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Novel antigen vehicles

Immunity is the ability of an organism to recognise and defend itself against specific pathogens or antigens. IDM has developed an immunisation method using microparticles, which carry antigens on their surface and induce the specific activation of the relevant cells of the immune system.
Novel antigen vehicles
The immune system provides a remarkable defense system, which involves the production of antibodies and the generation of specialised lymphocytes against specific antigens. The antigens are substances from a pathogen or foreign organism that provoke an immune response. This leads to an orchestrated activation of millions of cells of several types and functions at multiple sites in the body. Each antigen may have several small parts (epitopes), which are recognised and interact with different antibodies.

The immune response may be humoral (antibody-mediated) or cellular (cell mediated). Humoral immunity involves antibodies, which are produced by a subset of lmphocytes called B cells, and constitute the defense mechanism against bacteria and viruses that circulate freely in body fluids, before they enter cells. Cellular immunity involves a specialised set of lymphocytes called T cells that recognise foreign antigens on the surface of cells, organisms or tissues. This response makes up the defense against bacteria and viruses that are inside host cells and are inaccessible to antibodies.

It is of crucial importance, while designing an immunisation method or vaccine, to identify and achieve the precise activation of the intended cells. The specificity of the immune response is well optimised by the use of a suitable antigen vehicle. IDM has developed synthetic polymer microparticles carrying on their surface one or more proteins. The coupling of the protein is covalent, so as to avoid the liberation of the antigen in a soluble form. The orientation of the immune response (cellular/humoral) is modified by adjusting the protein concentration and size on the surface of the particle.

The average diameter of the particles is between 0,25 and 1,5 microns, leading the associated antigens to be presented only to T cells and inducing their immune response. The microparticles can be made of biocompatible polymers, such as acrylic polymers, copolymers of lactic and glycolic acids or lactic acid polymers.

Related information

Record Number: 80921 / Last updated on: 2005-09-18
Domain: Biology, Medicine