Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Mar 2;12(3):e0173161.
doi: 10.1371/journal.pone.0173161. eCollection 2017.

Early type I Interferon response induces upregulation of human β-defensin 1 during acute HIV-1 infection

Björn Corleis  1 , Antonella C Lisanti  1 , Christian Körner  1 , Abigail E Schiff  1 , Eric S Rosenberg  2 , Todd M Allen  1 , Marcus Altfeld  1 , Douglas S Kwon  1   2
Affiliations

Early type I Interferon response induces upregulation of human β-defensin 1 during acute HIV-1 infection

Björn Corleis et al. PLoS One. .

Abstract

HIV-1 is able to evade innate antiviral responses during acute infection to establish a chronic systemic infection which, in the absence of antiretroviral therapy (ART), typically progresses to severe immunodeficiency. Understanding these early innate immune responses against HIV-1 and their mechanisms of failure is relevant to the development of interventions to better prevent HIV-1 transmission. Human beta defensins (HBDs) are antibacterial peptides but have recently also been associated with control of viral replication. HBD1 and 2 are expressed in PBMCs as well as intestinal tissue, but their expression in vivo during HIV-1 infection has not been characterized. We demonstrate that during acute HIV-1 infection, HBD1 but not HBD2 is highly upregulated in circulating monocytes but returns to baseline levels during chronic infection. HBD1 expression in monocytes can be induced by HIV-1 in vitro, although direct infection may not entirely account for the increase in HBD1 during acute infection. We provide evidence that HIV-1 triggers antiviral IFN-α responses, which act as a potent inducer of HBD1. Our results show the first characterization of induction of an HBD during acute and chronic viral infection in humans. HBD1 has been reported to have low activity against HIV-1 compared to other defensins, suggesting that in vivo induced defensins may not significantly contribute to the robust early antiviral response against HIV-1. These data provide important insight into the in vivo kinetics of HBD expression, the mechanism of HBD1 induction by HIV-1, and the role of HBDs in the early innate response to HIV-1 during acute infection.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. HBD1 is upregulated in PBMCs during acute HIV-1 infection.
Samples from HIV-1 uninfected (HIV-), HIV-1 untreated chronic progressors (PG), HIV-1 chronic ART treated (CT) and acutely HIV-1 infected (Acute) individuals were analyzed for HBD1 expression. HBD1 transcription in PBMCs (A, B) or gut pinch biopsies (C, D) was determined by qPCR. Grey color indicates subjects with matched gut biopsy samples. (A) HBD1 expression in blood of acutely infected subjects (n = 32) was found to be significantly higher compared to HIV-1 individuals from PG (n = 8), CT (n = 9) or HIV- (n = 17) subjects (Kruskal-Wallis and Dunn’s multiple comparison test with error bars indicate min and max of boxplots). (B) Longitudinal sampling of individuals (n = 10) showed significant downregulation of HBD1 in chronic HIV-1 infection compared to acute infection (Wilcoxon matched-pairs signed rank test). (C, D) No significant differences in HBD1 expression in ileum (C) or colon (D) was found between HIV- (n = 5), PG (n = 4), CT (n = 9) and HIV acute infected subjects (n = 4), (Kruskal-Wallis and Dunn’s multiple comparison test and median with interquartile range).
Fig 2
Fig 2. HBD1 is expressed by circulating monocytes and gut epithelial cells.
(A, B) Cells were sorted from 5 different bulk colon excess tissue (n = 5) or PBMCs (n = 5), RNA extracted and HBD1 transcription quantified by qPCR. For colon, epithelial cells were identified using the surface marker CD326 and CD45 (S2 Fig). For PBMCs, monocytes were identified as CD14+, DCs as CD11c+ (mDCs) or CD123+ (pDCs) and lymphocytes as CD3+CD19+ (S2 Fig). Epithelial cells were the main producers of HBD1 in colon whereas CD14+ cells were the main producers in PBMCs. (C, D) The frequency of HBD1 producing cells is not altered during acute infection. Frequency of monocytes (C) and DC (D) populations in PMBCs from HIV-1- (n = 9) or acutely (Acute; n = 8) infected individuals was determined by flow cytometry. Conventional monocytes were identified as CD14+ CD16-, inflammatory monocytes as CD14+ CD16+ and mDCs as well as pDCs as described above (S2 Fig). No significant difference in cell frequencies was found between HIV-1- and sample from subjects with acute HIV-1 infection for any of the analyzed cell populations (Kruskal-Wallis and Dunn’s multiple post comparison test). (A-D) Data points are presented with median and interquartile range.
