Background

The impact of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) infection on host gene expression in Spodoptera exigua 4th instar larvae was investigated through the use of 454 sequencing-based RNA-seq of cDNA libraries developed from insects challenged with active AcMNPV or heat-inactivated AcMNPV.

Methodology/Principal Findings

By comparing the two cDNA libraries, we show that 201 host genes are significantly up-regulated and 234 genes are significantly down-regulated by active AcMNPV infection. Down-regulated host genes included genes encoding antimicrobial peptides, namely three gloverin isoforms and an attacin, indicating that the viral infection actively repressed the expression of a portion of the host immune gene repertoire. Another interesting group of down-regulated host genes included genes encoding two juvenile hormone binding proteins and a hexamerin, all of which are involved in juvenile hormone regulation. The expression of these genes was enhanced by the topical application of Juvenile Hormone III (JHIII) in the insects challenged with heat-inactivated AcMNPV. However, infection with the active virus strongly suppresses the expression of these three genes, regardless of the absence or presence of JHIII.

Conclusions/Significance

Using RNA-seq, we have identified groups of immune-regulated and juvenile hormone-regulated genes that are suppressed by infection with active AcMNPV. This information and further studies on the regulation of host gene expression by AcMNPV will provide the tools needed to enhance the utility of the virus as an effective protein expression system and as an insecticide.

Purpose

The purpose of this study was to evaluate a new technique for localizing impacted mesiodens using its horizontal magnification ratio on panoramic radiographs.

Materials and Methods

Location-magnification equation of a panoramic equipment was obtained from horizontal magnification ratio of a metal ball which was located variable positions from the center of image layer at interval of 2 mm. Panoramic radiographs were obtained from a skull phantom with a metal ball which was a substitute for impacted mesiodens and was embedded 10mm(Group 1), 15mm(Group 2), and 20mm(Group 3) posterior to the central incisor. Each group obtained 7 panoramic radiographs at variable positions and one periapical radiograph. Three methods were used to estimate the actual width of the incisors and the balls which were used to calculate the magnification ratio. The methods included using the actual incisor width and the calculated ball width (Method 1), using the actual incisor width and the ball widths measured on periapical radiograph (Method 2), and using the incisor and the ball widths measured on periapical radiograph (Method 3). The location of the metal ball was calculated by using the location-magnification equation.

Results

The smallest difference between the calculated and the actual distance was 0.1±0.7 mm in Group 1/Method 3. The largest difference was -4.2±1.6 mm in Group 3/Method 2. In all groups, method 3 was the most accurate.

Conclusion

Quantitative localization of impacted mesiodens is possible by using panoramic radiograph.

Objectives

The Xq28 region containing IRAK1 and MECP2 has been identified as a risk locus for systemic lupus erythematosus (SLE) in previous genetic association studies. However, due to the strong linkage disequilibrium between IRAK1 and MECP2, it remains unclear which gene is affected by the underlying causal variant(s) conferring risk of SLE.

Methods

We fine-mapped ≥136 SNPs in a ~227kb region on Xq28, containing IRAK1, MECP2 and 7 adjacent genes (L1CAM, AVPR2, ARHGAP4, NAA10, RENBP, HCFC1 and TMEM187), for association with SLE in 15,783 case-control subjects derived from 4 different ancestral groups.

Results

Multiple SNPs showed strong association with SLE in European Americans, Asians and Hispanics at P<5×10−8 with consistent association in subjects with African ancestry. Of these, 6 SNPs located in the TMEM187-IRAK1-MECP2 region captured the underlying causal variant(s) residing in a common risk haplotype shared by all 4 ancestral groups. Among them, rs1059702 best explained the Xq28 association signals in conditional testings and exhibited the strongest P value in trans-ancestral meta-analysis (Pmeta=1.3×10−27, OR=1.43), and thus was considered to be the most-likely causal variant. The risk allele of rs1059702 results in the amino acid substitution S196F in IRAK1 and had previously been shown to increase NF-κB activity in vitro. We also found that the homozygous risk genotype of rs1059702 was associated with lower mRNA levels of MECP2, but not IRAK1, in SLE patients (P=0.0012) and healthy controls (P=0.0064).

Conclusion

These data suggest contributions of both IRAK1 and MECP2 to SLE susceptibility.

Objective

T cells from patients with SLE express increased amounts of PP2Ac which contribute to decreased production of IL-2. Because IL-2 is important in the regulation of several aspects of the immune response, it has been proposed that PP2Ac contributes to the expression of SLE. This study was designed to determine whether genetic variants of PPP2AC are linked to the expression of SLE and specific clinical manifestations and account for the increased expression of PP2Ac.

Methods

We conducted a trans-ethnic study consisting of 8,695 SLE cases and 7,308 controls from four different ancestries. Eighteen single-nucleotide polymorphisms (SNPs) across the PPP2CA were genotyped using an Illumina custom array. PPP2CA expression in SLE and control T cells was analyzed by real-time PCR.

Results

A 32-kb haplotype comprised of multiple SNPs of PPP2CA showed significant association with SLE in Hispanic Americans (HA), European Americans (EA) and Asians but not in African-Americans (AA). Conditional analyses revealed that SNP rs7704116 in intron 1 showed consistently strong association with SLE across Asian, EA and HA populations (pmeta=3.8×10−7, OR=1.3[1.14–1.31]). In EA, the largest ethnic dataset, the risk A allele of rs7704116 was associated with the presence of renal disease, anti-dsDNA and anti-RNP antibodies. PPP2CA expression was approximately 2-fold higher in SLE patients carrying the rs7704116 AG genotype than those carrying GG genotype (p = 0.008).

Conclusion

Our data provide the first evidence for an association between PPP2CA polymorphisms and elevated PP2Ac transcript levels in T cells, which implicates a new molecular pathway for SLE susceptibility in EA, HA and Asians.