Heterologous Protection Research Articles

A bovine respiratory syncytial virus strain with mutations in subgroup-specific antigenic domains of the G protein induces partial heterologous protection in cattle

Bovine respiratory syncytial virus (BRSV) strains are tentatively divided in subgroups A, AB and B, based on antigenic differences of the G protein. A Dutch BRSV strain (Waiboerhoeve: WBH), could not be assigned to one of the subgroups, because the strain did not react with any monoclonal antibody against the G protein. We describe here that the WBH strain has accumulated critical mutations in subgroup-specific domains of the G protein gene, which also occur but then independently in G protein genes of BRSV subgroup A or B strains. Although the comparison of nucleotide residues 256–792 of the G gene of the WBH strain with those of subgroup A and B strains showed that the G gene of the WBH strain is different from that of BRSV subgroup A and B strains, the sequence divergence was not more than observed within the G genes of human respiratory syncytial virus subgroup A or B strains. The WBH strain did not induce severe disease after experimental infection of calves, and induced partial protection against a heterologous challenge. Despite the dissimilarity of the conserved central regions of the G protein of the WBH strain and that of the challenge strain, a secondary antibody response against this region was induced in WBH-infected calves after challenge. We conclude that complete BRSV virus can partially protect against a BRSV infection with a strain that contains an antigenic dissimilar G protein.

Heterologous Protection of Mice from a Lethal Human H1N1 Influenza A Virus Infection by H3N8 Equine Defective Interfering Virus: Comparison of Defective RNA Sequences Isolated from the DI Inoculum and Mouse Lung

We have examined the RNAs involved in the heterologous protection of adult mice from otherwise lethal intranasal infection with mouse-adapted human A/WSN (H1N1) by defective interfering (DI) equine A/equine/Newmarket/7339/79 (H3N8: EQV) influenza virus, as well as the RNAs involved in the protection of WSN- or EQV-infected mice by their homologous DI viruses. The aim of this study was to describe the types of defective RNAs present in protected mice in order to guide the design of potentially protective DI RNAs. The interfering and mouse-protecting activity of DI virus was destroyed by prolonged UV irradiation (iDI virus) demonstrating that protection correlated with an active DI genome, and not viral antigen. Protected mice were all infected but suffered a lower degree of morbidity than those given iDI virus. The DI EQV inoculum contained defective segment 1–8 RNAs while DI WSN inoculum contained only defective segment 1–6 RNAs. However lungs of mice given EQV + DI EQV contained only defective segments 1–4 or 1–6 RNAs (mouse-to-mouse variation), while control mice given EQV or EQV + iDI EQV contained few very defective RNAs. Thus prevention of death was the result of quantitative and/or qualitative differences in defective RNAs administered to the mice. Only defective segments 1–3 RNAs were isolated from the lungs of mice given WSN + DI WSN, confirming the earlier report of Noble and Dimmock (1995). A detailed analysis showed that most defective RNAs isolated from the lungs of mice protected from a lethal WSN infection by DI EQV were EQV in origin. Thus, as no infectious EQV was present, these defective RNAs from the DI EQV inoculum must have been heterologously replicated in mouse lung by WSN. All defective segment 3–6 RNAs isolated were of EQV origin, indicating that they were replicated by WSN in preference to its own. Defective segments 1 and 2 were a mixture of EQV and WSN RNAs. Of 17 defective EQV segment 1–3 sequences from mouse lung, all but three differed in their primary central deletion from 20 defective RNAs isolated from the inoculum. No bias in the break points was evident. A number of minor deletions of 2 or more nts were also present in defective EQV and WSN RNAs in segments 1 and 2, but none in segment 3. Their 5′, but not 3′, breakpoints were heterogeneous, suggesting that defective RNAs were generated during positive strand synthesis. Two cloned EQV-defective segment 3 RNAs were chimeras containing a 30 nt insert from segment 1. Most defective RNAs possessed at least 178 nts from the 5′ end of vRNA. The amount of 5′ sequence present in those RNAs correlated with the segment of origin, suggesting that this was the minimum required for propagation of viral RNA in mouse lung and hence possibly for protection also.

Protective role of gamma interferon during the recall response to influenza virus.

