Adenovirus 41 growth in semi-permissive cells shows multiple-hit kinetics

Abstract

Adenovirus type 41 infection of semi-permissive Chang conjunctival cells, monitored by fluorescent focus assay, followed multiple-hit kinetics. In non-permissive human cells, type 41 showed infectivity with two-hit kinetics in the presence of type 2. Type 41 infectivity was seen to be directly proportional to input concentration (one-hit) only in 293 cells, a continuous human line expressing Ad 5 E1 products.

Detection of Infectious Adenovirus in Cell Culture bymRNA ReverseTranscription-PCR

“…However, Ad41 has been successfully propagated in several cell lines, including G293, a line of human embryo kidney cells transformed with the Ad5 E1 region (13,28). Ad41 is known to infect G293 cells in accordance with a single-hit model, which means that only one virus is sufficient to infect G293 cells productively (27). This single-hit model suggests that an mRNA RT-PCR assay should be able to detect a single infectious Ad41 particle in a G293 cell culture.…”

The subgroup F adenoviruses

“…This could be explained in part by a reduced transactivation of other early promoters by Ela products and therefore longer periods of time required for accumulating critical concentrations of certain products. In keeping with this, it was found that four to five infectious virus particles are required to infect productively each Chang conjunctival cell (Tiemessen & Kidd, 1990). Collaboration between a number of genomes may therefore be necessary to attain critical levels of a certain product(s) to allow progression of the infectious cycle.…”

“…Genes encoding a putative 59 kDa fibre polypeptide in Ad40 (Kidd & Erasmus, 1989) and 60.5 kDa fibre polypeptide in Ad41 (N. J. Pieniazek et al, 1989a;Kidd et al, 1990) have been characterized. There is a high degree of identity between the 59 kDa and 60.5 kDa fibre proteins of these viruses, except in the shaft region.…”

“…Pieniazek et al, 1989a;Kidd et al, 1990), whereas the corresponding Ad40 protein has 21 (Kidd & Erasmus, 1989). A study of several Ad40 and Ad41 DNA variants indicated that the 15 amino acid difference in polypeptide length is a type-specific difference among subgroup F adenoviruses in general, with the exception of two uncommon isolates of Ad41, which had a 15 amino acid block deletion different to that of Ad40 (Kidd et al, 1990). The long fibre gene product has been designated polypeptide IV-2 by Davison et al (1993).…”

“…Firstly, productive and semi-productive growth of Ad41 and Ad40 in 293 cells, respectively, is most likely due to the provision of E1 functions in trans. With Ad41, an average of one infectious virus particle was found to be sufficient to productively infect each 293 cell (Tiemessen & Kidd, 1990). However, reports of loss of infectivity upon passage of Ad41 in 293 cells (D. Pieniazek et al, 1990a) and poor growth of Ad40 in these cells (Chiba et al, 1983;Uhnoo et al, 1983;Brown, 1985;van Loon et al, 1985) suggest that the provision of E1 functions alone is not sufficient to overcome growth restriction.…”