Identification of surrogate rodent hosts for larval Onchocerca lienalis and induction of protective immunity in a model system.
The objectives of this project were to screen a variety of inbred rodent species and strains to determine their usefulness as surrogate hosts for the study of the early larval development of Onchocerca lienalis and then to use a selected model to study the induction of protective immunity. In the primary screen, 6 strains of mice, 5 strains of rats, jirds, and multimammate rats were tested. Animals were infected with fresh O. lienalis by subcutaneous implantation of third-stage larvae (L3) contained in diffusion chambers covered with 5.0-microns pore-size membranes. After 7 days the chambers were recovered, and larval viability and growth were assessed. Approximately one-half of inoculated larvae were recovered alive regardless of the host tested. Larvae were implanted in CBA/J and DBA/2J mice in chambers covered with membranes that prevented host cells from entering; survival and growth rates of the larvae were not altered by the absence of cells from the chambers. Cryopreserved larvae were implanted in chambers with 5.0-microns pore-size membranes in CBA/J and DBA/2J mice and Wistar Furth rats for 3-28 days. No statistically significant difference was seen in the larval recoveries on days 3-28 in all 3 hosts. Statistically significant increases in length were seen in the 3 strains from day 3 to day 14, after which growth appeared to cease. Molting from L3 to fourth-stage larvae was observed in all 3 hosts beginning on day 3, with most larvae completing the molt by day 7.(ABSTRACT TRUNCATED AT 250 WORDS)
Abraham
D
D
Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Eberhard
M L
ML
Lange
A M
AM
Yutanawiboonchai
W
W
Perler
F B
FB
Lok
J B
JB
D000818:Animals; D015925:Cryopreservation; D015194:Diffusion Chambers, Culture; D004195:Disease Models, Animal; D005849:Gerbillinae; D007114:Immunization; D007814:Larva / Q000254:growth & development / Q000276:immunology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009115:Muridae; D009854:Onchocerca / Q000254:growth & development* / Q000276:immunology; D009855:Onchocerciasis / Q000276:immunology* / Q000469:parasitology; D051381:Rats; D011919:Rats, Inbred Strains