IOWA STATE UNIVERSITY
We have developed a model system to determine biologic activity of unit carbohydrates in altering immune responses. This model consists of 1um fluorescent latex beads coated with pathogen cap sugars, specifically M. bovis Mannosylated-Lipoarabinomannan (ManLAM), infectious L. mexicana and L. major promastigote Lipophosphoglycan (LPG), and in vitro non-infective mutant L. donovani LPG (nvLPG). Our data has supported our original hypothesis that cap sugars from virulent chronic disease pathogens can be
an immune-inhibitory portion of carbohydrate chains. Comparison of in vitro responses to five structurally and pathogenically different cap sugars placed onto the surface of latex beads has provided the basis of our model system to determine how different carbohydrate structures alter early pathogen-based inflammatory responses. Successful funding of this supplemental request will create jobs by employing a post-doctoral research scientist and providing jobs and mentored scientific training to a post-DVM graduate and veterinary
students. Importantly, we have strong evidence that exposure of macrophages to these cap sugars bound to latex beads, leads to altered IL-12p40 production peaking at 20-36 hrs post-stimulation. We propose two experimental aims which build on the findings of our current R21 indicating that ManLAM based cap sugar coated beads alter the ability of macrophages to prime the production of pro-inflammatory TH1-priming cytokines through an NF-kB, TLR2 mediated mechanism in vitro. The first scientific aim will substantiate that TLR2 also plays a role in the cap-sugar coated bead effect in vivo by treating TLR2-/- mice with these beads and co-infecting with L. major similar to studies we are performing in wild-type C57BL6 mice. Our second scientific aim is to determine how cap-sugar coated-bead based alterations in macrophage cytokine effector function also differentially changes macrophage ability to make nitrite and eliminate internal pathogens in vitro. The contribution of this request will be employment of a highly qualified post-doctoral research scientist to accelerate the tempo of this work and to provide critical workforce expansion training through research employment, scientific mentoring and critical training to clinically-trained veterinary scientists.