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Sang-moo Kang - One of the best experts on this subject based on the ideXlab platform.

  • MPL and CpG combination adjuvants promote homologous and heterosubtypic Cross Protection of inactivated split influenza virus vaccine.
    Antiviral Research, 2018
    Co-Authors: Eun-ju Ko, Sang-moo Kang
    Abstract:

    Abstract Annual vaccination is not effective in conferring Cross-Protection against antigenically different influenza viruses. Therefore, it is of high priority to improve the Cross protective efficacy of influenza vaccines. We investigated the adjuvant effects of monophosphoryl lipid A (MPL) and oligodeoxynucleotide CpG (CpG) on promoting homologous Protection and Cross-Protection after vaccination of C57BL/6 and BALB/c mice with inactivated split virus. Combination adjuvant effects of MPL and CpG on improving homologous and Cross protective vaccine efficacy were evident as shown by higher levels of homologous and Cross-reactive binding IgG and hemagglutination inhibiting antibodies. Combination adjuvant effects on enhancing the protective efficacy against homologous and heterosubtypic virus were demonstrated by less weight loss, lower airway inflammatory disease, and better control of viral loads as well as prevention of inflammatory cytokines and cellular infiltrates. Overall, the findings in this study suggest that a combination adjuvant of different toll-like receptor ligands exhibits a unique pattern of innate and adaptive immune responses, contributing to improved homologous and heterosubtypic Cross-Protection by inactivated split virion influenza vaccination.

  • Roles of antibodies to influenza A virus hemagglutinin, neuraminidase, and M2e in conferring Cross Protection.
    Biochemical and biophysical research communications, 2017
    Co-Authors: Yu-jin Kim, Yu-na Lee, Min Chul Kim, Ki-hye Kim, Yu-jin Jung, Sang-moo Kang
    Abstract:

    Although neuraminidase (NA) is the second major viral glycoprotein of influenza virus, its immune mechanism as a vaccine target has been less considered. Here we compared the properties of antibodies and the efficacy of Cross Protection by N1 and N2 NA proteins, inactivated split influenza vaccines (split), and tandem repeat extracellular domain M2 on virus-like particles (M2e5x VLP). Anti-NA immune sera could confer better Cross-Protection against multiple heterologous influenza viruses correlating with NA inhibition activity compared to split vaccine immune sera. Whereas split vaccine was superior to NA in conferring homologous Protection. NA and M2e immune sera each showed comparable survival Protection. Protective efficacy by NA immune sera was lower in Fc receptor common γ-chain deficient mice but comparable in C3 complement deficient mice compared to that in wild type mice, suggesting a role of Fc receptor in NA immunity.

  • Mechanisms of Cross-Protection by Influenza Virus M2-based Vaccines
    Immune network, 2015
    Co-Authors: Yu-na Lee, Min Chul Kim, Young-tae Lee, Yu-jin Kim, Sang-moo Kang
    Abstract:

    Current influenza virus vaccines are based on strain-specific surface glycoprotein hemagglutinin (HA) antigens and effective only when the predicted vaccine strains and circulating viruses are well-matched. The current strategy of influenza vaccination does not prevent the pandemic outbreaks and Protection efficacy is reduced or ineffective if mutant strains emerge. It is of high priority to develop effective vaccines and vaccination strategies conferring a broad range of Cross Protection. The extracellular domain of M2 (M2e) is highly conserved among human influenza A viruses and has been utilized to develop new vaccines inducing Cross Protection against different subtypes of influenza A virus. However, immune mechanisms of Cross Protection by M2e-based vaccines still remain to be fully elucidated. Here, we review immune correlates and mechanisms conferring Cross Protection by M2e-based vaccines. Molecular and cellular immune components that are known to be involved in M2 immune-mediated Protection include antibodies, B cells, T cells, alveolar macrophages, Fc receptors, complements, and natural killer cells. Better understanding of protective mechanisms by immune responses induced by M2e vaccination will help facilitate development of broadly Cross protective vaccines against influenza A virus.

