No abstract

Fasciola hepatica is a prevalent helminth parasite of livestock. Infection results in polarization of the host's immune response and generation of type 2 helper (Th2) immune responses, which are known to be inhibitory to Th1 responses. Bovine tuberculosis (BTB) is a bacterial disease of economic and zoonotic importance. Control polices for this disease rely on extensive annual testing and a test-and-slaughter policy. The correct diagnosis of BTB relies on cell-mediated immune responses. We established a model of coinfection of F. hepatica and Mycobacterium bovis BCG to examine the impact of helminth infection on correct diagnosis. We found the predictive capacity of tests to be compromised in coinfected animals and that F. hepatica infection altered macrophage function. Interleukin-4 and gamma interferon expression in whole-blood lymphocytes restimulated in vitro with M. bovis antigen was also altered in coinfected animals. These results raise the question of whether F. hepatica infection can affect the predictive capacity of tests for the diagnosis of BTB and possibly also influence susceptibility to BTB and other bacterial diseases. Further studies on the interplay between helminth infection and BTB are warranted.

Fasciola hepatica, a trematode helminth, causes an economically important disease (fasciolosis) in ruminants worldwide. Proteomic analysis of the parasite provides valuable information to understand the relationship between the parasite and its host. Previous studies have identified various parasite proteins, some of which are considered as vaccine candidates or important drug targets. However, the approximate distribution and abundance of the proteins on the surface and within internal parts of the liver fluke are unknown. In this study, two fractions including surface protein fraction (representing surface part of the parasite, near subplasma membrane of the tegument and above the basal membrane of the tegument) and internal protein fraction (representing internal part of the parasite, mainly deeper sides of the tegument including subbasal membrane and other further internal elements of the parasite) were obtained. Components of these two fractions were investigated by an advanced proteomics approach using a high-definition mass spectrometer with nano electrospray ionization source coupled to a high-performance liquid chromatography system (nanoUPLC-ESI-qTOF-MS). FABP1 was found highly abundant in the SPF fraction. Potentially novel F. hepatica proteins showing homology with AKT interacting protein (Xenopus tropicalis), sterol O-acyltransferase 2 (Homo sapiens), and integrin beta 7 (Mus musculus) were identified with high quantities in only the surface fraction of the parasite and may be possible candidates for future control strategies.

Infection with Fasciola hepatica causes an economically important disease in ruminants. Variability in parasite load may indicate innate differences in the host immune system. This study aimed to investigate the immunological mechanisms that are associated with variability in parasite burden following experimental F. hepatica infection in cross-bred sheep. Of a total of 16 animals, four were randomly chosen as uninfected controls, and the remainder infected with 100 viable metacercariae. Uninfected animals were used as the control group for evaluation of cytokine gene expression levels. For comparative analysis, specific animals were selected on the basis of extremes of fluke burdens, and were categorised into light (n = 4) and heavy burdened (n = 3) cohorts. Serum antibody levels, haematological parameters, and expression of IL-4 and IFN-gamma genes in hepatic lymph nodes were equivalent in both groups. However, significant differences in mitogen-specific lymphocyte proliferation in vitro and in expression of TGF-beta1 and IL-10 genes in hepatic lymph nodes were observed at acute and chronic phases of infection, respectively. These results provide useful information in developing further understanding of natural resistance to fasciolosis in sheep.

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Cerebrofaciothoracic dysplasia (CFT) (OMIM #213980) is a multiple congenital anomaly and intellectual disability syndrome involving the cranium, face, and thorax. The characteristic features are cranial involvement with macrocrania at birth, brachycephaly, various CT/MRI findings including hypoplasia of corpus callosum, enlargement of septum pellicidum, and diffuse hypodensity of the grey matter, flat face, hypertelorism, cleft lip and cleft palate, low-set, posteriorly rotated ears, short neck, and multiple costal and vertebral anomalies. The underlying genetic defect remains unknown. Using combination of homozygosity mapping and whole-exome sequencing, we identified a homozygous nonsense founder mutation, p.Arg87Ter (c.259 C>T), in the human transmembrane and coiled-coil domains protein 1 (TMCO1) in four out of five families of Turkish origin. The entire critical region on chromosome 1q24 containing TMCO1 was excluded in the fifth family with characteristic findings of CFT providing evidence for genetic heterogeneity of CFT spectrum. Another founder TMCO1 mutation has recently been reported to cause a unique genetic condition, TMCO1-defect syndrome (OMIM #614132). TMCO1-defect syndrome shares many features with CFT. This study supports the fact that "TMCO1-defect syndrome," initially thought to represent a distinct disorder, indeed belongs to the genetically heterogeneous CFT dysplasia spectrum.

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Background A healthy microbiome influences host physiology through a mutualistic relationship, which can be important for the host to cope with cellular stress by promoting fitness and survival. The mammalian microbiome is highly complex and attributing host phenotypes to a specific member of the microbiome can be difficult. The model organism Caenorhabditis elegans and its native microbiome, discovered recently, can serve as a more tractable, experimental model system to study host-microbiome interactions. In this study, we investigated whether certain members of C. elegans native microbiome would offer a benefit to their host and putative molecular mechanisms using a combination of phenotype screening, omics profiling and functional validation. Results A total of 16 members of C. elegans microbiome were screened under chemically-induced toxicity. Worms grown with Chryseobacterium sp. CHNTR56 MYb120 or Comamonas sp. 12022 MYb131, were most resistant to oxidative chemical stress (SiO2 nanoparticles and juglone), as measured by progeny output. Further investigation showed that Chryseobacterium sp. CHNTR56 positively influenced the worm’s lifespan, whereas the combination of both isolates had a synergistic effect. RNAseq analysis of young adult worms, grown with either isolate, revealed the enrichment of cellular detoxification mechanisms (glutathione metabolism, drug metabolism and metabolism of xenobiotics) and signaling pathways (TGF-beta and Wnt signaling pathways). Upregulation of cysteine synthases (cysl genes) in the worms, associated with glutathione metabolism, was also observed. Nanopore sequencing uncovered that the genomes of the two isolates have evolved to favor the specific route of the de novo synthesis pathway of vitamin B6 (cofactor of cysl enzymes) through serC or pdxA2 homologs. Finally, co-culture with vitamin B6 extended worm lifespan. Conclusions In summary, our study indicates that certain colonizing members of C. elegans have genomic diversity in vitamin B6 synthesis and promote host fitness and lifespan extension. The regulation of host cellular detoxification genes (i.e. gst) along with cysl genes at the transcriptome level and the bacterium-specific vitamin B6 synthesis mechanism at the genome level are in an agreement with enhanced host glutathione-based cellular detoxification due to this interspecies relationship. C. elegans is therefore a promising alternative model to study host-microbiome interactions in host fitness and lifespan.