Post-transcriptional restriction of human adenovirus expression in monkey cells

The capacity of freshly explanted human peripheral blood lymphocytes (PBL) to support the replication of human adenovirus type 2 (Ad2) was investigated. Unlike other types of human cells, PBL were found to be highly nonpermissive. Ad2 adsorbed 30 to 40% of both T and non-T cells. Virus uncoating was very slow and inefficient, resulting in a 40-fold reduction compared with HEp-2 cells. On a population basis, viral DNA synthesis was reduced 460-fold and infectious virus production was reduced 106-fold. Only 0.35% of PBL produced infectious centers, yielding 0.8 PFU per infected cell. Phytohemagglutinin stimulation increased DNA synthesis 23-fold, infectious centers l1-fold, and virus yield 14-fold. We conclude that resting human PBL are highly nonpermissive to Ad2 infection and that phytohemagglutinin can only marginally lift this nonpermissiveness.

mentioning

confidence: 99%

Nonpermissivity of human peripheral blood lymphocytes to adenovirus type 2 infection

Horváth

Weber

1988

“…Neither the nature of the block to adenovirus multiplication in monkey cells nor how SV40 enhances adenovirus growth is understood. In adenovirus-infected monkey cells, the early events of the adenovirus infection cycle are unaffected and nornal amounts of early viral proteins and viral DNA are synthesized (9,11,15,34), but some late virion proteins are synthesized in greatly reduced amounts (2,8,11,13,15,27), and this can be correlated with reduced levels of their mRNA's (21). Whether the reduced level of these proteins results from reduced transcription, destruction ofthe mRNA (or its precursors) due to a failure to modify, process, or transport the RNA, or an inability to translate the mRNA has not been determined.…”

mentioning

confidence: 99%

Simian Virus 40 Mutants with Deletions at the 3′ End of the Early Region Are Defective in Adenovirus Helper Function

Cole

Crawford

Berg

1979

“…The pattern of E4 expression reported here differs from that observed by Anderson and Klessig (3), who observed normal E4 expression in abortive infections. This difference probably reflects differences in the permissivity to adenovirus growth of different African green monkey kidney cell strains (15,58).…”

Section: Discussionmentioning

confidence: 99%

Defective synthesis of early region 4 mRNAs during abortive adenovirus infections in monkey cells

Ross

Ziff

1992

Human adenovirus 2 grows poorly in monkey cells, partly because of defects in late gene expression. Since deletions in early region 4 (E4) cause similar defects in late gene expression, we examined E4 mRNA expression in abortive infections. Processing of E4 mRNAs was defective during abortive infections, most likely at the level of splicing. At early times in productive infections in HeLa cells, the major E4 species produced is a 2-kb mRNA; at late times, a shift occurs so that smaller spliced E4 mRNAs are also produced. In CV-1 cells, a nonpermissive monkey cell line, this shift did not take place and only the 2-kb species was produced at late times, suggesting a defect in E4 mRNA splicing during abortive infections. The adenovirus DNA-binding protein (DBP) was required for normal processing of E4 mRNAs, since a host range mutant (hr602) containing an altered DBP gene showed a normal late E4 mRNA pattern in CV-1 cells; in addition, DBP was required during infections in HeLa cells for late E4 mRNA expression. DBP was not required for production of the late E4 pattern in transient expression assays in HeLa or 293 cells, suggesting that a second factor in addition to the DBP, present during infection but not transfection, modulates E4 mRNA processing.