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41.
After the Second World War, in Italy Q Fever or Coxiellosis has been shown a significant relevance, a recrudescence with an epidemic state for over ten years. Later, the infectious disease occurred as endemic since the 80s, the outbreaks were just isolated. Workflows analysis of some authors has demonstrated the spread out of the infection throughout Italian herds with a prevalence ranging from 1.2 per cent to 10 per cent. Our survey carried out throughout Campania area in cattle has shown a real positivity over 14 per cent performing the IFAT for the detection of IgG antibodies for Coxiella burnetii. Therefore, it has been so important to stress the influence of cattle farming management in stables as a real risk of Coxiellosis. For example, the Relative Risk (RR) has been registrated about 6.84 (2.18相似文献   
42.
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44.

Background

Heterogeneity in B-type natriuretic peptide (BNP) levels, especially among individuals with acute heart failure with normal left ventricular ejection fraction (HFNEF), can cause confusion in interpreting results. We investigated the characteristics of cases of acute HFNEF with only modestly elevated BNP.

Methods

One hundred forty-two patients with acute or acute exacerbation of chronic HFNEF were divided into two groups by BNP level: BNP < 100 pg/ml (NB group, n = 45) and BNP ≥ 100 pg/ml (B group, n = 97). We compared clinical findings, echocardiography results, and neurohormonal factors between these two groups.

Results

In the NB group, a history of open-heart surgery (OHS) was more frequent (71% vs. 22%, p < 0.0001) and hypertension was less frequent (p = 0.0005). Left atrial diameter (LAd) was higher (p = 0.0026), while interventricular septal thickness, posterior wall thickness, relative wall thickness, left ventricular mass index were lower (p = 0.0005, p = 0.0225, p = 0.0114, p = 0.0051, respectively) in the NB group. In patients with HFNEF, a history of OHS remained an independent predictor of BNP level (< 100 pg/ml) after adjustment for hypertension, age, LAd, and interventricular septal thickness (odds ratio 3.6, p = 0.0252).

