone morphogenic protein 2 (BMP2), resulting in low immune response levels and enabled defect healing.

Novus Biologicals offers CD8 alpha reagents for your research needs including:

PMIDs

  1. 1702726
  2. 1980112
  3. 1608966
  4. 20211938
  5. 22796166

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