  • Cross-Protection by co-immunization with influenza hemagglutinin DNA and inactivated virus vaccine using coated microneedles.
    Journal of controlled release : official journal of the Controlled Release Society, 2013
    Co-Authors: Yeu-chun Kim, Sang-moo Kang, Richard W. Compans, Dae-goon Yoo, Mark R Prausnitz
    Abstract:

    The need for annual revaccination against influenza is a burden on the healthcare system, leads to low vaccination rates and makes timely vaccination difficult against pandemic strains, such as during the 2009 H1N1 influenza pandemic. In an effort toward achieving a broadly protective vaccine that provides Cross-Protection against multiple strains of influenza, this study developed a microneedle patch to co-immunize with A/PR8 influenza hemagglutinin DNA and A/PR8 inactivated virus vaccine. We hypothesize that this dual component vaccination strategy administered to the skin using microneedles will provide Cross-Protection against other strains of influenza. To test this hypothesis, we developed a novel coating formulation that did not require additional excipients to increase coating solution viscosity by using the DNA vaccine itself to increase viscosity and thereby enable thick coatings of DNA vaccine and inactivated virus vaccine on metal microneedles. Co-immunization in this way not only generated robust antibody responses against A/PR8 influenza but also generated robust heterologous antibody responses against pandemic 2009 H1N1 influenza in mice. Challenge studies showed complete Cross-Protection against lethal challenge with live pandemic 2009 H1N1 virus. Control experiments using A/PR8 inactivated influenza virus vaccine with placebo DNA coated onto microneedles produced lower antibody titers and provided incomplete Protection against challenge. Overall, this is the first study showing DNA solution as a microneedle coating agent and demonstrating Cross-Protection by co-immunization with inactivated virus and DNA vaccine using coated microneedles.

  • vaccination inducing broad and improved Cross Protection against multiple subtypes of influenza a virus
    Proceedings of the National Academy of Sciences of the United States of America, 2011
    Co-Authors: Jaemin Song, Richard W. Compans, Nico Van Rooijen, Jadranka Bozja, Sang-moo Kang
    Abstract:

    Development of an influenza vaccine that provides broadly Cross-protective immunity has been a scientific challenge for more than half a century. This study presents an approach to overcome strain-specific Protection by supplementing conventional vaccines with virus-like particles (VLPs) containing the conserved M2 protein (M2 VLPs) in the absence of adjuvants. We demonstrate that an inactivated influenza vaccine supplemented with M2 VLPs prevents disease symptoms without showing weight loss and confers complete Cross Protection against lethal challenge with heterologous influenza A viruses including the 2009 H1N1 pandemic virus as well as heterosubtypic H3N2 and H5N1 influenza viruses. Cross-protective immunity was long-lived, for more than 7 mo. Immune sera from mice immunized with M2 VLP supplemented vaccine transferred Cross Protection to naive mice. Dendritic and macrophage cells were found to be important for this Cross Protection mediated by immune sera. The results provide evidence that supplementation of seasonal influenza vaccines with M2 VLPs is a promising approach for overcoming the limitation of strain-specific Protection by current vaccines and developing a universal influenza A vaccine.

Shin-ichi Tamura - One of the best experts on this subject based on the ideXlab platform.

  • secretory iga antibodies provide Cross Protection against infection with different strains of influenza b virus
    Journal of Medical Virology, 2004
    Co-Authors: Yasuko Asahiozaki, Yujiro Suzuki, Takeshi Kurata, Shin-ichi Tamura, Tomoki Yoshikawa, Yoichiro Iwakura, Tetsutaro Sata
    Abstract:

