Adjuvant-free immunization with infective filarial larvae as lymphatic homing antigen carriers

In the manuscript, ‘Adjuvant-free immunization with infective filarial larvae as lymphatic homing antigen carriers’ we present an innovative approach to the intravital labeling of lymphatic filaria L. sigmodontis with fluorescent molecules or non-filarial protein (ovalbumin, OVA). Fluorescent labeling of filariae had no immediate adverse effects on their phenotype as the labeled filariae were able to infect the host and populate its lymphatic system. We also show that filariae with conjugated proteins can be used as an antigen carrier to induce a Th1 immune response against OVA when OVA-conjugated worms are used as an adjuvant-free vaccine.
The article aims to demonstrate the feasibility of turning infectious filariae into natural lymphatic homing vehicles that can carry endogenous adjuvants and antigens of choice. Despite the concise nature of the manuscript, the results it presents validate two key aims that will be of interest to distinct audiences. First, we demonstrate that direct or sandwich labeling of helminths preserves the invasiveness of the larvae, making intravital labeling an instrumental technique for the study of the early phase of helminths infections. Further, we show that antigens cross-linked to filariae can be used as a tool in the development of alternative methods of vaccination to induce Th-1-type cellular immunity. Because the topic of this article lies at the crossroads of various scientific disciplines, we believe that this intriguing hypothesis will attract broad scientific interest, not limited to the fields of parasitology, bioengineering or vaccine design.