Conclusion

We found associations between acute HFNEF with less elevated BNP and a history of OHS. In a patient suspected of HFNEF, a history of OHS is considered diagnostic evidence of presence of diastolic heart failure when plasma levels of BNP are less elevated.  相似文献   
45.
Listeria monocytogenes enters non-phagocytic cells by binding its surface proteins inlA (internalin) and inlB to the host’s E-cadherin and Met, respectively. The two internalins play either separate or cooperative roles in the colonization of infected tissues. Here, we studied bacterial uptake into HeLa cells using an L. monocytogenes mutant strain (ΔinlA) carrying a deletion in the gene coding for inlA. The ΔinlA mutant strain showed the capability to invade HeLa cells. The monoclonal anti-β3- and anti-β1-integrin subunit antibodies prevented bacterial uptake into the cells, while the anti-β2- and anti-β4-integrin subunit antibodies failed to affect L. monocytogenes entry into HeLa cells. Three structurally distinct disintegrins (kistrin, echistatin and flavoridin) also inhibited bacterial uptake, showing different potencies correlated to their selective affinity for the β3- and β1-integrin subunits. In addition to inducing Met phosphorylation, infection of cells by the L. monocytogenes ΔinlA mutant strain promoted the tyrosine phosphorylation of the focal adhesion-associated proteins FAK and paxillin. Our findings provide the first evidence that β3- and β1-integrin receptors play a role in the inlB-dependent internalization of L. monocytogenes into host cells.  相似文献   
46.
Here we describe a novel vaccine vector for expressing human immunodeficiency virus (HIV) antigens. We show that recombinant attenuated yellow fever vaccine virus 17D expressing simian immunodeficiency virus SIVmac239 Gag sequences can be used as a vector to generate SIV-specific CD8+ T-cell responses in the rhesus macaque. Priming with recombinant BCG expressing SIV antigens increased the frequency of these SIV-specific CD8+ T-cell responses after recombinant YF17D boosting. These recombinant YF17D-induced SIV-specific CD8+ T cells secreted several cytokines, were largely effector memory T cells, and suppressed viral replication in CD4+ T cells.None of the vaccine regimens tested in human immunodeficiency virus (HIV) vaccine efficacy trials to date have either reduced the rate of HIV infection or reduced the level of HIV replication. Structural features and the enormous variability of the envelope glycoprotein have frustrated efforts to induce broadly reactive neutralizing antibodies against HIV (10). Investigators have therefore focused their attention on T-cell-based vaccines (40). Simian immunodeficiency virus (SIV) challenge of rhesus macaques vaccinated with T-cell-based vaccines has shown that it is possible to control virus replication after SIV infection (22, 41, 42). The recent STEP trial of a recombinant Ad5-vectored vaccine was widely seen as an important test of this concept (http://www.hvtn.org/media/pr/step111307.html) (9, 25). Unfortunately, vaccinees became infected at higher rates than the controls (9). While it is still not clear what caused the enhanced infection rate in the vaccinated group, future Ad5-based human vaccine trials may be difficult to justify. We therefore need to develop new vaccine vectors for delivering SIV and HIV genes. Several other viral vectors currently under consideration include nonreplicating adenovirus (Ad)-based vectors (1, 21, 22), Venezuelan equine encephalitis (VEE) virus (12, 20), adeno-associated virus (AAV) (19), modified vaccinia virus Ankara (MVA) (3, 4, 13, 15, 18, 38), NYVAC (6), cytomegalovirus (CMV) (16), and replicating Ad (30). However, only a few of these have shown promise in monkey trials using rigorous SIV challenges.We explored whether the small (11-kb) yellow fever vaccine flavivirus 17D (YF17D) might be a suitable vector for HIV vaccines. The YF17D vaccine is inexpensive, production and quality control protocols already exist, and it disseminates widely in vivo after a single dose (27). Importantly, methods for the manipulation of the YF17D genome were recently established (7, 8, 24, 28). This effective vaccine has been safely used on >400 million people in the last 70 years (27). Additionally, the YF17D strain elicits robust CD8+ T-cell responses in humans (26). Chimeric YF17D is presently being developed as a vaccine for other flaviviruses, such as Japanese encephalitis virus (28), dengue virus (14), and West Nile virus (29). Inserts expressing a malaria B-cell epitope have been engineered into the E protein of YF17D (7). In murine models, recombinant YF17D viruses have generated robust and specific responses to engineered antigens inserted between the 2B and NS3 proteins in vivo (24, 35).We first used the YF17D vaccine virus to infect four Mamu-A*01-positive macaques. The vaccine virus replicated in these four animals and induced neutralizing antibodies in all four macaques by 2 weeks postvaccination (Fig. 1A and B). To monitor the CD8+ T-cell immune response against YF17D, we scanned its proteome for peptides that might bind to Mamu-A*01 using the major histocompatibility