Calreticulin is Transiently Induced after Immunogen Treatment in the Fat Body of the Silkworm Bombyx mori

抄録

Calreticulin (CRT) is a multifunctional endoplasmic reticulum (ER) lumen protein, which is also involved in innate immunity. To study the involvement of CRT in the insect immune response, silkworm larvae of Bombyx mori were treated with lipopolysaccharide (LPS). LPS treatment induced an increase in CRT mRNA in the fat body only, and not in hemocytes, the midgut, silk gland, or Malpighian tubule. Time course analysis indicated that significant CRT mRNA expression by the fat body was induced 6h after LPS injection, and returned to the normal level within 24h. The NIAS-Bm-aff3 cell line, which was established from the fat body of B. mori, showed a similar expression pattern on LPS exposure. Since the fat body is capable of a humoral response in insect innate immunity, our results suggests that CRT is induced by the activation of the humoral immune system in the fat body of Bombyx mori.