RESUMEN
Effects of protective resistance on lymphatic lesions and granulomatous inflammation in infected jirds (Meriones unguiculatus). Experimental Parasitology 77, 395-404. The hypothesis that protective immune responses play a role in the induction of filarial-associated lymphatic lesions was tested in jirds immunized twice with 75 Brugia pahangi radiation-attenuated third-stage larvae. Lymphatic lesions and granulomatous reactivity were compared in immunized, infected, and naive jirds at both acute and chronic periods following challenge with 100 third-stage larvae. Challenge worm burdens were reduced in immunized jirds at both infection periods. The ratio of lymph thrombi to lymphatic worms, an indicator of lymphatic lesion severity, was significantly greater in immunized jirds than in nonimmunized-challenged jirds during acute but not chronic infections. Parasite-specific-granulomatous hypersensitivity was assessed by measurements of granuloma areas around B. pahangi-soluble adult worm antigen-coated sepharose beads embolized in the lungs prior to necropsy. Marked granulomatous inflammatory responses seen during the acute period in both immunized-challenged and nonimmunized-challenged jirds were significantly reduced in similar jirds during chronic periods. Jirds with existing B. pahangi infections were not resistant to homologous challenge infection and had fewer lymphatic lesions and reduced granulomatous inflammatory responses to soluble adult worm antigen compared to previously naive jirds at acute periods postchallenge. These data suggest that protective immune responses increase the severity of filariae-induced lymphatic inflammation. The subsequent modulation of these lesions is probably associated with parasites that survived the protective immune response.
Asunto(s)
Brugia pahangi , Filariasis/veterinaria , Granuloma/veterinaria , Sistema Linfático/parasitología , Animales , Eosinófilos/inmunología , Filariasis/inmunología , Filariasis/parasitología , Filariasis/patología , Gerbillinae , Granuloma/parasitología , Interacciones Huésped-Parásitos , Inflamación/parasitología , Inflamación/veterinaria , Masculino , Vacunación/veterinariaRESUMEN
The ability of oral tetracycline to inhibit the development of third-stage infective larvae (L3) of Brugia pahangi to adult worms in jirds was studied using 2 experimental protocols. Jirds treated with 1.4% tetracycline in drinking water for a period beginning 30 days before inoculation of L3 until 30 days post-inoculation (DPI) had 97% reduction in adult worm recovery compared to untreated controls. Jirds that received 1.2% tetracycline in drinking water beginning 1 day before until either 12 or 26 DPI had adult worm recoveries of 11% and < 1%, respectively. Untreated jirds and those given tetracycline beginning at or later than 13 DPI had similar adult worm recovery (27-29%). Prepatent periods were prolonged, and circulating microfilariae were reduced in jirds given tetracycline from 27 to 54 DPI compared to controls. These data indicate that tetracycline administered to jirds in drinking water inhibits B. pahangi development from L3 to adult worms and suggest that this effect occurs during early larval development. Tetracycline administered to infected jirds prior to and continuing through the onset of patency can also affect development of microfilaremia.