Infect. 80 tropical countries, affects 120 million people and is caused by or the closely related parasite have been used extensively over the past 10 years to study host-parasite interactions. Although the original studies of brugian infection in mice used the subcutaneous route of infection, it was later discovered that intraperitoneal (i.p.) infections with L3 allowed more accurate determinations of worm burdens (19). CAL-130 Hydrochloride When injected i.p., the parasites develop normally and infection progresses to patency in permissive hosts with similar kinetics to mosquito-transmitted infection. Moreover, the parasites remain in the peritoneal cavity and can be easily recovered by peritoneal lavage (8). This method has been widely accepted for the study of filarial biology and host-parasite interactions. Normal immunocompetent inbred C57BL/6 and BALB/cByJ mice are refractory to infection with brugian parasites. However, infection develops to patency in immunodeficient or RAG-1?/? mice that lack an adaptive immune system (20). This suggests that mice can support the normal development of these organisms and that immunocompetent mice are able to actively clear the infection due to an efficient immune response. Studies using T-cell-deficient NUDE mice with or demonstrated that CAL-130 Hydrochloride these mice develop patent infection and harbor parasites as late as 240 days postinfection (28, 29, CAL-130 Hydrochloride 31, 33, 34). Furthermore, the susceptibility of NUDE mice to infection was reversed by immune reconstitution with neonatal thymocytes from wild-type syngeneic mice or by implantation of neonatal thymus grafts several weeks prior to infection (32). Our previous studies demonstrated a role for B lymphocytes in protection against infection and the potential of na?ve peritoneal cells to transfer this protection to immunodeficient mice (22). In this communication we report the transfer of protection against to T-cell-deficient mice with primed purified peritoneal B lymphocytes and analyze possible mechanisms of B-cell-mediated protection against infection. MATERIALS AND METHODS Mice. All mice used in this study were young adult males. The mouse strains that were used are listed in Table ?Table1.1. They were maintained in the Association for Assessment and Accreditation of CXCL5 Laboratory Animal Care-accredited vivarium of the University of Connecticut Health Center (UCHC) in microisolator chambers and permitted lab chow and sterile water ad libitum. For the colonies that were bred and maintained at the UCHC facility, random mice were regularly phenotyped to ensure genetic purity of the colony. All procedures on mice were performed after appropriate review by and clearance from the institutional Laboratory Animal Welfare Committee. TABLE 1. Mouse strains used locusNo B or T cellsB6.129P2-locusNo B1 B cells; other defects as wellBALB/cByJBALB/cNoneNoneBALB/c JHDBALB/c JHDSame as in C57BL/6 JH?/?Same as in C57BL/6 JH?/?BALB/c locusNo MHC class II antigens or CD4 T cells Open in a separate window aAll mice from the Jackson Laboratory came from the research colonies of L. D. Shultz, except C57BL/6 JH?/? were from William Weidanz, Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, Madison, and BALB/c JHD were from Mark Shlomchik, Departments of Laboratory Medicine and Immunobiology, Yale University School of Medicine, New Haven, Conn. Infective larvae. or infective larvae were obtained either from the laboratory of Thomas Klei (Louisiana State University), TRS Inc., Athens, Ga., or the University of Georgia (Athens), through a contract with the National Institutes of Health (U.S.-Japan Collaborative Program in Filariasis). Infective larvae were shipped in Ham’s complete medium as described previously CAL-130 Hydrochloride (35). Upon arrival, the larvae were resuspended in fresh RPMI 1640 cell culture medium (GIBCO Life Technologies, Grand Island, N.Y.), aliquoted, and counted prior to injection. Infection and parasite recovery. Mice were infected i.p. with 45 to 50 L3 in 400 l of RPMI unless stated otherwise. For priming, mice were injected with 25 to 40 L3 i.p. Mice were euthanized in a CO2 chamber at various times following challenge infection. The peritoneal cavities were washed with RPMI, supplemented with 5 USP U of heparin (American Pharmaceutical Partners, Inc., Los Angeles, Calif.)/ml to recover viable L3, L4, or adult worms. In addition, the mice were soaked in Tris or phosphate-buffered saline (PBS) with their peritoneal cavities open, to.