During secondary immune responses to influenza virus, virus-specific T memory cells are a major source of gamma interferon (IFN-gamma). We assessed the contribution of IFN-gamma to heterologous protection against the A/WSN/33 (H1N1) virus of wild-type and IFN-gamma-/- mice previously immunized with the A/HK/68 (H3N2) virus. The IFN-gamma-/- mice displayed significantly reduced survival rates subsequent to a challenge with various doses of the A/WSN/33 virus. This was associated with an impaired ability of the IFN-gamma-/- mice to completely clear the pulmonary virus by day 7 after the challenge, although significant reduction of the virus titers was noted. However, the IFN-gamma-/- mice developed type A influenza virus cross-reactive cytotoxic T lymphocytes (CTLs) similar to the wild-type mice, as demonstrated by both cytotoxicity and a limiting-dilution assay for the estimation of CTL precursor frequency. The pulmonary recruitment of T cells in IFN-gamma-/- mice was not dramatically affected, and the percentage of CD4(+) and CD8(+) T cells was similar to that of wild-type mice. The T cells from IFN-gamma-/- mice did not display a significant switch toward a Th2 profile. Furthermore, the IFN-gamma-/- mice retained the ability to mount significant titers of WSN and HK virus-specific hemagglutination-inhibiting antibodies. Together, these results are consistent with a protective role of IFN-gamma during the heterologous response against influenza virus independently of the generation and local recruitment of cross-reactive CTLs.

Large- and small-scale preparation of bacteriophage lambda lysate and DNA.

BioTechniquesVol. 25, No. 1 BenchmarksOpen AccessLarge- and Small-Scale Preparation of Bacteriophage λ Lysate and DNAMing-Tsan Su, Tyamagondlu V. Venkatesh & Rolf BodmerMing-Tsan Su*Address correspondence to Ming-Tsan Su, Department of Biology, 830 N. University Street, Natural Sciences Building, University of Michigan, Ann Arbor, MI 48109-1048, USA. Internet: E-mail Address: mingtsan@biology.lsa.umich.eduUniversity of Michigan, Ann Arbor, MI, USASearch for more papers by this author, Tyamagondlu V. VenkateshUniversity of Michigan, Ann Arbor, MI, USASearch for more papers by this author & Rolf BodmerUniversity of Michigan, Ann Arbor, MI, USASearch for more papers by this authorPublished Online:15 Aug 2018https://doi.org/10.2144/98251bm08AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinkedInRedditEmail FiguresReferencesRelatedDetailsCited ByCharacterisation of broad-spectrum phiKZ like jumbo phage and its utilisation in controlling multidrug-resistant Pseudomonas aeruginosa isolatesMicrobial Pathogenesis, Vol. 172Application of novel lytic bacteriophages to control Vibrio parahaemolyticus load in seafood4 January 2022 | Journal of Consumer Protection and Food Safety, Vol. 17, No. 1Identification of in vivo expressed proteins in live attenuated lipopolysaccharide mutant that mediates heterologous protection against Leptospira sppVeterinary Microbiology, Vol. 262Isolation, Characterization, and Comparison of Efficiencies of Bacteriophages to Reduce Planktonic and Biofilm-Associated Staphylococcus aureus13 August 2020 | Journal of Health and Allied Sciences NU, Vol. 10, No. 03Comprehensive Evaluation of the Safety and Efficacy of BAFASAL® Bacteriophage Preparation for the Reduction of Salmonella in the Food Chain10 July 2020 | Viruses, Vol. 12, No. 7Characterization of a bacteriophage with broad host range against strains of Pseudomonas aeruginosa isolated from domestic animals17 June 2019 | BMC Microbiology, Vol. 19, No. 1Complete genome sequences of Aeromonas and Pseudomonas phages as a supportive tool for development of antibacterial treatment in aquaculture8 January 2019 | Virology Journal, Vol. 16, No. 1Nanobiotechnology: Current and Future Perspectives in Combating Microbial Pathogenesis24 January 2020T4-like Escherichia coli phages from the environment carry blaCTX-M24 May 2018 | Letters in Applied Microbiology, Vol. 67, No. 1Nanomedizin auf Phagenbasis: von Sonden zu Therapeutika für eine Präzisionsmedizin12 January 2017 | Angewandte Chemie, Vol. 129, No. 8Phage‐Enabled Nanomedicine: From Probes to Therapeutics in Precision Medicine24 January 2017 | Angewandte Chemie International Edition, Vol. 56, No. 8Isolation and Characterization of the Lytic Cold-Active Bacteriophage MYSP06 from the Mingyong Glacier in China23 October 2015 | Current Microbiology, Vol. 72, No. 2Maximizing yields of virulent phage: The T4/Escherichia coli system as a test caseJournal of Theoretical Biology, Vol. 364Isolation and characterization of broad spectrum bacteriophages lytic to Vibrio harveyi from shrimp farms of Kerala, India14 November 2013 | Letters in Applied Microbiology, Vol. 58, No. 3Chemoprevention utility of silibinin and Cdk4 pathway inhibition in Apc −/+ ice27 March 2013 | BMC Cancer, Vol. 13, No. 1Export of the pneumococcal phage SV1 lysin requires choline-containing teichoic acids and is holin-independent11 December 2012 | Molecular Microbiology, Vol. 87, No. 2Isolation and Partial Characterization of a Virulent Bacteriophage IHQ1 Specific for Aeromonas punctata from Stream Water27 September 2011 | Microbial Ecology, Vol. 63, No. 4The Autolysin LytA Contributes to Efficient Bacteriophage Progeny Release in Streptococcus pneumoniaeJournal of Bacteriology, Vol. 191, No. 17Identification and characterization of bacteriophages specific to the catfish pathogen, Edwardsiella ictaluriJournal of Applied Microbiology, Vol. 105, No. 6Isolation and Characterization of Bacteriophages Infecting the Fish Pathogen Flavobacterium psychrophilumApplied and Environmental Microbiology, Vol. 74, No. 13Prevalence of human pathogenic enteric viruses in bivalve molluscan shellfish and cultured shrimp in south west coast of IndiaInternational Journal of Food Microbiology, Vol. 122, No. 3Molecular characterization of Vibrio harveyi bacteriophages isolated from aquaculture environments along the coast of IndiaEnvironmental Microbiology, Vol. 9, No. 2Antigenic Subclasses of Polytropic Murine Leukemia Virus (MLV) Isolates Reflect Three Distinct Groups of Endogenous Polytropic MLV-Related Sequences in NFS/N MiceJournal of Virology, Vol. 77, No. 19A new bacteriophage, VHML, isolated from a toxin-producing strain of Vibrio harveyi in tropical AustraliaJournal of Applied Microbiology, Vol. 89, No. 4Molecular Evidence for a New Bacteriophage of Borrelia burgdorferiJournal of Bacteriology, Vol. 181, No. 23Mutations in a gene encoding a new oxygen-regulated photoreceptor protein cause dominant retinitis pigmentosaNature Genetics, Vol. 22, No. 3 Vol. 25, No. 1 Follow us on social media for the latest updates Metrics Downloaded 1,460 times History Published online 15 August 2018 Published in print July 1998 Information© 2018 Author(s)PDF download

