Responses ofMastomys coucha, that have been infected withBrugia malayiand treated with diethylcarbamazine or albendazole, to re-exposure to infection

Abstract

The responses of Mastomys coucha to re-exposure to infection with homologous infective larvae (L(3)) of Brugia malayi were investigated, after initial infections with the nematode had been treated subcutaneously for 5 days with diethylcarbamazine (DEC; 150 mg citrate/kg. day) or albendazole (ALB; 50 mg/kg. day). The parasite burdens, serum concentrations of IgG reacting with a soluble somatic extract of adult B. malayi (BmAS), and cytokine and lymphocyte-proliferative responses to filarial antigen (BmAS) or mitogen (concanavilin A or lipopolysaccharide) were studied. The results demonstrated, for the first time, that re-infection with L(3) was only successful in the DEC-treated animals, not the ALB-treated ones. When the ALB-treated animals were re-exposed, interferon-gamma production decreased, lymphocyte-proliferative responses either remained the same (with concanavilin A) or decreased (with BmAS), and concentrations of specific IgG decreased. When the DEC-treated animals were re-exposed, microfilaraemias re-appeared and, although production of interferon-gamma decreased, there were no detectable lymphocyte proliferative responses, and concentrations of specific IgG remained unchanged. Taken together, the results indicate that, at least in the M. coucha model of human filariasis, ALB but not DEC treatment may help to prevent the development of re-infections.

A Comprehensive, Model-Based Review of Vaccine and Repeat Infection Trials for Filariasis

“…Mastomys rodents that were cleared of infection by using albendazole displayed resistance to subsequent infection. However, this might not be due to the chemically abbreviated infection, as the control group, which received only albendazole, was also resistant to infection (61).…”

“…Infections have been chemically abbreviated by using either albendazole or diethylcarbamazine (DEC) (61). Abbreviation of infection with DEC does not elicit any significant protection against future infection (61).…”

Identification of Brugia malayi adult worm molecules immunoreactive with sera of infected animals treated with antifilarial and re-infected with homologous infection and their role in the establishment of infection in Mastomys coucha

“…The reasons for this are not clear. Our previous study showed that treatment with ALB inhibits the development of new incoming infection while treatment with DEC facilitates it (Khan et al, 2004). These findings suggested that alterations in the specific immunological responses may play an important role in the development of reinfection.…”

Expression of different filarial parasite adult stage antigens during course of DEC treatment in mouse model of Brugian filariasis

“…Our previous work has optimised mouse model of Brugian filariasis Khan et al, 2004), and its chemotherapeutic responses to DEC and IVM match with those reported for humans. Therefore, we successfully applied DEC treatment and reinfection approach to investigate changes in parasite antigens during course of DEC treatment.…”

“…Infective third stage larvae (L 3 ) of B. malayi were obtained from laboratory bred female Aedes aegypti fed on microfilaraemic Mastomys coucha as described previously Khan et al, 2004).…”