RESUMEN
The peopling of the Pacific was a complex sequence of events that is best reconstructed by reconciling insights from various disciplines. Here we analyze the human polyomavirus JC (JCV) in Highlanders of Papua New Guinea (PNG), in Austronesian-speaking Tolai people on the island of New Britain, and in nearby non-Austronesian-speaking Baining people. We also characterize JCV from the Chamorro of Guam, a Micronesian population. All JCV strains from PNG and Guam fall within the broad Asian group previously defined in the VP1 gene as Type 2 or Type 7, but the PNG strains were distinct from both genotypes. Among the Chamorro JCV samples, 8 strains (Guam-1) were like the Type 7 strains found in Southeast Asia, while nine strains (Guam-2) were distinct from both the mainland strains and most PNG strains. We identified three JCV variants within Papua New Guinea (PNG-1, PNG-2 and PNG-3), but none of the Southeast Asian (Type 7) strains. PNG-1 strains were present in all three populations (Highlanders and the Baining and Tolai of New Britain), but PNG-2 strains were restricted to the Highlanders. Their relative lack of DNA sequence variation suggests that they arose comparatively recently. The single PNG-3 strain, identified in an Austronesian-speaking Tolai individual, was closely related to the Chamorro variants (Guam-2), consistent with a common Austronesian ancestor. In PNG-2 variants a complex regulatory region mutation inserts a duplication into a nearby deletion, a change reminiscent of those seen in the brains of progressive multifocal leukoencephalopathy patients. This is the first instance of a complex JCV rearrangement circulating in a human population.
Asunto(s)
Proteínas de la Cápside , Cápside/genética , Genoma Viral , Virus JC/genética , Adulto , Secuencia de Bases , Cápside/orina , Estudios de Cohortes , Evolución Molecular , Eliminación de Gen , Genes Duplicados , Genotipo , Guam , Humanos , Virus JC/química , Datos de Secuencia Molecular , Mutación , Nueva Guinea , Dinámica Poblacional , Origen de RéplicaRESUMEN
Five genotypes of human polyomavirus JC (JCV) have been detected so far by nucleotide sequencing and by restriction fragment length polymorphism analysis. These genotypes are the result of geographically based virus evolution. However, interesting aspects of genotyping could involve both pathogenetic and diagnostic aspects. The product from amplification of JCV sequences, found in urine from 12 healthy individuals from different countries, have been analysed by denaturing gradient gel electrophoresis (DGGE) and by nucleotide sequencing. The aim of this study was to assess if the DGGE analysis could be used to study the variability of the JCV genome. The target sequence of this study was 233 bp long, within the gene coding for the VP1, known to contain several type-determining sites. Four DGGE patterns have been observed among our strains. Five strains, from African individuals, were of type 3 and exhibited the same electrophoretic pattern, clearly distinguishable from that of the type 1 strains detected in the urine from 6 European individuals. Five type 1 strains shared a similar DGGE pattern, slightly different from that of the sixth. A different pattern characterised as a type 2 strain was detected in the urine from a Peruvian individual. These results suggest that DGGE analysis could be used as a screening assay for choosing strains for nucleotide sequencing. The analysis of a fragment larger than the one used in this study could allow the identification of more types and subtypes.
Asunto(s)
Proteínas de la Cápside , Cápside/orina , ADN Viral/orina , Poliomavirus/genética , Adolescente , Adulto , Anciano , Virus BK/genética , Secuencia de Bases , Cápside/genética , ADN Viral/análisis , Electroforesis , Femenino , Humanos , Virus JC/genética , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADNRESUMEN
A rapid and simple quantitative dot immunoassay for a cell-adapted reference strain of cytomegalovirus (CMV) and for wild strains of CMV present in clinical urine samples was developed. The assay was performed on nitrocellulose paper dotted with several dilutions of viral pellets free of cellular debris. Viral dilutions were treated with a monoclonal antibody to the major component of the viral capsid. To amplify the reaction, a three-dimensional complex of streptavidin and biotinylated horseradish peroxidase was used as the detector system. The dot immunoassay, which does not require cell cultures, yielded results within one day. A significant correlation was found between CMV titers obtained by dot immunoassay and CMV infectious units determined by immunoalkaline phosphatase staining of CMV-late antigen positive cells.
