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Toll like receptor (TLR) ligands are important adjuvant candidates, causing antigen presenting cells to release inflammatory mediators, leading to the recruitment and activation of other leukocytes. The aim of this study was to define the response of human blood derived dendritic cells and macrophages to three TLR ligands acting singly or in combination, Poly I:C (TLR3), GLA (TLR4) and R848 (TLR7/8). Combinations of TLR agonists have been shown to have a synergistic effect on individual cytokines, here we look at the global inflammatory response measuring both cytokines and chemokines. Using a custom Luminex assay we saw dose responses in several mediators including CCL3 (MIP1α), IL-1α, IL-1β, IL-12, CXCL10 (IP-10) and IL-6, all of which were significantly increased by the combination of R848 and GLA, even when low dose GLA was added. The synergistic effect was inhibited by specific MAP kinase inhibitors blocking the kinases p38 and JNK but not MEK1. Combining TLR adjuvants also had a synergistic effect on cytokine responses in human mucosal tissue explants. From this we conclude that the combination of R848 and GLA potentiates the inflammatory profile of antigen presenting cells. Since the pattern of inflammatory mediators released can alter the quality and quantity of the adaptive immune response to vaccination, this study informs vaccine adjuvant design.

Age affects the immune response to vaccination, with individuals at the extremes of age responding poorly. The initial inflammatory response to antigenic materials shapes the subsequent adaptive response and so understanding is required about the effect of age on the profile of acute inflammatory mediators. In this study we measured the local and systemic inflammatory response after influenza vaccination or infection in neonatal, young adult and aged mice. Mice were immunized intramuscularly with inactivated influenza vaccine with and without the adjuvant MF59 and then challenged with H1N1 influenza. Age was the major factor affecting the inflammatory profile after vaccination: neonatal mice had more interleukin-1α (IL-1α), C-reactive protein (CRP) and granulocyte-macrophage colony-stimulating factor (GMCSF), young adults more tumour necrosis factor-α (TNF), and elderly mice more interleukin-1 receptor antagonist (IL-1RA), IL-2RA and interferon-γ-induced protein 10 (IP10). Notably the addition of MF59 induced IL-5, granulocyte colony-stimulating factor (G-CSF), Keratinocyte Chemotractant (KC) and monocyte chemoattractant protein 1 (MCP1) in all ages of animals and levels of these cytokines correlated with antibody responses. Age also had an impact on the efficacy of vaccination: neonatal and young adult mice were protected against challenge, but aged mice were not. There were striking differences in the localization of the cytokine response depending on the route of exposure: vaccination led to a high serum response whereas intranasal infection led to a low serum response but a high lung response. In conclusion, we demonstrate that age affects the inflammatory response to both influenza vaccination and infection. These age-induced differences need to be considered when developing vaccination strategies for different age groups.

The small hydrophobic (SH) gene of respiratory syncytial virus (RSV), a major cause of infant hospitalization, encodes a viroporin of unknown function. SH gene knockout virus (RSV ΔSH) is partially attenuated in vivo , but not in vitro , suggesting that the SH protein may have an immunomodulatory role. RSV ΔSH has been tested as a live attenuated vaccine in humans and cattle, and here we demonstrate that it protected against viral rechallenge in mice. We compared the immune response to infection with RSV wild type and RSV ΔSH in vivo using BALB/c mice and in vitro using epithelial cells, neutrophils, and macrophages. Strikingly, the interleukin-1β (IL-1β) response to RSV ΔSH infection was greater than to wild-type RSV, in spite of a decreased viral load, and when IL-1β was blocked in vivo , the viral load returned to wild-type levels. A significantly greater IL-1β response to RSV ΔSH was also detected in vitro , with higher-magnitude responses in neutrophils and macrophages than in epithelial cells. Depleting macrophages (with clodronate liposome) and neutrophils (with anti-Ly6G/1A8) demonstrated the contribution of these cells to the IL-1β response in vivo , the first demonstration of neutrophilic IL-1β production in response to viral lung infection. In this study, we describe an increased IL-1β response to RSV ΔSH, which may explain the attenuation in vivo and supports targeting the SH gene in live attenuated vaccines. IMPORTANCE There is a pressing need for a vaccine for respiratory syncytial virus (RSV). A number of live attenuated RSV vaccine strains have been developed in which the small hydrophobic (SH) gene has been deleted, even though the function of the SH protein is unknown. The structure of the SH protein has recently been solved, showing it is a pore-forming protein (viroporin). Here, we demonstrate that the IL-1β response to RSV ΔSH is greater in spite of a lower viral load, which contributes to the attenuation in vivo . This potentially suggests a novel method by which viruses can evade the host response. As all Pneumovirinae and some Paramyxovirinae carry similar SH genes, this new understanding may also enable the development of live attenuated vaccines for both RSV and other members of the Paramyxoviridae .

Background Knowledge of the oncogenic signaling pathways of T-cell acute lymphoblastic leukemia (T-ALL) remains limited. Constitutive aberrant activation of the nuclear factor kappa B (NF-κB) signaling pathway has been detected in various lymphoid malignancies and plays a key role in the development of these carcinomas. The zinc finger-containing protein, A20, is a central regulator of multiple NF-κB-activating signaling cascades. A20 is frequently inactivated by deletions and/or mutations in several B-and T-cell lymphoma subtypes. However, few A20 mutations and polymorphisms have been reported in T-ALL. Thus, it is of interest to analyze the expression characteristics of A20 and its regulating factors, including upstream regulators and the CBM complex, which includes CARMA1, BCL10, and MALT1. Methods The expression levels of CARMA1, BCL10, MALT1, A20, and NF-κB were detected in peripheral blood mononuclear cells (PBMCs) from 21 patients with newly diagnosed T-ALL using real-time PCR, and correlations between the aberrant expression of these genes in T-ALL was analyzed. Sixteen healthy individuals, including 10 males and 6 females, served as controls. Results Significantly lower A20 expression was found in T-ALL patients (median: 4.853) compared with healthy individuals (median: 8.748; P = 0.017), and significantly increased expression levels of CARMA1 (median: 2.916; P = 0.034), BCL10 (median: 0.285; P = 0.033), and MALT1 (median: 1.201; P = 0.010) were found in T-ALL compared with the healthy individuals (median: 1.379, 0.169, and 0.677, respectively). In contrast, overexpression of NF-κB (median: 0.714) was found in T-ALL compared with healthy individuals (median: 0.335; P = 0.001). A negative correlation between the MALT1 and A20 expression levels and a positive correlation between CARMA1 and BCL10 were found in T-ALL and healthy individuals. However, no negative correlation was found between A20 and NF-κB and the MALT1 and NF-κB expression level in the T-ALL group. Conclusions We characterized the expression of the CARMA-BCL10-MALT1-A20-NF-κB pathway genes in T-ALL. Overexpression of CARMA-BCL10-MALT in T-ALL may contribute to the constitutive cleavage and inactivation of A20, which enhances NF-κB signaling and may be related to T-ALL pathogenesis.