IMMUNOGENICITY OF RNA-PROTEIN FRACTION ISOLATED FROM AXENIC ENTAMOEBA HISTOLYTICA (NIH:200)

SummaryThe immunogenicity of Entamoeba histolytica RNA (EhRNA) was studied in guinea-pigs. Animals immunized with a single dose of EhRNA and Freund's complete adjuvant (FCA) showed a high level of cell-mediated immune response (CMIR) as assessed by percent leucocyte migration inhibition (74·8 ± 2·9) after 1 week of immunization. This response faded away gradually and by week 5 after immunization the percent leucocyte migration inhibition was 27·1 ± 8·27, which is quite close to control values. The immunogenic activity of EhRNA was found to be specific, since yeast RNA failed to elicit immunological responses, and was RNase-sensitive. The CMIR could be maintained at its high level by giving boosters or multiple doses. Anti-EhRNA antibodies (haemagglutinins or precipitins) could not be demonstrated at any stage.Australian Journal of Experimental Biology and Medical Science (1984) 62, 117–123; doi:10.1038/icb.1984.11