    This study examined whether secretory IgA (S-IgA) antibodies (Abs) could confer Cross-protective immunity against infection with influenza B viruses of antigenically distinct lineages. Wild-type or polymeric Ig receptor (pIgR)-knockout (KO) mice were immunized by infection with different B viruses or by intranasal (i.n.) administration with different inactivated vaccines. Four weeks later mice were challenged with either the B/Ibaraki/2/85 virus, representative of the B/Victoria/2/87 (B/Victoria)-lineage, or B/Yamagata/16/88 virus, representative of the B/Yamagata-lineage. Three days after challenge, nasal wash and serum specimens were assayed for IgA and IgG Abs specific for challenge viral antigens and for Protection against challenge viruses. In wild-type mice, B/Ibaraki (or B/Yamagata) Cross-reactive IgA Abs were detected at higher levels when infected or immunized with homologous-lineage viruses and at lower levels when infected or immunized with heterologous-lineage viruses. There was a correlation between the amount of nasal Cross-reactive IgA Ab and the efficacy of Cross-Protection with a homologous-lineage virus. In mice lacking the pIgR, nasal Cross-protective IgA Abs were only marginally detected in vaccinated mice and an accumulation of IgA in the serum was observed. This reduction of nasal IgA was accompanied by inefficient Cross-Protection against the B/Ibaraki (or B/Yamagata) virus infection. These results suggest that challenge viral-antigen Cross-reactive S-IgA in nasal secretions induced by i.n. infection or vaccination is involved in providing Cross-Protection against challenge infection with virus within either the B/Victoria- or B/Yamagata-lineage.

  • Cross-Protection against a lethal influenza virus infection by DNA vaccine to neuraminidase.
    Vaccine, 2000
    Co-Authors: Ze Chen, Takeshi Kurata, Shin-etsu Kadowaki, Yukari Hagiwara, Tomoki Yoshikawa, Kazutoshi Matsuo, Shin-ichi Tamura
    Abstract:

    Abstract Cross-Protection against a lethal influenza virus infection was examined in BALB/c mice immunized with plasmid DNAs encoding the neuraminidase (NA) from different subtype A viruses. Each NA-DNA was administered twice, 3 weeks apart, at the dose of 1 μg per mouse by particle-mediated DNA transfer to the epidermis (gene gun) or at a dose of 30 μg per mouse by electroporation into the muscle. Three weeks after the second vaccination, the mice were challenged with lethal doses of homologous or heterologous viruses and the ability of each NA-DNA to protect the mice from influenza was evaluated by determining the lung virus titers, body weight and survival rates. The H3N2 virus NA-DNA conferred Cross-Protection against lethal challenge with antigenic variants within the same subtype, but failed to provide Protection against infection by a different subtype virus (H1N1). The degree of Cross-Protection against infection was related to titers of the Cross-reacting antibodies. These results suggest that NA-DNA can be used as a vaccine component to provide effective Protection against infection not only with homologous virus but also with drift viruses.

  • Cross-Protection against influenza virus infection in mice vaccinated by combined nasal/subcutaneous administration.
    Vaccine, 1995
    Co-Authors: Hideki Asanuma, Fusaoki Koide, Yujiro Suzuki, Takashi Nagamine, Chikara Aizawa, Takeshi Kurata, Shin-ichi Tamura
    Abstract:

    Abstract The effects of a combination of intranasal (i.n.) and subcutaneous (s.c.) administration of inactivated influenza vaccine for priming and boosting on the Cross-Protection against antigenically drifted virus challenge were examined in Balb/c mice. Mice were primed through the i.n. or s.c. route with a CTB ∗ -A/Kumamoto/37/79 (H1N1) combined vaccine (CTB ∗ : cholera toxin B subunit supplemented with 0.2% of the holotoxin) and boosted through the i.n. or s.c. route with another drift virus vaccine, A/Bangkok/10/83 (H1N1), 4 weeks later. Two weeks after boosting, the mice were challenged with a third drift virus, A/Yamagata/120/86 (H1N1). The combination of i.n. priming and i.n. boosting afforded the highest Cross-Protection, while combinations of s.c. priming and i.n. or s.c. boosting afforded little Cross-Protection. In parallel with the protective activity, anti-A/Yamagata haemagglutinin-reactive IgA and IgG antibodies were detected in nasal and bronchoalveolar wash specimens. These results suggest that Cross-Protection against a variant virus challenge is most favourably provided by i.n. priming with the CTB ∗ combined vaccine and i.n. boosting with the vaccine, which optimally induces Cross-protective IgA and IgG antibodies.

