Diseases, Conditions, Syndromes

SARS-CoV-2 antibodies detectable up to seven months post COVID-19 onset

A new study led by Marc Veldhoen, principal investigator at Instituto de Medicina Molecular João Lobo Antunes (iMM; Portugal) with an interdisciplinary team of clinicians and researchers from Faculdade de Medicina da Universidade ...

Oncology & Cancer

Taking the itch out of cancer immunotherapy

Using the body's immune system to fight cancer has great potential, but can also bring serious side effects, including itchy and painful skin reactions. But now, researchers from Japan have found how these skin reactions ...

Diseases, Conditions, Syndromes

Scientists develop new way to test for COVID-19 antibodies

When Dr. Stephen Smith of Seattle Children's Research Institute came down with muscle aches, gastrointestinal distress and a sudden loss of smell in late February, he suspected he had COVID-19. The testing criteria had yet ...

Diseases, Conditions, Syndromes

Convalescent plasma of limited use for COVID-19: study

Plasma taken from the blood of people who have recovered from COVID-19 and given to people sick with the disease does not reduce their chances of getting seriously ill or dying, new research has found.

Oncology & Cancer

Researchers discover molecular link between diet and risk of cancer

An international team of researchers has identified a direct molecular link between meat and dairy diets and the development of antibodies in the blood that increase the chances of developing cancer. This connection may explain ...

Diseases, Conditions, Syndromes

Neuropilin-1 drives SARS-CoV-2 infectivity, finds breakthrough study

In a major breakthrough an international team of scientists, led by the University of Bristol, has potentially identified what makes SARS-CoV-2 highly infectious and able to spread rapidly in human cells. The findings, published ...

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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