TY - JOUR
T1 - Contributions of immune responses to developmental resistance in Lymantria dispar challenged with baculovirus
AU - McNeil, James
AU - Cox-Foster, Diana
AU - Slavicek, James
AU - Hoover, Kelli
N1 - Funding Information:
We thank Mike Grove, Scott Geib, and Michelle Pfeiffer for technical assistance and advice. We also thank Roger Fuester of the USDA, ARS Beneficial Insects Research Lab, Newark, DE and Dawn Gundersen-Rindal of USDA Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, MD for supplying wasps of G. flavicoxis . This study would not have been possible with the assistance of many undergraduate students in the lab. Funding was provided by the National Science Foundation IOB Program , Grant No. IBN-0077710 awarded to Hoover, a USDA Forest Service Joint Venture agreement to Hoover, and a National Science Foundation Graduate Research Fellowship to McNeil.
PY - 2010/9
Y1 - 2010/9
N2 - How the innate immune system functions to defend insects from viruses is an emerging field of study. We examined the impact of melanized encapsulation, a component of innate immunity that integrates both cellular and humoral immune responses, on the success of the baculovirus Lymantria dispar multiple nucleocapsid nucleopolyhedrovirus (LdMNPV) in its host L. dispar. L. dispar exhibits midgut-based and systemic, age-dependent resistance to LdMNPV within the fourth instar; the LD50 in newly molted larvae is approximately 18-fold lower than in mid-instar larvae (48-72h post-molt). We examined the role of the immune system in systemic resistance by measuring differences in hemocyte immunoresponsiveness to foreign targets, hemolymph phenoloxidase (PO) and FAD-glucose dehydrogenase (GLD) activities, and melanization of infected tissue culture cells. Mid-instar larvae showed a higher degree of hemocyte immunoresponsiveness, greater potential PO activity (pro-PO) at the time the virus is escaping the midgut to enter the hemocoel (72h post-inoculation), greater GLD activity, and more targeted melanization of infected tissue, which correlate with reduced viral success in the host. These findings support the hypothesis that innate immune responses can play an important role in anti-viral defenses against baculoviruses and that the success of these defenses can be age-dependent.
AB - How the innate immune system functions to defend insects from viruses is an emerging field of study. We examined the impact of melanized encapsulation, a component of innate immunity that integrates both cellular and humoral immune responses, on the success of the baculovirus Lymantria dispar multiple nucleocapsid nucleopolyhedrovirus (LdMNPV) in its host L. dispar. L. dispar exhibits midgut-based and systemic, age-dependent resistance to LdMNPV within the fourth instar; the LD50 in newly molted larvae is approximately 18-fold lower than in mid-instar larvae (48-72h post-molt). We examined the role of the immune system in systemic resistance by measuring differences in hemocyte immunoresponsiveness to foreign targets, hemolymph phenoloxidase (PO) and FAD-glucose dehydrogenase (GLD) activities, and melanization of infected tissue culture cells. Mid-instar larvae showed a higher degree of hemocyte immunoresponsiveness, greater potential PO activity (pro-PO) at the time the virus is escaping the midgut to enter the hemocoel (72h post-inoculation), greater GLD activity, and more targeted melanization of infected tissue, which correlate with reduced viral success in the host. These findings support the hypothesis that innate immune responses can play an important role in anti-viral defenses against baculoviruses and that the success of these defenses can be age-dependent.
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U2 - 10.1016/j.jinsphys.2010.03.020
DO - 10.1016/j.jinsphys.2010.03.020
M3 - Article
C2 - 20350551
AN - SCOPUS:77955173252
SN - 0022-1910
VL - 56
SP - 1167
EP - 1177
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
IS - 9
ER -