TLR-2 and TLR-4 agonists favor expansion of CD4+ T cell subsets implicated in the severity of neuromyelitis optica spectrum disorders.

BACKGROUND: High frequency of circulating Th17 cell subsets expressing TLR2, TLR4 and TLR9 was observed in Neuromyelitis optica spectrum disorder (NMOSD) patients, a severe humoral autoimmune disease of the central nervous system. Our objective was to evaluate the direct effects of different TLR ligands on CD4+ T-cells form those patients. METHODS: CD4+ T-cell cultures from NMOSD and healthy individuals were stimulated with different TLR ligands and the cell proliferation and cytokine profile was analyzed by [3H] TdR up take and ELISA/ cytometry, respectively. The plasma levels of CD14 were determined by ELISA. RESULTS: Here, Pam3C (TLR2) and LPS (TLR4) induced significant cell proliferation and IL-6, IL-17 and IL-21 production by CD4+ T-cells from NMOSD. Additionally, while both TLR ligands were more potent in favoring the expansion of TFH-like cells, Pam3C reduced the frequency of IL-10-secreting FoxP3+and FoxP3- CD4+ T-cells. With regard to disease severity, the levels of IL-6, IL-17 and IL-21 produced by CD4+ T-cells, as well as the frequency of TFH-like cells, in response to TLR2 and TLR4 agonists were positively correlated with neurological disabilities and the occurrence of new acute relapses during follow up. Finally, circulating levels of CD14, an indirect marker of microbial translocation, were positively correlated with IL-6, IL-17 and IL-21 release by Pam3C- and LPS-activated CD4+ T-cells. CONCLUSIONS: In summary, our data suggest that microbial antigens may affect NMOSD outcomes by favoring an imbalance between Th17 and TFH-like cells and regulatory T cell subsets.

The expansion of circulating IL-6 and IL-17-secreting follicular helper T cells is associated with neurological disabilities in neuromyelitis optica spectrum disorders.

Due to their function in assisting B cells, TFH cells may be involved in the production of pathogenic IgG in neuromyelitis optica spectrum disorder (NMOSD). In the present study, the proportion of IL-6+ and IL-17+ TFH cell subsets was higher in NMOSD patients than healthy individuals. The frequency of both TFH cell subsets were directly associated with disease activity. By contrast, NMOSD patients with a higher proportion of IL-10+ TFH cell subsets showed a lower neurological disabilities score. In summary, all findings suggest that expansion of peripheral IL-6+ and IL-17+ TFH cells may be involved in the severity of NMOSD.

Dengue Virus IgM Serotyping by ELISA with Recombinant Mutant Envelope Proteins.

We developed an IgM-based ELISA that identifies the dengue virus serotype of recent infections. Dominant serotypes were detectable in 91.1% of samples from travelers and 86.5% of samples from residents of endemic regions; 97.1% corresponded to the serotype identified by PCR. This ELISA enables more accurate reporting of epidemiologic findings.

Effects of proteasome inhibitor MG-132 on the parasite Schistosoma mansoni.

Proteasome is a proteolytic complex responsible for intracellular protein turnover in eukaryotes, archaea and in some actinobacteria species. Previous work has demonstrated that in Schistosoma mansoni parasites, the proteasome inhibitor MG-132 affects parasite development. However, the molecular targets affected by MG-132 in S. mansoni are not entirely known. Here, we used expression microarrays to measure the genome-wide changes in gene expression of S. mansoni adult worms exposed in vitro to MG-132, followed by in silico functional analyses of the affected genes using Ingenuity Pathway Analysis (IPA). Scanning electron microscopy was used to document changes in the parasites' tegument. We identified 1,919 genes with a statistically significant (q-value ≤ 0.025) differential expression in parasites treated for 24 h with MG-132, when compared with control. Of these, a total of 1,130 genes were up-regulated and 790 genes were down-regulated. A functional gene interaction network comprised of MG-132 and its target genes, known from the literature to be affected by the compound in humans, was identified here as affected by MG-132. While MG-132 activated the expression of the 26S proteasome genes, it also decreased the expression of 19S chaperones assembly, 20S proteasome maturation, ubiquitin-like NEDD8 and its partner cullin-3 ubiquitin ligase genes. Interestingly, genes that encode proteins related to potassium ion binding, integral membrane component, ATPase and potassium channel activities were significantly down-regulated, whereas genes encoding proteins related to actin binding and microtubule motor activity were significantly up-regulated. MG-132 caused important changes in the worm tegument; peeling, outbreaks and swelling in the tegument tubercles could be observed, which is consistent with interference on the ionic homeostasis in S. mansoni. Finally, we showed the down-regulation of Bax pro-apoptotic gene, as well as up-regulation of two apoptosis inhibitor genes, IAP1 and BRE1, and in contrast, down-regulation of Apaf-1 apoptotic activator, thus suggesting that apoptosis is deregulated in S. mansoni exposed to MG-132. A considerable insight has been gained concerning the potential of MG-132 as a gene expression modulator, and overall the data suggest that the proteasome might be an important molecular target for the design of new drugs against schistosomiasis.