Homologous and heterologous protection after single intranasal administration of live attenuated recombinant Bordetella pertussis.

While single-dose mucosal immunization is best achieved by the use of attenuated live microorganisms, attenuation generally results in decreased immunogenicity. We attenuated Bordetella pertussis by the deletion of the pertussis toxin gene. A single intranasal administration of this strain protected against subsequent challenge as well as did the parent strain and better than immunization with commercial vaccine. Unexpectedly, this attenuation resulted in increased immunogenicity against the protective antigen filamentous hemagglutinin (FHA). In addition, immunogenicity was also enhanced against the Schistosoma mansoni Sm28GST genetically fused to FHA, resulting in protection against the parasite, as characterized by a reduction in worm burden and egg charge, after a single intranasal administration. Thus, attenuated recombinant B. pertussis strains are promising vectors for the simultaneous protection against pertussis and heterologous diseases by a single intranasal administration.

Field resistance against potato virus Y infection using natural and genetically engineered resistance genes

Commercial tobacco cultivars BB16 (burley) and PBD6 (dark air cured) were transformed with the coat protein gene of lettuce mosaic potyvirus (LMV). Transgenic BB16 plants showed resistance to potato virus Y (PVY) infection, against the necrotic strain PVY-N Versailles, as well as the resistance breaking necrotic strain PVY-N 107. Transgenic PBD6, which carries the recessive ‘va’ gene conferring resistance to PVY, was also protected against PVY-N 107. In the progenies of most BB16 and PBD6 transformants, 45% to 100% of the inoculated plants were immune to PVY infection. The rest of the plants were tolerant, with atypical attenuated non necrotic symptoms and reduced virus accumulation. No recovery was observed in the tolerant plants, which stably expressed detectable level of LMV coat protein. This suggested a protein-mediated mechanism of heterologous protection.

