Lumpy skin disease virus does not replicate productively in insect cell lines

Lumpy skin disease virus (LSDV) is a capripoxvirus of cattle causing a severe disease that results in substantial economic impact to affected communities. The virus is endemic across sub-Saharan Africa, and has recently entered Europe and the Balkans. The virus is thought to be transmitted by an insect vector, but little is known about the role of the vector in the LSDV cycle.

In order to investigate interactions between LSDV and insect vectors this work studied the permissivity of insect cell lines for LSDV. Insect cell lines were inoculated with LSDV strain Cameroon at a multiplicity of infection (MOI) of 5. The mammalian cell line MDBK was infected as a positive control. Samples were collected up to a week after infection and virus amounts measured using titrated plaque assays in order to construct a growth curve.

Lumpy skin disease virus replicated in the MDBK mammalian cell line, increasing by 3log10 over the 7 day incubation from 2×104 pfu/ml to 2×107 pfu/ml. In contrast, no replication of LSDV was detected in the insect cell lines.

This work shows that LSDV does not productively replicate in insect cell lines and supports the current hypothesis that the insects act as mechanical rather than biological vectors of the virus.