Can an allograft become harmonious with its recipient by analogous mechanisms to the long-term survival of a parasite in its host? Transplantation is similar to parasitism and chronic parasite infection can prolong allograft survival

Organ transplantation is very similar to the parasitism, the immune responses to the allograft and parasite share some general characters in acute stage. But host-parasite interplay seems harmonious and clinically asymptomatic carriers act as long-term reservoirs for transmission even several decades. It is proposed that the allograft also can survive long-term like the parasite harmonious with the host if we exploit the mechanism of the parasitism. How can the parasite escape the immunologic cleaning? Recent research found that: (1) Almost all the parasites infection can break the balance of Th1/Th2 and induce the Th2 bias. The level of cytokine excreted by Th2 is increased. (2) Parasite infection can interfere in antigen presentation processing through cystatins and “dendritic cell paralysis”. (3) Regulatory T cells were found surrounding the local site of parasite worms. (4) Parasite infections can switch of eicosanoid metabolism, and the anti-inflammatory mediator of the plasma is increasingly manifest in the chronic infection stage. And in animal model, chronic infection can prolong the allograft survival. If the hypotheses are correct, it will give another novel therapeutic option for patients with organ transplantation.