Oncology & Cancer

Researchers convert pro-tumor macrophages into cancer killers

Epithelial cancers, such as cancers of the lung and pancreas, use the ανβ3 molecule to gain drug resistance to standard cancer therapies and to become highly metastatic. In a paper published in Cancer Research, University ...

Immunology

It's Fab! A hidden touch of antibody

In our immune system, antibodies recognize viruses, bacteria and even cancer cells through their Fab arms, initiating recruitment of leucocytes for the destruction of these invaders. The recruitment is mediated by receptors ...

Diseases, Conditions, Syndromes

Ebola expert weighs in on news of a potential cure

Scientists recently reported that two treatments saved the lives of people infected with the Ebola virus—with the New York Times reporting that roughly 90% of newly infected patients were saved—suggesting we are ever ...

Overweight & Obesity

Gut-brain connection helps explain how overeating leads to obesity

Eating extra servings typically shows up on the scale later, but how this happens has not been clear. A new study published today in the Journal of Clinical Investigation by a multi-institutional team led by researchers at ...

Diseases, Conditions, Syndromes

Lassa virus' soft spot revealed

As this year's Lassa fever outbreak in Nigeria is finally ebbing, the total tally came to more than 600 infected people, one-quarter of them dead. Thousands more die each year, uncounted in rural villages throughout West ...

Medications

Bringing cancer medication safely to its destination

Treating cancer more selectively and more effectively—this could be achieved with an innovative technology developed by teams of researchers at the Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and the ...

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Antibody

Antibodies (also known as immunoglobulins, abbreviated Ig) are gamma globulin proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses. They are typically made of basic structural units—each with two large heavy chains and two small light chains—to form, for example, monomers with one unit, dimers with two units or pentamers with five units. Antibodies are produced by a kind of white blood cell called a plasma cell. There are several different types of antibody heavy chains, and several different kinds of antibodies, which are grouped into different isotypes based on which heavy chain they possess. Five different antibody isotypes are known in mammals, which perform different roles, and help direct the appropriate immune response for each different type of foreign object they encounter.

Although 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. This region is known as the hypervariable region. Each of these variants can bind to a different target, known as an antigen. This huge diversity of antibodies allows the immune system to recognize an equally wide diversity of antigens. The unique part of the antigen recognized by an antibody is called an epitope. These epitopes bind with their antibody in a highly specific interaction, called induced fit, that allows antibodies to identify and bind only their unique antigen in the midst of the millions of different molecules that make up an organism. 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, for example, binding to a part of a pathogen that it needs to cause an infection.

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. Antibody genes also re-organize in a process called class switching that changes the base of the heavy chain to another, creating a different isotype of the antibody that retains the antigen specific variable region. This allows a single antibody to be used by several different parts of the immune system. Production of antibodies is the main function of the humoral immune system.

This text uses material from Wikipedia, licensed under CC BY-SA