Association of polymorphous light eruption with NOD-2 and TLR-5 gene polymorphisms

BACKGROUND

Polymorphous light eruption (PLE) is a common, immunologically mediated, photosensitive skin disease. After ultraviolet-B (UV-B) irradiation, patients with PLE show reduced Langerhans cell (LC) depletion in the epidermis, which results in a non-suppressive microenvironment in the skin. Interestingly, severe acute graft-versus-host-disease (aGvHD) occurred in stem cell transplanted patients that showed no or incomplete depletion of LCs after UVB-irradiation. Genetic variation in nucleotide-binding oligomerization domain 2 (NOD-2) and toll-like receptor 5 (TLR-5) genes also confers susceptibility to aGvHD.

OBJECTIVES

We hypothesized that PLE is associated with genetic variation in the NOD-2 and TLR-5 genes.

METHODS

We investigated single nucleotid polymorphisms (SNPs) of NOD-2 (R702W, G908R, 3020Cins) and TLR-5 (A592S, P616L, N392STOP) in skin biopsies of PLE-patients (n=143) and in healthy controls (n=104) using restriction fragment-length polymorphism analysis.

RESULTS

The frequency of NOD-2 alleles with the SNP R702W was significantly higher in PLE than in controls (31.8% vs 6.3%; p<0.0001), and homozygous carriers of this mutation were more common in PLE (27.9% vs 0%; p<0.0001). For SNP 3020Cins, the allele frequency (7.3% vs 0.7%; p=0.0025) and the number of heterozygotes (14.7% vs 1.3%; p=0.0019) were higher in PLE. The frequency of alleles with the N392STOP SNP of the TLR5 gene, which is associated with a truncated, non-functional receptor, was significantly higher in PLE (21% vs 5%; 7% vs 1% homozygotes, 28% vs 8% heterozygotes; p<0.0001). The other SNPs did not differ significantly.

CONCLUSIONS

This study yielded a high frequency of functional SNPs in the NOD-2 and TLR-5 genes in PLE. The same SNPs are associated with aGvHD and there are similarities in the reaction of LCs after UVB-irradiation between aGvHD and PLE. This leads to the hypothesis that PLE-patients may be more susceptible to developing GvHD after stem-cell transplantation, an assumption that needs to be investigated further.

Cumulative Signaling Through NOD-2 and TLR-4 Eliminates the Mycobacterium Tuberculosis Concealed Inside the Mesenchymal Stem Cells

For a long time, tuberculosis (TB) has been inflicting mankind with the highest morbidity and mortality. Although the current treatment is extremely potent, a few bacilli can still hide inside the host mesenchymal stem cells (MSC). The functional capabilities of MSCs are known to be modulated by TLRs, NOD-2, and RIG-1 signaling. Therefore, we hypothesize that modulating the MSC activity through TLR-4 and NOD-2 can be an attractive immunotherapeutic strategy to eliminate the Mtb hiding inside these cells. In our current study, we observed that MSC stimulated through TLR-4 and NOD-2 (N2.T4) i) activated MSC and augmented the secretion of pro-inflammatory cytokines; ii) co-localized Mtb in the lysosomes; iii) induced autophagy; iv) enhanced NF-κB activity via p38 MAPK signaling pathway; and v) significantly reduced the intracellular survival of Mtb in the MSC. Overall, the results suggest that the triggering through N2.T4 can be a future method of immunotherapy to eliminate the Mtb concealed inside the MSC.

A Novel X-Linked Inhibitor of Apoptosis Deficient Variant Showing Attenuated Epstein-Barr Virus Response

We report on 2 Asian siblings with X-linked inhibitor of apoptosis deficiency that arose from a novel deletion that presented with Epstein-Barr virus disease and hemophagocytic lymphohistiocytosis. This disease is ascribed to dysfunction in the nucleotide binding and oligomerization domain receptor pathway, tested using a modified muramyl dipeptide-mediated assay.

Safety, tolerability and pharmacodynamics of a novel immunomodulator, MIS416, in patients with chronic progressive multiple sclerosis

Background

Preclinical studies have demonstrated that MIS416, a bacterially derived immune modulator, targets myeloid cells following systemic delivery. MIS416 stimulated myeloid cells have the capacity to regulate innate inflammation, a potential therapeutic target for progressive multiple sclerosis.

Objectives

To determine the safety, tolerability, pharmacodynamics and maximum tolerated dose and/or recommended Phase 2 dose of MIS416.

Methods

An open-label, non-randomized, phase II, dose-escalation study, in patients with progressive multiple sclerosis: dose-escalation phase, with MIS416 administered once weekly for four weeks to determine maximum tolerated dose; and dose-confirmation phase, administered once weekly for up to 12 weeks.

Results

The safety profile indicates the majority of adverse events were mild or moderate, tolerable, self-limiting and consistent with the known bioactivity of MIS416 (acute flu-like symptoms). Maximum tolerated dose was not reached. A dose of 500 µg/week was recommended for the Phase 2 dose.

Conclusion

MIS416 is well tolerated at a dose of 500 µg/week. The adverse event profile is consistent with the mechanism of action of MIS416, indicating bioactivity within the signal transduction pathways and supported by induction of a known MIS416 pharmacodynamic marker. It is recommended that safety and efficacy of MIS416 is investigated further in a larger randomized controlled trial.

http://clinicaltrials.gov reference NCT01191996