Clearance-inducing antibodies are responsible for protection against the acute phase of Trypanosoma cruzi infection in mice.

A study was conducted on mice infected with strains Y and CL of Trypanosoma cruzi. The ability of anti-Y and anti-CL sera to induce complement-mediated lysis, immune clearance and protection against the acute phase of the infection was studied using homologous anti-Y or anti-CL serum tested with the Y or CL strain, or heterologous anti-Y serum tested with the CL strain or anti-CL serum tested with the Y strain. Complement-mediated lysis was induced by both homologous and heterologous antisera but protection was afforded only by homologous antisera. Immune clearance was induced by homologous but not by heterologous antisera. Antisera with high clearance ability were able to confer protection whereas antisera with high lytic ability were not. These results show a high correlation between the antibody ability to induce clearance and to confer protection and suggest that clearance rather than lysis is responsible for protection against the acute phase of the infection. The mechanism of antibody protection against the acute phase of the infection is discussed.

Antigenic and S-1 Genomic Characterization of the Delaware Variant Serotype of Infectious Bronchitis Virus

A previously unrecognized infectious bronchitis virus (IBV) serotype, referred to hereafter as the Delaware variant (DE var), was isolated from commercial broiler chickens during a severe, widespread respiratory disease epornitic in the Delmarva peninsula region of the United States in January-March 1992. The DE var serotype was found to be antigenically unrelated by virus-neutralization (VN) test to nine reference IBV serotypes from North America. Additional VN tests indicated that the DE var isolates (DE/072/92, DE/121/ 92, DE/152/92, and DE/174/92) from broilers were fully or partially neutralized by monospecific antisera prepared against themselves and against two IBV field isolates (DE/492/90 and DE/903/90) recovered from a Delmarva commercial layer flock experiencing egg production losses in 1990. Antigenic relatedness values determined by VN indicated layer isolate DE/492/90 was more closely related to the broiler DE var isolates than was layer isolate DE/903/90. Cross-challenge tests performed in specific-pathogen-free chickens also demonstrated the antigenic similarity of the broiler (DE/072/92 and DE/174/92) and the layer isolates (DE/492/90 and DE/903/90), with heterologous strain protection values ranging from 55% to 100%. Protection values of DE var isolates vs. Massachusetts 41 and Arkansas DPI were considerably lower (0-60%). The S-1 gene of the US/DE/072/92 isolate of the DE var serotype was amplified by reverse transcription polymerase chain reaction, cloned, and sequenced. The DE var S-1 gene sequence was compared with the S-1 gene sequences of IBV serotypes from North America, Europe, and Australia. A dendrogram based on this analysis supported the conclusion that the DE var serotype is highly novel among IBV. A high degree of similarity (> 88%) was observed between the S-1 genes of the DE var broiler isolates (DE/072/92 and DE/174/92) and layer isolates (DE/492/90 and DE/903/90). These data, taken with the VN and cross-challenge results, establish a genetic as well as an antigenic link between the isolates from layers and broilers and indicate the DE var serotype was responsible for both infectious bronchitis outbreaks.

Intranasal priming with recombinant Bordetella pertussis for the induction of a systemic immune response against a heterologous antigen

One of the current goals in vaccine development is the noninvasive administration of protective antigens via mucosal surfaces. In this context, the gut-associated lymphoid tissues have already been extensively explored. Vaccination via the nasal route has only recently been the focus of intensive investigation, and no live vector specifically designed for the respiratory mucosa is yet available. In this study we show that intranasal administration of the recombinant Bordetella pertussis BPGR60, producing the Schistosoma mansoni 28-kDa glutathione S-transferase (Sm28GST) protective antigen fused to filamentous hemagglutinin, induces priming in mice for the production of serum antibodies. In addition to significant levels of anti-Sm28GST immunoglobulin A (IgA) antibodies, high levels of anti-Sm28GST serum antibodies were obtained after intranasal boost with the purified antigen or infection with S. mansoni following intranasal priming with BPGR60. These antibodies were of the IgG1, IgG2a, and IgG2b isotypes, suggesting a mixed immune response. No priming was observed in animals that had received nonrecombinant B. pertussis or purified Sm28GST, indicating specific priming by BPGR60. This priming was also evident in immune protection against S. mansoni challenge. Significant protection against worm burden and egg output was obtained in mice primed with BPGR60 and intranasally boosted with purified Sm28GST. A lower but still significant degree of protection against egg output was also obtained in mice infected with a single dose of BPGR60. These results indicate that intranasal administration of recombinant B. pertussis can prime for serum antibody responses against a foreign antigen and for heterologous protection.

