Mouse Anti-Human CD14 Hybridoma [4D21]

Although monosodium urate (MSU) crystals are known to trigger inflammation, published data on soluble uric acid (sUA) in this context are discrepant. We hypothesized that diverse sUA preparation methods account for this discrepancy and that an animal model with clinically relevant levels of asymptomatic hyperuricemia and gouty arthritis can ultimately clarify this issue. To test this, we cultured human monocytes with different sUA preparation solutions and found that solubilizing uric acid (UA) by prewarming created erroneous results because of UA microcrystal contaminants triggering IL-1 beta release. Solubilizing UA with NaOH avoided this artifact, and this microcrystal-free preparation suppressed LPS- or MSU crystal-induced monocyte activation, a process depending on the intracellular uptake of sUA via the urate transporter SLC2A9/GLUT9. CD14(+) monocytes isolated from hyperuricemic patients were less responsive to inflammatory stimuli compared with monocytes from healthy individuals. Treatment with plasma from hyperuricemic patients impaired the inflammatory function of CD14(+) monocytes, an effect fully reversible by removing sUA from hyperuricemic plasma. Moreover, Alb-creERT2;Glut9(lox/lox) mice with hyperuricemia (serum UA of 9-11 mg/di) showed a suppressed inflammatory response to MSU crystals compared with Glut9(lox/lox) controls without hyperuricemia. Taken together, we unravel a technical explanation for discrepancies in the published literature on immune effects of sUA and identify hyperuricemia as an intrinsic suppressor of innate immunity, in which sUA modulates the capacity of monocytes to respond to danger signals. Thus, sUA is not only a substrate for the formation of MSU crystals but also an intrinsic inhibitor of MSU crystal-induced tissue inflammation.

Objectives Elite controllers (ECs), viraemic controllers (VCs), and long-term nonprogressors (LTNPs) control HIV viral replication or maintain CD4 T-cell counts without antiretroviral therapy, but may have increased cardiovascular disease (CVD) risk compared to HIV-uninfected persons. We evaluated subclinical carotid and coronary atherosclerosis and inflammatory biomarker levels among HIV controllers, LTNPs and noncontrollers and HIV-uninfected individuals in the Multicenter AIDS Cohort Study (MACS) and the Women's Interagency HIV Study (WIHS). Methods We measured carotid plaque presence and common carotid artery intima-media thickness (IMT) in 1729 women and 1308 men, and the presence of coronary artery calcium and plaque in a subgroup of men. Associations between HIV control category and carotid and coronary plaque prevalences were assessed by multivariable regression analyses adjusting for demographics and CVD risk factors. Serum inflammatory biomarker concentrations [soluble CD163 (sCD163), soluble CD14 (sCD14), galectin-3 (Gal-3), galectin-3 binding protein (Gal-3BP) and interleukin (IL)-6] were measured and associations with HIV control category assessed. Results We included 135 HIV controllers (30 ECs) and 135 LTNPs in the study. Carotid plaque prevalence and carotid IMT were similar in HIV controllers, LTNPs and HIV-uninfected individuals. HIV controllers and LTNPs had lower prevalences of carotid plaque compared to viraemic HIV-infected individuals. The prevalence of coronary atherosclerosis was similar in HIV controllers/LTNPs compared to HIV-uninfected and viraemic HIV-infected men. Controllers and LTNPs had higher concentrations of sCD163 and sCD14 compared to HIV-uninfected persons. Conclusions Subclinical CVD was similar in HIV controllers, LTNPs and HIV-uninfected individuals despite elevated levels of some inflammatory biomarkers. Future studies of HIV controllers and LTNPs are needed to characterize the risk of CVD among HIV-infected persons.