For humans, IFN-α consists of a group of proteins that are greater than 85% homologous by amino acid sequence. A lot of individual human IFN-α subtypes have been identified and many have different properties. For the moment, we don’t know exactly why there are multiple IFN-α subtypes. A variety of studies suggested they possess overlapping but also unique sets of biological activities. Quantification of IFN is essential but usually methods don’t take account all IFN types. In this post, I would like to focus on a relevant ELISA kit to avoid this problem.
Stem Cells: a great tool for biomedical research! From the embryo at a very early stage of development, stem cells have two important capabilities: to multiply to infinity by simple division and to give rise to all kind of cells of the organism. These properties offer many opportunities, not only for the regenerative medicine but also for the study of genetic diseases and development of new treatments.
One of the first thing to do when you’re working on this kind of cells is to check if they are really stem cells, i.e their stemness. It can be highlighted by different markers by IF, WB, etc…
Today, I invite you to look at a popular antibody allowing you to monitor the level of differentiation of your cellular model as well as an innovation related to antibody array and stem cell research.
Early in 2015, researchers of The University of Queensland Diamantina Institute (Australia) have shown a very sensible approach to the discovery of new biomarkers associated to transition from non-metastatic tumours to metastatic tumours in osteosarcoma. Not to be a spoiler, but they found that the uPA/uPAR axis is crucial for this, and can be used as a prognostic biomarker. In fact, inhibition of this axis can inhibit the metastasis in this type of tumours. (Endo-Muñoz et al. DOI: 10.1371/journal.pone.0133592).
I don’t want to focus on the biomarker per se, but rather, on the process that this lab followed to discover this new biomarker. [Read more…]
New techniques such as cDNA microarrays have enabled us to analyse global gene expression. However, almost all cell functions are executed by proteins, which cannot be studied simply through DNA and RNA techniques. In fact, experimental analysis clearly shows disparity can exist between the relative expression levels of mRNA and their corresponding proteins (1).
Therefore, analysis of the proteomic profile is critical, especially in processes that rely on secreted proteins (e.g. inflammation). The conventional approach to analysing multiple protein expression levels has been to use 2-D SDS-PAGE coupled with mass spectrometry. However, these methods are slow, expensive, labor-intensive and require specialised equipment. Moreover, these traditional methods of proteomics are not sensitive enough to detect most secreted biomarkers (typically at pg/ml concentrations).
For some years now, antibody arrays have been available to study markers and publish their discoveries in various areas like Immunology, Atherosclerosis, Inflammation, Angiogenesis, Immunoediting and even signaling pathways (ex. phosphorylation, Receptor Tyrosine Kinases…). So far, however, and in spite of the growing demand by researchers working on stem cells, there were no antibody arrays for this area of research, meaning that individual Western Blots had to be performed. But not any more! [Read more…]
First at all, a quick reminder… Cytokines play important roles in inflammation, innate immunity, angiogenesis and cell growth. They are involved in a lot of disease processes like cancer, obesity and inflammatory and neurobiological diseases.
The RayBio® Membrane-Based Antibody Arrays (C-Series) are tools for screening and comparing expression levels of many cytokines, growth factors, proteases, soluble receptors, and other proteins in a wide variety of sample type.
After these brief definitions, today I would like to introduce you to a new tool allowing multiple cytokine detection. RayBio C-series Neurobiological Discovery Arrays will help you to measure several factors in inflammation, immunology. This method is very popular and can be used for two species: human and mouse.
If you are using protein immunoblots, we would like to share with you some recent publications in top-tier journals highlighting the applications of Antibody Arrays for secretome studies. These arrays act as a multiplex western blot, detecting up to 274 proteins in one experiment with high specificity.
So rather than using hundreds of antibodies or ELISAs, or stripping and re-probing blots, you can use Antibody Arrays and compare expression levels of many cytokines, growth factors, receptors, and other proteins in a single assay!. And if you are too busy or prefer experts to take care of your valuable samples, do not hesitate to contact tebu-bio’s laboratory, a certified service provider, for performing your array experiments for Biomarker discovery and Protein Multiplex quantification.
Below you’ll find a selection of publications published in 2015 based on various types of Antibody Arrays:
- Human Cytokine array 6 in Blood – Balakumaran A. et al. “Bone marrow skeletal stem/progenitor cell defects in patients with dyskeratosis congenita and telomere biology disorders. Blood. 2015 Jan 29;125(5):793-802. doi: 10.1182/blood-2014-06-566810.
- Human Cytokine array 5 in Oncogene – Sharif GM. et al. “Cell growth density modulates cancer cell vascular invasion via Hippo pathway activity and CXCR2 signaling.” Oncogene. 2015 Mar 16. doi: 10.1038/onc.2015.44.
- Mouse Cytokine array 1000 in PLoS One – Arshad A et al. (2015) “Simultaneous Irradiation of Fibroblasts and Carcinoma Cells Repress the Secretion of Soluble Factors Able to Stimulate Carcinoma Cell Migration.” PLoS ONE 10(1): e0115447. doi:10.1371/journal. pone.0115447.
