Objective       To establish a WASp-deficient mouse (129S6/SvEvTac-Was

tm1Sbs

/J) model of induced systemic infection with murine cytomegalovirus (MCMV) and investigate the infection characteristics.       Methods       WAS-null mice were randomly chosen as model grou

p and blank control group respectively (n=6 for each group). They were infected with 1×10

5

PFU MCMV (0.2 mL) by intra-peritoneal administration. WASp+/+ mice were used as infection control (n=6). All experimental mice were under closely observation and sacrificed in 9 d after the intraperitoneal injection. Tissue samples were collected under aseptic conditions from each experimental mouse. Salivary glands were taken for virus separation and titer test. The histological changes of the main visceral organs and tissues were examined after HE staining

and the mRNA expression of MCMV gB was detected by RT-PCR. Flow cytometry was used to detect the percentage of MCMV cytotoxic T lymphocytes (CTLs) in splenic lymphocytes from model group and infection control group.       Results       Compared with WASp+/+ mice infection control

the general condition of infected mice in WASp-/-  infection groups was getting worse after the infection in terms of body weight reduction

lack of movement

more piloerection

with a mortality of 1/6. In 9 d after infection

cytomegalovirus was found in the salivary glands of both infection groups

and MCMV gB mRNA was positive in the heart

liver

lung

kidney and salivary glands

with the expression level significant higher in the WASp-/-  infection group than in WASp+/+ infection control (P0.05). No MCMV mRNA was detected in mice without the infection. Histopathological injury was found in the livers

kidneys

lungs and hearts

and the lung was the critical target organ. The proportion of MCMV CTLs in splenic lymphocytes had no significant difference among these groups (P=0.26).       Conclusion       An acute virus-infection model is established for the first time by intra-peritoneal injection of 1×10

5

PFU MCMV in adult WASp-/- mice. More obvious and severe manifestations of acute infection are observed in WASp-deficient mice than in wide type

with lung as the critical target organ. There is no obvious change in the proportion of MCMV CTLs after the primary infecti

on between the deficient and wild type mice.