complex (MHC) pathway algorithm (31). We synthesized the 52 YF17D-derived peptides most likely to bind to Mamu-A*01 based on their predicted affinity for this MHC class I molecule. We then used a gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) assay to screen these peptides in YF17D-immunized animals at several time points after vaccination and discovered that four Mamu-A*01-binding peptides, LTPVTMAEV (LV91285-1293), VSPGNGWMI (VI93250-3258), MSPKGISRM (MM92179-2187), and TTPFGQQRVF (TF102853-2862), were recognized in vivo (Fig. (Fig.1C).1C). Using a previously reported protocol (26), we also observed CD8+ T-cell activation in all four animals (Fig. 1D and E). Thus, as was observed previously, the YF17D vaccine virus replicates in Indian rhesus monkeys (36) and induces neutralizing antibodies, yellow fever 17D-specific Mamu-A*01-restricted CD8+ T-cell responses, and CD8+ T-cell activation.Open in a separate windowFIG. 1.YF17D replicates and induces neutralizing antibodies, virus-specific CD8+ T cells, and the activation of CD8+ T cells in rhesus macaques. (A) Replication of YF17D during the first 10 days after vaccination with two different doses, as measured by quantitative PCR (Q-PCR) using the following primers: forward primer YF-17D 10188 (5′-GCGGATCACTGATTGGAATGAC-3′), reverse primer YF-17D 10264 (5′-CGTTCGGATACGATGGATGACTA-3′), and probe 6-carboxyfluorescein (6Fam)-5′-AATAGGGCCACCTGGGCCTCCC-3′-6-carboxytetramethylrhodamine (TamraQ). (B) Titer of neutralizing antibodies determined at 2 and 5 weeks after YF17D vaccination. (C) Fresh PBMC from vaccinees (100,000 cells/well) were used in IFN-γ ELISPOT assays (41) to assess T-cell responses against YF17D. We used 4 epitopes (LTPVTMAEV [LV91285-1293], VSPGNGWMI [VI93250-3258], MSPKGISRM [MM92179-2187], and TTPFGQQRVF [TF102853-2862]) predicted to bind to Mamu-A*01 as defined by the MHC pathway algorithm (31). All IFN-γ ELISPOT results were considered positive if they were ≥50 SFC/106 PBMC and ≥2 standard deviations over the background. (D) Identification of activated CD8+ T cells after vaccination with YF17D based on the expression of the proliferation and proapoptotic markers Ki-67 and Bcl-2, respectively (26). We stained whole blood cells with antibodies against CD3 and CD8. We then permeabilized and subsequently labeled these cells with Bcl-2- and Ki-67-specific antibodies. The flow graphs were gated on CD3+ CD8+ lymphocytes. (E) Expression kinetics of Ki-67 and Bcl-2 in CD8+ T cells after vaccination with YF17D.We next engineered the YF17D vaccine virus to express amino acids 45 to 269 of SIVmac239 Gag (rYF17D/SIVGag45-269) by inserting a yellow fever codon-optimized sequence between the genes encoding the viral proteins E and NS1. This recombinant virus replicated and induced neutralizing antibodies in mice (data not shown). We then tested the rYF17D/SIVGag45-269 construct in six Mamu-A*01-positive Indian rhesus macaques. We found evidence for the viral replication of rYF17D/SIVGag45-269 for five of these six macaques (Fig. (Fig.2A).2A). However, neutralizing antibodies were evident for all six animals at 2 weeks postvaccination (Fig. (Fig.2B).2B). Furthermore, all animals developed SIV-specific CD8+ T cells after a single immunization with rYF17D/SIVGag45-269 (Fig. (Fig.2C).2C). To test whether a second dose of this vaccine could boost virus-specific T-cell responses, we administered rYF17D/SIVGag45-269 (2.0 × 105 PFU) to four macaques on day 28 after the first immunization and monitored cellular immune responses. With the exception of animal r04091, the rYF17D/SIVGag45-269 boost did not increase the frequency of the vaccine-induced T-cell responses. This recombinant vaccine virus also induced CD8+ T-cell activation in the majority of the vaccinated animals (Fig. (Fig.2D2D).Open in a separate windowFIG. 2.rYF17D/SIVGag45-269 replicates and induces neutralizing antibodies, virus-specific CD8+ T cells, and the activation of CD8+ T cells in rhesus macaques. (A) Replication of rYF17D/SIVGag45-269 during the first 10 days after vaccination with two different doses as measured by Q-PCR using the YF17D-specific primers described in the legend of Fig. Fig.1.1. (B) Titer of neutralizing antibodies determined at 2 and 5 weeks after rYF17D/SIVGag45-269 vaccination. The low levels of neutralization for animal r02013 were observed in three separate assays. (C) Fresh PBMC from vaccinees (100,000 cells/well) were used in IFN-γ ELISPOT assays to assess T-cell responses against the YF17D vector (red) and the SIV Gag(45-269) insert (black) at several time points postvaccination. We measured YF17D-specific responses using the same epitopes described in the legend of Fig. Fig.1.1. For SIV Gag-specific responses, we used 6 pools of 15-mers overlapping by 11 amino acids spanning the entire length of the SIVmac239 Gag insert. In addition, we measured Mamu-A*01-restricted responses against the dominant Gag181-189CM9 and subdominant Gag254-262QI9 epitopes. Four animals received a second dose of rYF17D/SIVGag45-269 on day 28 after the first vaccination (dashed line). (D) Expression kinetics of Ki-67 and Bcl-2 in CD8+ T cells after vaccination