RESUMEN
Vaccination is the most effective mean of preventing influenza virus infections. However, vaccination-induced adverse reactions of the nervous system, the causes of which are unknown, lead to concerns on the safety of influenza A vaccine. In this study, we used flow cytometry, cell ELISA, and immunofluorescence to find that H1-84 monoclonal antibody (mAb) against the191/199 region of the H1N1 influenza virus hemagglutinin (HA) protein binds to neural cells and mediates cell damage. Using molecular simulation software, such as PyMOL and PDB viewer, we demonstrated that the HA191/199 region maintains the overall structure of the HA head. Since the HA191/199 region cannot be removed from the HA structure, it has to be altered via introducing point mutations by site-directed mutagenesis. This will provide an innovative theoretical support for the subsequent modification the influenza A vaccine for increasing its safety.
Asunto(s)
Anticuerpos Monoclonales de Origen Murino , Glicoproteínas Hemaglutininas del Virus de la Influenza , Subtipo H1N1 del Virus de la Influenza A , Simulación de Dinámica Molecular , Neuronas/metabolismo , Anticuerpos Monoclonales de Origen Murino/química , Anticuerpos Monoclonales de Origen Murino/inmunología , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Línea Celular Tumoral , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Humanos , Subtipo H1N1 del Virus de la Influenza A/química , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/inmunología , Mutagénesis Sitio-Dirigida , Neuronas/patología , Dominios ProteicosRESUMEN
Previous studies have indicated that two monoclonal antibodies (mAbs; A1-10 and H1-84) of the hemagglutinin (HA) antigen on the H1N1 influenza virus cross-react with human brain tissue. It has been proposed that there are heterophilic epitopes between the HA protein and human brain tissue (Guo et al. in Immunobiology 220:941-946, 2015). However, characterisation of the two mAbs recognising the heterophilic epitope on HA has not yet been performed. In the present study, the common antigens of influenza virus HA were confirmed using indirect enzyme-linked immunosorbent assays and analysed with DNAMAN software. The epitopes were localized to nine peptides in the influenza virus HA sequence and the distribution of the peptides in the three-dimensional structure of HA was determined using PyMOL software. Key amino acids and variable sequences of the antibodies were identified using abYsis software. The results demonstrated that there were a number of common antigens among the five influenza viruses studied that were recognised by the mAbs. One of the peptides, P2 (LVLWGIHHP191-199), bound both of the mAbs and was located in the head region of HA. The key amino acids of this epitope and the variable regions in the heavy and light chain sequences of the mAbs that recognised the epitope are described. A heterophilic epitope on H1N1 influenza virus HA was also introduced. The existence of this epitope provides a novel perspective for the occurrence of nervous system diseases that could be caused by influenza virus infection, which might aid in influenza prevention and control.
Asunto(s)
Antígenos Heterófilos/inmunología , Antígenos Virales/inmunología , Epítopos/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática , Mapeo Epitopo , Pruebas de Inhibición de Hemaglutinación , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Péptidos/inmunología , Programas InformáticosRESUMEN
The percentage rate of Epstein-Barr virus (EBV)-positive cases of Hodgkin's lymphoma (HL) ranges between 20 and 70% in various studies worldwide. To further explore the definite rate in China, three methods, including immunohistochemistry for EBV latent membrane protein 1 (LMP1), in situ hybridization (ISH) for EBV-encoded RNA (EBER)-1 and polymerase chain reaction (PCR) for EBV BamHIW fragment, were employed to detect EBV in 59 cases of HL in China using paraffin-embedded tissue samples. Our results revealed that the PCR method presented the highest (44/59, 74.6%) detection rate among the three methods. The other two methods identified 66.1% (39/59, LMP1) and 67.8% (40/59, EBER1 ISH) EBV-positive results, respectively. Three samples were positive for LMP1 but negative when using EBER1 ISH, while another four samples were EBER1-positive but LMP1-negative. Of the four major histopathological subtypes of HL, the lymphocyte predominant (LR) subtype is the one most frequently associated with EBV, followed by the mixed cellularity (MC), nodular sclerosis (NS) and lymphocyte depletion (LD) subtypes. Our results also indicated the seldomly reported fact that EBV-positive cases in children were more numerous than those of adults with HL.
