subject: Chimeric Antibodies [print this page] Chimeric antibodies are antibodies produced by combining the genetic material from a non human source with genetic material from a human being. Usually the composition of chimeric antibodies is two-thirds human. This helps reduce the risk of adverse reactions to foreign antibodies when used in the therapeutic setting. Humanisation of antibodies is a similar concept where the human genetic component is about 90% increasing its compatibility with human cells.
Research related to chimeric antibodies dates back to the 1980s, when recombinant technology and its uses in genetic research were investigated. Recombinant technology allows the splicing of genetic material from difference sources. This can then be fused. With a chimeric antibody which contains antibodies from animal cell culture and human genes, probable reactions with the animal genetic material can be identified and researched.
A number of chimeric antibodies based drugs have been approved for use by human beings with more in the pipeline. These compounds manifest as monoclonal antibodies which are produced by cloning the parent cell. The resulting antibodies are then used in treating diseases. Drugs whose names end with ximab are made from chimeric antibodies and drugs with humanized antibodies end with zumab suffix to help indentify them. Examples are Trastuzumab (or Herceptin) used in breast cancer and Infliximab (or Remicade) in autoimmune disorders.
What are humanized antibodies?
Antibodies from non human species whose protein sequence has been altered to increase their resemblance to natural antibodies in humans are called humanized antibodies. The humanization process relates to monoclonal antibodies developed for human use in non human settings, as in the case of antibodies in cancer fighting drugs.Protein sequences of antibodies thus generated are dissimilar to the natural human antibodies, making them potentially immunogenic in humans.
Monoclonal antibody sequencing
In monoclonal antibody sequencing, an antigen is injected into the animal, to trigger the production of antibodies. The cells are then cultured and fused with diseased cells. These fused cells result in different types of antibodies from which the required antibody can be chosen, purified and grown to create monoclonal antibodies. These are purified antibodies from single parent cell clones. The chimeric antibody is made with recombinant technology.
Sometimes, monoclonal antibodies may not be as effective as expected or even cause unfavorable reactions as a result of the foreign animal DNA used in antibody sequencing. This problem can be resolved by using a chimeric antibody which gets rid of part of the animal DNA. Antibodies as a result of humanization are even better as they further minimize the risk of undesired reactions. Medications developed using humanization are effective in treating diseases as they can be used to focus on a specific antigen in the infected cell without affecting the other cells in the body.
Today, molecular biology has progressed to the point of offering the ability to control immunoglobulin molecules to create more effective chimeric antibodies with unique properties. Antibodies like these are more effective in the treatment of diseases as they are tailored to show reduced immunogenicity. This increases its therapeutic value resulting in faster patent approvals and more treatment options for a number of diseases.
