New virus-specific T-helper epitopes of foot-and-mouth disease viral VP1 protein.

Immunogenicity studies of synthetic peptides from different regions of VP1 protein of foot-and-mouth disease virus strain A22 revealed the following active fragments: 39-61, 50-69, 135-159, 175-189, 170-189 and 197-213. Testing of virus neutralizing antibody production in rabbits primed by peptides and then inoculated by the virus showed that only peptides 135-159 and 170-189 were able to induce the functional T-cell helper activity. Localization of virus-specific T-cell recognition sites in sequences 135-159 and 170-189 was confirmed in in vitro recognition experiments of the virus by peptide activated mice lymphocytes.

[Is the Arg-Gly-Asp sequence the site for foot-and-mouth disease virus binding with cell receptor?]. / Iavliaetsia li posledovatel'nost' Arg-Gly-Asp uchastkom sviazyvaniia virusa iashchura s kletochnym retseptorom?

The Arg-Gly-Asp sequence is being found in an increasing wide range of proteins with "adhesive" function. Studying a series of synthetic peptide fragments of VP1 protein of FMDV, we showed that peptides containing the Arg-Gly-Asp sequence, but not control peptides, inhibited FMDV binding to pig kidney cells in vitro, thus indicating participation of that sequence in FMDV binding to host cells.

[Synthesis and immunogenic properties of peptides--fragments of the immunodominant regions of the VP1 protein of the Asia-1 type of foot- and-mouth disease virus]. / Sintez i immunogennye svoistva peptidov--fragmentov immunodominantnykh raionov belka VP1 virusa iashchura tipa Aziia-1.

Potential immunodominant epitopes were predicted on the basis of a theoretical analysis of the antigenic structure of the VP1 protein of the type Asia-1 foot-and-mouth disease virus. Peptides corresponding to the 140-153, 136-153, 132-153, 143-157, 137-157, and 193-208 fragments of the VP1 protein sequence were synthesized by the solid phase method, and the immunogenic properties of the peptides were studied on guinea pigs. The shortest peptide exhibiting the protective effect was found to correspond to the, 140-153 fragment of the VP1 sequence. The Plm-(Gly)3-(140-153)-(Gly)2-Lys(Plm)-Leu and [Ac-(140-153)-(Gly)3]8-(Lys)7-Gly synthetic constructions in combination with adjuvants provided up to 80% protection of immunized animals against infection with the foot-and-mouth disease virus.

[Synthetic peptides simulating the protective epitopes of VP1 protein of foot-and-mouth disease virus type O and A]. / Modelirovanie s pomoshch'iu sinteticheskikh peptidov protektivnykh épitopov belka VP1 virusa iashchura serotipov O i A.

In a search of novel approaches to cattle protection from foot-and-mouth disease we have prepared a series of peptides from the major antigenic region 130-160 of the VP1 protein. The 144-159 peptide as well as 141-152, 141-148, 148-159 segments (strain O1K) were inactive in all in vitro and in vivo experiments on virus inhibiting. On the other band, synthetic 136-152, 136-148 O1K sequences as well as 131-149, 140-149 A22 sequences afforded 50 to 100% protection, both in the free state and conjugated with keyhole limpet hemocyanin. Therefore the 136-145 region should be considered as an essential part of the major sequential epitope, necessary for full-scale antiviral immune response. We also believe that the 136-152 segment is so far the smallest peptide capable of eliciting virus neutralizing antibodies and antiviral protection without conjugation with a high-molecular carrier.

[Antigenic structure of the foot-and-mouth disease virus. III. Immunogenic properties of synthetic peptides of the sequence of the immunodominant region of VP1 proteins of the O1K and A22 strains of foot-and-mouth virus]. / Anigennaia struktura virusa iashchura. III. Immunogennye svoistva sinteticheskikh peptidov posledovatel'nosti immunodominantnogo raiona belkov VP1 shtammov O1K i A22 virusa iashchura.

