Abstract: SA-PO590
In ANCA Vasculitis, Low-Density Neutrophils Express High Levels of Autoantigen Genes, but Expression in Normal-Density Neutrophils Correlates with Activation by ANCA
Session Information
- Glomerular Diseases: Immunology, Inflammation - II
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Agosto-Burgos, Christian, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Herrera, Carolina A., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Jones, Britta E., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Starmer, Joshua, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Bass, William, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Poulton, Caroline J., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Blazek, Lauren N., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Henderson, Candace Dione, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Hu, Yichun, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Hogan, Susan L., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Hu, Peiqi, Univeristy of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Xiao, Hong, Univeristy of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Jennette, J. Charles, Univeristy of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Free, Meghan E., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Falk, Ronald J., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Ciavatta, Dominic J., University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
Background
Neutrophils are a heterogenous cell population, a primary source of expression of autoantigen genes in ANCA vasculitis, and central to the pathology of ANCA vasculitis; however, it is unclear the impact neutrophil heterogeneity and expression has on disease pathology.
Methods
Low-density neutrophils (LDNs) and normal-density neutrophils (NDNs) were isolated from peripheral blood of 137 ANCA vasculitis patients and 54 healthy controls (HC). Expression of MPO and PRTN3 was measured by quantitative RT-PCR. LDNs were immunophenotyped by flowcytometry. Oxidative burst in response to MPO-ANCA was measured with dihydrorhodamine assay in LDNs and NDNs without in vitro priming.
Results
Increased MPO and PRTN3 expression was detected in LDNs and NDNs from patients during active disease compared to HC, with the largest difference in LDNs. Surface markers CD10 and CD15 revealed LDNs contained mature and immature neutrophils; both contributed to autoantigen expression. The frequency of LDN subtypes was similar between HC and patients regardless of disease activity. The frequency of immature LDNs did not correlate with MPO or PRTN3 expression in LDNs. LDNs were refractory to MPO-ANCA induced oxidative burst, while MPO-ANCA induced robust activation of NDNs, that correlated with MPOexpression.
Conclusion
LDNs may be a bystander of chronic inflammation or contribute to alternative mechanisms of disease pathology. In NDNs the association between MPO gene expression and MPO-ANCA induced NDN activation argues autoantigen gene expression influences disease pathogenesis and a therapeutic strategy could be suppressing expression.
Oxidative burst in LDNs (left) and NDNs (right) from ANCA vasculitis patients. Histograms show DHR fluorescence following activation with HC IgG (organge), MPO-ANCA IgG (purple), or PMA (green).
Funding
- NIDDK Support