TY - JOUR
T1 - Relationship between the successful infection by entomopathogenic nematodes and the host immune response
AU - Li, X. Y.
AU - Cowles, R. S.
AU - Cowles, E. A.
AU - Gaugler, R.
AU - Cox-Foster, D. L.
N1 - Funding Information:
We thank Dr. Yi Wang for his advice and encouragement; Dr. Chris Brey for aiding in the initiation of this research and for helping to find the two strains of S. glaseri with the greatest infectivity in grubs; and Mr. Owen Thompson for aiding in maintaining the nematode strains. The S. glaseri NC strain was a gift from Dr. Mary Barbercheck and the S. scarabaei were obtained from Dr. Albrecht Koppenhöfer. We appreciate help from Dr. Paul Heller. This research is in part the doctoral dissertation of Dr. Li, and he was funded by graduate assistantships from the Department of Entomology, Penn State University. We appreciate committee members (Drs A. Daniel Jones, Kelli Hoover and Liwang Cui) and in particular Dr. Stephen L. Rathbun for statistical input. This research was funded by USDA Grant (No. 02-35316-12255, “Genetic Engineering of Nematodes for Suppression of Insect Cellular Immune Response”).
PY - 2007/3
Y1 - 2007/3
N2 - Reproduction of entomopathogenic nematodes requires that they escape recognition by a host's immune system or that they have mechanisms to escape encapsulation and melanization. We investigated the immune responses of larvae for the greater wax moth (Galleria mellonella), tobacco hornworm (Manduca sexta), Japanese beetle (Popillia japonica), northern masked chafer (Cyclocephala borealis), oriental beetle (Exomala orientalis) and adult house crickets (Acheta domesticus), challenged with infective juveniles from different species and strains of entomopathogenic nematodes. The in vivo immune responses of hosts were correlated with nematode specificity and survival found by infection assays. In P. japonica, 45% of injected infective juveniles from Steinernema glaseri NC strain survived; whereas the hemocytes from the beetle strongly encapsulated and melanized the Heterorhabditis bacteriophora HP88 strain, S. glaseri FL strain, Steinernema scarabaei and Steinernema feltiae. Overall, H. bacteriophora was intensively melanized in resistant insect species (E. orientalis, P. japonica and C. borealis) and had the least ability to escape the host immune response. Steinernema glaseri NC strain suppressed the immune responses in susceptible hosts (M. sexta, E. orientalis and P. japonica), whereas S. glaseri FL strain was less successful. Using an in vitro assay, we found that hemocytes from G. mellonella, P. japonica, M. sexta and A. domestica recognized both nematode species quickly. However, many S. glaseri in M. sexta and H. bacteriophora in G. mellonella escaped from hemocyte encapsulation by 24 h. These data indicate that, while host recognition underlies some of the differences between resistant and susceptible host species, escape from encapsulation following recognition can also allow successful infection. Co-injected surface-coat proteins from S. glaseri did not protect H. bacteriophora in M. sexta but did protect H. bacteriophora in E. orientalis larva; therefore, surface coat proteins do not universally convey host susceptibility. Comparisons of surface coat proteins by native and SDS-PAGE demonstrated different protein compositions between H. bacteriophora and S. glaseri and between the two strains of S. glaseri.
AB - Reproduction of entomopathogenic nematodes requires that they escape recognition by a host's immune system or that they have mechanisms to escape encapsulation and melanization. We investigated the immune responses of larvae for the greater wax moth (Galleria mellonella), tobacco hornworm (Manduca sexta), Japanese beetle (Popillia japonica), northern masked chafer (Cyclocephala borealis), oriental beetle (Exomala orientalis) and adult house crickets (Acheta domesticus), challenged with infective juveniles from different species and strains of entomopathogenic nematodes. The in vivo immune responses of hosts were correlated with nematode specificity and survival found by infection assays. In P. japonica, 45% of injected infective juveniles from Steinernema glaseri NC strain survived; whereas the hemocytes from the beetle strongly encapsulated and melanized the Heterorhabditis bacteriophora HP88 strain, S. glaseri FL strain, Steinernema scarabaei and Steinernema feltiae. Overall, H. bacteriophora was intensively melanized in resistant insect species (E. orientalis, P. japonica and C. borealis) and had the least ability to escape the host immune response. Steinernema glaseri NC strain suppressed the immune responses in susceptible hosts (M. sexta, E. orientalis and P. japonica), whereas S. glaseri FL strain was less successful. Using an in vitro assay, we found that hemocytes from G. mellonella, P. japonica, M. sexta and A. domestica recognized both nematode species quickly. However, many S. glaseri in M. sexta and H. bacteriophora in G. mellonella escaped from hemocyte encapsulation by 24 h. These data indicate that, while host recognition underlies some of the differences between resistant and susceptible host species, escape from encapsulation following recognition can also allow successful infection. Co-injected surface-coat proteins from S. glaseri did not protect H. bacteriophora in M. sexta but did protect H. bacteriophora in E. orientalis larva; therefore, surface coat proteins do not universally convey host susceptibility. Comparisons of surface coat proteins by native and SDS-PAGE demonstrated different protein compositions between H. bacteriophora and S. glaseri and between the two strains of S. glaseri.
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U2 - 10.1016/j.ijpara.2006.08.009
DO - 10.1016/j.ijpara.2006.08.009
M3 - Article
C2 - 17275827
AN - SCOPUS:33846826562
SN - 0020-7519
VL - 37
SP - 365
EP - 374
JO - International Journal for Parasitology
JF - International Journal for Parasitology
IS - 3-4
ER -