TY - JOUR
T1 - The M2 protein of live, attenuated influenza vaccine encodes a mutation that reduces replication in human nasal epithelial cells
AU - Wohlgemuth, Nicholas
AU - Ye, Yang
AU - Fenstermacher, Katherine J.
AU - Liu, Hsuan
AU - Lane, Andrew P.
AU - Pekosz, Andrew
N1 - Funding Information:
We thank the members of the Pekosz laboratory, Sabra Klein, and members of the Klein laboratory for useful and critical discussions of the data. The work was supported by the Shikani/El Hibri Prize for Discovery and Innovation (AP), R01 AI097417 (AP), HHSN272201400007C (AP), R01 AI072502 (APL) and T32 AI007417 (NW).
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/12/4
Y1 - 2017/12/4
N2 - The influenza A virus components of the live, attenuated influenza vaccine (LAIV) encode the HA and NA gene segments from a circulating virus strain and the remaining gene segments from the cold-adapted master donor virus, A/Ann Arbor/6/1960 (H2N2). The master donor virus imparts at least three phenotypes: temperature-sensitivity (ts), attenuation (att), and cold-adaption (ca). The genetic loci responsible for the att and ts phenotypes of LAIV were mapped to PB1, PB2, and NP by reverse genetics experiments using immortalized cell lines. However, some in vivo studies have demonstrated that the M segment, which acquired an alanine (Ala) to serine (Ser) mutation at M2 position 86 during cold adaption – a mutation found in no other influenza A virus strain - contributes to the att phenotype. Prior studies have shown this region of the M2 cytoplasmic tail to be critical for influenza virus replication. Using reverse genetics, we demonstrate that certain amino acid substitutions at M2 positions 83 and 86 alter the replication of influenza A/Udorn/307/72 (H3N2). Importantly, substitution of a Ser at M2 position 86 reduces A/Udorn/307/72 replication in differentiated primary human nasal epithelial cell (hNECs) cultures, but does not considerably affect replication in MDCK cells. When a Ser was substituted for Ala at M2 86 in LAIV, the virus replicated to higher titers and with faster kinetics in hNEC cultures, implicating this amino acid change as contributing to LAIV attenuation. Increased replication also resulted in increased production of IFN-λ. These data indicate the LAIV associated Ser mutation at M2 position 86 contributes to the att phenotype and is associated with a differential regulation of interferon in LAIV infection.
AB - The influenza A virus components of the live, attenuated influenza vaccine (LAIV) encode the HA and NA gene segments from a circulating virus strain and the remaining gene segments from the cold-adapted master donor virus, A/Ann Arbor/6/1960 (H2N2). The master donor virus imparts at least three phenotypes: temperature-sensitivity (ts), attenuation (att), and cold-adaption (ca). The genetic loci responsible for the att and ts phenotypes of LAIV were mapped to PB1, PB2, and NP by reverse genetics experiments using immortalized cell lines. However, some in vivo studies have demonstrated that the M segment, which acquired an alanine (Ala) to serine (Ser) mutation at M2 position 86 during cold adaption – a mutation found in no other influenza A virus strain - contributes to the att phenotype. Prior studies have shown this region of the M2 cytoplasmic tail to be critical for influenza virus replication. Using reverse genetics, we demonstrate that certain amino acid substitutions at M2 positions 83 and 86 alter the replication of influenza A/Udorn/307/72 (H3N2). Importantly, substitution of a Ser at M2 position 86 reduces A/Udorn/307/72 replication in differentiated primary human nasal epithelial cell (hNECs) cultures, but does not considerably affect replication in MDCK cells. When a Ser was substituted for Ala at M2 86 in LAIV, the virus replicated to higher titers and with faster kinetics in hNEC cultures, implicating this amino acid change as contributing to LAIV attenuation. Increased replication also resulted in increased production of IFN-λ. These data indicate the LAIV associated Ser mutation at M2 position 86 contributes to the att phenotype and is associated with a differential regulation of interferon in LAIV infection.
KW - Influenza
KW - LAIV
KW - Respiratory epithelial cells
KW - Vaccines
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U2 - 10.1016/j.vaccine.2017.10.018
DO - 10.1016/j.vaccine.2017.10.018
M3 - Article
C2 - 29079099
AN - SCOPUS:85033487904
VL - 35
SP - 6691
EP - 6699
JO - Vaccine
JF - Vaccine
SN - 0264-410X
IS - 48
ER -