Monoclonal antibody against Saint Louis encephalitis prM viral protein.

Saint Louis encephalitis virus belongs to Flavivirus genus; Flaviviridae family jointly with other medically important flaviviruses including dengue virus and West Nile virus. The biological properties and functions of prM flavivirus protein are under investigation due to its importance in the generation of infectious virion and host interactions. Monoclonal antibodies have become powerful tools in this approach. Also the use of monoclonal antibodies has been successfully applied for antigenic analysis, clinical diagnosis and treatments. Here, using an immunofluorescence assay we describe a monoclonal antibody (mAb 3D2) that uniquely recognizes native prM Saint Louis encephalitis virus protein expressed in either C6/36-HT or Vero cells. In conclusion, mAb3D2 has significant potential for use in (a) the diagnosis of infections caused by this virus and (b) therapeutic use to treat patients infected by this virus and fundamental research to understand the role of the prM in the Saint Louis encephalitis virus infectious process.

Monoclonal antibody to dengue capsid protein: its application in dengue studies

Dengue fever (DF) and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) are considered the most important arthropod-borne viral diseases in terms of morbidity and mortality. The emergency and severity of dengue (Den) infections increase the necessity of an early, quick and effective dengue laboratory diagnostic. Viral isolation is considered a gold standard for diagnosis of dengue infection using monoclonal antibodies (mAbs) as a tool for determining serotype specificity. Alternatives have been used to improve sensitivity and time to dengue diagnosis. Based on the early expression of dengue C protein in the life cycle, we focused our study on the application of an anti-dengue 2 virus capsid protein mAb in dengue diagnosis. The kinetic expression of dengue-2 capsid in mosquito cells and its immuno-localization in experimentally infected suckling albin Swiss (OF-1) mice brain tissues was established. The results demonstrate the possible utility of this mAb in early dengue diagnosis versus traditional isolation. In addition, a preliminary study of an enzyme immunoassay method using 8H8 mAb for specific detection of dengue C protein antigen was performed, making possible recombinant C protein quantification. The results suggest that detection of dengue capsid protein could be useful in the diagnosis of early dengue infection(AU)

Development of a monoclonal antibody specific to a recombinant envelope protein from dengue virus type 4 expressed in Pichia pastoris.

A mouse monoclonal antibody (MAb, 4B6) was able to recognize dengue virus type 4 envelope (E) protein both as a recombinant protein in Pichia pastoris and when it was present in infected brains of suckling mice. 4B6 was characterized by enzyme-linked immunoadsorbent assay (ELISA), hemaglutination inhibition, neutralization, and immunoblot. The MAb was isotyped as IgG2a. It was serotype 4 specific and it inhibited hemaglutination and neutralized homologous virus. It did not enhance infection of P338D1 cells by dengue type 4 virus strain H-241 strain. This MAb was reactive with recombinant E protein and dengue 4 virus, as revealed by Western blot. In vivo, MAb 4B6 conferred passive protection in mice challenged with homologous virus. Currently, this MAb is being used to purify recombinant E protein for further studies.

[Monoclonal antibodies to dengue virus 4: the spectrum of the reactivity to 4 serotypes of dengue]. / Anticuerpos monoclonales al virus dengue 4: espectro de reactividad a los 4 serotipos del dengue.

These types of monoclonal antibodies 8E8, 3F7 and 1E9 to dengue 4 virus H-241 strain. These monoclonal antibodies show various patterns of reactivity to the four dengue serotypes and different antigen preparations of serotype 4 when they were tested in various serological methods. The monoclonal antibody 8E8 exhibited a specificity of serotype (D-2; by hemagglutination inhibition); subcomplex (D-2 and D-4 by immunofluorescence) and complex (by immunoperoxidase technique). It was able to neutralize by 80% homologous virus and it turned out to be the only reactive monoclonal antibody in the complement fixation test. The monoclonal 3F7 did not react to by hemagglutination inhibition, recognized serotypes D-1, D-2, D-3 and D-4 by immunofluorescence and only serotypes D1 and D4 by immunoperoxidase technique but it was unable to neutralize the homologous virus. The 1E9 antibody was reactive to serotypes D1, D-2, D-3 and D-4 only by hemagglutination inhibition and neutralized serotype D-4. All the monoclonal antibodies were able to react to various dengue antigens through an ELISA of double antibody and showed fluorescent activity against 38th pass in Beagle dog kidney culture; however, they could not react to a D-4 recombinant antigen.

Monoclonal antibodies raised to the dengue-2 virus (Cuban: A15 strain) which recognize viral structural proteins.

Mouse monoclonal antibodies (MAbs) were raised to dengue-2 virus (D-2V) Cuban (A15) strain and the cell culture supernatants were screened by ELISA using the homologous virus. Three MAb-secreting lines were further characterized using immunoblot, haemaglutination, complement-fixation, and neutralization assays. One of these, MAb 8H8, weakly reacted with the viral nonstructural-1 protein (NS1) but more specifically identified the capsid protein (C), MAb 3E1 recognized in serological assays D-2V A15 but it had a weak reaction to C protein by immunodetection whereas another, MAb 4G3, weakly neutralized the homologous virus isolate and blocked the binding of specific anti-envelope (E) Mab, and its reaction with this protein could not be confirmed using immunoblot assays. These reagents are now being used to compare virulent plus avirulent Caribbean viruses antibody dependent enhancement (ADE) assays.

[Monoclonal antibodies which recognize herpes simplex virus and their possible diagnostic application]. / Anticuerpos monoclonales (AcM) que reconocen el virus herpes simple (HSV) y su posible aplicación al diagnóstico.

It is reported the obtention of monoclonal antibodies, which are capable of recognizing HSV-1 and HSV-2 viruses, by the conventional technology of cellular fusion. The monoclonal antibodies of highest positivity according to the indirect immunofluorescence technique were partially characterized. It was determined the neutralizing capacity of 2 of them (278-F7 and 70-G10), which were used to identify isolations of clinical specimens by indirect immunofluorescence. These monoclonal antibodies recognized HSV-1 up to a dilution of 1:2 560.