Jb. Domachowske et al., Pulmonary eosinophilia and production of MIP-1 alpha are prominent responses to infection with pneumonia virus of mice, CELL IMMUN, 200(2), 2000, pp. 98-104
Human eosinophils secrete two distinct ribonucleases that have antiviral ac
tivity against pathogens of the family Paramyxoviridae. To examine the role
of eosinophils and their ribonucleases in host defense against paramyxovir
us pathogens in vivo we have developed a mouse model involving a viral path
ogen that naturally targets a rodent host. In this work we describe infecti
on of Balb/c mice with pneumonia virus of mice (PVM, strain J3666), a param
yxovirus pathogen found frequently among rodent populations. We show here t
hat pulmonary eosinophilia is an immediate response to infection with PVM,
with bronchoalveolar lavage fluid containing 12-14% eosinophils obtained as
early as day 3 postinoculation, Infection is accompanied by the production
of macrophage inflammatory protein-1-alpha (MIP-1 alpha), a chemokine that
has been associated with the pulmonary eosinophilia observed in response t
o respiratory syncytial virus infection in humans and with enhanced clear a
nce of influenza virus in mice. Interestingly, we observed no changes in ex
pression of the chemoattractants eotaxin and RANTES in response to PVM infe
ction, and interleukin-5 remained undetectable throughout. These responses-
clinical pathology, viral recovery, pulmonary eosinophilia, and production
of MIP-1 alpha-will provide a means for exploring the role of eosinophils,
eosinophil secretory ribonucleases, and eosinophil chemoattractants in host
defense against PVM and related paramyxovirus pathogens in vivo. (C) 2000
Academic Press.