Immunogenic and protective properties of uncoupled and KLH-conjugated peptides covering the sequence of the immunodominant region of VP1 proteins of the O1K and A22 strains of foot-and-mouth disease virus have been studied. The uncoupled peptides 136-148 O1K, 136-152 O1K, 131-149 A22 and 140-149 A22 were shown to be immunogenic in guinea pigs and induced 50-100% protection against homologous virus. On the other hand, the A22 specific peptides, in contrast to the O1K peptides, were not immunogenic in rabbits. Immunization of nonresponders with the A22 specific peptides containing the O1K peptide can bypass nonresponsiveness to the A22 peptide in terms of the antibody production. The induced antibodies showed virus-neutralizing activity in vitro.

[Protection of naturally susceptible animals against foot-and-mouth disease with a peptide, synthesized on a lysine matrix]. / Zashchita estestvenno-vospriimchivykh zhivotnykh ot iashchura peptidom, sintezirovannym na lizinovoi matritse.

A peptide VP1-(142-158)-MAP (Multiple antigen peptide system) consisting of two parts: a lysine matrix made up of three levels of lysine residues coupled with each other and amino acid sequence 142-158 of VP1 of FMD virus strain A(22)550--has been synthesized. Guinea-pigs inoculated with 20 mkg of the peptide incorporated with Freund's complete adjuvant were protected against challenge with 500 ID50 of homologous FMD virus. Sheep were immunized with a single inoculation of the peptide in a dose of 1.0 mg. Cattle inoculated twice with 1.5 mg of the peptide with incomplete adjuvant on the basis of synthetic oil developed high virus-specific antibody titres both after the first (5.3-7.6 log2 ND50/0.1 ml) and the second inoculation (10.2-11.0 log2 ND50/0.1 ml). The peptide-immunized animals were resistant to challenge with homologous virulent virus in a dose of 10(4) ID50. The immunogenic and protective capacities of the peptide VP1-(142-158)-MAP were shown to be greater as compared with those of its linear analogue-peptide VP1-(141-160).

[Synthetic peptide designs based on immunoactive fragments of the VP1 protein of the foot-and-mouth disease virus strain A22]. / Sinteticheskie peptidnye konstruktsii na osnove immunoaktivnykh fragmentov belka VP1 virusa iashchura shtamma A22.

Peptide constructs consisting of 44-53 aa were synthesized on the basis of sequences 135-159, 170-190 and 197-213 of VP1 from the foot-and-mouth disease A22 strain. Immunogenic and protective properties of the peptide constructs were studied in guinea pigs and mice of three lines. The constructs were shown to induce higher levels of antibodies and exhibit higher protective effects than the separate peptides. The most active among the peptides studied was the construct involving the VP1 fragments 135-160 and 170-190: it protected pigs from the experimental infection by the foot-and-mouth disease virus.

[Protection from foot-and-mouth disease virus in naturally-susceptible animals by a linear polymer of a synthetic peptide]. / Zashchita ot iashchura estestvenno-vospriimchivykh zhivotnykh lineinym polimerom sinteticheskogo peptida.

Linear polymer of a peptide corresponding to the fragment 142-155 of the foot-and-mouth disease virus A22(550) protein (VP1) was synthesized. Whereas the monomeric peptide was only slightly immunogenic, the polymer induced virus-neutralizing antibodies in rabbits and protected 100% guinea pigs. Sheep vaccinated once and cattle vaccinated twice were stable against infection with the homologous virulent foot-and-mouth disease virus.

[Antigenic structure of the foot-and-mouth disease virus. II. Synthesis of protective peptides from the major immunogenic region of VP1 protein of foot-and-mouth disease virus type A22]. / Antigennaia struktura virusa iashchura. II. Sintez protektivnykh peptidov posledovatel'nosti osnovnogo immunogennogo raiona belka VP1 virusa iashchura shtamma A22.

Earlier we found that the immune response and antiviral protection from FMDV can be achieved by immunization with uncoupled FMDV peptides. In a search of approaches to animal protection from FMDV A22 strain we prepared a series of peptides corresponding to the putative antigenic determinants. Synthetic 131-149 and 140-149 sequences afforded 50 to 80% protection, both in the free state and conjugated with keyhole limpet hemocyanin. We believe that the 140-149 segment is so far the smallest peptide capable of eliciting specific antiviral protection without conjugation with a high molecular carrier.

