Abstract
Human plasmacytoid dendritic cells (PDC) are the major producers of type I interferons (IFN) after stimulation with CpG oligodeoxynucleotides (ODN). HIV-1-infected patients show a deficit in PDC numbers and function with progression of disease. CpG ODN appear to be attractive therapeutics to support the impaired innate immunity in HIV-1 infection. PDC counts, phenotype, and function were analyzed in 23 HIV-infected untreated individuals and 16 controls. Markers for migration (CCR7), activation (CD80), maturation (CD83), and endocytosis (BDCA2) were evaluated at baseline and 20 h after in vitro stimulation with class A, B, C, and P ODN. PDC counts and the expression of BDCA2 on these cells were significantly lower in HIV-1-infected subjects compared to controls (both p < 0.001). After stimulation with CpG ODN, CD80 and CD83 were upregulated to a similar extent in patients and controls, whereas CCR7 was upregulated more efficiently by CpG-P and CpG-C than CpG-A in HIV-1-infected individuals compared to controls. The IFN-α induction significantly differed for the CpG ODN classes (A > P > C > B) in patients and controls (p < 0.05). Functional PDC deficits in IFN-α and TNF-α induction were particularly evident in subjects with less than 500 CD4+ cells/μl. CpG-P ODNs not only induced remarkable IFN-α production in patient PBMCs, but also significantly upregulated the antibacterial and antiviral CXC chemokine IP-10. In conclusion, PDC counts, phenotype, and function are significantly impaired in HIV-1-infected subjects. Optimized P-class ODN may be effective in reversing this innate immune defect, which should be further evaluated in vivo.
Get full access to this article
View all access options for this article.
