Infection of guinea pigs with two strains of lymphocytic choriomeningitis virus

In order to study the lesions produced by lymphocytic choriomeningitis virus (LCMV) adult guinea-pigs were inoculated intraperitoneally with 1000 PFU of the WE or the Armstrong strain of LCMV. The animals were sacrificed at 3, 7, 10 and 14 days p.i. and samples were taken for hematological, histopathological and virological studies. In the guinea-pigs infected with the WE strain there was destruction of the splenic red pulp with high titers of virus and different degrees of pneumonitis. The hematological studies showed lymphopenia from day 7 p.i. onwards and focal bone marrow necrosis. In the animals infected with the Armstrong strain there was a very moderate neutropenia and virus multiplication was less than 2 logs, comparing with WE, in every case. The presence of large numbers of polymorphonuclear neutrophil (PMN) in the splenic red pulp and in the lung infiltrate previous to the mentioned lesions, encourage the interpretation that the damage is somehow mediated by these cells. The guinea-pigs infected with the WE strain could represent a very convenient model to study the role of PMN in viral diseases, as well as the non-immune pathogenetic mechanisms for LCMV.