High resistance to plum pox virus (PPV) in transgenic plants containing modified and truncated forms of PPV coat protein gene

Two modified plum pox virus (PPV) coat protein (CP) gene constructs, designed to reduce putative biological risks associated with heteroen capsidation, were integrated into Nicotiana benthamiana plants. The first one contained a deletion of the nucleotides encoding for the DAG amino acid triplet involved in virus aphid-transmission. In the second one, the first 420 nucleotides of the PPV CP gene were removed. We present here the analysis and the selection throughout the generations of PPV-resistant transgenic lines containing these constructs. In most of the lines, a recovery phenotype was observed and was associated with a down-regulation of the transgene products (RNA or protein). We also describe two lines that were highly resistant to PPV. This immunity was correlated with a high number of transgene copies (at least three) and with low or undetectable transgene RNA levels. No heterologous protection was observed against other potyviruses. These characteristics indicate that the described resistance against PPV was RNA-mediated and can be classified as a 'sense suppression' or homology-dependent resistance. Moreover, the production of a highly resistant line containing the PPV CP gene with one third of its 5′ end deleted indicated that this region is not necessary to trigger the plant resistance mechanism(s)

Transformation of Plum with the Papaya Ringspot Virus Coat Protein Gene and Reaction of Transgenic Plants to Plum Pox Virus

Transgenic plum plants expressing the papaya ringspot virus (PRV) coat protein (CP) were produced by Agrobacterium-mediated transformation of hypocotyl slices. Hypocotyl slices were cocultivated with Agrobacterium tumefaciens strain C58/Z707 containing the plasmid pGA482GG/CPPRV-4. This plasmid carries the PRVCP gene construct and chimeric NPTII and GUS genes. Shoots were regenerated on Murashige and Skoog salts, vitamins, 2% sucrose, 2.5 μm indolebutyric acid, 7.5 μm thidiazuron, and appropriate antibiotics for selection. Integration of the foreign genes was verified through kanamycin resistance, GUS assays, polymerase chain reaction (PCR), and Southern blot analyses. Four transgenic clones were identified. Three were vegetatively propagated and graft-inoculated with plum pox virus (PPV)-infected budwood in a quarantine, containment greenhouse. PPV infection was evaluated over a 2- to 4-year period through visual symptoms, enzyme-linked immunosorbent assay, and reverse transcriptase PCR assays. While most plants showed signs of infection and systemic spread of PPV within l-6 months, one plant appeared to delay the spread of virus and the appearance of disease symptoms. Virus spread was limited to basal portions of this plant up to 19 months postinoculation, but, after 32 months symptoms were evident and virus was detected throughout the plant. Our results suggest that heterologous protection with PRVCP, while having the potential to delay PPV symptoms and spread throughout plum plants, may not provide an adequate level of long-term resistance.

Inducible immunity with a pilus preparation booster vaccination in an animal model of Haemophilus ducreyi infection and disease

Using the temperature-dependent rabbit model of Haemophilus ducreyi infection as a quantitative virulence assay, we tested the abilities of two bacterial antigen preparations to induce protection against subsequent infection and disease. Lipooligosaccharide (LOS) and a pilus preparation were purified from H. ducreyi 35000 and were used in a booster immunization procedure. The serologic response to each immunogen was monitored by enzyme immunoassay. H. ducreyi virulence was assayed by intraepithelial inoculation and subsequent measurement of disease for homologous strain 35000 or clinical isolate RO-34. LOS and the pilus preparation induced humoral responses. The kinetics of the LOS antibody response suggest a type 1 T-independent response, whereas the pilus preparation induced an anamnestic response. An inoculum of 10(5) CFU of H. ducreyi 35000 or RO-34 consistently produced ulcerative chancroidal lesions in naive rabbit controls. Immunization with LOS did not modify the virulence of H. ducreyi 35000. Immunization with the strain 35000 pilus preparation significantly reduced the severity of disease and the duration of infection and disease compared with controls, with either homologous or heterologous strain infection. The histology of lesions from pilus preparation-vaccinated rabbits compared with that of lesions from controls revealed accelerated lymphoid cell recruitment, more prominent plasma cell infiltrate, and reduction in subsequent histiocytic infiltration. We conclude that both LOS and the pilus preparation are immunogenic and that the latter induces homologous and heterologous strain protection in this animal model of infection and disease.

