Monocytes and B cells support active replication of Chandipura virus.

Background: Interaction between immune system and Chandipura virus (CHPV) during different stages of its life cycle remain poorly understood. The exact route of virus entry into the blood and CNS invasion has not been clearly defined. The present study was undertaken to assess the population in PBMC that supports the growth of virus and to detect active virus replication in PBMC as well as its subsets.

Development and characterization of reverse genetics system for the Indian West Nile virus lineage 1 strain 68856.

Our previous studies on West Nile virus (WNV) strains isolated from human patients in India suggested substantial variation at the genetic level reflecting their variable pathogenesis. This study describes the development of reverse genetics system for a neurovirulent WNV isolate 68856 and its characterization. Full length viral cDNA was cloned into bacterial artificial chromosome (BAC) under the transcription control of T7 promoter.

Activated CD56(+) lymphocytes (NK+NKT) mediate immunomodulatory and anti-viral effects during Japanese encephalitis virus infection of dendritic cells in-vitro.

Japanese encephalitis virus (JEV) remains one of the major causative agents of pediatric encephalitis. Interaction of dendritic cells (DCs) with innate lymphocytes (NK and NKT) represents a crucial event during anti-viral innate immune response. In the current study, we have tried to understand the interaction between JEV, human monocyte derived DCs (MDDCs), and CD56(+) cells (NK+NKT) in-vitro.

Neutralization escape variant of West Nile virus associated with altered peripheral pathogenicity and differential cytokine profile.

In order to understand the factors influencing pathogenicity of a virus, two neutralization escape (NE) variants were selected from wild type lineage 1 West Nile virus (WNV) 68856 strain pathogenic by intra-peritoneal (i.p.) route using monoclonal antibodies (MAbs) against envelope (E) protein.

Japanese encephalitis virus produces a CD4+ Th2 response and associated immunoprotection in an adoptive-transfer murine model.

Japanese encephalitis is an acute infection of the central nervous system caused by Japanese encephalitis virus (JEV). The importance of an effective humoral response in preventing JEV infection has already been established, although the contribution of cellular immunity remains unclear. This study used an experimental murine model to understand the protective effects of cell-mediated immunity in JEV infection.

Detection and isolation of Japanese encephalitis virus from blood clots collected during the acute phase of infection.

Clinical specimens from an encephalitis outbreak in the Lakhimpur area of Uttar Pradesh, India, were investigated for identification and characterization of the etiologic agent. IgM capture ELISA showed recent Japanese encephalitis virus (JEV) infection. JEV isolation was attempted from white blood cells (WBCs) separated from blood clots of 12 patients (9 IgM positive and 3 negative) by serial co-culturing with phytohemagglutinin P-stimulated peripheral blood mononuclear leukocytes (PBMCs) obtained from pre-screened JEV sero-negative healthy individuals.

Chimeric T helper-B cell peptides induce protective response against Japanese encephalitis virus in mice.

Virus neutralizing MAb binding and T helper cell stimulating peptide epitopes from structural and non-structural proteins of Japanese encephalitis virus were delineated. It was observed that priming by T helper peptides potentiated neutralizing antibody response against JE virus. Immunization with chimeric T helper - B cell peptides could thus protect mice from lethal challenge with JE virus.

Incidence of neutralizing antibodies to Chandipura virus in domestic animals from Karimnagar and Warangal Districts of Andhra Pradesh, India.

In order to determine the possible role of domestic animals in the outbreak of acute encephalitis associated with Chandipura virus (CPV) among children in Andhra Pradesh in 2003, a serological survey of domestic animals was carried out during the epidemic in July 2003. Out of 180 animal sera from highly affected areas of the Karimnagar and Warangal districts of Andhra Pradesh 33 (18.3%) had virus neutralizing (VN) antibodies to CPV.

Monoclonal antibody raised against envelope glycoprotein peptide neutralizes Japanese encephalitis virus.

Epitopes on envelope glycoprotein of Indian strain of Japanese encephalitis virus were delineated by prediction methods. Monoclonal antibodies (MAb) raised against a putative B cell epitope peptide, reacted with the virion in ELISA and immunofluorescence assays. One MAb was also able to neutralize the virus.

Circulation of group A rotavirus subgroups and serotypes in Pune, India, 1990-1997.

Group A rotavirus-positive stool specimens, collected from 432 hospitalized patients of all age groups with diarrhoea during 1990-1997 from Pune, India, were characterized for subgroups (SGs) and G serotypes (1, 2, 3, 4, 6, 8, and 10). ELISA for subgrouping was carried out by employing subgroup I and II-specific monoclonal antibodies (MAbs). For serotyping, MAbs against G1 (Ku), G2 (S2), G3 (Yo), and G4 (ST-3) were used.

Loss of virus specific epitopes on JE virus 'E' glycoprotein by acetone treatment.

Background & Objectives: Some Japanese encephalitis (JE) virus strains have been placed in group II based on the loss of reactivity against Hs (H = HI positive; s = JE virus specific) group of monoclonal antibodies (MAbs) in haemagglutination-inhibition (HI) test employing sucrose acetone (SA) extracted antigens. Also acetone-fixation of cells infected with some of the virus strains results in the loss of immunofluorescence (IF) against virus specific MAbs. The present study was undertaken to elucidate the effect of acetone on virus specific haemagglutination (HA) epitopes expressed on 'E' glycoprotein of group II strains of JE virus.

Susceptibility of BL6 nude (congenitally athymic) mice to Japanese encephalitis virus by the peripheral route.

Studies on the susceptibility of adult BL6 nude (congenitally athymic, nu/nu) mice, their euthymic littermates (+/nu) and Swiss mice to Japanese encephalitis (JE) virus inoculated subcutaneously were carried out. The mice were observed over a period of 60 days p.i.

Serological response to Japanese encephalitis vaccine in a group of school children in South Arcot district of Tamil Nadu.

A trial with Biken Japanese encephalitis (JE) vaccine made in Japan was carried out in South Arcot district of Tamil Nadu state, India. A total of 113 school children were included in the trial. The efficacy (as determined by serological response) and safety of the vaccine were evaluated.

Selection of a neutralization-escape variant strain of Japanese encephalitis virus using monoclonal antibody.

An Indian strain of Japanese encephalitis virus (JEV), 733913, a human isolate from Bankura, West Bengal in 1973, with all the functional epitopes designated by a panel of murine monoclonal antibodies (MAbs), was treated with one of the JEV specific HI reactive MAb(Hs-I). This led to selection of a neutralization-escape variant which showed loss of reaction to three different MAbs belonging to the same domain (Hs) and assumed similar characteristics to another JEV strain (755468) also isolated from Bankura in 1975 from mosquitoes. It is possible that selection of such variant might occur in presence of pre-existing JE antibody (Hs-I type) in pigs which are amplifying hosts of JEV.