First report of persistent dengue-1-associated autoimmune neurological disturbance: neuromyelitis optica spectrum disorder.

Dengue virus (DENV) causes immune-mediated diseases. Neurological involvement represents a severe condition that is rarely observed in DENV-1 infection. Neuromyelitis optica (NMO)/NMO spectrum disorders (NMOSD) are idiopathic immune-mediated demyelinating syndromes of the central nervous system. We report a 17-year-old female with oligosymptomatic DENV-1 viremia, diagnosed as NMOSD. Magnetic resonance imaging showed spinal cord and brainstem lesions. Antibody for aquaporin 4 was negative. DENV-1 RNA infection was detected by serial RT-PCR and confirmed by phylogenetic analysis in serum. Although there are some reports of NMO post-dengue infection, there are not any published accounts of NMOSD with coexistent and persistent DENV-1 infection.

Expansion of IL-6+ Th17-like cells expressing TLRs correlates with microbial translocation and neurological disabilities in NMOSD patients.

Different microbial antigens, by signaling through toll-like receptors (TLR), may contribute to Th17-mediated autoimmune diseases, such as neuromyelitis optica spectrum disorder (NMOSD). The objective of this study was to determine the proportion of different Th17-like cell subsets that express TLR in NMOSD patients. For this study, the frequency of different Th17 cell subsets expressing TLR subsets in healthy individuals (n=20) and NMOSD patients (n=20) was evaluated by cytometry. The peripheral levels of soluble CD14 (sCD14) and cytokines were determined by ELISA. Our results demonstrated that the proportion of peripheral CD4+ T cells expressing TLR2, 4 and 9 was significantly higher in NMOSD samples than in healthy subjects. In NMOSD, these cells are CD28+PD-1-CD57- and produce elevated levels of IL-17. Among different TLRs+ Th17-like subsets, the proportion of those that co-express IL-17 and IL-6 was significantly higher in NMOSD patients, which was positively correlated with sCD14 levels and EDSS score. By contrast, the percentage of TLRs+Treg17 cells (IL-10+IL-17+) was negatively related to sCD14 and the severity of NMOSD. In conclusion, the expansion of peripheral IL-6-producing TLR+ Th17-like cells in NMOSD patients was associated with both bacterial translocation and disease severity.

Immune activation in amniotic fluid from Zika virus-associated microcephaly.

Recent advances in the understanding of neuropathogenesis associated with Zika virus (ZIKV) infection has led to descriptions of neonatal microcephaly cases. However, none of these reports have evaluated the humoral response during ZIKV infection. We report here polyfunctional immune activation associated with increased interferon-gamma-inducible protein 10, interleukin (IL)-6, IL-8, vascular endothelial growth factor (VEGF), monocyte chemoattractive protein 1 (MCP-1), and granulocyte colony-stimulating factor (G-CSF) levels in the amniotic fluid of ZIKV-positive pregnant women with neonatal microcephaly. These cytokines have been associated not only with neuronal damage, but also with differentiation and proliferation of neural progenitor cells. Our results suggested that the immune activation caused by ZIKV infection in the uterine environment could also interfere with fetal development. ANN NEUROL 2017;81:152-156.