Antikropps

Antikropps is the Swedish term for antibodies, glycoproteins produced by plasma cells of the immune system. They are key effectors of the adaptive immune response and recognize specific antigens on pathogens or foreign substances.

Structure: Each antibody is a Y-shaped molecule composed of two identical heavy chains and two identical light chains linked by disulfide bonds. The variable regions form the antigen-binding sites, determining specificity, while the Fc region mediates interactions with immune cells and with components of the complement system.

Generation: B cells rearrange V(D)J gene segments to create diverse antigen receptors. Upon antigen exposure, B cells differentiate into plasma cells that secrete soluble antibodies. Class switching changes the antibody isotype (IgM, IgG, IgA, IgD, IgE) and thus effector function; somatic hypermutation increases affinity.

Functions: Antibodies neutralize pathogens and toxins, promote pathogen uptake by phagocytes (opsonization), activate the classical complement pathway, and mediate antibody-dependent cellular cytotoxicity. They can also cross-link antigens and influence immune signaling through Fc receptors.

Types and applications: Polyclonal antibodies are a mixture produced by multiple B-cell clones; monoclonal antibodies derive from a single clone and are widely used as diagnostics and therapeutics. Antibodies play roles in autoimmunity (autoantibodies) and in therapeutics for cancer, infectious diseases, and inflammatory conditions. In diagnostics, antibodies are central to serology, immunohistochemistry, and ELISA.

Clinical relevance: Serology tests detect antibodies to determine prior exposure or vaccination status. Vaccination aims to elicit protective antibody responses. Immunodeficiencies can impair antibody production or function.

Note: In Swedish, the standard term is antikroppar (plural). Antikropps may appear as possessive or in nonstandard usage.