205194a0Nature2054967196501091941940028-0836196510.1038/205194a0ukNatureNatureNATUREnatureNature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public./nature/journal/v205/n4967issueJournal homeArchiveCurrent issueAdvance online publicationPrivacy policySubscribeNature Publishing GroupCurrent issue205194a0Immune Response induced by RNA-Immuno-carrier extracted from Heterologous Immune Sera AU - MICHELAZZI, L. AU - BALDINI, I. AU - NOVELLI, A. AU - NANNI, G.Institute of General Pathology, University of Genoa, Italy.THE importance of nucleoproteins in antibody-globulin production is well known1,2. In previous experiments3,4 an evident increase of the content of RNA in the [gamma]-globulin fraction in immune sera has been observed. The RNA extracted from the serum of immunized rabbits is capable of eliciting in normal rabbits the production of antibodies against the same antigens used for immunizing the animals from which this RNA-immuno-carrier (RNA-I-C) was taken. The following investigations were undertaken to ascertain whether an RNA-I-C extracted from the serum of immunized animals of one species was able to induce antibody production in animals of a different species.Young male rabbits were immunized by 68 intravenous injections of red blood cells (RBC) of rat or guinea-pig. The RNA-I-C extracted4 from sera of rabbits immunized with guinea-pig RBC was introduced into normal rats; normal guinea-pigs were treated with RNA-I-C obtained from sera of rabbits immunized with rat RBC. The amount of RNA introduced in each animal of both groups, by a single intracardiac injection, was 0.28 mg/100 g body-weight. At intervals of 24, 48, 72 and 96 h after RNA injection, blood samples were collected and the sera were subjected to haemagglutination tests and macroscopic and Spectrophotometric4 haemolysis tests. Table 1.IMMUNE RESPONSE OF RATS TREATED WITH RNA FROM ANTIGUINEA-PIG RBC HYPERMMUNE RABBIT SERA AND OF GUINEA-PIGS TREATED WITH RNA FROM ANTI RAT RBC HYPPERMMUNUE RABBIT SERA. Guinea-pig ! & BC Rat RBC ^ Hi its treated with a mti-guinea- Guinea-pigs treated L with anti- pig BBC H NA rat BBC E ^NA ha ?magglutination haemolysis haBmagglutination hsemolysis Controls 0 0 0 0 24 h 1 ;80 1:80 1:80 1:40 48 h 1:320 1:160 1:320 1:80 72 h 1:80 1:80 1:40 1:20 96 h neg.[ast] neg. neg. neg. [ast] Negative ii 3 less than 10. Fig. 1. Spectrophotometric behaviour of rat BBC or guinea-pig RBC haemolysis by: At normal rat serum; B, normal guinea-pig serum; C, serum from rat 48 h after injection of anti-guinea-pig RBC RNA; D, serum from guinea-pig 48 h after injection of anti-rat B.BC RNA Fig. 2. Immunofluorescence test; guinea-pig HBO incubated at 37 C with serum (1:10) from rat 48 h after injection of BNA- I-C from rabbit anti-guinea-pig RBC sera, and then incubated with fluorescent anti-rat globulins The results of haemagglutinations and haemolysis are summarized in Table 1. The kinetic behaviour of haemolysis observed spectrophotometrically is shown in Fig. 1. The antigen-antibody reaction was also shown by the indirect immunofluorescent technique (Fig. 2), Cheek tests of RNA preparations were made by spectrophotometry in ultra-violet light. The data confirm the possibility of eliciting an immune response by RNA-I-C extracted from the serum of immunized animals of a different species. This investigation was supported by grants from C.N.R., Rome, and from the Mmistero della Pubblica Istruzione, Italy.Michelazzi, , L., Boll. Ist. Sier. Mil., 29, 28 (1950).Fishman, , M., and Adler, , F. L., J. Exp. Med., 117, 595 (1963).ArticlePubMedISIChemPortMichelazzi, , L., Nanni, , G., and Baldini, , I., Reported to Meeting, Soc. Ital. Biol. Sperim. (March 25, 1964).Michelazzi, , L., Nanni, , G., Baldini, , I., and Novelli, , A., Experientia, 20, 447 (1964).ArticlePubMedISIChemPort