Immunologic relevance of the cuticle and epicuticle of larval Dirofilaria immitis and Toxocara canis.

Investigations of the immunobiology of tissue stages of larval nematodes reveal several common, immunologically relevant features associated with the cuticle and epicuticle. First, commonality exists between surface and excretory-secretory antigens. Second, larval surfaces are often directly involved in evasion of host immune responses. Third, antigens present on the parasite surface can be involved in immunopathology, either directly through tissue damage or via systemic immunomodulatory events. Finally, in some instances, correlations can be inferred between immune protection and surface antigens. These concepts are illustrated through research on larval Dirofilaria immitis and Toxocara canis.