  • Formulation of inactivated influenza vaccines for providing effective Cross-Protection by intranasal vaccination in mice
    Vaccine, 1994
    Co-Authors: Shin-ichi Tamura, Hideki Asanuma, Takashi Nagamine, Chikara Aizawa, Y. Ito, Keiko Yoshizawa, Takeshi Kurata
    Abstract:

    Attempts were made to formulate an inactivated influenza vaccine to provide effective Cross-Protection by intranasal vaccination in mice. Mice were immunized with a nasal site-restricted volume of various HA vaccines (split-product virus vaccines), prepared from some of the H1N1 subtype viruses which circulated in humans from 1934 to 1986, together with cholera toxin B subunit (CTB) as an adjuvant. Four weeks later, they were challenged intranasally with a lethal dose of the earliest H1N1 virus strain, A/PR/8/34 (PR8) or the latest virus strain, A/Yamagata/120/86 (Yamagata/86). The adjuvant-combined vaccines, prepared from drift H1N1 viruses, A/Kumamoto/37/79 and A/Bangkok/10/83, provided a higher degree of Cross-Protection against a challenge with Yamagata/86 than with PR8. A booster with another drift virus vaccine given 4 weeks after the primary vaccination increased the Protection against Yamagata/86; the effect was higher when mice were vaccinated with a later strain as the second antigen than when boosted with PR8. These results suggest that vaccination with a later virus strain followed by another later strain in a two-dose nasal vaccination regimen gives effective Cross-Protection against the current epidemic virus strains.

  • Cross-Protection against influenza virus infection afforded by trivalent inactivated vaccines inoculated intranasally with cholera toxin B subunit.
    Journal of immunology (Baltimore Md. : 1950), 1992
    Co-Authors: Shin-ichi Tamura, Hideki Asanuma, Takashi Nagamine, Chikara Aizawa, Y. Ito, Yoshihiro Hirabayashi, Yutaka Suzuki, Takeshi Kurata
    Abstract:

    Cross-Protection against influenza virus infection was examined in mice, immunized intranasally with a nasal site-restricted volume of inactivated vaccines together with cholera toxin B subunit (CTB) as an adjuvant. The mice were challenged with either a small or a large volume of mouse-adapted virus suspension, each of which gave virgin mice either a predominant upper or lower respiratory tract infection. A single dose of a monovalent influenza A H3N2 virus vaccine with CTB provided complete Cross-Protection against the small-volume challenge with a drift virus within the same subtype, but a slight Cross-Protection against the large-volume challenge. A second dose of another drift virus vaccine increased the efficacy of Cross-Protection against the large-volume challenge. Similar Cross-Protection against H1N1, H3N2, or B type drift virus challenge was provided in the mice having received a primary dose of a mixture of H1N1, H3N2, and B virus vaccines with CTB and a second dose of another trivalent vaccine. The degree of Cross-Protection against the small- and the large-volume infection paralleled mainly the amount of Cross-reacting IgA antibodies to challenge virus hemagglutinin in the nasal wash and that of Cross-reacting IgG antibodies in the bronchoalveolar wash, respectively. On the other hand, in mice immunized subcutaneously with the trivalent vaccines having no Cross-reacting IgA antibodies, the efficacy of Cross-Protection was not so high as that of nasal vaccination. These results suggest that the nasal inoculation of trivalent vaccines with CTB provides Cross-Protection against a broader range of viruses than does the current parenteral vaccination.

Takeshi Kurata - One of the best experts on this subject based on the ideXlab platform.

