With more than 170,000 publications in 2016, inflammation remains a “hot” topic in today’s Life Science research (source: Google Scholar). Interestingly, ELISA kits are still one of the most popular tools for the accurate quantification of human cytokines involved in this biological process. Here, we review the 5 protein targets most studied by our clients, together with their favourite ELISA kits by RayBiotech in the field of inflammation.
Today, I’d like to give you an overview about methods in actin research with validated R&D products and kits which will allow you to measure binding to actin and effects on the polymerisation dynamics of actin.
Actin functions as one of the major cytoskeleton structures. It is involved in a plethora of processes in cell biology: stabilizing the cell shape, cell movements (e.g. cell migration) and intracellular movements and transport mechanisms.
Actin is a 43 kDa protein that is very highly conserved between species. Actin has three main isotypes (α-actin, β-actin and γ-actin), which show >90% amino-acid (aa) homology between isotypes and >98% homology within members of a particular isotypic group. [Read more…]
The term Autophagy was introduced by Christian de Duve during the Ciba Foundation Symposium on Lysosomes – which was held in London in February 1963. In 1974 he was honoured with the Nobel price in Physiology or Medicine for his pioneering research about peroxisomes and lysosomes. In 2016, once more, a pioneer in the field of autophagy research won the Nobel price: Yoshinori Ohsumi, a Japanese researcher, whose findings “led to a new paradigm in our understanding of how the cell recycles its content”.
Autophagy (Autophagocytosis) describes the fundamental catabolic mechanism during which cells degrade dysfunctional and unnecessary cellular components. This process is driven by the action of lysosomes and promotes survival during starvation periods as the cellular energy level can thus be maintained. [Read more…]
StemBeads® FGF2 is a revolutionary growth factor supplement that offers a more efficient way to grow FGF2 dependent stem cell cultures.
This supplement delivers a steady release of growth factor into your media of choice creating a more stable environment allowing for:
- Reduction of media changes by 67%
- Better culture quality through reduction of spontaneous differentiation
- No change of culture conditions – use your favourite media
I hear you thinking “Well, that’s just more marketing promises… “. Well, it isn’t, it’s real life!
Just read on and see some of the feedback from researchers… [Read more…]
Protein arrays enable the analysis of the biological function / activity of dozens to hundreds of proteins in one experiment (e.g. auto-antibody detection, protein-protein interactions, small molecule screening…). In this post, let’s review the recent Raybiotech Protein Arrays focusing on Immunology.
Immunotherapy represents a field in Drug Discovery which is quickly developing and leading to significant progress in treatments of a number of diseases, especially cancer. The approach is based on inducing, enhancing, or surpressing an immune response. Therapeutic manipulation of immunopathways has led to promising clinical results . The first therapeutic antibodies directed against the checkpoint receptor PD-1 have been already brought to the market (Nivolumab, Pembrolizumab) by Bristol Myers Squibb and Merck/MSD respectively, and approved for the treatment of diverse cancer types.
Today, I would like to review tools to build up a comprehensive assay set up for cell based inhibitor screening on PD-1 / PD-L1/PD-L2 binding. [Read more…]
Research tools aimed at exploring mitochondria are becoming more and more popular and cover multiple experimental applications. They go from primary antibodies validated for immuno-assays (see “10 Mitochondrial marker antibodies“) to fluorescent probes for mitochondria-related events monitor in living-cells (e.g. MitoPeDPP for live cell imaging, mitophagy or singlet Oxygen (1O2) detection…). Here I’d like to introduce 3 new molecules developed by Focus Biomolecules to further decipher mitochondrial biology.
ADCC is a simple but important mechanism for the immune system to target diseased or infected cells. Antibodies bind to specific antigens on the surface of the target cell (see Fig 1). PBMCs or natural killer (NK) cells, express Fc receptors on their cell surface and act as the effector cells. Interaction between the Fc region of the antibody and the Fc receptor induces the effector cell to degranulate, releasing IFN-γ, granzymes, and other cytotoxic compounds that lyse the target cell.
ADCC is not only a natural part of the adaptive immune response, but animal experiments have shown that it can also be seen as an important mechanism of action of therapeutic monoclonal antibodies (1), including the breast cancer drug trastuzumab, and rituximab, a drug used to treat diseases which show overactive, dysfunctional, or excessive numbers of B cells (e.g. lymphomas).
Cell lines to build up cellular ADCC screening assays
To enable researchers to build up a cellular ADCC screening system, BPS Biosciences have developed 2 reporter cell lines, which can replace NK cells or PBMCs in such a cellular assay (see Fig 2). The system is based on Jurkat cells that stably express human FcγRIIIa (CD16a), the receptor for the Fc region of human IgG. The FcγRIIIa on the Jurkat cells binds to the IgG on the surface of the target cell. This crosslinking causes the Jurkat cells to activate NFAT transcription, which induces the expression of luciferase and can be easily detected using the ONE-Step™ Luciferase Detection Reagents.
The effectiveness of ADCC depends on how well the effector cells are activated after the engagement of FcγRIIIa. Human FcγRIIIa displays dimorphism at amino acid 158 – one allele (V158) encodes a high Fc affinity receptor variant, while the other (F158) encodes a lower Fc affinity receptor variant. BPS offers 2 different ADCC cell lines expressing either of these Fc receptors to allow selective antibody binding analyses using each type of receptor.
- ADCC Bioassay Effector Cell, F variant (Low Affinity)
- ADCC Bioassay Effector Cell V variant (High Affinity)
Get more information about our ADCC cell lines – just leave your questions or comments in the form below!
(1) Clynes, RA, Towers, TL, Presta, LG, Ravetch, JV; Inhibitory Fc receptors modulate in vivo cytotoxicity against tumor targets; Nat Med. 6 (4): 443-446 (2000)
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Determining the linkage of polyubiquitin on target proteins is challenging. The traditional methods are either through Mass Spectrometry or immunoblot with linkage specific antibodies, which are cumbersome. LifeSensors has developed the UbiTest assay, a more definitive method for demonstrating the ubiquitylation linkage of a protein, which is to couple immunoprecipitation of polyubiquitylated protein with digestion by a linkage specific deubiquitylase prior to immunoblot analysis. An increased signal for the unmodified substrate or a decreased signal of polyubiquitylated substrate at high molecular weight after K48/K63 specific DUB treatment is a clear indication that the protein was K48/K63 ubiquitylated. [Read more…]