Immunofluorescence assay for detection of human metapneumovirus-specific antibodies by use of baculovirus-expressed fusion protein.
Human metapneumovirus (hMPV) has recently been identified as an etiological agent of acute respiratory infections. The hMPV fusion (F) protein has been indicated to be a major antigenic determinant that mediates effective neutralization and protection against hMPV infection. We developed a new immunofluorescence assay (IFA) using Trichoplusia ni (Tn5) insect cells infected with a recombinant baculovirus-expressing hMPV F protein (Bac-F IFA). A total of 200 serum samples from Japanese people 1 month to 41 years old were tested for immunoglobulin G antibodies to hMPV F protein by Bac-F IFA. The results were compared with those of the conventional IFA based on hMPV-infected LLC-MK2 cells (hMPV IFA). The titers obtained by the two IFAs correlated well (correlation coefficient of 0.88), and the concordance of seroreactivities between the two IFAs was 91% (kappa=0.76). For 192 of the 200 serum samples, the titers obtained by the Bac-F IFA were equal to or higher than those obtained by the hMPV IFA. These results indicated that the Bac-F IFA was more sensitive than the hMPV IFA and that the majority of the antibodies detected by the hMPV IFA reacted with the hMPV F protein. The Bac-F IFA is a more reliable, sensitive, and specific method for the detection of hMPV antibodies than is the hMPV IFA.
Ishiguro
Nobuhisa
N
Department of Pediatrics, Hokkaido University Graduate School of Medicine, N-15, W-7, Kita-ku, Sapporo 060-8638, Japan.
Ebihara
Takashi
T
Endo
Rika
R
Ma
Xiaoming
X
Shirotsuki
Ryo
R
Ochiai
Susumu
S
Ishiko
Hiroaki
H
Kikuta
Hideaki
H
D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D005455:Fluorescent Antibody Technique / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D029121:Metapneumovirus / Q000276:immunology*; D018184:Paramyxoviridae Infections / Q000097:blood / Q000175:diagnosis*; D011994:Recombinant Proteins / Q000276:immunology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D014764:Viral Proteins / Q000276:immunology
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D014764:Viral Proteins