Crossword clues for antibody
antibody
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Antibody \An"ti*bod`y\ ([a^]n"t[i^]*b[o^]d`[y^]), n.
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(Med., Physiol. Chem.) Any of various bodies or substances in the blood which act in antagonism to harmful foreign bodies, as toxins or the bacteria producing the toxins. Normal blood serum apparently contains various antibodies, and the introduction of toxins or of foreign cells also stimulates production of their specific antibodies by the immune system.
Note: In certain ``autoimmune'' diseases, the immune system of an organism may produce antibodies to parts of the organism's own structure, and can cause considerable damage and even death as a result.
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(Med., Physiol. Chem.) more narrowly, any of the immunoglobulins present in the blood serum or other body fluids of an animal, which reacts with a specific antigenic substance, whether the antibody was produced as a consequence of the stimulus provided by the antigen, or was pre-existing prior to exposure of the organism to the antigen.
Note: The soluble antibodies present in serum are complex globins (proteins) with both constant and variable regions in the polypeptide chains, the variable region being responsible for the reaction of the antibody with its specific antigen. Typically, antibodies of more than one structure may react with a given antigen, and any given antigen may stimulate production of more than one antibody. Methods have been developed to grow cells in tissue culture which produce predominantly only one specific antibody, and such antibodies thus produced (called monoclonal antibodies) are highly specific in their reactions to molecular strucures, and are used as valuable reagents in biochemical technology.
Douglas Harper's Etymology Dictionary
Wiktionary
n. (context immunology English) A protein produced by B-lymphocytes that binds to a specific antigen.
WordNet
n. any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response
Wikipedia
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to identify and neutralize pathogens such as bacteria and viruses. The antibody recognizes a unique molecule of the harmful agent, called an antigen, via the Fab's variable region. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (similarly analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by other parts of the immune system, or can neutralize its target directly (for example, by blocking a part of a microbe that is essential for its invasion and survival). Depending on the antigen, the binding may impede the biological process causing the disease or may activate macrophages to destroy the foreign substance. The ability of an antibody to communicate with the other components of the immune system is mediated via its Fc region (located at the base of the "Y"), which contains a conserved glycosylation site involved in these interactions. The production of antibodies is the main function of the humoral immune system.
Antibodies are secreted by B cells of the adaptive immune system, mostly by differentiated B cells called plasma cells. Antibodies can occur in two physical forms, a soluble form that is secreted from the cell to be free in the blood plasma, and a membrane-bound form that is attached to the surface of a B cell and is referred to as the B-cell receptor (BCR). The BCR is found only on the surface of B cells and facilitates the activation of these cells and their subsequent differentiation into either antibody factories called plasma cells or memory B cells that will survive in the body and remember that same antigen so the B cells can respond faster upon future exposure. In most cases, interaction of the B cell with a T helper cell is necessary to produce full activation of the B cell and, therefore, antibody generation following antigen binding. Soluble antibodies are released into the blood and tissue fluids, as well as many secretions to continue to survey for invading microorganisms.
Antibodies are glycoproteins belonging to the immunoglobulin superfamily. They constitute most of the gamma globulin fraction of the blood proteins. They are typically made of basic structural units—each with two large heavy chains and two small light chains. There are several different types of antibody heavy chains that define the five different types of crystallisable fragments (Fc) that may be attached to the antigen-binding fragments. The five different types of Fc regions allow antibodies to be grouped into five isotypes. Each Fc region of a particular antibody isotype is able to bind to its specific Fc Receptor (except for IgD, which is essentially the BCR), thus allowing the antigen-antibody complex to mediate different roles depending on which FcR it binds. The ability of an antibody to bind to its corresponding FcR is further modulated by the structure of the glycan(s) present at conserved sites within its Fc region. The ability of antibodies to bind to FcRs helps to direct the appropriate immune response for each different type of foreign object they encounter. For example, IgE is responsible for an allergic response consisting of mast cell degranulation and histamine release. IgE's Fab paratope binds to allergic antigen, for example house dust mite particles, while its Fc region binds to Fc receptor ε. The allergen-IgE-FcRε interaction mediates allergic signal transduction to induce conditions such as asthma.
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. This region is known as the hypervariable region. Each of these variants can bind to a different antigen. This enormous diversity of antibody paratopes on the antigen-binding fragments allows the immune system to recognize an equally wide variety of antigens. The large and diverse population of antibody paratope is generated by random recombination events 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. This recombinational process that produces clonal antibody paratope diversity is called V(D)J or VJ recombination. Basically, the antibody paratope is polygenic, made up of three genes, V, D, and J. Each paratope locus is also polymorphic, such that during antibody production, one allele of V, one of D, and one of J is chosen. These gene segments are then joined together using random genetic recombination to produce the paratope. The regions where the genes are randomly recombined together is the hyper variable region used to recognise different antigens on a clonal basis.
Antibody genes also re-organize in a process called class switching that changes the one type of heavy chain Fc fragment 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 different types of Fc receptors, expressed on different parts of the immune system.
Antibody is a 2002 science fiction thriller directed and edited by Christian McIntire that debuted as a Sci Fi Pictures TV-movie on the Sci Fi Channel on February 8, 2002.
A scientist ( Lance Henriksen) leads a team in an experimental miniaturized craft injected into the bloodstream of a dying terrorist ( Julian Vergov) whose body conceals a computer chip that will trigger a nuclear explosion in the U.S. Capitol Building in less than 24 hours.
An antibody is a type of protein used by the immune system.
Antibody or antibodies may also refer to:
- Antibodies (film), a 2005 German film
- Antibody (film), 2002 science fiction film
Usage examples of "antibody".
The usual reason for antibody testing is as a check to see if somebody needs to renew their shots.
Also, there are situations where testing for the antibody to a pathogen suspected of causing a condition can make sense, given the right circumstances.
A positive HIV result from somebody who is completely symptom-free, on the other hand, means either that the antibody has been carried from birth without the virus ever having been encountered, or that the virus has been successfully neutralized to the point of invisibility.
The antibody coating seemed to stiffen and tighten and the bacterium within writhed.
To retrieve and decode that sliver, Riveroma needs a string of information that will be found coded onto a specific antibody which he will find in your bloodstream.
Tell us how we get our hands on the antibody, or I unleash Jack and Carl on you.
A survivor was important because he or she would have developed an antibody to combat the virus, or antigen.
With the antibody identified, scientists could at least be creating blood tests for screening out carriers.
If this is a virus infection, we might only need to find an antibody for inoculation to stop it in its tracks.
Controls were needed, to be certain that the antibody suspension alone was bringing about the changes seen and not something else.
Preliminary skin-tests of the antibody suspension showed no sign of untoward reaction.
But when they had tried to apply the antibody in the afflicted patients, the response had been totally unexpected.
A specific antibody used against a specific virus should have destroyed the virus or slowed its progress, and there seemed to be no rational explanation for the dreadful response of the uninfected ones who had been inoculated for protection.
Even those of us who have not been affected so far are beginning to feel the early symptoms of the antibody attack.
Once trapped in the node, the bacterium is handled by antibodies or, if that fails, by white cells mobilized for battle.