Immunocytochemical localization and distribution of human albumin in Wuchereria bancrofti adult worms

To determine whether albumin is present on adult worms of Wuchereria bancro fti, thin sections of resin-embedded parasites were incubated with a specif ic antiserum to human albumin, With the exception of the epicuticle, all la yers of the cuticle and the hypodermis were intensely labeled. Concentratio n of gold particles was observed within infoldings of the hypodermal membra ne. Moderate labeling of the thin basement membrane that lines the pseudoce lomic cavity and the gonoduct was also observed. Within the uterus, ovular membranes labeled intensely; groups of organized particles were seen below ovular membranes and also within invaginations of microfilarial embryos. In contrast, few gold particles were seen on the surface of mature intrauteri ne microfilariae. No labeling was observed in control sections incubated wi th antiserum preadsorbed with purified human albumin. The findings suggest that human albumin may be essential for the nutrition and development of W bancrofti microfilariae.