Age-Associated Decrease in TLR Function in Primary Human Dendritic Cells Predicts Influenza Vaccine Response

Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06520, USA.
The Journal of Immunology (Impact Factor: 4.92). 03/2010; 184(5):2518-27. DOI: 10.4049/jimmunol.0901022
Source: PubMed


We evaluated TLR function in primary human dendritic cells (DCs) from 104 young (age 21-30 y) and older (> or =65 y) individuals. We used multicolor flow cytometry and intracellular cytokine staining of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) and found substantial decreases in older compared with young individuals in TNF-alpha, IL-6, and/or IL-12 (p40) production in mDCs and in TNF-alpha and IFN-alpha production in pDCs in response to TLR1/2, TLR2/6, TLR3, TLR5, and TLR8 engagement in mDCs and TLR7 and TLR9 in pDCs. These differences were highly significant after adjustment for heterogeneity between young and older groups (e.g., gender, race, body mass index, number of comorbid medical conditions) using mixed-effect statistical modeling. Studies of surface and intracellular expression of TLR proteins and of TLR gene expression in purified mDCs and pDCs revealed potential contributions for both transcriptional and posttranscriptional mechanisms in these age-associated effects. Moreover, intracellular cytokine production in the absence of TLR ligand stimulation was elevated in cells from older compared with young individuals, suggesting a dysregulation of cytokine production that may limit further activation by TLR engagement. Our results provide evidence for immunosenescence in DCs; notably, defects in cytokine production were strongly associated with poor Ab response to influenza immunization, a functional consequence of impaired TLR function in the aging innate immune response.

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    • "For example, it has been reported that DCs and monocytes obtained from old subjects produced more cytokines than those form adults (Alvarez-Rodriguez et al., 2012; Hearps et al., 2012). On the other hand, others have reported no change or lower production in old compared to adult subjects (Gon et al., 1996; van Duin et al., 2007b; Panda et al., 2010). In the case of PBMCs, studies have yielded increased production of cytokines and chemokines [including CCL3, CCL5, IL-6, TNFa, and IL-1b (Fagiolo et al., 1993; Pulsatelli et al., 2000)] in the elderly population, which is contrasting to our results. "
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    ABSTRACT: Aging leads to dysregulation of multiple components of the immune system that results in increased susceptibility to infections and poor response to vaccines in the aging population. The dysfunctions of adaptive B and T cells are well documented, but the effect of aging on innate immunity remains incompletely understood. Using a heterogeneous population of peripheral blood mononuclear cells (PBMCs), we first undertook transcriptional profiling and found that PBMCs isolated from old individuals (≥ 65 years) exhibited a delayed and altered response to stimulation with TLR4, TLR7/8, and RIG-I agonists compared to cells obtained from adults (≤ 40 years). This delayed response to innate immune agonists resulted in the reduced production of pro-inflammatory and antiviral cytokines and chemokines including TNFα, IL-6, IL-1β, IFNα, IFNγ, CCL2, and CCL7. While the major monocyte and dendritic cell subsets did not change numerically with aging, activation of specific cell types was altered. PBMCs from old subjects also had a lower frequency of CD40+ monocytes, impaired up-regulation of PD-L1 on monocytes and T cells, and increased expression of PD-L2 and B7-H4 on B cells. The defective immune response to innate agonists adversely affected adaptive immunity as TLR-stimulated PBMCs (minus CD3 T cells) from old subjects elicited significantly lower levels of adult T-cell proliferation than those from adult subjects in an allogeneic mixed lymphocyte reaction (MLR). Collectively, these age-associated changes in cytokine, chemokine and interferon production, as well as co-stimulatory protein expression could contribute to the blunted memory B- and T-cell immune responses to vaccines and infections. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.
    Aging cell 02/2015; 14(3). DOI:10.1111/acel.12320 · 6.34 Impact Factor
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    • "Other investigators have challenged this conclusion and assert that viral RNA is active in the split vaccine [13]. In humans, Panda et al. identified an age-associated decrease in TLR function that can predict in vivo serological responses in SV immunized subjects [14]. It still remains unclear whether this association is causal or if the SV influenza vaccine can engage TLRs. "
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    ABSTRACT: Seasonal influenza vaccination is one of the most common medical procedures and yet the extent to which it activates the immune system beyond inducing antibody production is not well understood. In the United States, the most prevalent formulations of the vaccine consist of degraded or “split” viral particles distributed without any adjuvants. Based on previous reports we sought to determine whether the split influenza vaccine activates innate immune receptors—specifically Toll-like receptors. High-dimensional proteomic profiling of human whole-blood using Cytometry by Time-of-Flight (CyTOF) was used to compare signaling pathway activation and cytokine production between the split influenza vaccine and a prototypical TLR response ex vivo. This analysis revealed that the split vaccine rapidly and potently activates multiple immune cell types but yields a proteomic signature quite distinct from TLR activation. Importantly, vaccine induced activity was dependent upon the presence of human sera indicating that a serum factor was necessary for vaccine-dependent immune activation. We found this serum factor to be human antibodies specific for influenza proteins and therefore immediate immune activation by the split vaccine is immune-complex dependent. These studies demonstrate that influenza virus “splitting” inactivates any potential adjuvants endogenous to influenza, such as RNA, but in previously exposed individuals can elicit a potent immune response by facilitating the rapid formation of immune complexes.
    Vaccine 10/2014; 32(45). DOI:10.1016/j.vaccine.2014.07.115 · 3.62 Impact Factor
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    • "Age-associated dysregulation of TLR signaling has been reported to contribute to the increased morbidity and mortality from infectious diseases found in geriatric patients [40], [41]. γδ T cells are also known to display numerical and functional alteration with aging [37], [42]–[44]. "
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    ABSTRACT: γδ T cells express several different toll-like receptor (TLR)s. The role of MyD88- dependent TLR signaling in TCR activation of murine γδ T cells is incompletely defined. Here, we report that Pam3CSK4 (PAM, TLR2 agonist) and CL097 (TLR7 agonist), but not lipopolysaccharide (TLR4 agonist), increased CD69 expression and Th1-type cytokine production upon anti-CD3 stimulation of γδ T cells from young adult mice (6-to 10-week-old). However, these agonists alone did not induce γδ T cell activation. Additionally, we noted that neither PAM nor CL097 synergized with anti-CD3 in inducing CD69 expression on γδ T cells of aged mice (21-to 22-month-old). Compared to young γδ T cells, PAM and CL097 increased Th-1 type cytokine production with a lower magnitude from anti-CD3- stimulated, aged γδ T cells. Vγ1+ and Vγ4+ cells are two subpopulations of splenic γδ T cells. PAM had similar effects in anti-CD3-activated control and Vγ4+ subset- depleted γδ T cells; whereas CL097 induced more IFN-γ production from Vγ4+ subset-depleted γδ T cells than from the control group. Finally, we studied the role of MyD88-dependent TLRs in γδ T cell activation during West Nile virus (WNV) infection. γδ T cell, in particular, Vγ1+ subset expansion was significantly reduced in both MyD88- and TLR7- deficient mice. Treatment with TLR7 agonist induced more Vγ1+ cell expansion in wild-type mice during WNV infection. In summary, these results suggest that MyD88-dependent TLRs provide co-stimulatory signals during TCR activation of γδ T cells and these have differential effects on distinct subsets.
    PLoS ONE 09/2014; 9(9):e108156. DOI:10.1371/journal.pone.0108156 · 3.23 Impact Factor
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