Recognition of a multiple antigen peptide containing sequence from mimotope of the dengue type 3 virus NS4B protein by human antibodies.

Objective: To evaluate the recognition of NS4B mimotope, as multiple antigen peptide (MAP), by dengue antibodies presents in serum samples from patients with different serotype infections.

Methods: A MAP containing mimotope sequence was synthesized and used to evaluate the recognition of NS4B mimotope as MAP by a panel of 66 human sera from dengue cases by an indirect ELISA assay.

Results: The MAP differentiated between sera from dengue viruses infected patients and sera from healthy individuals and the best reactivity was shown by serum from dengue type 3 virus patients.

Asymptomatic dengue infection in a Cuban population confirms the protective role of the RR variant of the FcgammaRIIa polymorphism.

The role of human Fcgamma receptors (FcgammaR) has been recognized considerably over the last years. These receptors vary in their affinity for IgG subclasses and the intracellular signals elicited by them. Allelic variants of FcgammaR genes may influence the biological phagocyte activity, accounting for an inherited pre-disposition to disease.

Identification of Dengue-specific B-Cell Epitopes by Phage-display Random Peptide Library.

Background: Dengue is the most important human viral disease transmitted by arthropod vectors. The availability of random peptide libraries (RPL) displayed on phage has provided a powerful tool for selecting sequences that mimic epitopes from microorganisms that are useful for diagnostic and vaccine development purposes. In this paper, we describe peptides that resemble the antigenic structure of B-cell epitopes of dengue virus identified from a phage-peptide library using human sera containing polyclonal antibodies against dengue virus.

Phage-displayed antibody fragments recognizing dengue 3 and dengue 4 viruses as tools for viral serotyping in sera from infected individuals.

The current study shows the usefulness of dengue-3- and dengue-4-specific phage-displayed antibody fragments as tools for viral detection and serotyping in sera from infected individuals. C6/36 HT cells were inoculated with acute-phase sera from patients, and supernatants were collected daily and analyzed by ELISA using phage-displayed antibody fragments as serotype-specific detector reagents. Serotyping of most samples was possible as early as two to three days postinoculation.

Selection of phage-displayed human antibody fragments on Dengue virus particles captured by a monoclonal antibody: application to the four serotypes.

Antibody fragments to the four Dengue virus serotypes were isolated from a human universal naïve library using phage display technology. Phage-displayed antibody fragments were selected on Dengue virus particles directly captured from infected Vero cells supernatant by an anti-dengue monoclonal antibody, in order to avoid laborious virus concentration/purification procedures. A total of nine phage-displayed antibody fragments were obtained.

West Nile Virus infection in humans and horses, Cuba.

A surveillance system to detect West Nile virus (WNV) was established in Cuba in 2002. WNV infection was confirmed by serologic assays in 4 asymptomatic horses and 3 humans with encephalitis in 2003 and 2004. These results are the first reported evidence of WNV activity in Cuba.

Diagnosis of dengue virus infection by the visual and simple AuBioDOT immunoglobulin M capture system.

The Dengue IgM Capture ELISA (MAC-ELISA) is the immunoenzymatic system recommended by the Pan American Health Organization and the World Health Organization for the serological diagnosis of dengue virus infection due to its high sensitivity, ease of performance, and use of a single acute-phase serum sample. However, tests with this enzyme-linked immunosorbent assay (ELISA) system are time-consuming and require equipment for washing, incubation, and reading of the results. AuBioDOT is a multistep visual diagnostic immunoassay that uses technology based on the immunoglobulin M (IgM) capture ELISA principle.

MAC-ELISA and ELISA inhibition methods for detection of antibodies after yellow fever vaccination.

The IgM antibody capture ELISA (MAC-ELISA) and ELISA inhibition methods for the detection of antibodies against dengue virus were modified to detect antibodies against yellow fever virus. Tests were carried out in 21 persons vaccinated with 17D and compared with the Plaque reduction neutralizing test. Of 17 naive subjects vaccinated, 16 (94%) seroconverted using the MAC-ELISA test and 14 (82%) seroconverted (or >/=fourfold titer increase) in the ELISA inhibition method.

Immune response to synthetic peptides of dengue prM protein.

The immunological activities of five synthetic peptides of the prM protein of dengue-2 (DEN-2) virus containing B cell epitopes were evaluated in BALB/c mice. Two peptides elicited neutralizing antibodies against all four DEN serotypes. Virus-specific proliferative responses were demonstrated in mice immunized with four of the five peptides, demonstrating the presence of T cell epitopes.