Anti-idiotypic vaccines consist of
antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
that have three-dimensional immunogenic regions, termed
idiotope
In immunology, an idiotope is the unique set of antigenic determinants (epitopes) of the variable portion of an antibody. In some cases it can be the actual antigen-binding site, and in some cases it may comprise variable region sequences outside ...
s, that consist of
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
sequences that bind to
cell receptor
In biochemistry and pharmacology, receptors are chemical structures, composed of protein, that receive and transduce signals that may be integrated into biological systems. These signals are typically chemical messengers which bind to a recepto ...
s. Idiotopes are aggregated into
idiotype
In immunology, an idiotype is a shared characteristic between a group of immunoglobulin or T-cell receptor (TCR) molecules based upon the antigen binding specificity and therefore structure of their variable region. The variable region of antigen ...
s specific to their target antigen. An example of an anti-idiotype antibody is
Racotumomab
Racotumomab
(trade name Vaxira) is a therapeutic cancer vaccine for the treatment of solid tumors that is currently under clinical development by Recombio, an international public-private consortium with the participation of the Center of Molec ...
.
Production and use
To produce an anti-idiotypic vaccine, antibodies that bind
tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
-associated antigens (TAA) are isolated and injected into mice. To the
murine
The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. Members of this subfamily are called murines. In terms of species richness, this subfamily is larger than all mammal families excep ...
immune system
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...
, the TAA antibodies are antigens and cause an immunogenic reaction producing murine antibodies that can bind to the "TAA idiotype" and is said to be "anti-idiotypic". The resulting murine antibodies are harvested and used to vaccinate other mice. The resulting antibodies in the second set of mice have a three-dimensional binding site that mimics the original antibodies that bind tumor-associated antigens. These antibodies are combined with an
adjuvant In pharmacology, an adjuvant is a drug or other substance, or a combination of substances, that is used to increase the efficacy or potency of certain drugs. Specifically, the term can refer to:
* Adjuvant therapy in cancer management
* Analgesic ...
and given as a vaccine. The murine immune system essentially "amplifies" a small mass of TAA antibodies into a much larger mass used to vaccinate
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s. Because the antibody produced using the "anti-idiotypic" process closely resembles the original epitope of the antigen, these antibodies can be used to induce immune responses from cellular to antibody-antigen for a given antigen, ''e. g.'', TAA, when administered as a vaccine to a human. They are mainly used for high risk cancer patients.
References
*''Ansel's Pharmaceutical Dosage Forms and Drug Delivery System'' (Page 513) ({{ISBN, 0-7817-4612-4)
Vaccines