Effects of the number of amino acid residues in the signal segment upstream or downstream of the NS2B-3 cleavage site on production and secretion of prM/M-E virus-like particles of West Nile virus.
Expression of genes for precursor M (prM) and envelope (E) proteins of West Nile virus (WNV) leads to the production of small, capsidless, and non-infectious virus-like particles (VLPs) possessing the E antigen which is responsible for viral entry and immune protection. It has been reported that processing of the secretion signal affects viral release. We examined the secretion efficiency of VLPs into the culture medium from RK13 or 293T cells transfected with expression vectors for prM and E proteins of WNV which were constructed to comprise different lengths of signal peptides upstream of the prM-E domain. The number of amino acid residues present in the segment markedly affected the production, processing, and secretion of VLPs. Secreted VLPs possessed both the processed M protein and the glycosylated E protein. In addition, immunization with VLPs induced neutralizing antibodies in C3H/HeN mice. These results indicate that the number of amino acid residues comprising the N-terminus of the signal segment controls the efficiency of assembly, maturation, and release of VLPs in the absence of viral protease, which in turn indicates the potential of VLPs as a candidate for an effective WNV subunit vaccine.
Takahashi
Hidehiro
H
Department of Pathology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan. htakahas@nih.go.jp
Ohtaki
Naohiro
N
Maeda-Sato
Masae
M
Tanaka
Michiko
M
Tanaka
Keiko
K
Sawa
Hirofumi
H
Ishikawa
Toyokazu
T
Takamizawa
Akihisa
A
Takasaki
Tomohiko
T
Hasegawa
Hideki
H
Sata
Tetsutaro
T
Hall
William W
WW
Kurata
Takeshi
T
Kojima
Asato
A
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D006031:Glycosylation; D006801:Humans; D051379:Mice; D016254:Mutagenesis, Insertional; D021382:Protein Sorting Signals; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014771:Virion / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D014902:West Nile virus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D021382:Protein Sorting Signals; D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins; C074932:prM protein, Flavivirus