Influenza A virus infection engenders a poor antibody response against the ectodomain of matrix protein 2
| Autor: | Robert B. Couch, Krystyna Mozdzanowska, Manxin Zhang, Walter Gerhard, Henry Hoff, Jing Qi Feng, William H. Wunner, Darya Zharikova |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Blotting
Western Enzyme-Linked Immunosorbent Assay Biology medicine.disease_cause Antibodies Viral lcsh:Infectious and parasitic diseases law.invention Viral Matrix Proteins 03 medical and health sciences Mice Western blot law Virology Influenza Human Influenza A virus medicine Animals Humans lcsh:RC109-216 030304 developmental biology Immunoassay 0303 health sciences Viral matrix protein medicine.diagnostic_test 030306 microbiology Research 3. Good health Titer Infectious Diseases Ectodomain Recombinant DNA biology.protein Antibody HeLa Cells |
| Zdroj: | Virology Journal Virology Journal, Vol 3, Iss 1, p 102 (2006) |
| ISSN: | 1743-422X |
| Popis: | BackgroundMatrix protein 2 (M2) is an integral tetrameric membrane protein of influenza A virus (IAV). Its ectodomain (M2e) shows remarkably little diversity amongst human IAV strains. As M2e-specific antibodies (Abs) have been shown to reduce the severity of infection in animals, M2e is being studied for its capability of providing protection against a broad range of IAV strains. Presently, there is little information about the concentration of M2e-specific Abs in humans. Two previous studies made use of ELISA and Western blot against M2e peptides and recombinant M2 protein as immunosorbents, respectively, and reported Ab titers to be low or undetectable. An important caveat is that these assays may not have detected all Abs capable of binding to native tetrameric M2e. Therefore, we developed an assay likely to detect all M2e tetramer-specific Abs.ResultsWe generated a HeLa cell line that expressed full length tetrameric M2 (HeLa-M2) or empty vector (HeLa-C10) under the control of the tetracycline response element. These cell lines were then used in parallel as immunosorbents in ELISA. The assay was standardized and M2e-specific Ab titers quantified by means of purified murine or chimeric (mouse variable regions, human constant regions) M2e-specific Abs in the analysis of mouse and human sera, respectively. We found that the cell-based ELISA was substantially more effective than immobilized M2e peptide in detecting M2e-specific Abs in sera of mice that had recovered from repetitive IAV infections. Still, titers remained low (< 5 μg/ml) even after two consecutive infections but increased to ~50 μg/ml after the third infection. Competition with free M2e peptide indicated that ~20% of M2e-specific Abs engendered by infection reacted with M2e peptide. In humans presenting with naturally acquired influenza virus infection, 11 of 24 paired sera showed a ≥ 4-fold increase in M2e-specific Ab titer. The Ab response appeared to be of short duration as titers were very low (average 0.2 μg/ml) in all patients at onset of infection and in controls, in spite of evidence for previous exposure to IAV.ConclusionThe results provide convincing evidence that M2e-specific Ab-mediated protection is currently lacking or suboptimal in humans. |
| Databáze: | OpenAIRE |
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