by Jack
Antibodies (also known as immunoglobulins) are a type of protein that is found in blood or other bodily fluids of vertebrates (mammals), and are used by the immune system to identify and eliminate foreign objects, such as bacteria and viruses. Once it’s been wiped out our antibodies are programmed to go after it even faster if its re-introduced, which is why there are some diseases that we can only get once – we’ve built up an immunity. New research suggests antibodies may replace antibiotics.
How they work: Antibodies are produced by a white blood cell called a plasma cell and there are five different antibody types known in mammals. They perform different roles, and help direct the right immune response for each different type of foreign object they encounter. Pretty cool, eh?
Though the general structure of all antibodies is very similar, a small region at the tip of the protein is extremely variable, allowing millions of antibodies with slightly different tip structures, or [antigen] binding sites, to exist. Each of these variants can bind to a different target, known as an antigen.
Diversity makes us stronger: This huge diversity of antibodies in our system allows the immune system to recognize an equally wide variety of antigens. The unique part of the antigen recognized by an antibody is called the epitope. These epitopes bind with their antibody in a highly specific interaction. This is called an induced fit, and it allows antibodies to identify and bind only their unique antigen. Recognition of an antigen by an antibody ”tags” it for attack by other parts of the immune system. Antibodies can also neutralize targets directly by binding to a part of a pathogen that it needs to cause an infection or replication.
The large and diverse population of antibodies is generated by random combinations of a set of gene segments that encode different antigen binding sites (or ”paratopes”), followed by random mutations in this area of the antibody gene, which create further
diversity.
Production of antibodies is the main function of your body’s immune system.
Science has identified 11 broad uses for human antibodies and while the technical explanation may only be suitable only for 4th year medical students, let’s just say that the five kinds of antibodies we have in our bodies and their 11 know categories of use are designed to handle virtually every threat by a pathogen entering your body.
However, as good as this system may be even an antibody has it’s limits and they may not always recognize the invader or they may recognize it too late. In that case they can be overwhelmed by rapidly multiplying pathogens, i.e., virus or bacteria.
Currently we face the threat of viral and bacterial infections that are resistant to antibiotics. This happens because bacteria and viruses [evolve] very quickly. During this evolution they make mistakes as they copy themselves. This leads to a slightly different bacteria or virus. Science does this on purpose to come up with designer drugs that are just different enough to fill a specific purpose the latter version couldn’t.
So, if there is a drug that is harming the bacteria or virus then eventually one of the flawed copies will be resistant to the drug. When this happens it replicates a whole new strain of bacteria or virus that is drug resistant.
We are fast approaching a time when antiviral drugs will be virtually useless, but hopefully not before science is able to come up with a whole new therapy.
This is where it gets really interesting and that returns us to the [antibody]! Our own immune system holds the key to saving the human race, but only if we can rev up the body’s immune system sufficiently. If we can, well, the results could be mind boggling.
A supercharged immune system could in theory wipe out any bacterial or viral infection before they even knew what hit em! They won’t be able mutate fast enough to keep up with a super aggressive antibody. And once our immune system are treated – we’re good for a lifetime.
The way it looks right now is those super antibodies will have to evolve from a culture that attacks one particular pathogen, up to a cultured antibody that has been exposed to every disease known to man and then used like a vaccine.
It sounds like such a simple solution, but it’s really not. However, the good news says existing technology makes it’s within our reach. For example, we now know the basics of antibodies can target foreign matter in our blood stream and tissues and which antibodies work best on a given category of pathogens and that’s a big start.
The next step will be to use antibodies to seek out damaged DNA. That opens the door for a cure to whole host of genetic diseases. Imagine, if we can vaccinate with specific designer antibodies that will attack and eliminate damaged DNA, we could possibly cure every genetic disease known!
This latter area will require far more research than modifying an antibody to attack a particular type of cancer cell, which is in itself going to be quite a challenge. However, we are close to doing just that. Perhaps in a few years, a decade or two, but we are very close to unlocking the secret of the humble antibody and then programming it to do what we want. The cure disease could be right around the corner and we certainly hope so, because time is not on our side…antibiotics will no longer be effective in a few decades.
http://www-users.med.cornell.edu/~jawagne/Antibody_Approaches.html
http://huehueteotl.wordpress.com/2007/09/07/how-antibodies-fight-hiv-new-evidence/
http://www.protocol-online.org/biology-forums-2/posts/15909.html
http://wanttoknowit.com/what-are-antibodies/
http://bacteriamuseum.org/cms/How-We-Fight-Bacteria/our-immune-system-fights-against-bacteria.html
http://www.genzyme.com/Research/Technology-Platforms.aspx