< i > Strongyloides stercoralis < /i > and HTLV-1 coinfection in CD34 < sup > + < /sup > cord blood stem cell humanized mice: Alteration of cytokine responses and enhancement of larval growth

In this study, a model of HTLV-1 andS.stercoralis coinfection in CD34+ umbilical cord blood hematopoietic stem cell engrafted humanized mice was established. An increased level of mortality was observed in the HTLV-1 and coinfected animals when compared to theS.stercoralis infected group. The mortality was not correlated with proviral loads or total viral RNA. Analysis of cytokine profiles showed a distinct shift towards Th1 responses in HTLV-1 infected animals, a shift towards Th2 cytokines inS.stercoralis infected animals and elevated TNF- α responses in coinfected animals. HTLV-1 infected and coinfection groups showed a significant, yet non-clonal expansion of the CD4+CD25+ T-cell population. Numbers of worms in the coinfection group did not differ from those of theS.stercoralis infected group and no autoinfective larvae were found. However, infective larvae recovered from the coinfection group showed an enhancement in growth, as was seen in mice withS.stercoralis hyperinfection caused by treatment with steroids. Humanized mice coinfected withS.stercoralis and HTLV-1 demonstrate features associated with human infection with these pathogens and provide a unique opportunity to study the interaction between these two infectionsin vivo in the context of human immune cells.
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research