Use of Recombinant Nucleoproteins in Enzyme-Linked Immunosorbent Assays for Detection of Virus-Specific Immunoglobulin A (IgA) and IgG Antibodies in Influenza Virus A- or B-Infected Patients

Abstract

The nucleoprotein genes of influenza virus A/Netherlands/018/94 (H3N2) and influenza virus B/Harbin/7/94 were cloned into the bacterial expression vector pMalC to yield highly purified recombinant influenza virus A and B nucleoproteins. With these recombinant influenza nucleoproteins, enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of influenza virus A- and B-specific immunoglobulin A (IgA) and IgG serum antibodies. Serum samples were collected at consecutive time points after the onset of clinical symptoms from patients with confirmed influenza virus A or B infections. Nucleoprotein-specific IgA antibodies were detected in 41.2% of influenza virus A-infected patients and in 66.7% of influenza virus B-infected patients on day 6 after the onset of clinical symptoms. In serum samples taken on day 21 (influenza virus A-infected patients) or day 28 (influenza virus B-infected patients), nucleoprotein-specific IgA antibodies could be detected in 58.8 and 58.3% of influenza virus A- and B-infected patients, respectively. At the same time, IgG antibody rises were detected in 88.2% of influenza virus A-infected patients and in 95.8% of influenza virus B-infected patients. On comparison, hemagglutination inhibition assays detected antibody titer rises in 81.3 and 72.7% of patients infected with influenza viruses A and B, respectively. In contrast to the detection of nucleoprotein-specific IgG antibodies or hemagglutination-inhibiting antibodies, the detection of nucleoprotein-specific IgA antibodies does not require paired serum samples and therefore can be considered an attractive alternative for the rapid serological diagnosis of influenza.

Latent class analysis of diagnostic tests for adenovirus,Bordetella pertussisand influenza virus infections in German adults with longer lasting coughs

“…The commercial ELISA systems employed in this study used nucleoproteins for influenza A and B serology and hexon protein for adenovirus serology. For influenza serology these tests have been successfully used in diagnostic serology [22] with a good sensitivity and specificity. For adenovirus respiratory infections in non-immunocompromised adults, isotype-specific ELISA systems were only rarely used [23], but displayed sufficient sensitivity and specificity.…”

Dendritic cells are crucial for maintenance of tertiary lymphoid structures in the lung of influenza virus–infected mice

“…FDC (M2; BD) was single stained. For detection of NP-positive cells, slides were incubated with recombinant NP (Voeten et al, 1998) before FITC-labeled anti-NP staining. Slides were digitized on a Digital Zoom Microscope (Hamamatsu).…”

Antigen processing for MHC class I restricted presentation of exogenous influenza A virus nucleoprotein by B-lymphoblastoid cells

“…rNP of influenza virus A/HongKong/2/68; H3N2 (A/HK/2/68), A/Netherlands/18/94; H3N2 (A/Neth/18/94), and B/Harbin/7/94 (B/Har/7/94) was produced as described previously [23]. In brief, the nucleoprotein (NP)‐encoding genes were cloned at the 3′ end of the maltose‐binding protein (MBP)‐encoding gene using the bacterial expression vector pMalC (New England Biolabs, Beverly, MA, USA) to yield fusion proteins consisting of MBP at the N‐terminus and NP at the C‐terminus.…”