The entorhinal cortex of the Megachiroptera: a comparative study of Wahlberg’s epauletted fruit bat and the straw-coloured fruit bat

This study describes the organisation of the entorhinal cortex of the Megachiroptera, straw-coloured fruit bat and Wahlberg’s epauletted fruit bat. Using Nissl and Timm stains, parvalbumin and SMI-32 immunohistochemistry, we identified five fields within the medial (MEA) and lateral (LEA) entorhinal areas. MEA fields E _CL and E _C are characterised by a poor differentiation between layers II and III, a distinct layer IV and broad, stratified layers V and VI. LEA fields E _I, E _R and E _L are distinguished by cell clusters in layer II, a clear differentiation between layers II and III, a wide columnar layer III and a broad sublayer Va. Clustering in LEA layer II was more typical of the straw-coloured fruit bat. Timm-staining was most intense in layers Ib and II across all fields and layer III of field E _R. Parvalbumin-like staining varied along a medio-lateral gradient with highest immunoreactivity in layers II and III of MEA and more lateral fields of LEA. Sparse SMI-32-like immunoreactivity was seen only in Wahlberg’s epauletted fruit bat. Of the neurons in MEA layer II, ovoid stellate cells account for ~38%, polygonal stellate cells for ~8%, pyramidal cells for ~18%, oblique pyramidal cells for ~6% and other neurons of variable morphology for ~29%. Differences between bats and other species in cellular make-up and cytoarchitecture of layer II may relate to their three-dimensional habitat. Cytoarchitecture of layer V in conjunction with high encephalisation and structural changes in the hippocampus suggest similarities in efferent hippocampal → entorhinal → cortical interactions between fruit bats and primates.     

Absence of IFNγ expression induces neuronal degeneration in the spinal cord of adult mice

Background  

Interferon gamma (IFNγ) is a pro-inflammatory cytokine, which may be up-regulated after trauma to the peripheral or central nervous system. Such changes include reactive gliosis and synaptic plasticity that are considered important responses to the proper regenerative response after injury. Also, IFNγ is involved in the upregulation of the major histocompatibility complex class I (MHC class I), which has recently been shown to play an important role in the synaptic plasticity process following axotomy. There is also evidence that IFNγ may interfere in the differentiation and survival of neuronal cells. However, little is known about the effects of IFNγ absence on spinal cord neurons after injury.     

Cloning,characterization, and expression of two α-amylase genes from Aspergillus niger var. awamori

Summary Using synthetic oligonucleotide probes, we cloned genomic DNA sequences encoding an -amylase gene from Aspergillus niger var. awamori (A. awamori) on a 5.8 kb EcoRI fragment. Hybridization experiments, using a portion of this cloned fragment to probe DNA from A. awamori, suggested the presence of two -amylase gene copies which were subsequently cloned as 7 kb (designated as amyA) and 4 kb (amyB) HindIII fragments. DNA sequence analysis of the amyA and amyB genes revealed the following: (1) Both genes are arranged as nine exons and eight introns; (2) The nucleotide sequences of amyA and amyB are identical throughout all but the last few nucleotides of their respective coding regions; (3) The amyA and amyB genes from A. awamori share extensive homology (98% identity) with the genes encoding Taka-amylase from A. oryzae. In order to test whether both amyA and amyB were functional in the genome, we constructed vectors containing gene fusions of either amyA and amyB to bovine prochymosin cDNA and used these vectors to transform A. awamori. Transformants which contained either the amyA- or amyB-prochymosin gene fusions produced extracellular chymosin, suggesting that both genes are functional.Smith Kline Beecham Pharmaceuticals, King of Prussia, PA, USA.     

CXCL12, CXCR4 and IFNγ genes expression: implications for proinflammatory microenvironment of breast cancer

Signals from the microenvironment have a profound influence on the maintenance or progression of breast cancer. In the present study, the frequency of CXCL12 rs1801157 polymorphism in peripheral blood and the expression of CXCL12, CXCR4 and IFNγ mRNA in normal and mammary gland tumor tissues were assessed in breast cancer patients. Genotyping was performed by polymerase chain reaction followed by restriction fragment length polymorphism and expression analyses by quantitative RT-PCR. A lower CXCL12 mRNA relative expression was observed among allele A carriers when compared to GG carriers (p = 0.012). ER-positive breast cancer allele A carriers showed a significantly lower expression of CXCL12 mRNA within tumor tissue than in normal breast tissue when compared to GG ER-positive patients (p = 0.016). CXCR4 mRNA (p < 0.001) and CXCL12 mRNA (p = 0.02) relative expressions were significantly correlated with relative IFNγ mRNA expression. Allele A carriers presenting high levels of IFNγ had a significantly higher expression of CXCR4 mRNA in tumor tissue than GG patients (p = 0.026). It is possible that allele A carrier hormone receptor–positive patients could be more susceptible to metastasis development, since they present a lower CXCL12 expression in tumor tissue, and tumor cells expressing CXCR4 could migrate toward CXCL12 gradient. IFNγ expression increases in order to improve immune response and could favor higher CXCR4 expression leading to migration of cells, possibly of metastatic ones, too.     