Comparison of mucosal and systemic humoral immune responses and subsequent protection in mice orally inoculated with a homologous or a heterologous rotavirus

Rotaviruses are the single most important cause of severe diarrhea in young children worldwide, and vaccination is probably the most effective way to control the disease. Most current live virus vaccine candidates are based on the host range-restricted attenuation of heterologous animal rotaviruses in humans. The protective efficacy of these vaccine candidates has been variable. To better understand the nature of the heterologous rotavirus-induced active immune response, we compared the differences in the mucosal and systemic immune responses generated by heterologous (nonmurine) and homologous (murine) rotaviruses as well as the ability of these infections to produce subsequent protective immunity in a mouse model. Sucking mice were orally inoculated with a heterologous simian or bovine rotavirus (strain RRV or NCDV) or a homologous murine rotavirus (wild-type or tissue culture-adapted) strain EHP at various doses. Six weeks later, mice were challenged with a virulent murine rotavirus (wild-type strain ECW) and the shedding of viral antigen in feces was quantitated. Levels of rotavirus-specific serum immunoglobulin G (IgG) and fecal IgA prior to challenge were measured and correlated with subsequent viral shedding or protection. Heterologous rotavirus-induced active protection was highly dependent on the strain and dose of the virus tested. Mice inoculated with a high dose (10(7) PFU per mouse) of RRV were completely protected, while the protection was diminished in animals inoculated with NCDV or lower doses of RRV. The ability of a heterologous rotavirus to stimulate a detectable intestinal IgA response correlated with the ability of the virus to generate protective immunity. Serum IgG titer did not correlate with protection. Homologous rotavirus infection, on the other hand, was much more efficient at inducing both mucosal and systemic immune responses as well as protection regardless of the virulence of the virus strain or the size of the immunizing dose.

Protective immunity induced in squirrel monkeys with recombinant apical membrane antigen-1 of Plasmodium fragile.

Saimiri sciureus boliviensis monkeys were immunized with the Plasmodium fragile form of the merozoite apical membrane antigen-1 produced using the baculovirus expression system and combined with Montanide ISA 720 adjuvant. Following three immunizations, monkeys were challenged with 10,000 P. fragile trophozoite parasites. Antibody titers determined by fluorescence microscopy indicated an enhanced response following the second immunization. Four of five control animals had parasite counts > 5% 18-26 days following challenge. Four of five immunized monkeys had reduced levels of maximum parasitemia or delays in accumulated parasite counts, suggestive of protection. Rechallenge of the animals with P. falciparum resulted in three of four adjuvant control animals developing patent parasitemia whereas none of five immunized animals were infected, suggesting some level of heterologous protection.

Recombinant vaccinia virus expressing PrM and E glycoproteins of louping ill virus: induction of partial homologous and heterologous protection in mice

Recombinant vaccinia viruses expressing either the premembrane/truncated envelope (PrM/TrE) or truncated envelope (TrE) protein of louping ill virus were constructed. Both constructs expressed authentic E proteins as determined by their size and antigenic reactivity with a panel of monoclonal antibodies. The deletion of the C-terminal hydrophobic domain of the envelope glycoprotein resulted in the secretion of E protein into the supernatant culture medium. The immunisation of mice with these recombinant viruses showed that the recombinant expressing PrM/TrE proteins induced neutralising and protective antibodies against challenge with louping ill or tick-borne encephalitis virus, but that the recombinant expressing the E or the TrE protein alone failed to induce any detectable immune responses against homologous or heterologous virus challenge.

Passive Cross-Protection Provided by Antisera Directed against In-Vivo-Expressed Antigens of Pasteurella multocida

Chicken antisera produced against the detergent-insoluble fraction of in vivo-grown P-1059 (serotype 3) Pasteurella multocida passively protected against heterologous X-73 (serotype 1) challenge. Likewise, antisera from chickens that survived infection by live P-1059 provided passive heterologous protection. The two antisera, which contained cross-protection antibodies, were adsorbed with the detergent-insoluble fraction of in vitro-grown P-1059 and still passively cross-protected against heterologous serotype challenge. The proteins of in vivo-grown P-1059 that had molecular weights of 204,000, 192,000, 179,000, and 153,000, which were recognized by the adsorbed antisera on immunoblots, may be responsible for cross-protection.

