Studies on the Role of Irradiated Filarial Parasites in Inducing Immunoprophylaxis Against Experimental Filariasis. Part of a Coordinated Programme on the Use of Nuclear Techniques in the Preparation of Vaccines Against Parasitic

摘要

The effect of ionizing radiation at various doses on the growth of Litomosoides carinii infective third stage larvae and on the protection conferred by such larvae against filarial infections was studied in albino rats. At radiation doses of 30 K rads and below the larvae developed into adults in retarded and sterile forms. No such development was seen when the larvae were irradiated at doses of 38 K rads and above. A high degree of protection was observed when the animals were immunized with 3 doses of infective larvae attenuated with 38 or 40 K rads of radiation. This degree of protection was not observed with larvae irradiated at other dose levels nor when the number of immunizations were reduced to two. The concurrent injection with heat killed Coryne-bacterium parva at immunization increased the level of protection. This was not observed when the C. parva organisms were replaced with Freunds Complete Adjuvant. Protection was best demonstrated when the challenge was given more than 30 days following the last immunization. The immunized animals showed the presence of serum dependent cellular adhesion to microfilarial and this correlated well with protection. (Atomindex citation 10:484619)