Fig 3
Fig 3. HIV-1 induces HBD1 in vitro but is unlikely to be sufficient in vivo.
(A-C) CD14+ monocytes isolated using Miltenyi MACS technology were incubated with either HIV-1 R5, poly I:C (TLR3 ligand), 5’ppp-dsRNA (RIG-I ligand), R837 (TLR7 ligand), LPS (TLR4 ligand) or FLA-ST (TLR5 ligand), or left untreated. After 24 h cells were harvested and RNA extracted. Relative expression of HBD1 (A, C) or HBD2 (B) was assessed using quantitative PCR. HBD1 expression was found to be significantly increased in monocytes when incubated with HIV-1 R5, poly I:C or 5’pppdsRNA (A), whereas LPS and FLA-ST induced HBD2 (B). (C) Significant upregulation of HBD1 by HIV-1 was only achieved at 1x10^6 infection HIV-1 particles (i.p.) (Kruskal-Wallis and Dunn’s multiple post comparison test). Data points are presented with median and interquartile range which each dot representing an independent experiment from a different healthy control subject. (D) HBD1 transcription in PBMCs of subjects with acute HIV-1 infection (Fig 1A) was plotted against the corresponding viral load which each dot representing one subject. No significant correlation was found between viral load and HBD1 transcription (Spearman r correlation). (E, F) CD4+ T cells or CD14+ monocytes were isolated from PBMCs and incubated with either β-lactamase packaged HIV-1 X4 (CXCR4 tropic)/ HIV-1 R5 (CCR5 tropic) or left untreated. Where indicated cells were pre-treated with the CCR5 antagonist maraviroc (Mav) for 30min before HIV-1 treatment. All virus contained Vpr-BlaM which allowed assessment of HIV-1 entry into cells 12h after exposure. The highest entry was observed in CD4+ T cells by HIV-1 X4, whereas HIV-1 R5 entered CD4+ T cells as well CD14+ monocytes at low frequency. The graph shows the median and interquartile range with each dot representing one independent experiment from a different healthy control subject (F).
Fig 4
Fig 4. IFN-α is a potent inducer of HBD1 in monocytes in vitro and correlates with HBD1 transcription in vivo.
(A, B) CD14+ monocytes (A n = 11 and B n = 5) were isolated from PBMCs and incubated with different concentrations of recombinant IFN-α2 or left untreated. Where indicated cells were treated with either an anti-IFN-α or an isotype control antibody 30 min before stimulation with 50 pg/ml recombinant IFN-α2. Relative expression of HBD1 and ISG15 was assessed using quantitative PCR. IFN-α2 was found to significantly upregulate HBD1 and ISG15. Each dot represents one independent experiment from a different healthy control subject. (C, D) Human PBMCs were isolated from whole blood from HIV-1 uninfected (HIV-) (C n = 5, D n = 9), HIV-1 untreated chronic progressors (PG) (C n = 9, D n = 14) and acutely HIV-1 infected (Acute) individuals (C n = 12, D n = 15). IFNα (IFNA) transcription of PBMCs was assessed by qPCR. IFNA and ISG15 were both significantly upregulated in acutely but not chronically infected subjects compared to HIV-uninfected control subjects (A-D) Kruskal-Wallis and Dunn’s multiple comparison test with graphs showing median and interquartile range. (E, F) HBD1 transcription in PBMCs of subjects with acute HIV-1 infection (Fig 1A) was plotted against the corresponding transcription of IFNA (E) or ISG15 (F) with each dot representing one subject. ISG15 and IFNA were found to significantly correlate with HBD1 transcription in acutely infected individuals (Spearman r correlation).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Hazlett L, Wu M. Defensins in innate immunity. Cell Tissue Res. 2011;343(1):175–88. Epub 2010/08/24. 10.1007/s00441-010-1022-4 - DOI - PubMed
    1. Wiesner J, Vilcinskas A. Antimicrobial peptides: the ancient arm of the human immune system. Virulence. 2010;1(5):440–64. Epub 2010/12/24. 10.4161/viru.1.5.12983 - DOI - PubMed
    1. Cederlund A, Gudmundsson GH, Agerberth B. Antimicrobial peptides important in innate immunity. Febs J. 2011;278(20):3942–51. Epub 2011/08/19. 10.1111/j.1742-4658.2011.08302.x - DOI - PubMed
    1. Yang D, Biragyn A, Hoover DM, Lubkowski J, Oppenheim JJ. Multiple roles of antimicrobial defensins, cathelicidins, and eosinophil-derived neurotoxin in host defense. Annu Rev Immunol. 2004;22:181–215. Epub 2004/03/23. 10.1146/annurev.immunol.22.012703.104603 - DOI - PubMed
    1. Ganz T. The role of antimicrobial peptides in innate immunity. Integr Comp Biol. 2003;43(2):300–4. Epub 2003/04/01. 10.1093/icb/43.2.300 - DOI - PubMed
-