  • secretory iga antibodies provide Cross Protection against infection with different strains of influenza b virus
    Journal of Medical Virology, 2004
    Co-Authors: Yasuko Asahiozaki, Yujiro Suzuki, Takeshi Kurata, Shin-ichi Tamura, Tomoki Yoshikawa, Yoichiro Iwakura, Tetsutaro Sata
    Abstract:

    This study examined whether secretory IgA (S-IgA) antibodies (Abs) could confer Cross-protective immunity against infection with influenza B viruses of antigenically distinct lineages. Wild-type or polymeric Ig receptor (pIgR)-knockout (KO) mice were immunized by infection with different B viruses or by intranasal (i.n.) administration with different inactivated vaccines. Four weeks later mice were challenged with either the B/Ibaraki/2/85 virus, representative of the B/Victoria/2/87 (B/Victoria)-lineage, or B/Yamagata/16/88 virus, representative of the B/Yamagata-lineage. Three days after challenge, nasal wash and serum specimens were assayed for IgA and IgG Abs specific for challenge viral antigens and for Protection against challenge viruses. In wild-type mice, B/Ibaraki (or B/Yamagata) Cross-reactive IgA Abs were detected at higher levels when infected or immunized with homologous-lineage viruses and at lower levels when infected or immunized with heterologous-lineage viruses. There was a correlation between the amount of nasal Cross-reactive IgA Ab and the efficacy of Cross-Protection with a homologous-lineage virus. In mice lacking the pIgR, nasal Cross-protective IgA Abs were only marginally detected in vaccinated mice and an accumulation of IgA in the serum was observed. This reduction of nasal IgA was accompanied by inefficient Cross-Protection against the B/Ibaraki (or B/Yamagata) virus infection. These results suggest that challenge viral-antigen Cross-reactive S-IgA in nasal secretions induced by i.n. infection or vaccination is involved in providing Cross-Protection against challenge infection with virus within either the B/Victoria- or B/Yamagata-lineage.

  • Cross-Protection against a lethal influenza virus infection by DNA vaccine to neuraminidase.
    Vaccine, 2000
    Co-Authors: Ze Chen, Takeshi Kurata, Shin-etsu Kadowaki, Yukari Hagiwara, Tomoki Yoshikawa, Kazutoshi Matsuo, Shin-ichi Tamura
    Abstract:

    Abstract Cross-Protection against a lethal influenza virus infection was examined in BALB/c mice immunized with plasmid DNAs encoding the neuraminidase (NA) from different subtype A viruses. Each NA-DNA was administered twice, 3 weeks apart, at the dose of 1 μg per mouse by particle-mediated DNA transfer to the epidermis (gene gun) or at a dose of 30 μg per mouse by electroporation into the muscle. Three weeks after the second vaccination, the mice were challenged with lethal doses of homologous or heterologous viruses and the ability of each NA-DNA to protect the mice from influenza was evaluated by determining the lung virus titers, body weight and survival rates. The H3N2 virus NA-DNA conferred Cross-Protection against lethal challenge with antigenic variants within the same subtype, but failed to provide Protection against infection by a different subtype virus (H1N1). The degree of Cross-Protection against infection was related to titers of the Cross-reacting antibodies. These results suggest that NA-DNA can be used as a vaccine component to provide effective Protection against infection not only with homologous virus but also with drift viruses.

