Increased susceptibility of mice with XID mutation to Brugia malayi infection

Abstract

Infective larvae (L3) of the human filarial parasite Brugia malayi are rapidly eliminated from immunocompetent mice, while in nude as well as SCID mice they develop into mature adult parasites. We now report our attempts to infect mice with X-linked immunodeficiency with larval stages of B. malayi. CBA/N strain of mice has an XID mutation that renders them deficient in producing of antibodies to T-independent antigens such as polysaccharides while they respond normally to protein antigens. Groups of deficient (CBA/N) as well as normal mice (CBA/CaJ) were infected with L3 stages of B. malayi. About 8% of the larvae developed into juvenile adults by 45-50 days postinfection in CBA/N mice while only 0.75% of worms could be recovered from +/+ mice. There was no significant growth or development of parasites beyond 50 days in CBA/N mice. On the contrary, worm recovery decreased progressively in CBA/N mice after 50 days. Only about 2.6% and 1.25% of the worms could be recovered by 90 and 120 days post-infection in CBA/N mice. There was no significant difference between the two strains of mice in antibody levels to soluble adult worm antigens nor in their ability to make antibodies to the surface of the developing larvae. We propose the use of CBA/N mice for studies on the development of protective immunity to larval stages of the human filarial parasite and for screening potential anti-larval drugs.