Comparison of enteric Adenovirus infection in various human cell lines

Growth of the fastidious enteric adenoviruses 40 and 41 was compared in different human cell lines. Purified virions were used to infect the following cell lines: A549; KB; Chang's conjunctiva; 293; HeLa. Both types of enteric adenovirus were infectious for each cell line, with the exception of adenovirus 40 in HeLa cells. Relatively low infectious titers were obtained from each cell type following infection with adenovirus 40 (TCID₅₀ average = 10^−1.5), whereas adenovirus 41 replicated to significantly higher titer (TCID₅₀ average = 10^−3.0). For both viruses, the highest infectious titers were obtained with A549 and KB cells. A time course experiment performed to quantitate the amount of hexon present in A549 and KB cells infected with each virus indicated that while the kinetics of accumulation were similar for both viruses, the concentration of type 41 hexon was significantly greater than that for type 40 in either cell line. The concentration of type 41 hexon was similar in each cell type; for type 40, a greater concentration of hexon was obtained in the A549 cell line than in the KB cells. The results indicate the distinct replication characteristics exhibited by adenovirus 40 are not due to a restriction in a specific host cell, and, because purified virions were used, not attributable to interference that might occur with co-infection from multiple viruses present in the same clinical specimen. We conclude the differences observed in the replication of these viruses are independent of host cell type and are associated, uniquely, with each virus.