CD209

What is CD209 Protein?

CD209, or DC-SIGN, hangs out on immune cell surfaces like those of dendritic cells and macrophages. Imagine it as a lookout, catching intruders by grabbing onto specific sugars that decorate viruses or bacteria. The cool thing is, it helps the immune system decide when to attack by recognizing these foreign patterns. However, it's not all good news; some viruses like HIV, ebola, and even the pesky COVID-19 virus actually exploit CD209 to sneak into cells. With its role in both defense and sneak attacks by pathogens, CD209 is a hot topic in research, especially for designing therapies that block bad guys without messing with the essential functions of your immune system.

What is the Function of CD209 Protein?

CD209, often called DC-SIGN, is pretty much a lookout on immune cells such as dendritic cells and macrophages. It acts like a sensor, spotting intruders by hooking onto specific sugar molecules found on the surface of many viruses and bacteria. Once it's latched onto these sugars, it doesn't just sit around; it kicks off a series of immune responses. This protein is also involved in helping the immune cells communicate and can even assist viruses like HIV and SARS-CoV-2 in entering host cells, which isn't great but shows its wide range of interactions. Blocking this protein's action is being looked at as a way to slow down some infections or overly aggressive immune responses, especially in the case of severe cases of illnesses like COVID-19.

CD209 Related Signaling Pathway

CD209, or DC-SIGN, plays a key role in the immune system as it helps spot and respond to pathogens. It sits on the surface of certain immune cells like dendritic cells and macrophages. This protein acts as a kind of lookout, recognizing nasty invaders by binding to specific sugar molecules commonly found on viruses and bacteria. By doing so, it kicks off a series of immune responses. It's like a first alert that triggers further actions to tackle infections, playing into the larger web of immune signaling that battles pathogens.

CD209 Related Diseases

CD209, or DC-SIGN, plays a role in how our body deals with certain diseases, acting like a gateway for some nasty viruses to sneak into immune cells. This protein is like a handle virus particles use to get a grip on the host's cells. Notably, it's been linked to illnesses like COVID-19, Ebola, and HIV, where the viruses exploit CD209 to infect cells more efficiently. The way it aids these viruses suggests it's a key player in how some infections spread and worsen, potentially affecting the severity of diseases by influencing how the body's immune response gets triggered or dampened. Understanding its interactions could be critical for developing treatments that block these entry points, offering a way to fend off these infections.

Fig1. Potential implication of CD209 inhibitor in preventing SARS-CoV-2 damage in tumor patients. (Jinyuan Li, 2022)

Bioapplications of CD209

Recombinant CD209 protein, often known for its role as DC-SIGN, is used a lot in research and industry, mainly because it's a key player in immune system studies. Scientists use it to dive into how our bodies recognize and fight off pathogens, like viruses and bacteria. It's also a tool for developing new vaccines or treatments by figuring out how to block harmful interactions with viruses such as HIV or even something like COVID-19. Plus, in industrial settings, it's helping in the creation of diagnostic tests, giving us better ways to catch infections early. So, whether it's in labs for basic research or in industry for creating new tech, recombinant CD209 is pretty versatile.

Case Study 1: Vanessa Porkolab, 2018

On the surface of dendritic cells, C-type lectin receptors (CLRs) are key in spotting sugar-based signatures from harmful invaders and help regulate immune responses. But sometimes, these receptors get tricked by nasty viruses and bacteria. That's why making molecules that can precisely target one specific CLR—either to tweak the immune response or stop an infection—is super valuable in medicine. One example is trying to block DC-SIGN, which helps HIV latch onto T cells, without disrupting langerin, which clears the virus away. This is tricky since both receptors recognize similar sugars. In our research, we compared how well DC-SIGN and langerin stick to natural sugars, discovering that while both latch onto GlcNAc, adding sulfate groups can tilt preference towards langerin. We used special mutagenesis and X-ray analysis, finding that adding a 6-sulfate group to the sugar made it more specific to langerin. A particular part of langerin, the K313 residue, was key in its binding. With this info, we crafted a new sugar-like compound that specifically targets DC-SIGN over langerin. Tests showed our compound kept the natural binding feel but had a better grip and was exclusively for DC-SIGN.

Fig1. Inhibition curves for DC-SIGN (left) and langerin (right).

Fig2. Titration of glycomimetic 7 onto DC-SIGN ECD functionalized surface.

Case Study 2: Jonathan Cramer, 2021

DC-SIGN is a type of pattern recognition receptor found on macrophages and dendritic cells, playing a key role in how our bodies recognize invading pathogens. It's kind of a catch-all gateway for many nasty viruses like SARS-CoV-2, Ebola, and HIV-1. With the whole COVID-19 crisis, scientists have been eyeing DC-SIGN because it might be behind some of those severe cases by sparking intense immune responses. Blocking the virus from latching onto DC-SIGN could be a smart move to tone down these responses and stop the disease from getting worse. Researchers recently stumbled upon a new group of molecules that act as DC-SIGN blockers. These molecules, built from triazole-based mannose lookalikes, can stop SARS-CoV-2 from attaching to cells that have DC-SIGN, and even prevent the virus from using this receptor to hop onto other cells. This breakthrough offers a promising avenue for crafting super-targeted therapies against a range of viral threats by focusing on DC-SIGN.

Fig3. Thermal denaturation curve of DC-SIGN CRD in the absence and presence of 2 mM 9.

Fig4. Glycoprotein binding assay: DC-SIGN+ B-THP-1 cells were incubated with 10 nM Cy5-labeled SARS-CoV-2 spike glycoprotein S1 subunit.

CD209 has several biochemical functions, for example, carbohydrate binding,mannose binding,metal ion binding. Some of the functions are cooperated with other proteins, some of the functions could acted by CD209 itself. We selected most functions CD209 had, and list some proteins which have the same functions with CD209. You can find most of the proteins on our site.

CD209 has direct interactions with proteins and molecules. Those interactions were detected by several methods such as yeast two hybrid, co-IP, pull-down and so on. We selected proteins and molecules interacted with CD209 here. Most of them are supplied by our site. Hope this information will be useful for your research of CD209.

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