  • Cross-Protection against influenza virus infection in mice vaccinated by combined nasal/subcutaneous administration.
    Vaccine, 1995
    Co-Authors: Hideki Asanuma, Fusaoki Koide, Yujiro Suzuki, Takashi Nagamine, Chikara Aizawa, Takeshi Kurata, Shin-ichi Tamura
    Abstract:

    Abstract The effects of a combination of intranasal (i.n.) and subcutaneous (s.c.) administration of inactivated influenza vaccine for priming and boosting on the Cross-Protection against antigenically drifted virus challenge were examined in Balb/c mice. Mice were primed through the i.n. or s.c. route with a CTB ∗ -A/Kumamoto/37/79 (H1N1) combined vaccine (CTB ∗ : cholera toxin B subunit supplemented with 0.2% of the holotoxin) and boosted through the i.n. or s.c. route with another drift virus vaccine, A/Bangkok/10/83 (H1N1), 4 weeks later. Two weeks after boosting, the mice were challenged with a third drift virus, A/Yamagata/120/86 (H1N1). The combination of i.n. priming and i.n. boosting afforded the highest Cross-Protection, while combinations of s.c. priming and i.n. or s.c. boosting afforded little Cross-Protection. In parallel with the protective activity, anti-A/Yamagata haemagglutinin-reactive IgA and IgG antibodies were detected in nasal and bronchoalveolar wash specimens. These results suggest that Cross-Protection against a variant virus challenge is most favourably provided by i.n. priming with the CTB ∗ combined vaccine and i.n. boosting with the vaccine, which optimally induces Cross-protective IgA and IgG antibodies.

  • Formulation of inactivated influenza vaccines for providing effective Cross-Protection by intranasal vaccination in mice
    Vaccine, 1994
    Co-Authors: Shin-ichi Tamura, Hideki Asanuma, Takashi Nagamine, Chikara Aizawa, Y. Ito, Keiko Yoshizawa, Takeshi Kurata
    Abstract:

    Attempts were made to formulate an inactivated influenza vaccine to provide effective Cross-Protection by intranasal vaccination in mice. Mice were immunized with a nasal site-restricted volume of various HA vaccines (split-product virus vaccines), prepared from some of the H1N1 subtype viruses which circulated in humans from 1934 to 1986, together with cholera toxin B subunit (CTB) as an adjuvant. Four weeks later, they were challenged intranasally with a lethal dose of the earliest H1N1 virus strain, A/PR/8/34 (PR8) or the latest virus strain, A/Yamagata/120/86 (Yamagata/86). The adjuvant-combined vaccines, prepared from drift H1N1 viruses, A/Kumamoto/37/79 and A/Bangkok/10/83, provided a higher degree of Cross-Protection against a challenge with Yamagata/86 than with PR8. A booster with another drift virus vaccine given 4 weeks after the primary vaccination increased the Protection against Yamagata/86; the effect was higher when mice were vaccinated with a later strain as the second antigen than when boosted with PR8. These results suggest that vaccination with a later virus strain followed by another later strain in a two-dose nasal vaccination regimen gives effective Cross-Protection against the current epidemic virus strains.

  • Cross-Protection against influenza virus infection afforded by trivalent inactivated vaccines inoculated intranasally with cholera toxin B subunit.
    Journal of immunology (Baltimore Md. : 1950), 1992
    Co-Authors: Shin-ichi Tamura, Hideki Asanuma, Takashi Nagamine, Chikara Aizawa, Y. Ito, Yoshihiro Hirabayashi, Yutaka Suzuki, Takeshi Kurata
    Abstract:

    Cross-Protection against influenza virus infection was examined in mice, immunized intranasally with a nasal site-restricted volume of inactivated vaccines together with cholera toxin B subunit (CTB) as an adjuvant. The mice were challenged with either a small or a large volume of mouse-adapted virus suspension, each of which gave virgin mice either a predominant upper or lower respiratory tract infection. A single dose of a monovalent influenza A H3N2 virus vaccine with CTB provided complete Cross-Protection against the small-volume challenge with a drift virus within the same subtype, but a slight Cross-Protection against the large-volume challenge. A second dose of another drift virus vaccine increased the efficacy of Cross-Protection against the large-volume challenge. Similar Cross-Protection against H1N1, H3N2, or B type drift virus challenge was provided in the mice having received a primary dose of a mixture of H1N1, H3N2, and B virus vaccines with CTB and a second dose of another trivalent vaccine. The degree of Cross-Protection against the small- and the large-volume infection paralleled mainly the amount of Cross-reacting IgA antibodies to challenge virus hemagglutinin in the nasal wash and that of Cross-reacting IgG antibodies in the bronchoalveolar wash, respectively. On the other hand, in mice immunized subcutaneously with the trivalent vaccines having no Cross-reacting IgA antibodies, the efficacy of Cross-Protection was not so high as that of nasal vaccination. These results suggest that the nasal inoculation of trivalent vaccines with CTB provides Cross-Protection against a broader range of viruses than does the current parenteral vaccination.

