IL11-mediated stromal cell activation may not be the master regulator of pro-fibrotic signaling downstream of TGFβ

Fibrotic diseases, such as idiopathic pulmonary fibrosis (IPF) and systemic scleroderma (SSc), are commonly associated with high morbidity and mortality, thereby representing a significant unmet medical need. Interleukin 11 (IL11)-mediated cell activation has been identified as a central mechanism for promoting fibrosis downstream of TGFβ. IL11 signaling has recently been reported to promote fibroblast-to-myofibroblast transition, thus leading to various pro-fibrotic phenotypic changes. We confirmed increased mRNA expression of IL11 and IL11Rα in fibrotic diseases by OMICs approaches and in situ hybridization. However, the vital role of IL11 as a driver for fibrosis was not recapitulated. While induction of IL11 secretion was observed downstream of TGFβ signaling in human lung fibroblasts and epithelial cells, the cellular responses induced by IL11 was quantitatively and qualitatively inferior to that of TGFβ at the transcriptional and translational levels. IL11 blocking antibodies inhibited IL11Rα-proximal STAT3 activation but failed to block TGFβ-induced profibrotic signals. In summary, our results challenge the concept of IL11 blockade as a strategy for providing transformative treatment for fibrosis.

Analysis of calibration results of radiation survey meters used for area monitoring

Analyses of the results of calibration of survey meters carried out at the Secondary Standards Dosimetry Laboratory (SSDL) in Ghana over a period of 4 y (2008-2011) are reported. The calibration factors (CFs) of the set of survey meters indicated that ∼91.04 % were within the acceptable limit of ± 20.0 %. A higher percentage of the survey meters indicated CFs in the range of 0.95-1.15 except a few of them which indicated values <0.55. Some of the survey meters also recorded CFs >1.15. The degree of uncertainty in the measurements ranged from 0.03 to 17 % with the majority of them ranging from 0.03 to 6.0 % and a few of them >6.0 %. The results show that most of the survey meters calibrated were within the requirements of the regulations and may provide data for future development of calibration techniques in the country.

Sheep monoclonal antibodies prevent systemic effects of botulinum neurotoxin A1

Botulinum neurotoxin (BoNT) is responsible for causing botulism, a potentially fatal disease characterized by paralysis of skeletal muscle. Existing specific treatments include polyclonal antisera derived from immunized humans or horses. Both preparations have similar drawbacks, including limited supply, risk of adverse effects and batch to batch variation. Here, we describe a panel of six highly protective sheep monoclonal antibodies (SMAbs) derived from sheep immunized with BoNT/A1 toxoid (SMAbs 2G11, 4F7) or BoNT/A1 heavy chain C-terminus (HcC) (SMAbs 1G4, 5E2, 5F7, 16F9) with or without subsequent challenge immunization with BoNT/A1 toxin. Although each SMAb bound BoNT/A1 toxin, differences in specificity for native and recombinant constituents of BoNT/A1 were observed. Structural differences were suggested by pI (5E2 = 8.2; 2G11 = 7.1; 4F7 = 8.8; 1G4 = 7.4; 5F7 = 8.0; 16F9 = 5.1). SMAb protective efficacy vs. 10,000 LD50 BoNT/A1 was evaluated using the mouse lethality assay. Although not protective alone, divalent and trivalent combinations of SMabs, IG4, 5F7 and/or 16F9 were highly protective. Divalent combinations containing 0.5–4 μg/SMAb (1–8 μg total SMAb) were 100% protective against death with only mild signs of botulism observed; relative efficacy of each combination was 1G4 + 5F7 > 1G4 + 16F9 >> 5F7 + 16F9. The trivalent combination of 1G4 + 5F7 + 16F9 at 0.25 μg/SMAb (0.75 μg total SMAb) was 100% protective against clinical signs and death. These results reflect levels of protective potency not reported previously.

Schistosoma mansoni: use of a subtractive cloning strategy to search for RFLPs in parasite-resistant Biomphalaria glabrata

A subtractive cloning strategy has been applied for the identification of two cDNA clones whose corresponding transcripts were elevated in Schistosoma mansoni-resistant (BS-90) compared to susceptible (M-line) snails. Clone pBS11 encoded a 1.9-kb transcript that was more elevated compared to a 500-bp transcript encoded by clone pBS12. Consequently, more attention was focused on the molecular characterization of clone pBS11. Results showed that the transcript encoded by this clone was expressed in the albumen gland and was developmentally regulated. Sequence analysis of pBS11 demonstrated the presence of an open reading frame that corresponded to a novel Biomphalaria glabrata albumen gland gene product. Comparative Southern analysis of the resistant and susceptible snail lines using pBS11 as probe indicated the presence of a BamHI and EcoRI RFLP between the two strains.

Schistosoma mansoni: changes in the albumen gland of Biomphalaria glabrata snails selected for nonsusceptibility to the parasite

The LAC-line strain of the snail Biomphalaria glabrata has very low susceptibility to the parasite Schistosoma mansoni and a very low reproductive potential. Upon examination of the reproductive tract of these snails, light and electron microscopy revealed obvious abnormalities in the albumen gland. Secretory cells that are normally cuboidal in susceptible NMRI (F0) snails were squamous in LAC-line snails. These LAC-line cells contained small secretory granules and negligible rough endoplasmic reticulum and Golgi, compared to large granules and an extensive array of both organelles in F0 albumen gland cells. Comparative analyses of soluble protein extracts of F0 and LAC-line albumen glands showed several qualitative differences. Among the most prominent was an 18-kDa protein in F0 snails that was remarkably reduced in the soluble protein extracts of LAC-line snails. Also, metabolic incorporation of [35S]-methionine was impaired in LAC-line albumen glands. Whether these albumen gland changes are caused by decreased susceptibility to parasitism is yet to determined.

Ultrastructure of the ventral sucker of Schistosoma mansoni cercaria

The ventral sucker of Schistosoma mansoni cercaria is a cup-shaped structure that is attached to the ventral surface of the organism by a homogeneous connective tissue that surrounds the acetabular glands. The sucker consists of an extensive complex of circular and longitudinal muscles. The longitudinal muscles extend outward in a radial pattern to form the cup of the organ. Intermingled with the muscles are nerve bundles and subtegumental cells (cytons). Dendritic nerve fibers connect to sensory papillae which are found on the surface tegument. Two types of sensory papillae are present: a commonly found unsheathed uniciliated papilla, and a previously unidentified tegumental encapsulated structure. Tegument with spines covers the ventral sucker, although the tegumental encapsulated sensory papilla lacks spines.