Different antiviral effects of IFNα and IFNβ in an HBV mouse model

Interferons α and β (IFNα and IFNβ) are type I interferons produced by the host to control pathogen propagation. However, only a minority of chronic hepatitis B (CHB) patients generate a sustained response after treatment with recombinant IFNα. The anti-HBV effect of IFNβ and the underlying mechanism are not well-understood. Here, we compared the antiviral activities of IFNα and IFNβ by application of IFNα or IFNβ expression plasmids using the well-established HBV hydrodynamic injection (HI) mouse model. Injection of IFNα expression plasmid could significantly reduce HBV serum markers including HBsAg, HBeAg and HBV DNA as well as the number of HBcAg positive cells in the liver, while IFNβ showed only a weak inhibition of HBV replication. In contrast to IFNβ, IFNα resulted in elevated expression levels of IFN stimulated genes (ISGs) as well as the proinflammatory cytokine interleukin 6 (IL6) in the liver. Moreover, IFNβ treated mice showed higher expression levels of the anti-inflammatory cytokines IL10 and TGFβ in the liver compared to IFNα. Our results demonstrated that both IFNα and IFNβ exert antiviral activities against HBV in HI mouse model, but IFNα is more effective than IFNβ.     

IL-17 and IFN-γ expression in lymphocytes from patients with active tuberculosis correlates with the severity of the disease

Th1 lymphocytes are crucial in the immune response against Mycobacterium tuberculosis. Nevertheless, IFN-γ alone is not sufficient in the complete eradication of the bacteria, suggesting that other cytokines might be required for pathogen removal. Th17 cells have been associated with M. tuberculosis infection, but the role of IL-17-producing cells in human TB remains to be understood. Therefore, we investigated the induction and regulation of IFN-γ and IL-17 during the active disease. TB patients were classified as High and Low Responder individuals according to their T cell responses against the antigen, and cytokine expression upon M. tuberculosis stimulation was investigated in peripheral blood and pleural fluid. Afterwards, the potential correlation among the proportions of cytokine-producing cells and clinical parameters was analyzed. In TB patients, M. tuberculosis induced IFN-γ and IL-17, but in comparison with BCG-vaccinated healthy donors, IFN-γ results were reduced significantly, and IL-17 was markedly augmented. Moreover, the main source of IL-17 was represented by CD4(+)IFN-γ(+)IL-17(+) lymphocytes, a Th1/Th17 subset regulated by IFN-γ. Interestingly, the ratio of antigen-expanded CD4(+)IFN-γ(+)IL-17(+) lymphocytes, in peripheral blood and pleural fluid from TB patients, was correlated directly with clinical parameters associated with disease severity. Indeed, the highest proportion of CD4(+)IFN-γ(+)IL-17(+) cells was detected in Low Responder TB patients, individuals displaying severe pulmonary lesions, and longest length of disease evolution. Taken together, the present findings suggest that analysis of the expansion of CD4(+)IFN-γ(+)IL-17(+) T lymphocytes in peripheral blood of TB patients might be used as an indicator of the clinical outcome in active TB.     

Tissue-based IL-10 signalling in helminth infection limits IFNγ expression and promotes the intestinal Th2 response

Type 2 immunity is activated in response to both allergens and helminth infection. It can be detrimental or beneficial, and there is a pressing need to better understand its regulation. The immunosuppressive cytokine IL-10 is known as a T helper 2 (Th2) effector molecule, but it is currently unclear whether IL-10 dampens or promotes Th2 differentiation during infection. Here we show that helminth infection in mice elicits IL-10 expression in both the intestinal lamina propria and the draining mesenteric lymph node, with higher expression in the infected tissue. In vitro, exogenous IL-10 enhanced Th2 differentiation in isolated CD4⁺ T cells, increasing expression of GATA3 and production of IL-5 and IL-13. The ability of IL-10 to amplify the Th2 response coincided with its suppression of IFNγ expression and in vivo we found that, in intestinal helminth infection, IL-10 receptor expression was higher on Th1 cells in the small intestine than on Th2 cells in the same tissue, or on any Th cell in the draining lymph node. In vivo blockade of IL-10 signalling during helminth infection resulted in an expansion of IFNγ⁺ and Tbet⁺ Th1 cells in the small intestine and a coincident decrease in IL-13, IL-5 and GATA3 expression by intestinal T cells. These changes in Th2 cytokines correlated with reduced expression of type 2 effector molecules, such as RELMα, and increased parasite egg production. Together our data indicate that IL-10 signalling promotes Th2 differentiation during helminth infection at least in part by regulating competing Th1 cells in the infected tissue.     

