Signaling via interleukin-4, receptor alpha chain is required for successful vaccination against schistosomiasis in BALB/c mice

Radiation-attenuated (RA) schistosome larvae are potent stimulators of innate immune responses at the skin site of exposure (pinna) that are likely to be important factors in the development of Th1-mediated protective immunity. In addition to causing an influx of neutrophils, macrophages, and dendritic cells (DCs) into the dermis, RA larvae induced a cascade of chemokine and cytokine secretion following in vitro culture of pinna biopsy samples. While macrophage inflammatory protein 1 and interleukin-1 (IL-1) were produced transiently within the first few days, the Th1-promoting cytokines IL-12 and IL-18 were secreted at high levels until at least day 14. Assay of C3H/HeJ mice confirmed that IL-12 secretion was not due to lipopolysaccharide contaminants binding Toll-like receptor 4. Significantly, IL-12 p40 secretion was sustained in pinnae from vaccinated mice but not in those from nonprotected infected mice. In contrast, IL-10 was produced from both vaccinated and infected mice. This cytokine regulates IL-12-associated dermal inflammation, since in vaccinated IL-10/ mice, pinna thickness was greatly increased concurrent with elevated levels of IL-12 p40. A significant number of IL-12 p40 cells were detected as emigrants from in vitro-cultured pinnae, and most were within a population of rare large granular cells that were Ia, consistent with their being antigen-presenting cells. Labeling of IL-12 cells for CD11c, CD205, CD8, CD11b, and F4/80 indicated that the majority were myeloid DCs, although a proportion were CD11c F4/80, suggesting that macrophages were an additional source of IL-12 in the skin

Including Explicit Water Molecules as Part of the Protein Structure in MM/PBSA Calculations

Water is the natural medium of molecules in the cell and plays an important role in protein structure, function and interaction with small molecule ligands. However, the widely used molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) method for binding energy calculation does not explicitly take account of water molecules that mediate key protein–ligand interactions. We have developed a protocol to include water molecules that mediate ligand–protein interactions as part of the protein structure in calculation of MM/PBSA binding energies (a method we refer to as water–MM/PBSA) for a series of JNK3 kinase inhibitors. Improved correlation between water–MM/PBSA binding energies and experimental IC₅₀ values was obtained compared to that obtained from classical MM/PBSA binding energy. This improved correlation was further validated using sets of neuraminidase and avidin inhibitors. The observed improvement, however, appears to be limited to systems in which there are water-mediated ligand–protein hydrogen bond interactions. We conclude that the water–MM/PBSA method performs better than classical MM/PBSA in predicting binding affinities when water molecules play a direct role in mediating ligand–protein hydrogen bond interactions