Transient Intraperitoneal Residence ofLarvae in the Mongolian Gerbil ().

Abstract

Understanding the determinants of host specificity incan be advanced through the use of the nonpermissive Mongolian gerbil (jird) model. We hypothesized that host immunity dictatesestablishment following the third larval molt. Jirds were infected intraperitoneally with 100(permissive control) orthird-stage larvae (L3). Necropsies occurred at 1, 3, 10, and 36 days post infection (dpi) to quantify larvae via peritoneal lavage. Initial recovery at 1 dpi showed 37.4% forbut only 0.4% for(< 0.0001).recovery increased to 23.6% by 3 dpi, suggesting a period of transient tissue residence during the third molt. Recovery for both species decreased by 10 dpi.reached the immature adult stage (15.2%) by 36 dpi, whereas no viablewere recovered (< 0.0001). These findings suggest thatlarvae encounter a robust cellular response, primarily macrophages, shortly after the third molt. Identifying the specific larval stage at which establishment fails provides critical insight into the mechanisms governing filarial host specificity.