RESUMO
Two proteins (putative receptors) of 60 and 38 kDa, for chikungunya (CHIK) virus were detected in the brush border membrane fraction (BBMF) of the normal population of Aedes aegypti mosquitoes. Mosquitoes were infected orally with CHIK virus and infectivity checked by testing the head squashes. BBMF was prepared from proved positive and negative mosquitoes. The receptor proteins were found to be present in both the proved genotypes. However, dot-b'ot assays showed that the CHIK virus binding activity of BBMF/mg protein was noticeably low in the proved negative mosquitoes as compared to the positives. BBMF from the larvae of the normal populations also showed the presence of the receptor proteins, binding to CHIK virus. Receptor proteins from larvae as well as the adults were found glycosylated. CHIK virus receptor proteins of 24, 45, 58, 60 and 62 kDa were also seen in the membrane fraction of the C6/36 cells.
Assuntos
Aedes/metabolismo , Animais , Linhagem Celular , Vírus Chikungunya/metabolismo , Feminino , Intestinos/metabolismo , Fusão de Membrana , Microvilosidades/metabolismo , Receptores Virais/metabolismoRESUMO
During January-February, 1996, an outbreak of influenza-like illness occurred in Pune. The throat and nasal swabs collected from the patients during this outbreak were processed in MDCK and LLC-MK2 cell cultures and influenza A(H3N2) viruses were isolated. They were identified as being similar to the recent circulating global strains A/Johannesburg/33/94 and A/Wuhan/359/95.
Assuntos
Animais , Linhagem Celular , Surtos de Doenças , Variação Genética , Humanos , Índia/epidemiologia , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza A/genética , Influenza Humana/epidemiologiaRESUMO
DNA complementary to the single stranded RNA genome of Chikungunya (CHIK) virus with poly A tract was cloned into the plasmid pGEM-3Zf(-) and 5Zf(+) by blunt end ligation strategy. Clones containing the cDNA inserts were selected by X-gal, IPTG system. They were tested for the expression of structural protein(s) of CHIK virus by in situ enzyme immunoassay and Western blot. The former assay system showed the presence of expressed viral proteins. Analysis of Western blot shows that three structural proteins, E1, E2 and capsid (C) are expressed in Esch. coli. The molecular weights of envelope proteins E1 and E2 were 44-46 Kd and 42-44 Kd respectively, which are lesser than the actual molecular weights of virional proteins (50-52 Kd). This may be due to the absence of glycosylation of these proteins in Esch. coli. In clone no. 382, a high molecular weight protein (56-58 Kd) was observed, which was probably the unglycosylated form of P62 polyprotein coded by the virus during its multiplication. A small protein of MW 6-8 Kd was also expressed in clone nos. 382 and 504, and this appeared to be the unglycosylated form of E3 protein of CHIK virus.
Assuntos
Vírus Chikungunya/genética , Clonagem Molecular , DNA Viral/análise , Escherichia coli/genética , Regulação Viral da Expressão Gênica , RNA Viral/genética , Proteínas Estruturais Virais/genéticaRESUMO
A strain of Japanese encephalitis (JE) virus was passaged serially through primary chick kidney cell cultures (45 times) and primary baby hamster kidney cell cultures (21 times). The resultant virus lost its lethal effect to 3 wk old mice by the ic route and 10 day old mice by the ip route. The oligonucleotide fingerprint analysis of the parent and the passaged strains showed 64 spots in common; 17 spots were present in the parent strain which were absent in the passaged virus, while the latter had acquired 9 spots which were not present in the parent virus.
Assuntos
Animais , Linhagem Celular , Vírus da Encefalite Japonesa (Espécie)/genética , Mapeamento de Nucleotídeos , Oligonucleotídeos/análise , RNA Viral/análise , VirulênciaRESUMO
RNA fingerprint analysis was carried out with different strains of Japanese encephalitis virus which were isolated from Japan, China, India and Sri Lanka. From the similarity ratios, a similarity matrix was worked out which yielded a dendrogram. Geographical proximity of the place of isolation did not contribute much to the similarity of the fingerprint of the strains, nor did temporal proximity. The Japanese Nakayama strain had greater similarity with the Asansol strain from West Bengal. However, another strain from West Bengal, the Bankura strain, showed marked difference. Similarly the Bhopal and Beijing (China) strains were relatively close to each other while the Japanese JaGAr15460 strain was nearer to the strain from Gorakhpur. Serial mouse passage of the Asansol strain did not change the fingerprint pattern drastically.