HIV Outbreak Control With Effective Access to Care and Harm Reduction in North Carolina, 2017-2018.

Objectives. To assess and control a potential outbreak of HIV among people who inject drugs in Western North Carolina.Methods. Disease intervention specialists offered testing for hepatitis B and hepatitis C, harm reduction materials, and linkage to care to 7 linked people recently diagnosed with HIV who also injected drugs. Contacts were offered the same services and HIV testing. HIV genotype analysis was used to characterize HIV spread. We assessed testing and care outcomes by using state surveillance information.Results. Disease intervention specialists contacted 6 of 7 linked group members and received information on 177 contacts; among 96 prioritized contacts, 42 of 96 (44%) were exposed to or diagnosed with hepatitis C, 4 of 96 (4%) had hepatitis B, and 14 of 96 (15%) had HIV (2 newly diagnosed during the investigation). HIV genotype analysis suggested recent transmission to linked group members and 1 contact. Eleven of 14 with HIV were virally suppressed following the outbreak response.Conclusions. North Carolina identified and rapidly responded to an HIV outbreak among people reporting injecting drugs. Effective HIV care, the availability of syringe exchange services, and the rapid response likely contributed to controlling this outbreak.

A mouse Col4a4 mutation causing Alport glomerulosclerosis with abnormal collagen α3α4α5(IV) trimers.

A spontaneous mutation termed bilateral wasting kidneys (bwk) was identified in a colony of NONcNZO recombinant inbred mice. These mice exhibit a rapid increase of urinary albumin at an early age associated with glomerulosclerosis, interstitial nephritis, and tubular atrophy. The mutation was mapped to a location on chromosome 1 containing the Col4a3 and Col4a4 genes, for which mutations in the human orthologs cause the hereditary nephritis Alport syndrome. DNA sequencing identified a G-to-A mutation in the conserved GT splice donor of Col4a4 intron 30, resulting in skipping of exon 30 but maintaining the mRNA reading frame. Protein analyses showed that mutant collagen α3α4α5(IV) trimers were secreted and incorporated into the glomerular basement membrane (GBM), but levels were low, and GBM lesions typical of Alport syndrome were observed. Moving the mutation into the more renal damage-prone DBA/2J and 129S1/SvImJ backgrounds revealed differences in albuminuria and its rate of increase, suggesting an interaction between the Col4a4 mutation and modifier genes. This novel mouse model of Alport syndrome is the only one shown to accumulate abnormal collagen α3α4α5(IV) in the GBM, as also found in a subset of Alport patients. These mice will be valuable for testing potential therapies, for understanding abnormal collagen IV structure and assembly, and for gaining better insights into the mechanisms leading to Alport syndrome, and to the variability in the age of onset and associated phenotypes.

Genetic analysis of mesangial matrix expansion in aging mice and identification of Far2 as a candidate gene.

Aging of the kidney is associated with renal damage, in particular mesangial matrix expansion (MME). Identifying the genes involved in this process will help to unravel the mechanisms of aging and aid in the design of novel therapeutic modalities aimed at prevention and regression. In this study, structural changes in glomeruli of 24 inbred mouse strains were characterized in male mice at 6, 12, and 20 months of age. Haplotype association mapping was used to determine genetic loci associated with the presence of MME at 20 months. This analysis identified a significant association with a 200-kb haplotype block on chromosome 6 containing Far2. Sequencing revealed that mouse strains with MME contain a 9-bp sequence in the 5' untranslated region of Far2 that is absent in most of the strains without MME. Real-time PCR showed a two-fold increase in the expression of Far2 in the kidneys of strains with the insert, and subsequent experiments performed in vitro with luciferase reporter vectors showed that this sequence difference causes differential expression of Far2. Overexpression of Far2 in a mouse mesangial cell line induced upregulation of platelet activating factor and the fibrotic marker TGF-ß. This upregulation of MME-promoting factors may result, in part, from the FAR2-catalyzed reduction of fatty acyl-coenzyme A to fatty alcohols, which are possible precursors of platelet activating factor. Overall, these data suggest the identification of a novel pathway involved in renal aging that may yield therapeutic targets for reducing MME.

Uncovering genes and regulatory pathways related to urinary albumin excretion.

Identifying the genes underlying quantitative trait loci (QTL) for disease is difficult, mainly because of the low resolution of the approach and the complex genetics involved. However, recent advances in bioinformatics and the availability of genetic resources now make it possible to narrow the genetic intervals, test candidate genes, and define pathways affected by these QTL. In this study, we mapped three significant QTL and one suggestive QTL for an increased albumin-to-creatinine ratio on chromosomes (Chrs) 1, 4, 15, and 17, respectively, in a cross between the inbred MRL/MpJ and SM/J strains of mice. By combining data from several sources and by utilizing gene expression data, we identified Tlr12 as a likely candidate for the Chr 4 QTL. Through the mapping of 33,881 transcripts measured by microarray on kidney RNA from each of the 173 male F2 animals, we identified several downstream pathways associated with these QTL, including the glycan degradation, leukocyte migration, and antigen-presenting pathways. We demonstrate that by combining data from multiple sources, we can identify not only genes that are likely to be causal candidates for QTL but also the pathways through which these genes act to alter phenotypes. This combined approach provides valuable insights into the causes and consequences of renal disease.

Identification of novel genes associated with renal tertiary lymphoid organ formation in aging mice.

A hallmark of aging-related organ deterioration is a dysregulated immune response characterized by pathologic leukocyte infiltration of affected tissues. Mechanisms and genes involved are as yet unknown. To identify genes associated with aging-related renal infiltration, we analyzed kidneys from aged mice (≥20 strains) for infiltrating leukocytes followed by Haplotype Association Mapping (HAM) analysis. Immunohistochemistry revealed CD45+ cell clusters (predominantly T and B cells) in perivascular areas coinciding with PNAd+ high endothelial venules and podoplanin+ lymph vessels indicative of tertiary lymphoid organs. Cumulative cluster size increased with age (analyzed at 6, 12 and 20 months). Based on the presence or absence of clusters in male and female mice at 20 months, HAM analysis revealed significant associations with loci on Chr1, Chr2, Chr8 and Chr14 in male mice, and with loci on Chr4, Chr7, Chr13 and Chr14 in female mice. Wisp2 (Chr2) showed the strongest association (P = 5.00×10(-137)) in male mice; Ctnnbip1 (P = 6.42×10(-267)) and Tnfrsf8 (P = 5.42×10(-245)) (both on Chr4) showed the strongest association in female mice. Both Wisp2 and Ctnnbip1 are part of the Wnt-signaling pathway and the encoded proteins were expressed within the tertiary lymphoid organs. In conclusion, this study revealed differential lymphocytic infiltration and tertiary lymphoid organ formation in aged mouse kidneys across different inbred mouse strains. HAM analysis identified candidate genes involved in the Wnt-signaling pathway that may be causally linked to tertiary lymphoid organ formation.