Brain-derived neurotrophic factor modulates the severity of cognitive alterations induced by mutant huntingtin: Involvement of phospholipaseCγ activity and glutamate receptor expression

The involvement of brain-derived neurotrophic factor (BDNF) in cognitive processes and the decrease in its expression in Huntington's disease suggest that this neurotrophin may play a role in learning impairment during the disease progression. We therefore analyzed the onset and severity of cognitive deficits in two different mouse models with the same mutant huntingtin but with different levels of BDNF (R6/1 and R6/1:BDNF+/− mice). We observed that BDNF modulates cognitive function in different learning tasks, even before the onset of motor symptoms. R6/1:BDNF+/− mice showed earlier and more accentuated cognitive impairment than R6/1 mice at 5 weeks of age in discrimination learning; at 5 weeks of age in procedural learning; and at 9 weeks of age in alternation learning. At the earliest age at which cognitive impairment was detected, electrophysiological analysis was performed in the hippocampus. All mutant genotypes showed reduced hippocampal long term potentiation (LTP) with respect to wild type but did not show differences between them. Thus, we evaluated the involvement of BDNF-trkB signaling and glutamate receptor expression in the hippocampus of these mice. We observed a decrease in phospholipaseCγ activity, but not ERK, in R61, BDNF+/− and R6/1:BDNF+/− hippocampus at the age when LTP was altered. However, a specific decrease in the expression of glutamate receptors NR1, NR2A and GluR1 was detected only in R6/1:BDNF+/− hippocampus. Therefore, these results show that BDNF modulates the learning and memory alterations induced by mutant huntingtin. This interaction leads to intracellular changes, such as specific changes in glutamate receptors and in BDNF-trkB signaling through phospholipaseCγ.     

Altered synthesis of interferon-γ and expression of interferon-γ receptor by peripheral blood mononuclear cells from patients with IgA nephropathy and non-IgA proliferative glomerulonephritis

Previously we reported disease-specific interaction between interferon- (IFN-) and interleukin-4 (IL-4) in patients with IgA nephropathy (IgAN), suggesting the existence of unusual T cell behavior in this disease. In the present study, we investigated characteristic synthesis of interferon- (IFN-) and expression of IFN- receptor (IFN-R) in the peripheral blood mononuclear cells (PBMC) from patients with IgAN and other chronic proliferative glomerulonephritis (PGN). Heparinized peripheral blood samples were obtained from 38 patients with chronic mesangial proliferative glomerulonephritis (CGN; including 24 with IgA nephropathy) and 20 healthy controls. PBMC were isolated by gradient centrifugation and fragments were cultured in Iscove's modified Dulbecco's medium (IMDM) supplemented with 10% fetal calf serum (FCS) for 72 hr. IFN- concentrations in supernatants were evaluated by the enzyme-linked immunosorbent assay (ELISA). Other parts of PBMC pellets were reacted with anti-human IFN-R monoclonal antibody and FITC-labeled anti-mouse second antibody for analysis of IFN-R expression on these cells by FACScan. The remaining PBMC were fractionated into CD4⁺ T cells, CD8⁺ T cells, B cells, NK, cells and macrophages using the MACS cell sorting system. The isolated cells were evaluated for IFN- or IFN-R mRNA expression by the semiquantitative RT-PCR method.In vitro IFN- synthesis was enhanced in patients with CGN, and NK cells were revealed to be responsible for such enhancement. On the other hand, the expression of IFN-R on macrophages was suppressed in CGN patients. These results suggest that impairment of regulation of the IFN- system might be involved in the development of CGN.     

