Modular complement assemblies for mitigating inflammatory conditions.

Complement protein C3dg, a key linkage between innate and adaptive immunity, is capable of stimulating both humoral and cell-mediated immune responses, leading to considerable interest in its use as a molecular adjuvant. However, the potential of C3dg as an adjuvant is limited without ways of controllably assembling multiple copies of it into vaccine platforms. Here, we report a strategy to assemble C3dg into supramolecular nanofibers with excellent compositional control, using β-tail fusion tags.

Fusion of fibroblast growth factor 21 to a thermally responsive biopolymer forms an injectable depot with sustained anti-diabetic action.

Fibroblast growth factor 21 (FGF21) is under investigation as a type 2 diabetes protein drug, but its efficacy is impeded by rapid in vivo clearance and by costly production methods. To improve the protein's therapeutic utility, we recombinantly expressed FGF21 as a fusion with an elastin-like polypeptide (ELP), a peptide polymer that exhibits reversible thermal phase behavior. Below a critical temperature, ELPs exist as miscible unimers, while above, they associate into a coacervate.

Arginase Is Essential for Survival of Leishmania donovani Promastigotes but Not Intracellular Amastigotes.

Studies of Leishmania donovani have shown that both ornithine decarboxylase and spermidine synthase, two enzymes of the polyamine biosynthetic pathway, are critical for promastigote proliferation and required for maximum infection in mice. However, the importance of arginase (ARG), the first enzyme of the polyamine pathway in Leishmania, has not been analyzed in L. donovani To test ARG function in intact parasites, we generated Δarg null mutants in L.

Controlled release of biologics for the treatment of type 2 diabetes.

Type 2 diabetes is a rapidly growing disease that poses a significant burden to the United States healthcare system. Despite the many available treatments for the disease, close to half of diagnosed type 2 diabetes cases are not properly managed, largely due to inadequate patient adherence to prescribed treatment regimens. Methods for improving delivery - and thereby easing administration - of type 2 drugs have the potential to greatly improve patient health.

Genetic dissection of pyrimidine biosynthesis and salvage in Leishmania donovani.

Protozoan parasites of the Leishmania genus express the metabolic machinery to synthesize pyrimidine nucleotides via both de novo and salvage pathways. To evaluate the relative contributions of pyrimidine biosynthesis and salvage to pyrimidine homeostasis in both life cycle stages of Leishmania donovani, individual mutant lines deficient in either carbamoyl phosphate synthetase (CPS), the first enzyme in pyrimidine biosynthesis, uracil phosphoribosyltransferase (UPRT), a salvage enzyme, or both CPS and UPRT were constructed. The Δcps lesion conferred pyrimidine auxotrophy and a growth requirement for medium supplementation with one of a plethora of pyrimidine nucleosides or nucleobases, although only dihydroorotate or orotate could circumvent the pyrimidine auxotrophy of the Δcps/Δuprt double knockout.

IMP dehydrogenase deficiency in Leishmania donovani causes a restrictive growth phenotype in promastigotes but is not essential for infection in mice.

Leishmania cannot synthesize purines de novo and therefore must scavenge purines from its host for survival and growth. Biochemical and genomic analyses have indicated that Leishmania species express three potential routes for the synthesis of guanylate nucleotides: (1) a two-step pathway that converts IMP to GMP; (2) a three-step pathway that starts with the deamination of guanine to xanthine, followed by phosphoribosylation to XMP and then conversion to GMP; or (3) direct guanine phosphoribosylation by HGPRT. To determine the role of the first of these pathways to guanylate nucleotide synthesis, an L.

Spermidine synthase is required for virulence of Leishmania donovani.

Genetic lesions in the polyamine biosynthetic pathway of Leishmania donovani, the causal agent of visceral leishmaniasis, are conditionally lethal mutations that render the insect vector form of the parasite auxotrophic for polyamines. Recently, we have demonstrated that a Δodc L. donovani null mutant lacking ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, was profoundly compromised in its ability to infect mice, indicating that ODC is essential for the infectious mammalian stage of the parasite and further validating the enzyme as a possible drug target.

Oral putrescine restores virulence of ornithine decarboxylase-deficient Leishmania donovani in mice.

Administration of putrescine as a 1% solution in the drinking water ameliorated the profound loss of virulence exhibited by ornithine decarboxylase (ODC) deficient Leishmania donovani in mice. Furthermore, supplying α-difluoromethylornithine, an ODC inhibitor, at 2% in the drinking water reduced but did not eliminate infection with wild type L. donovani in the mouse model.

Linking NE1545 gene expression with cell volume changes in Nitrosomonas europaea cells exposed to aromatic hydrocarbons.

Nitrosomonas europaea, a model ammonia oxidizing bacterium, was exposed to a wide variety of aromatic hydrocarbons in 3 h batch assays. The expression of NE1545, a phenol sentinel gene involved in fatty acid metabolism, was monitored via quantitative real-time polymerase chain reaction (qRT-PCR) and a Coulter Counter technique was used to monitor changes in cell volume. Decreases in cell volume and NE1545 gene expression correlated strongly with exposure to aromatic hydrocarbons that possessed a single polar group substitution (e.