- Mouse Inflammation 1 in Laboratory Investigations – Wen J. et al. “Low doses of CMV induce autoimmune-mediated and inflammatory responses in bile duct epithelia of regulatory T cell-depleted neonatal mice. Lab Invest. 2015 Feb;95(2):180-92. doi: 10.1038/labinvest.2014.148.
- Mouse Q4000 in Clinical and Vaccine Immunology – Kurtz S., Elkins K. “Correlates of vaccine-induced protection against TB immune revealed in comparative analyses of lymphocyte populations.” Clinical and Vaccine Immunology, Accepted manuscript posted online 12 August 2015, doi: 10.1128/CVI.00301-15.
- Human G1000 in PLoS One – Gomez DL et al. (2015) “Neurogenin 3 Expressing Cells in the Human Exocrine Pancreas Have the Capacity for Endocrine Cell Fate. PLoS ONE 10(8): e0133862. doi:10.1371/ journal.pone.0133862.
- Human Apoptosis Array in Drug Design and Development – Ahmadipour F. et al. “Koenimbin, a natural dietary compound of Murraya koenigii (L) Spreng: inhibition of MCF7 breast cancer cells and targeting of derived MCF7 breast cancer stem cells (CD44+/CD24-/low): an in vitro study.” Drug Des Devel Ther. 2015 Feb 24;9:1193-208. doi: 10.2147/DDDT.S72127.
Contact us to know more on how we can help you to publish in high-quality journals!
Today, I’d like to give some tips & tricks on how to select an antibody… by reading its datasheet.
Obvious as it may seem, the datasheet is in fact contractual. It states the characteristics and guaranteed performance of a given product in general, or an antibody in particular. So it should be read carefully before taking a purchasing decision. No matter if you saw a great antibody detecting protein X in polar bear in some publication. If polar bear is not one of the validated species in the datasheet, the antibody is not guaranteed and you won’t get a replacement or refund. [Read more…]
Immunoediting of cytokine signals provides another area of pathways which tumours utilise to evade and potentially escape from immunological targeting. This post aims at shedding some light into the Tumour Microenvironment (TME) and particularly on how the tumour recruits accomplices to grow and disseminate. [Read more…]
Classically, it was known that CD4+ T cells, upon activation and expansion, develop into different T helper cell subsets with different cytokine profiles and distinct effector functions to effect the immune response. Until some years ago, T cells were divided into Th1 or Th2 cells, depending on the cytokines they produce (1).
However, a third subset of IL-17-producing effector T helper cells, called Th17 cells, was discovered and characterised. Th17 cells produce several factors that can be quantified with one single multiplex immunoassay (e.g. IL-17, IL-17F, and IL-22). Th17 cells seem to induce a massive tissue reaction owing to the broad distribution of the IL-17 and IL-22 receptors.
Th17 cells also secrete IL-21 to communicate with the cells of the immune system. The differentiation factors (TGF-β plus IL-6 or IL-21), the growth and stabilization factor (IL-23), and the transcription factors (STAT3, RORγt, and RORα) involved in the development of Th17 cells have also been identified. Th17 cells thereby seem to be mainly involved in clearing pathogens during host defense reactions and in inducing tissue inflammation in autoimmune disease.
Let’s focus on the role of TGF-β. Though it has been shown to positively regulate the development of murine T helper type 17 (Th17) cells, which of the intracellular signaling pathways are involved is controversial. A recent publication using protein antibody arrays found an increase of expression and phosphorylation of the following Smad-independent signaling molecules in Th17-polarized wild-type T cells: AKT1(Tyr474), AKT2 (Ser474), ERK1-p44/42 MAPK(Tyr204), mTOR(Thr2446), p38 MAPK(Thr180), Rac1/cdc42(Ser71), SAPK/JNK(Tyr185) and SP1(Thr739) (2).
Discovery of so many signaling molecules was only possible as the antibody arrays allowed the screen dozens (or even hundreds!) of targets in a simultaneous way. Probably, if the research had involved picking different targets and doing individual WBs, there would have been a byass on what markers to study, and some of the ones mentioned above may never have been detected.
Th17 cells also have a role in tumour microenvironment (TME). It has been found that the Th17 cell survival factor, IL-23, is overexpressed in tumor tissues isolated from mice and human breast cancer patients. It has been indicated that tumor-secreted PGE2 induces IL-23 production in the TME, leading to Th17 cell expansion. This inductive effect of PGE2 is mediated through cAMP/PKA signaling transduction pathway (3).
For further updates on effector molecules in the Th17 pathway, don’t hesitate to suscribe to our blog!
1.- Korn, R. et al (2009). Annual Review of Immunology. Vol. 27: 485-517. DOI: 10.1146/annurev.immunol.021908.132710.
2.- Hasan, M. et al (2015). Immunol Cell Biol. 2015 Aug;93(7):662-72. doi: 10.1038/icb.2015.21.
3.- Qian, X. et al (2013). J Immunol. 2013 Jun 1;190(11):5894-902. doi: 10.4049/jimmunol.1203141.