Comparing normal primary endocervical adenoepithelial cells to uninfected and influenza B virus infected human cervical adenocarcinoma HeLa cells.

Human adenocarcinoma HeLa cells surviving infection with low (10(-9) units), medium (10(-6) units), and high (10(-2) units) influenza B titers were compared to their uninfected precursors and to normal endocervical adenoepithelial and metaplastic cells using Papanikolaou-staining method and immunocytochemistry. Normal primary endocervical and infected HeLa cells surviving infection shared similar morphologic, phenotypic, and divisional patterns that differed drastically from those of uninfected HeLa cells. The number of infected hosts surviving 6-7 days of viral exposure did not change during 3-week follow-up period, and their cyclin E levels suggested that they had been arrested to the G1 phase of the cell cycle by viral stress. Our findings suggest that in addition to apoptosis, nononcogenic viral stress activated the expression of endocervical metaplastic-like motifs in surviving hosts. A mechanism of cell response to nononcogenic viral stress was proposed to explain these findings. We conclude that nononcogenic respiratory viruses specifically target and eliminate abnormal cells ectopically overexpressing appropriate receptors and may complement current treatments of cervical cancer.

Molecular and phylogenetic analysis of haemagglutinin and neuraminidase sequences from recent human influenza type A (H3N2) viral isolates in Southern Greece.

Eighteen haemagglutinin (HA1) gene segments and eleven neuraminidase (NA) genes of human influenza type A (H3N2) viruses isolated from non-vaccinated individuals presenting severe influenza-like illness at peak influenza activity in Southern Greece during the surveillance period 1996-1999, were subjected to sequence and phylogenetic analyses following propagation in embryonated hen's eggs. The HA1 gene segment of the clinical isolates differed from the recent reference influenza type A (H3N2) vaccine strains in an Ile at residue 186, a Val at residue 194 and a Val at residue 226 for one, two and thirteen isolates of the 1996-1997 and 1996-1999 periods, respectively. The analogous differences in the NA gene were confined in an Asp to Asn substitution at residue 198 in one A/Wuhan/359/95 (H3N2)-like isolate of the 1996-1997 period, primarily. In addition, phylogenetic analysis revealed that an isolate of the 1997-1998 period was a recombinant with its HA1 gene segment being closely related to that of A/Wuhan/359/95-like viruses and its NA to viruses of the A/Sydney/5/97 (H3N2) lineage. These findings confirmed the profound genetic instability of influenza type A (H3N2) viruses and underscored the importance for periodic molecular surveys of HA and NA in the effective prevention and management of viral outbreaks. Most importantly, however, they contributed the first complete epidemiological material for influenza in Southern Greece, the archival nature of which constitutes valuable reference for future surveys.