In humans, the type I interferon (IFN) family consists of 13 IFN‐α subtypes, IFN‐β and IFN‐o the newly discovered IFN‐like family consists of IFN‐λ1, ‐λ2 and ‐λ3. We have investigated the expression of type I and λ IFN genes following virus infections or Toll‐like receptor (TLR) triggering in monocyte‐derived DC (MDDC) and plasmacytoid DC (pDC). We found thatall IFN‐α, ‐β, ‐o and ‐λ subtypes are expressed in influenza‐virus‐infected MDDC or pDC. Conversely, differential type I IFN gene transcription was induced in MDDC and pDC stimulated by specific TLR agonists. TLR‐9 stimulation by CpG DNA induced the expression of all IFN‐α, ‐β, ‐o and ‐λ subtypes in pDC, whereas TLR‐4 stimulation by LPS, or TLR‐3 stimulation bypoly I:C, induced only IFN‐β and IFN‐λ gene expression in MDDC. The expression pattern of IFN regulatory factor (IRF)‐5 and IRF‐7 in MDDC and pDC was also determined. IRF‐5 was constitutively expressed in the two DC subsets whereas IRF‐7 was constitutive in pDC but its expression was induced along MDDC maturation. Overall, our data indicate that the coordinated expression of IFN‐λ with IFN‐β would be of crucial importance for the maturation of DC.

Emerging evidence points to an important role of autophagy in the immune response mediated by dendritic cells (DC) against Mycobacterium tuberculosis (Mtb). Since current vaccination based on Bacillus Calmette-Guerin (BCG) is unable to stop the tuberculosis epidemic, a deeper comprehension of the alterations induced by Mtb in DC is essential for setting new vaccine strategies. Here, we compared the capacity of virulent (H37Rv) and avirulent (H37Ra) Mtb strains as well as BCG to modulate autophagy in human primary DC. We found that Mtb H37Rv impairs autophagy at the step of autophagosome-lysosome fusion. In contrast, neither Mtb H37Ra nor BCG strains were able to hamper autophagosome maturation. Both these attenuated strains have a functional inhibition of the 6kD early secreted antigenic target ESAT-6, an effector protein of the ESAT-6 Secretion System-1(ESX-1)/type VII secretion system. Notably, the ability to inhibit autophagy was fully restored in recombinant BCG and Mtb H37Ra strains in which ESAT-6 s...

We report a case of Zika virus infection imported in Florence, Italy ex-Thailand, leading to a secondary autochthonous case, probably through sexual transmission. The two cases occurred in May 2014 but were retrospectively diagnosed in 2016 on the basis of serological tests (plaque reduction neutralisation) performed on stored serum samples. Our report provides further evidence that sexual transmission of Zika virus is possible.

As a result of their close association with the blood-brain barrier, astrocytes play an important role in regulating the homing of different leukocyt

We recently reported that dendritic cells (DC) infected with Mycobacterium tuberculosis (Mtb) produce Th1/IFN-γ-inducing cytokines, IFN-αβ and IL-12. In the present article, we show that maturing Mtb-infected DC express high levels of CCR7 and they become responsive to its ligand CCL21. Conversely, CCR5 expression was rapidly lost from the cell surface following Mtb infection. High levels of CCL3 and CCL4 were produced within 8 h after infection, which is likely to account for the observed CCR5 down-modulation on Mtb-infected DC. In addition, Mtb infection stimulated the secretion of CXCL9 and CXCL10. Interestingly, the synthesis of CXCL10 was mainly dependent on the Mtb-induced production of IFN-αβ. Indeed, IFN-αβ neutralization down-regulated CXCL10 expression, whereas the expression of CXCL9 appeared to be unaffected. The chemotactic activity of the Mtb-infected DC supernatants was evaluated by migration assays using activated NK, CD4+, and CD8+ cells that expressed both CCR5 and CXCR3. Mtb-induced expression of CCL3, CCL4, CXCL9, and CXCL10 was involved in the stimulation of NK and T cell migration. In accordance with the data on the IFN-αβ-induced expression of CXCL10, neutralization of IFN-αβ significantly reduced the chemotactic activity of the supernatant from Mtb-infected DC. This indicates that IFN-αβ may modulate the immune response through the expression of CXCL10, which along with CXCL9, CCL3, and CCL4 participates in the recruitment and selective homing of activated/effector cells, which are known to accumulate at the site of Mtb infection and take part in the formation of the granulomas.

We report a case of laboratory-confirmed Zika virus infection imported into Europe from the Americas. The patient developed fever, rash, and oedema of hands and feet after returning to Italy from Brazil in late March 2015. The case highlights that, together with chikungunya virus and dengue virus, three major arboviruses are now co-circulating in Brazil. These arboviruses represent a burden for the healthcare systems in Brazil and other countries where competent mosquito vectors are present.