A promising approach capitalizing on the specific and highly sensitive characteristics of the body's own immune system is demonstrated in the context of revealing pancreatic ductal adenocarcinoma cancer (PDAC). IgA from a local biofluid called gastrointestinal lavage fluid (GLF) is used to investigate glycan reactivity to show the potential of this approach. IgA antibody responses, just as with IgG, result in amplification of a small signal which aids in detecting changes from a healthy state. IgA from GLF was screened against glycan arrays containing 609 glycan structures to investigate differential binding patterns associated with the disease. Samples included PDAC (n = 14) and non-PDAC (n = 6). Non-PDAC conditions included samples from healthy patients and the potentially confounding conditions of colon cancer and its precancerous lesion, colon adenoma. Results demonstrated characteristic reactivity in the PDAC sample group to a glycan structure. Also, IgA non-reactive motifs arose showing remarkable consistency within and between sample groups. While sample sizes are too small to identify putative biomarkers, these data show the use of IgA from GLF to be a promising avenue of research for local disease biomarker discovery.

Cholesterol is an essential component of membranes, which is acquired by cells via receptor-mediated endocytosis of lipoproteins or via de novo synthesis. In specialized cells, anabolic enzymes metabolize cholesterol, generating steroid hormones or bile acids. However, surplus cholesterol cannot be catabolized due to the lack of enzymes capable of degrading the cholestane ring. The inability to degrade cholesterol becomes evident in the development and progression of cardiovascular disease, where the accumulation of cholesterol/cholesteryl-esters in macrophages can elicit a maladaptive immune response leading to the development and progression of atherosclerosis. The discovery of cholesterol catabolic pathways in Actinomycetes led us to the hypothesis that if enzymes enabling cholesterol catabolism could be genetically engineered and introduced into human cells, the atherosclerotic process may be prevented or reversed. Comparison of bacterial enzymes that degrade cholesterol to obtain carbon and generate energy with the action of human enzymes revealed that humans lack a 3-ketosteroid Δ 1 -dehydrogenase (Δ 1 -KstD), which catalyzes the C-1 and C-2 desaturation of ring A. Here we describe the construction, heterologous expression, and actions of a synthetic humanized Δ 1 -KstD expressed in Hep3B and U-937 cells, providing proof that one of three key enzymes required for cholesterol ring opening can be functionally expressed in human cells.

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