What does immunoglobulin do after a tick bite? - briefly
Immunoglobulins recognize and bind antigens delivered by tick saliva, neutralizing pathogens and flagging them for immune clearance. This binding triggers complement activation and opsonization, enhancing phagocytosis and preventing infection.
What does immunoglobulin do after a tick bite? - in detail
Immunoglobulins generated in response to a tick bite perform several coordinated actions that limit pathogen spread and modulate inflammation.
First, antigen‑specific IgM appears within days, binding surface proteins of bacteria, viruses, or protozoa introduced by the tick. This early antibody opsonizes microbes, enhancing phagocytosis by neutrophils and macrophages through Fcγ receptors.
Second, class‑switch recombination produces IgG subclasses that possess higher affinity and longer half‑life. IgG molecules neutralize toxins, block adhesion molecules, and trigger complement activation via the classical pathway, leading to formation of the membrane‑attack complex that lyses extracellular pathogens.
Third, IgA secreted at mucosal sites can be induced if the tick delivers agents that migrate to respiratory or gastrointestinal tracts. Secretory IgA prevents attachment of parasites and bacteria to epithelial cells, reducing systemic dissemination.
Fourth, IgE may be generated when tick saliva contains allergenic proteins. IgE binds high‑affinity FcεRI receptors on mast cells and basophils; cross‑linking by tick antigens initiates degranulation, releasing histamine and other mediators that increase vascular permeability, facilitating immune cell infiltration to the bite site.
Finally, immunoglobulin‑mediated feedback regulates B‑cell activity. High‑affinity antibodies engage inhibitory FcγRIIB receptors on activated B cells, tempering further antibody production and preventing excessive immune activation that could damage host tissue.
Overall, the antibody response after a tick attachment orchestrates pathogen neutralization, complement‑mediated killing, opsonophagocytosis, mucosal defense, and controlled inflammation, thereby contributing to the host’s ability to clear tick‑borne infections.