Heterologous and homologous protection against influenza A by DNA vaccination: optimization of DNA vectors.

We have recently shown that direct injection of DNA can be an effective vaccine strategy eliciting both humoral and cell-mediated immune responses. Vectors were designed specifically for vaccination by direct DNA injection and refined to improve plasmid production in Escherichia coli. The vectors consist of a pUC-19 backbone with the cytomegalovirus (CMV) IE1 enhancer, promoter, and intron A transcription regulatory elements and the BGH polyadenylation sequences driving the expression of the reporter gene CAT or influenza A nucleoprotein (NP) or hemagglutinin (HA). The respective vectors expressed high levels of chloramphenicol acetyltransferase (CAT) and NP in tissue culture, and yielded 14-15 mg of purified plasmid per liter of Escherichia coli culture. Immunization of mice with the NP and HA expression vectors resulted in protection from subsequent lethal challenges of influenza using either heterologous or homologous strains, respectively.

Heterologous Protection Against Influenza by Injection of DNA Encoding a Viral Protein

Cytotoxic T lymphocytes (CTLs) specific for conserved viral antigens can respond to different strains of virus, in contrast to antibodies, which are generally strain-specific. The generation of such CTLs in vivo usually requires endogenous expression of the antigen, as occurs in the case of virus infection. To generate a viral antigen for presentation to the immune system without the limitations of direct peptide delivery or viral vectors, plasmid DNA encoding influenza A nucleoprotein was injected into the quadriceps of BALB/c mice. This resulted in the generation of nucleoprotein-specific CTLs and protection from a subsequent challenge with a heterologous strain of influenza A virus, as measured by decreased viral lung titers, inhibition of mass loss, and increased survival.

Heterologous Resistance to Potato Virus Y in Transgenic Tobacco Plants Expressing the Coat Protein Gene of Lettuce Mosaic Potyvirus

Heterologous protection can provide resistance against virus infection in transgenic plants and was evaluated with two potyviruses, potato virus Y (PVY) and lettuce mosaic virus (LMV). PVY causes a serious disease of tobacco. Transgenic plants, Nicotiana tabacum cv. Xanthi, containing a modified coat protein (CP) gene of LMV have been generated and tested for resistance against PVY. Half of the 34 independent R 0 transgenic plants tested accumulated detectable levels of LMV coat protein (LMV CP+). These LMV CP+ plants were resistant to infection following sap inoculation with a necrotic strain of PVY (PVY-NV). Moreover, R 1 populations of five LMV CP+ lines tested were resistant to PVY-NV and to four other PVY strains [...]

Vaccination of Turkeys with Cell-Free Culture Filtrate of Pasteurella multocida: Effects of Dilution, Iron Chelation, and Heterologous Challenge

Two experiments were done to further define cell-free culture filtrate (CCF) from Pasteurella multocida and its endotoxin content in protecting turkeys against challenge. In the first experiment, the greater-than-30,000-molecular-weight fraction of P. multocida strain R44/6 (serotype 3/4/9/12) CCF was used in 10-fold dilutions given by air-sac inoculation or aerosol to vaccinate turkeys, which were subsequently challenged with either homologous (P-1059, serotype 3) or heterologous (X-73, serotype 1) strains. Endotoxin content of the CCF fraction was high. Compared with positive controls given either live Clemson University vaccine or a commercial bacterin, homologous protection was provided by undiluted CCF and 1:10 dilutions of CCF, but there was no heterologous protection. In the second experiment, CCF of strain R44/6 in regular and iron-limiting media and CCF of strain FC127B (serotype 1/4) were used alone or in combination to vaccinate turkeys, which were challenged as in the first experiment. Homologous but not heterologous protection occurred, even though growth of strain R44/6 in iron-limiting media reduced endotoxin content of CCF by approximately 93%. These results indicate that endotoxin levels of less than 10% but greater than 1% of those in CCF from regular media are sufficient to induce protection in turkeys against homologous challenge but that CCF from either regular or iron-limiting medium does not provide protection against heterologous challenge.