Immunity that is elicited by natural exposure to a pathogen or foreign substance or by vaccination.
Any substance that non-specifically stimulates the immune response to an antigen.
A protein (immunoglobulin) secreted by plasma cells that recognizes antigenic determinants on an antigen.
A substance recognized by antibody or a T cell receptor.
The part of an antigen, also known as an epitope, that is recognized by specific antibody or T cell receptor.
Variation in the serological reactivity of an antigen due to differences in amino acid sequences or chemical modifications.
A cell free fraction of blood that contains antibodies.
Attenuated vaccineA vaccine comprising a living microorganism that has been modified so that it is no longer able to produce disease (i.e. is attenuated) but has retained the ability to elicit a protective immune response.
B cellA type of white blood cell known as a lymphocyte that expresses membrane bound antibody. B cells specifically interact with antigen, a signal that causes the B cell to develop into an antibody-secreting cell or a memory cell.
Antibody that binds to bacteria and enables the immune system to kill the bacteria.
A macromolecular network, usually polysaccharide, that covers the surface of some bacteria. Capsules enable pathogenic bacteria to avoid killing by host defenses.
A molecule containing antigenic determinants recognized by T cells. Conjugation of a
poorly immunogenic polysaccharide (T cell independent antigen) to a carrier can improve the immunogenicity of the polysaccharide.
Cell mediated immunity
The part of the immune response mediated by antigen-specific T cells and various non-specific cells of the immune system. Cell-mediated immunity is largely responsible for providing protection against viruses, cancer and bacteria that are capable of living inside mammalian cells.
Identical cells arising from a single cell.
The ability of bacteria to establish and maintain themselves on the skin and mucous membranes. The colonization of these surfaces by bacteria is usually not harmful to the host and may indeed be benefical. However, for certain bacteria, colonization may be the first step leading to the development of disease.
The collective name for a group of proteins found in blood that is involved in killing foreign cells through cell lysis or opsonization and recruiting immune cells to sites of inflammation as well as contributing to the inflammatory process itself.
A process to chemically link two or more molecules e.g. a protein carrier molecule to a polysaccharide antigen.
Cytotoxic T lymphocytesA T cell that has the ability to kill cells presenting antigenic peptides.
Specialized cells that capture foreign antigens and present these antigens (i.e. antigen presenting cells) to other cells of the immune system.
The part of an antigen, also known as an an antigenic determinant, that is recognized by specific antibody or T cell receptor.