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P40: a promising new carrier protein
POSTER ABSTRACT
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(RAP-PCR) as a means of investigating conditionally expressed genes. These genes may contribute to vaccine efficacy and therefore provide information on potential novel vaccine leads. RNA was extracted from 5 vaccine substrains of BCG and studied in RAP-PCR using one random primer for both cDNA synthesis and PCR. From preliminary data, a 20-base primer has shown reproducible differential expression of certain bands. This differential expression is currently being investigated using Northern blotting for quantitative analysis. Bands that are confirmed to be differentially expressed will be sequenced and compared to sequence databases for potential biological function. This system can then be used to compare gene expression of differing substrains of BCG and different strains of mycobacteria, under a variety of growth conditions, both in vitro and in viva. RAP-PCR may provide a means of identifying differentially expressed genes and potential novel vaccine leads in an organism where genetic methods of investigation are difficult.
P40: a promising new carrier protein I. Rauly, L. Goestch, C. Libon, A. Beck, J.F. Haeuw, T.N. Guyen, T. Baussant, J.Y. Bonnefoy and N. Corvaia Centre d’lmmutwlogie F-74164
Pierre Fabre, 5, Av. Napolion III Saint Julien en Genevois (France)
BP 497 -
We have cloned a gene encoding for the outer membrane protein A (OmpA) of Klebsiella pneumoniae. The recombinant protein was expressed in large amounts in Escherichia coli. In order to evaluate the carrier-related properties of this molecule, rP40 was coupled to Gl’, a B-cell epitope derived from the respiratory syncytial virus, and its potency was compared to the gold standard reference, tetanus toxoid (‘IT). When tested in vivo, rP40-Gl’ conjugates generated a strong anti-Gl’ antibody response even in the absence of any adjuvant. The anti-G 1’ antibody response compared well to that obtained after immunization with IT-G 1’ . Interestingly, rP40 induced a mixed ThlEh2 like response in contrast to IT, which induced a Th2-like type of response. Moreover, in contrast to preimmunization with IT followed by IT-G1 immunization, no epitopic suppression was observed in mice preimmunized with rP40 and further immunized with rP40-Gl’. All together, these results demonstrate that rP40 is a promising new carrier protein suitable for human vaccination.
Factors determining antibody isotype in measles virus DNA vaccination I. Cardoso, N. Sixt, A. Vallier, J. Fayolle, R. Buckland and T. Wild INSERM
U404 “Immunite’ et Vaccination”, Ex-BLitiment Institut Pasteur de Lyon, Avenue Tony Gamier, 69365 Lyon Cedex 07 (France)
Plasmids encoding the measles virus (MV) antigens, haemagglutinin (HA) and nucleoprotein (NP), inoculated either intramuscularly (i.m.) or into the skin of BALB/c mice by the gene gun method, induced both humoral and CTL class-I-restricted immune responses. When using the i.m. route, the major antibody isotype induced by both the membrane HA and NP was IgG2a, consistent with a Thl response. However, immunization with a plasmid which directed the synthesis of a partially secreted form of HA mainly induced IgGl antibodies,
99
(RAP-PCR) as a means of investigating conditionally expressed genes. These genes may contribute to vaccine efficacy and therefore provide information on potential novel vaccine leads. RNA was extracted from 5 vaccine substrains of BCG and studied in RAP-PCR using one random primer for both cDNA synthesis and PCR. From preliminary data, a 20-base primer has shown reproducible differential expression of certain bands. This differential expression is currently being investigated using Northern blotting for quantitative analysis. Bands that are confirmed to be differentially expressed will be sequenced and compared to sequence databases for potential biological function. This system can then be used to compare gene expression of differing substrains of BCG and different strains of mycobacteria, under a variety of growth conditions, both in vitro and in viva. RAP-PCR may provide a means of identifying differentially expressed genes and potential novel vaccine leads in an organism where genetic methods of investigation are difficult.
P40: a promising new carrier protein I. Rauly, L. Goestch, C. Libon, A. Beck, J.F. Haeuw, T.N. Guyen, T. Baussant, J.Y. Bonnefoy and N. Corvaia Centre d’lmmutwlogie F-74164
Pierre Fabre, 5, Av. Napolion III Saint Julien en Genevois (France)
BP 497 -
We have cloned a gene encoding for the outer membrane protein A (OmpA) of Klebsiella pneumoniae. The recombinant protein was expressed in large amounts in Escherichia coli. In order to evaluate the carrier-related properties of this molecule, rP40 was coupled to Gl’, a B-cell epitope derived from the respiratory syncytial virus, and its potency was compared to the gold standard reference, tetanus toxoid (‘IT). When tested in vivo, rP40-Gl’ conjugates generated a strong anti-Gl’ antibody response even in the absence of any adjuvant. The anti-G 1’ antibody response compared well to that obtained after immunization with IT-G 1’ . Interestingly, rP40 induced a mixed ThlEh2 like response in contrast to IT, which induced a Th2-like type of response. Moreover, in contrast to preimmunization with IT followed by IT-G1 immunization, no epitopic suppression was observed in mice preimmunized with rP40 and further immunized with rP40-Gl’. All together, these results demonstrate that rP40 is a promising new carrier protein suitable for human vaccination.
Factors determining antibody isotype in measles virus DNA vaccination I. Cardoso, N. Sixt, A. Vallier, J. Fayolle, R. Buckland and T. Wild INSERM
U404 “Immunite’ et Vaccination”, Ex-BLitiment Institut Pasteur de Lyon, Avenue Tony Gamier, 69365 Lyon Cedex 07 (France)
Plasmids encoding the measles virus (MV) antigens, haemagglutinin (HA) and nucleoprotein (NP), inoculated either intramuscularly (i.m.) or into the skin of BALB/c mice by the gene gun method, induced both humoral and CTL class-I-restricted immune responses. When using the i.m. route, the major antibody isotype induced by both the membrane HA and NP was IgG2a, consistent with a Thl response. However, immunization with a plasmid which directed the synthesis of a partially secreted form of HA mainly induced IgGl antibodies,