Faculty Opinions recommendation of Interleukin 15-dependent crosstalk between conventional and plasmacytoid dendritic cells is essential for CpG-induced immune activation.

Abstract Despite optimal suppression of HIV replication, restoration of CD4+ T cells is not always achieved in antiretroviral therapy–treated individuals. Defective CD4 recovery in immunologic nonresponders is possibly associated with TLR-mediated immune activation driven by alterations of gut permeability. Hydroxychloroquine (HCQ) reduces endosomal TLR signaling; thus, we verified whether HCQ could dampen immune activation and be associated with an increase in CD4+ T cells. To this end, we enrolled in a prospective study 20 HIV-infected immunologic nonresponders (CD4 count < 200 cells/mL or CD4 increase < 5% in the last 12 months) who received 400 mg/day HCQ for 6 months. HCQ had a notable impact on immune activation as shown by significant modifications of the following parameters: (1) reduced plasma lipopolysaccharide; (2) decreased TLR4-expressing CD14+ cells, TLR4-mediated signal transduction, and mRNA synthesis; (3) reduced percentages of activated CD4+ (CD4+/Ki67+) and CD14+ (CD14+/CD69+) cells; (4) increased T-regulatory cells (Tregs), naive Tregs, and TLR4-expressing Tregs; (5) augmented plasmacytoid dendritic cells and reduced IFNα-secreting plasmacytoid dendritic cells; and (6) reduced IL-6 and TNFα production. HCQ-induced immune modulation was associated with increased percentages of circulating CD4+ T cells and was mostly retained 2 months after therapy interruption. HCQ reduces lipopolysaccharide/TLR-mediated immune activation; this compound could be a useful immunomodulant in HIV-infected patients. This study is registered at EutraCT as 2009-012499-28 with study number HLS01/2009-1-16-03-2009.

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An Imbalance of Two Functionally and Phenotypically Different Subsets of Plasmacytoid Dendritic Cells Characterizes the Dysfunctional Immune Regulation in Multiple Sclerosis

Yearbook of Neurology and Neurosurgery ◽

10.1016/j.yneu.2010.12.026 ◽

2011 ◽

Vol 2011 ◽

pp. 94

Author(s):

A. Minagar

Keyword(s):

Multiple Sclerosis ◽

Dendritic Cells ◽

Immune Regulation ◽

Plasmacytoid Dendritic Cells

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Decision letter for "cDC2 and plasmacytoid dendritic cells diminish from tissues of patients with non‐Hodgkin orbital lymphoma and idiopathic orbital inflammation"

10.1002/eji.201948370/v1/decision1 ◽

2019 ◽

Keyword(s):

Dendritic Cells ◽

Plasmacytoid Dendritic Cells ◽

Orbital Inflammation ◽

Idiopathic Orbital Inflammation ◽

Orbital Lymphoma

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Decision letter for "CD49d/CD29‐integrin controls the accumulation of plasmacytoid dendritic cells into the CNS during neuroinflammation"

10.1002/eji.201948086/v2/decision1 ◽

2019 ◽

Keyword(s):

Dendritic Cells ◽

Plasmacytoid Dendritic Cells

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Decision letter for "CD49d/CD29‐integrin controls the accumulation of plasmacytoid dendritic cells into the CNS during neuroinflammation"

10.1002/eji.201948086/v1/decision1 ◽

2019 ◽

Keyword(s):

Dendritic Cells ◽

Plasmacytoid Dendritic Cells

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PLASMACYTOID DENDRITIC CELLS FUNCTION IN HIV INFECTION

Clinical & Investigative Medicine ◽

10.25011/cim.v31i4.4808 ◽

2008 ◽

Vol 31 (4) ◽

pp. 13

Author(s):

Martin Hyrcza ◽

Mario Ostrowski ◽

Sandy Der

Keyword(s):

Dendritic Cells ◽

Influenza Virus ◽

Hiv Infection ◽

Gene Transcription ◽

Sendai Virus ◽

Plasmacytoid Dendritic Cells ◽

Type I Interferons ◽

Interferon Response ◽

Type I ◽

Type I Ifn

Plasmacytoid dendritic cells (pDCs) are innate immune cells able to produce large quantities of type I interferons (IFN) when activated. Human immunodeficiency virus (HIV)-infected patients show generalized immune dysfunction characterized in part by chronic interferon response. In this study we investigated the role of dendritic cells inactivating and maintaining this response. Specifically we compared the IFN geneactivity in pDCs in response to several viruses and TLR agonists. We hypothesized that 1) the pattern of IFN gene transcription would differ in pDCs treated with HIV than with other agents, and 2) that pDCs from patients from different stages of disease would respond differently to the stimulations. To test these hypotheses, we obtained pDCs from 15 HIV-infected and uninfected individuals and treated freshly isolated pDCs with either HIV (BAL strain), influenza virus (A/PR/8/34), Sendai virus (Cantell strain), TLR7 agonist(imiquimod), or TLR9 agonist (CpG-ODN) for 6h. Type I IFN gene transcription was monitored by real time qPCRfor IFNA1, A2, A5, A6, A8,A17, B1, and E1, and cytokine levels were assayed by Cytometric Bead Arrays forTNF?, IL6, IL8, IL10, IL1?, and IL12p70. pDC function as determined by these two assays showed no difference between HIV-infected and uninfected patients or between patients with early or chronic infection. Specifically, HIV did notinduce type I IFN gene expression, whereas influenza virus, Sendai virus and imiquimod did. Similarly, HIV failed to induce any cytokine release from pDCs in contrast to influenza virus, Sendai virus and imiquimod, which stimulatedrelease of TNF?, IL6, or IL8. Together these results suggest that the reaction of pDCs to HIV virus is quantitatively different from the response to agents such as virus, Sendai virus, and imiquimod. In addition, pDCs from HIV-infected persons have responses similar to pDCs from uninfected donors, suggesting, that the DC function may not be affected by HIV infection.

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