Colonic MUC2 mucin regulates the expression and antimicrobial activity of β-defensin 2

In this study we identified mechanisms at the colonic mucosa by which MUC2 mucin regulated the production of β-defensin in a proinflammatory milieu but functionally protected susceptible bacteria from its antimicrobial effects. The regulator role of MUC2 on production of β-defensin 2 in combination with the proinflammatory cytokine interleukin-1β (IL-1β) was confirmed using purified human colonic MUC2 mucin and colonic goblet cells short hairpin RNA (shRNA) silenced for MUC2. In vivo, Muc2^−/− mice showed impaired β-defensin mRNA expression and peptide localization in the colon as compared with Muc2^+/− and Muc2^+/+ littermates. Importantly, purified MUC2 mucin abrogated the antimicrobial activity of β-defensin 2 against nonpathogenic and enteropathogenic Escherichia coli. Sodium metaperiodate oxidation of MUC2 removed the capacity of MUC2 to stimulate β-defensin production and MUC2's inhibition of defensin antimicrobial activity. This study highlights that a defective MUC2 mucin barrier, typical in inflammatory bowel diseases, may lead to deficient stimulation of β-defensin 2 and an unbalanced microbiota that favor the growth of β-defensin-resistant microbes such as Clostridium difficile.     

Cloning, Recombinant Expression and Activity Studies of a Major Allergen “Enolase” from the Fungus Curvularia Lunata

Recombinant allergens are required to study allergy at the molecular level and are helpful tools for the improvement of diagnosis and therapy. In the present study, enolase was expressed from Curvularia lunata and analyzed for its immunological reactivity as an allergen. cDNA library was synthesized in λ zap vector and screened with sera obtained from C. lunata allergic patients. A cDNA clone with an ORF of 1.3 kb showed homology to enolases from different fungal sources. It was expressed in E. coli, purified from inclusion bodies yielding 0.5 mg/L and showed enzyme activity of 48 units/mg. It resolved as 48-kDa band on SDS-PAGE and was recognized by all the individual Curvularia positive patient sera in immunoblot and ELISA. r Cur l 2 stimulated patients’ PBMCs and supernatant of these cells showed elevated levels of Th 2 cytokines. Ten B cell epitopes were predicted using computational software and one showed 90% homology to an important IgE epitope of Cla h 6. The various parameters predicted by computational approach can be validated later as a future study to draw conclusive evidence about putative antigenic epitopes. This can further help in generating knowledge about residues important for IgE binding and developing therapeutic modalities.     

Australian patients’ perception of the efficacy of the physical activity referral scheme (PARS)

BackgroundOptimum physical activity (PA) interventions could be delivered via physical activity referral schemes (PARS) if utilised adequately. However, the evidence supporting PARS effectiveness is weak due to low uptake and non-adherence to interventions.ObjectivePatients’ experiences of PARS were explored to obtain in-depth insight into their perceived quality of care and practical ways to optimise the programme’s effectiveness.MethodsA sequential explanatory mixed methods design was employed to probe cross-sectional quantitative survey data (n = 111) on patients’ knowledge and beliefs about PA and PARS and qualitative interview data (n = 15) on their experiences of PARS. Informed by Donabedian framework of healthcare quality assessment, quantitative and qualitative findings were integrated to identify practical ways to enhance PARS effectiveness.ResultsParticipants displayed good PA knowledge, had positive beliefs and perceived PARS to be useful. Nonetheless, bottlenecks in the structure and process of PARS impact on patient health outcomes and hinder the programme’s uptake.ConclusionExploring other referral mechanisms into PARS such as self or nurse-initiated referrals could improve the programme’s visibility and effectiveness.Practice implicationsImproved support, enhanced visibility of EPs, ongoing interactions between GPs and EPs and education about referral pathways would foster improved uptake, adherence and health outcomes for patients.     

Precision and linearity targets for validation of an IFNγ ELISPOT, cytokine flow cytometry, and tetramer assay using CMV peptides

Background

Intestinal mucus production by hyperplasic goblet cells is a striking pathological feature of many parasitic helminth infections and is related to intestinal protection and worm expulsion. Induction of goblet cell hyperplasia is associated with TH2 immune responses, which in helminth infections are controlled primarily by IL-13, and also IL-4. In the study presented here we examine the goblet cell hyperplasic response to three experimental parasitic helminth infections; namelyNippostrongylus brasiliensis,Syphacia obvelataandSchistosoma mansoni.

Results

As expectedN. brasiliensisinfection induced a strong goblet cell hyperplasia dependent on IL-4/IL-13/IL-4Rα expression. In contrast, and despite previously published transiently elevated IL-4/IL-13 levels,S. obvelatainfections did not increase goblet cell hyperplasia in the colon. Furthermore, induction of goblet cell hyperplasia in response toS. mansonieggs traversing the intestine was equivalent between BALB/c, IL-4/IL-13^-/-and IL-4Rα^-/-mice.

Conclusion

Together these data demonstrate that intestinal goblet cell hyperplasia can be independent of TH2 immune responses associated with parasitic helminth infections.