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Inhibition of influenza M2-induced cell death alleviates its negative contribution to vaccination efficiency.

Ilyinskii PO, Gambaryan AS, Meriin AB, Gabai V, Kartashov A, Thoidis G, Shneider AM - PLoS ONE (2008)

Bottom Line: Both of these constructs provided statistically significant protection upon DNA vaccination, with construct NP-M1-M2-NS1 being the most effective.We conclude that incorporation of M2 into a vaccination regimen may be beneficial only when its apparent cytotoxicity-linked negative effects are neutralized.The possible significance of this data for influenza vaccination regimens and preparations is discussed.

View Article: PubMed Central - PubMed

Affiliation: Cure Lab, Canton, Massachusetts, United States of America. ilyinskii@curelab.com

ABSTRACT
The effectiveness of recombinant vaccines encoding full-length M2 protein of influenza virus or its ectodomain (M2e) have previously been tested in a number of models with varying degrees of success. Recently, we reported a strong cytotoxic effect exhibited by M2 on mammalian cells in vitro. Here we demonstrated a decrease in protection when M2 was added to a DNA vaccination regimen that included influenza NP. Furthermore, we have constructed several fusion proteins of conserved genes of influenza virus and tested their expression in vitro and protective potential in vivo. The four-partite NP-M1-M2-NS1 fusion antigen that has M2 sequence engineered in the middle part of the composite protein was shown to not be cytotoxic in vitro. A three-partite fusion protein (consisting of NP, M1 and NS1) was expressed much more efficiently than the four-partite protein. Both of these constructs provided statistically significant protection upon DNA vaccination, with construct NP-M1-M2-NS1 being the most effective. We conclude that incorporation of M2 into a vaccination regimen may be beneficial only when its apparent cytotoxicity-linked negative effects are neutralized. The possible significance of this data for influenza vaccination regimens and preparations is discussed.

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Related in: MedlinePlus

Survival of mice vaccinated with the combinations of pNP and pM2 after challenge with 100 LD50 of H5N2 influenza virus strain A/Mallard/Pennsylvania/10218/84.Animals were immunized and challenged as described in Materials and Methods.
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pone-0001417-g001: Survival of mice vaccinated with the combinations of pNP and pM2 after challenge with 100 LD50 of H5N2 influenza virus strain A/Mallard/Pennsylvania/10218/84.Animals were immunized and challenged as described in Materials and Methods.

Mentions: The level of protection provided by DNA vaccination with pNP, pM2, pNP+pM2 or vector plasmid was assessed for animal groups challenged with 100 LD50 of mouse-adapted H5N2 influenza virus. Vaccination with pNP resulted in 20% survival (Fig. 1). Protection data unequivocally suggested that in such experimental settings inclusion of pM2 into the immunization regimen is detrimental for protection (Fig. 1). Specifically, while the pM2-immunized group showed no effect on the dynamics of survival and disease similar to vector-immunized controls, the survival in pNP+pM2-immunized group was clearly impaired compared to immunization with pNP alone (Fig. 1) and this difference was statistically significant (p<0.05). There was no difference in viral titers between pNP and pNP+pM2 immunized groups, with the titer in the pM2-immunized group being somewhat lower (not shown).


Inhibition of influenza M2-induced cell death alleviates its negative contribution to vaccination efficiency.

Ilyinskii PO, Gambaryan AS, Meriin AB, Gabai V, Kartashov A, Thoidis G, Shneider AM - PLoS ONE (2008)

Survival of mice vaccinated with the combinations of pNP and pM2 after challenge with 100 LD50 of H5N2 influenza virus strain A/Mallard/Pennsylvania/10218/84.Animals were immunized and challenged as described in Materials and Methods.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2175529&req=5

pone-0001417-g001: Survival of mice vaccinated with the combinations of pNP and pM2 after challenge with 100 LD50 of H5N2 influenza virus strain A/Mallard/Pennsylvania/10218/84.Animals were immunized and challenged as described in Materials and Methods.
Mentions: The level of protection provided by DNA vaccination with pNP, pM2, pNP+pM2 or vector plasmid was assessed for animal groups challenged with 100 LD50 of mouse-adapted H5N2 influenza virus. Vaccination with pNP resulted in 20% survival (Fig. 1). Protection data unequivocally suggested that in such experimental settings inclusion of pM2 into the immunization regimen is detrimental for protection (Fig. 1). Specifically, while the pM2-immunized group showed no effect on the dynamics of survival and disease similar to vector-immunized controls, the survival in pNP+pM2-immunized group was clearly impaired compared to immunization with pNP alone (Fig. 1) and this difference was statistically significant (p<0.05). There was no difference in viral titers between pNP and pNP+pM2 immunized groups, with the titer in the pM2-immunized group being somewhat lower (not shown).

Bottom Line: Both of these constructs provided statistically significant protection upon DNA vaccination, with construct NP-M1-M2-NS1 being the most effective.We conclude that incorporation of M2 into a vaccination regimen may be beneficial only when its apparent cytotoxicity-linked negative effects are neutralized.The possible significance of this data for influenza vaccination regimens and preparations is discussed.

View Article: PubMed Central - PubMed

Affiliation: Cure Lab, Canton, Massachusetts, United States of America. ilyinskii@curelab.com

ABSTRACT
The effectiveness of recombinant vaccines encoding full-length M2 protein of influenza virus or its ectodomain (M2e) have previously been tested in a number of models with varying degrees of success. Recently, we reported a strong cytotoxic effect exhibited by M2 on mammalian cells in vitro. Here we demonstrated a decrease in protection when M2 was added to a DNA vaccination regimen that included influenza NP. Furthermore, we have constructed several fusion proteins of conserved genes of influenza virus and tested their expression in vitro and protective potential in vivo. The four-partite NP-M1-M2-NS1 fusion antigen that has M2 sequence engineered in the middle part of the composite protein was shown to not be cytotoxic in vitro. A three-partite fusion protein (consisting of NP, M1 and NS1) was expressed much more efficiently than the four-partite protein. Both of these constructs provided statistically significant protection upon DNA vaccination, with construct NP-M1-M2-NS1 being the most effective. We conclude that incorporation of M2 into a vaccination regimen may be beneficial only when its apparent cytotoxicity-linked negative effects are neutralized. The possible significance of this data for influenza vaccination regimens and preparations is discussed.

Show MeSH
Related in: MedlinePlus