Where is tick immunoglobulin made? - briefly
Tick immunoglobulin-like proteins are synthesized in the salivary gland cells of the tick and secreted into the host during blood feeding.
Where is tick immunoglobulin made? - in detail
Tick‑derived immunoglobulin‑like molecules are synthesized within the arthropod itself, primarily in the salivary glands that secrete the feeding apparatus. During the blood‑meal, epithelial cells of the salivary gland epithelium transcribe and translate genes encoding the immunoglobulin domains, which are then processed in the endoplasmic reticulum and packaged into secretory vesicles. The vesicles fuse with the apical membrane, releasing the proteins into the host‑blood interface.
Additional production sites include:
- Midgut epithelial cells – express a subset of Ig‑like proteins that may function in pathogen recognition and immune modulation.
- Hemocytes – circulating immune cells that synthesize soluble Ig‑like factors released into hemolymph for systemic defense.
The biosynthetic pathway follows standard eukaryotic mechanisms:
- Gene transcription in nucleus → mRNA export.
- Translation on rough ER → formation of disulfide‑bonded Ig domains.
- Glycosylation and folding in Golgi apparatus.
- Sorting to secretory granules in salivary glands or hemocytes.
- Exocytosis into saliva or hemolymph.
In laboratory settings, recombinant tick immunoglobulin fragments are produced using heterologous expression systems such as:
- Escherichia coli – for non‑glycosylated domains.
- Insect cell lines (Sf9, High Five) – for correctly folded, glycosylated proteins.
- Mammalian HEK293 cells – for high‑fidelity post‑translational modifications.
These platforms enable large‑scale purification for research and vaccine development. The natural source remains the tick’s secretory organs, while recombinant technologies provide controlled, scalable alternatives.