R. Hamasuna et al., PROTECTIVE EFFECT OF CARRAGEENAN AGAINST MURINE CYTOMEGALOVIRUS-INFECTION IN MICE, Antiviral chemistry & chemotherapy, 4(6), 1993, pp. 353-360
The protective effect of iota-carrageenan (CAR) was evaluated against
murine cytomegalovirus (MCMV) infection in mice. Female ICR mice were
challenged intraperitoneally (i.p.) with 3 LD50 of salivary gland-pass
aged MCMV. More than 0.5 mg of CAR showed a protective effect on mice
only when CAR was administered i.p. and then MCMV was inoculated i.p.
The protective effect of CAR was evidenced by an increase in plaque-fo
rming unit per LD50 and a decrease in the titre of infectious viruses
in the target organs. Neither a virucidal nor a virustatic effect on M
CMV was evidenced for CAR. The protective effect of CAR seemed to be h
ost-mediated. Pretreatment of mice with CAR augmented natural killer (
NK) activity of the spleen cells without elevating the serum interfero
n level. However, administration of anti-asialo GM1 antibody did not n
ullify the inhibitory effect of CAR on virus replication in the target
organs. MCMV infection induced leukopenia including neutropenia and l
ymphopenia in saline-treated mice. Pre-treatment with CAR protected mi
ce from those signs, except for slight lymphopenia. Administration of
cyclophosphamide induced severe leukopenia including neutropenia and l
ymphopenia even in CAR-treated mice. Under such conditions, the protec
tive effect of CAR against MCMV infection was abrogated by cyclophosph
amide. Thus, the protective effect of CAR seems to be non-NK-mediated.