Inducible immune proteins in the dampwood termite Zootermopsis angusticollis

Abstract

Dampwood termites, Zootermopsis angusticollis (Isoptera: Termopsidae), mount an immune response to resist microbial infection. Here we report on results of a novel analysis that allowed us to electrophoretically assess changes in hemolymph proteins in the same individual before and after exposure to a pathogen. We demonstrate that contact with a sublethal concentration of the entomopathogenic fungus Metarhizium anisopliae (Deuteromycotina:Hypomycetes) induces the production of protective proteins in nymphs, pseudergates (false workers), and soldiers. Termites exposed to an immunizing dosage of fungal conidia consistently showed an enhancement of constitutive proteins (62-85 kDa) in the hemolymph as well as an induction of novel proteins (28-48 kDa) relative to preimmunization levels. No significant differences in protein banding patterns relative to baseline levels in control and naïve termites were observed. Incubating excised and eluted induced proteins produced by immunized pseudergates or immunized soldiers with conidia significantly reduced the germination of the fungus. The fungistatic effect of eluted proteins differed significantly among five colonies examined. Our results show that the upregulation of protective proteins in the hemolymph underscores the in vivo immune response we previously recorded in Z. angusticollis.

Targeting an antimicrobial effector function in insect immunity as a pest control strategy

“…Wash samples were concentrated with a P10 Microcon filter (Millipore). Hemocytes were isolated from 10 chilled N. corniger workers (1 L per termite) as described (37).…”

Challenges for developing pathogen-based biopesticides against Varroa destructor (Mesostigmata: Varroidae)

“…To our knowledge, potential sublethal effects of EPF on honeybees have not been investigated. However, Rosengaus et al (2007) evaluated the contact of a sublethal dose of M. anisopliae on another social insect, the dampwood termite Zootermopsis angusticollis Hagen (Isoptera: Termopsidae) and found that exposure to the fungus induced the production of protective proteins in nymphs, pseudergates (false workers), and soldiers. Exposing honeybees to EPF may provoke a similar immune response, although whether such a response measurably affects colony health or reduces hive activity is another issue and is not known.…”

Effects of Caste on the Expression of Genes Associated with Septic Injury and Xenobiotic Exposure in the Formosan Subterranean Termite

“…Pioneering work by, e.g., [18], [19] showed that immunization via sub-lethal dosages of pathogens induces the production of AMPs in the termite hemolymph. A number of genes and peptides related to this kind of humoral immunity have been described in termites.…”

“…Among them are a transferrin gene which was up-regulated following exposure to an entomopathogenic fungus [20], termicin, spinigerin [18] and gram-negative binding proteins (GNBPs) which can act as both PRRs and AMPs in several termite species [21]. Production of AMPs appears to differ not only between species [22], but also between termites belonging to different colonies or castes [17], [19], [23]. The components of cellular immunity in termites are less well studied although melanization and encapsulation of foreign bodies have been frequently used as bioassay for immune competence (e.g., [24]).…”