"Antibody" - what is it, definition of the term
«Immunoglobulin» is a Y‑shaped protein synthesized by differentiated B lymphocytes, capable of binding distinct antigenic determinants with high specificity; the binding neutralizes toxins, blocks pathogen attachment, and flags the target for elimination by phagocytes or complement, while also generating long‑term immune memory that accelerates response upon re‑exposure.
Detailed information
Immunoglobulin molecules are Y‑shaped proteins produced by B lymphocytes. Each unit comprises two identical heavy chains and two identical light chains linked by disulfide bonds. Variable regions at the tips of the arms determine antigen specificity, while constant regions define effector functions. The primary classes include «IgG», «IgM», «IgA», «IgE», and «IgD», each differing in hinge flexibility, serum half‑life, and tissue distribution.
When ectoparasites such as ticks, true bugs, lice, or fleas attach to a host, they introduce salivary proteins and microbial agents. The immune system generates antigen‑binding proteins that recognize these foreign molecules, leading to opsonization, complement activation, or cellular cytotoxicity. Specificity toward vector‑derived antigens enables rapid clearance of inoculated pathogens and limits tissue damage at the bite site.
Key processes governing antibody generation:
- Somatic hypermutation introduces point mutations within variable region genes, enhancing affinity for vector antigens.
- Class‑switch recombination replaces the constant region, allowing transition from «IgM» to subclasses better suited for mucosal defense («IgA») or systemic neutralization («IgG»).
- Clonal expansion produces a pool of plasma cells that secrete high‑affinity immunoglobulins targeting tick salivary proteins, bug hemolymph components, louse cuticular proteins, or flea gut antigens.
Serological assays exploit the presence of these antigen‑specific proteins to assess exposure. Enzyme‑linked immunosorbent tests (ELISA) and immunoblotting detect circulating immunoglobulins against defined vector antigens, providing epidemiological data on infestation rates and informing control measures.
Therapeutic strategies incorporate passive transfer of purified immunoglobulins to confer immediate protection against vector‑borne infections. Vaccine designs often include recombinant vector antigens that elicit robust immunoglobulin responses, reducing pathogen transmission during feeding events.