ARS | Publication request: EFFECTS OF VITAMIN AND MICRONUTRIENT DEFICIENCIES ON THE IMMUNOCOMPETENCE OF LARVAL HELIOTHIS VIRESCENS

Submitted to: University of Missouri Life Sciences Week
Publication Type: Abstract Only
Publication Acceptance Date: March 21, 2006
Publication Date: April 19, 2006
Citation: Shelby, K. 2006. Effects of vitamin and micronutrient deficiencies on the immunocompetence of larval Heliothis virescens [abstract]. University of Missouri Life Sciences Week. Available: http://lifesciencesweek.missouri.edu/uploads06/formatted_abstracts/shelbyk@1.doc.

Technical Abstract: Dietary levels of specific essential nutrients, vitamins or micronutrients have been shown to influence a key fitness trait, immunocompetence. Se supplementation boosts larval lepidopteran resistance to per os baculovirus infection. Therefore, a study of the uptake and assimilation of vitamins C, E, Se, and other micronutrients by H. virescens larvae from diet was undertaken. Larvae fed diets containing 5-25 ppm Se exhibited 1) elevated plasma and tissue concentrations of Se, as measured by neutron activation analysis, 2) increased plasma virucidal activity against baculoviruses, as measured by endpoint dilution assay, and 3) higher resistance to per os baculovirus infection. This demonstrates that dietary Se levels are directly correlated with plasma Se levels, which are in turn correlated with baculovirus resistance. These results indicate that selenoproteins may have a role in antiviral immune response, and that identification and isolation of selenoproteins will provide insight into viral resistance mechanisms. Additional nutrients and phytochemicals have been evaluated for immunomodulatory activity. In contrast to the results with Se, Cr, Zn and ascorbate supplementation provided no significant benefit to baculovirus challenged larvae. HPLC analysis of plasma and other tissues demonstrated assimilation of dietary alpha- and delta-tocopherol from diet into gamma-tocopherol.