Xiao Huogen - One of the best experts on this subject based on the ideXlab platform.

  • Studies on the Mild Strain Cross-Protection of Papaya Ringspot Virus
    Virologica Sinica, 1995
    Co-Authors: Xiao Huogen, Fan Huai-zhong
    Abstract:

    The present paper reported the effects of the ineeulum concentration of protecting strain and challenge strain,position of challange inoculation on the effectiveness of PRV mild strain Cross-Protection.Some technical aspocts in developing and implementing a Cross Protection program were suggestedbased on the exporimental results.Furthermore,it was found that the breakdown of Cross-Protection,asdefined by the appearance of symptoms caused by the severe strains,was related to the increase in virusconcentratio...

  • Studies on the Cross-Protection among strains of papaya ringspot virus.
    Chinese journal of virology, 1994
    Co-Authors: Xiao Huogen, Fan Huaizhong
    Abstract:

    The present study showed that Cross-Protection occurred between the different strains of PRV. The protecting strains did not completely inhibit the invasion of the challenge strains into the protected plants and not the spread of the challenge strains in the protected plants either, but it did inhibit the multiplication of the challenge strains. It was further found that the more closely related the protecting and challenge strains were, the greater the degree of Cross-Protection was. The efficiency of Cross-Protection between the closely related PRV strains of South-China was positively related with the rate of multiplication and spread and the concentration of the protecting strains in the plant, but negatively related with those of the challenge strains. The results mentioned above suggested that in order to control papaya ringspot virus disease by means of Cross-Protection either with a classical method or with CP genetic engineering method, the local dominant strains or severe should be used as the experimental materials in the work of induction and screening of mild strains or obtaining transgenic plants. In this way, better results might be expected.

James N. Culver - One of the best experts on this subject based on the ideXlab platform.

  • Tobamovirus Cross Protection using a potexvirus vector.
    Virology, 1996
    Co-Authors: James N. Culver
    Abstract:

    Abstract Cross Protection is the ability of one virus to prevent or delay infection by a related challenge virus. To examine this phenomena, a potato X potexvirus (PVX) vector (Chapman et al., 1992, Plant J. 2, 549) was used to systemically express the tobacco mosaic tobamovirus (TMV) coat protein (CP) open reading frame in Nicotiana benthamiana. PVX constructs induce mild mosaic symptoms in N. benthamiana, whereas TMV infection results in rapid systemic necrosis and plant death. Healthy plants or plants preinfected with the unmodified PVX vector succumbed to necrosis within 1 week of TMV challenge inoculation. However, plants preinfected with PVX vectors expressing the TMV CP or RNA coding sequence displayed a 1- to 2-week delay in the appearance of TMV-induced necrosis along with reduced accumulations of TMV. Symptom delay and reductions in the accumulation of TMV were more pronounced in plants protected with the vector expressing the TMV CP than with the vector expressing a nontranslatable CP sequence. Protection was overcome more quickly using a 10-fold higher concentration of challenge inoculum and was ineffective against TMV RNA or a TMV construct expressing a distantly related tobamovirus CP. These findings demonstrate that both RNA and protein are involved in this Cross Protection phenomenon, but that CP is the main contributor to Protection. Taken together, these studies indicate that virus vectors can be used to simulate both Cross Protection and transgene-derived coat protein-mediated Protection, thus providing a new method to further investigate the mechanisms behind each.