[Antigenic structure of foot-and-mouth virus. IV. Synthesis and immunogenic properties of new fragments of the VP1 protein of food-and-mouth virus strain A22]. / Antigennaia struktura virusa iashchura. IV. Sintez i immunogennye svoistva novykh fragmentov belka VP1 virusa iashchura shtama A22.

A synthesis of new fragments of VP1 protein with the specificity of A22 strain of foot-and-mouth disease virus is described. Immunization with the free 136-152 peptide and KLH-conjugates of the peptides 136-152 and 197-213 induced 60-80% protection of guinea pigs against challenge with the A22 virus. Synthetic peptides corresponding to the 10-24, 50-69 and 175-189 sequences of VP1 did not show any protective activity. We have found that uncoupled peptides 175-189 and 197-213 are able to induce antipeptide antibodies. However, these antibodies did not possess any neutralizing activity. Immunization of animals with the mixture of (136-152)O1K and (175-189)A22 has led to inhibition of the immune response to the (136-152)O1K fragment.

[Antigenic structure of the foot-and-mouth virus. V. Protection of naturally susceptible animals from foot-and-mouth disease using a synthetic peptide]. / Antigennaia struktura virusa iashchura. V. Zashchita prirodonovospriimchivykh zhivotnykh ot zabolevaniia iashchurom s pomoshch'iu sinteticheskogo peptida.

We have synthesized the peptide representing 135-159 VP1 sequence of A22 strain of the foot-and-mouth disease virus (FMDV). The synthetic peptide induced 100% protection of guinea pigs against the disease. Two-fold immunization of cuttle with the peptide and single immunization of sheep induced full protection of the animals against A22 strain of FMDV.

[Antigenic structure of the foot-and-mouth virus. VI. Functional segments of the immunodominant region of the VP1 protein of foot-and-mouth virus strains O1K and A22]. / Antigennaia struktura virusa iashchura. VI. Funktsional'nye uchastki immunodominantnogo raiona belka VP1 virusa iashchura shtammov O1K i A22.

B- and T-epitopes have been localized within the protective fragments of VP1 protein, viz., 136-152 of the O1K strain and 135-159 of the A22 strain of the foot-and-mouth disease virus (FMDV). Antibodies eliciting after immunization of various animals with the 135-159 A22 peptide are directed to different sites of the peptide. Immunogenicity of fragments of the 135-159 A22 peptide on mice correlates with their activity on T-cells of the same animals and protective activity on guinea pigs. The investigations were carried out using synthetic fragments of the 136-152-O1K and 135-159-A22 peptides.

Synthetic vaccine against foot-and-mouth disease based on a palmitoyl derivative of the VP1 protein 135-159 fragment of the A22 virus strain.

The peptide Palm2 135-159, a dipalmitoyl derivative of the 135-159 fragment of VP1 protein of the foot-and-mouth disease virus strain A22 was synthesized. In the experiments on mice, guinea pigs and sheep Palm2 135-159 possesses greater immunogenic and protective activity than the nonacylated 135-159 peptide. The synthetic vaccine against foot-and-mouth disease for use in sheep was developed on the basis of the lipopeptide. Synthetic polymethylsiloxane oil was found to be a suitable adjuvant for this vaccine. The dependencies of protective and immunogenic effects from the dose of peptide were studied. The vaccine was found to be stable to storage for 1 year at 18 degrees C. It was shown that the synthetic vaccine provides 1 year protection of sheep against foot-and-mouth disease after a single administration. The vaccine is allowed for veterinary use in Russia.

A peptide construct containing B-cell and T-cell epitopes from the foot-and-mouth disease viral VP1 protein induces efficient antiviral protection.

A new peptide construct Palm135-158-GGA-170-188(Acm) has been synthesized and investigated in a number of in vitro and in vivo test systems. The construct contains a virus specific T-helper epitope within the 170-188 sequence of VP1, in addition to the main antigenic 135-158 region of the foot-and-mouth disease viral VP1 protein (strain A22). The construct has higher protective, antigenic, immunogenic and T-cell proliferative activity then the previously described shorter peptide Palm(2)135-159. The 170-188 part of the construct serves as a virus specific T-epitope, responsible for the enhanced immunogenic and protective activity of the construct.