with rYF17D/SIVGag45-269. This assay was performed as described in the legend of Fig. Fig.11.We could not detect differences in vaccine-induced immune responses between the group of animals vaccinated with YF17D and the group vaccinated with rYF17D/SIVGag45-269. There was, however, considerable animal-to-animal variability. Animal r02034, which was vaccinated with YF17D, exhibited massive CD8+ T-cell activation (a peak of 35% at day 14) (Fig. (Fig.1E),1E), which was probably induced by the high levels of viral replication (16,800 copies/ml at day 5) (Fig. (Fig.1A).1A). It was difficult to see differences between the neutralizing antibody responses induced by YF17D and those induced by rYF17D/SIVGag45-269 (Fig. (Fig.1B1B and and2B).2B). However, neutralizing antibodies in animal r02013 decreased by 5 weeks postvaccination. It was also difficult to detect differences in the YF17D-specific CD8+ T-cell responses induced by these two vaccines. Peak Mamu-A*01-restricted CD8+ T-cell responses against YF17D ranged from barely detectable (animal r02110 at day 11) (Fig. (Fig.1C)1C) to 265 spot-forming cells (SFCs)/106 peripheral blood mononuclear cells (PBMC) (animal r02034 at day 28) (Fig. (Fig.1C).1C). Similarly, three of the rYF17D/SIVGag45-269-vaccinated animals (animals r04091, r04051, and r02013) made low-frequency CD8+ T-cell responses against the Mamu-A*01-bound YF17D peptides, whereas the other three animals (animals r03130, r02049, and r02042) recognized these epitopes with responses ranging from 50 to 200 SFCs/106 PBMC (Fig. (Fig.2C).2C). For almost every rYF17D/SIVGag45-269-vaccinated animal, the Gag181-189CM9-specific responses (range, 50 to 750 SFCs/106 PBMC) were higher than those generated against the Mamu-A*01-restricted YF17D epitopes (range, 0 to 175 SFCs/106 PBMC), suggesting that the recombinant virus replicated stably in vivo (Fig. (Fig.2C).2C). Thus, the recombinant YF17D virus replicated and induced both virus-specific neutralizing antibodies and CD8+ T cells that were not demonstrably different from those induced by YF17D alone.Most viral vectors are usually more efficient after a prime with DNA or recombinant BCG (rBCG) (4, 11, 15, 18). We therefore used rYF17D/SIVGag45-269 to boost two macaques that had been primed with rBCG expressing SIV proteins (Fig. (Fig.3A).3A). We detected no SIV-specific responses after either of the two priming rBCG vaccinations. Unfortunately, while the recombinant YF17D virus replicated well in animal r01056, we found evidence for only low levels of replication of rYF17D/SIVGag45-269 on day 5 postvaccination for animal r01108 (7 copies/ml) (Fig. (Fig.3B).3B). Both animals, however, generated neutralizing antibodies at 2 weeks postvaccination (Fig. (Fig.3C).3C). Encouragingly, we detected high-frequency CD8+ T-cell responses in the Mamu-A*01-positive macaque (animal r01056) after boosting with rYF17D/SIVGag45-269 (Fig. 3D to F). These responses were directed mainly against the Mamu-A*01-restricted Gag181-189CM9 epitope, which is contained in the peptide pool Gag E (Fig. (Fig.3D).3D). Furthermore, the boost induced a massive activation of animal r01056''s CD8+ T cells, peaking at 35% at 17 days postvaccination (Fig. (Fig.3E).3E). Of these activated CD8+ T cells, approximately 10% were directed against the Gag181-189CM9 epitope, with a frequency of 3.5% of CD8+ T cells (Fig. (Fig.3E).3E). These epitope-specific CD8+ T cells made IFN-γ, tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein 1β (MIP-1β), and degranulated (Fig. (Fig.3F3F and data not shown). Thus, an rBCG prime followed by a recombinant yellow fever 17D boost induced polyfunctional antigen-specific CD8+ T cells.Open in a separate windowFIG. 3.rYF17D/SIVGag45-269 vaccination induced a robust expansion of Gag-specific responses in an rBCG-primed macaque. (A) Vaccination scheme. We immunized two rhesus macaques with rBCG intradermally (i.d.) (2.0 × 105 CFU), rBCG orally (107 CFU), and rYF17D/SIVGag45-269 subcutaneously (2.0 × 105 PFU) at 6-month intervals. rBCG was engineered to express 18 minigenes containing sequences of Gag, Vif, Nef, Rev, and Tat from SIVmac239. (B) Replication of rYF17D/SIVGag45-269 during the first 10 days after vaccination as measured by Q-PCR using the YF17D-specific primers described in the legend of Fig. Fig.1.1. (C) Titer of neutralizing antibodies determined at 2 and 5 weeks after rYF17D/SIVGag45-269 vaccination. (D) Fresh PBMC from animal r01056 (100,000 cells/well) were used in IFN-γ ELISPOT assays to assess T-cell responses against the YF17D vector (red) and the SIV Gag(45-269) insert (black) at several time points postvaccination. (E) Kinetics of CD8+ T-cell activation (as described in the legend of Fig. Fig.1)1) and expansion of Gag181-189CM9-specific CD8+ T cells in animal r01056 after vaccination with rYF17D/SIVGag45-269. (F) Vaccination with rYF17D/SIVGag45-269 induced robust CD8+ T-cell responses against Gag181-189CM9 in r01056. CD8+ T-cell activation (Ki-67+/Bcl-2) for baseline and day 13 are shown. Gag181-189CM9-specific responses were measured by tetramer staining and intracellular cytokine staining (ICS) with antibodies against MIP-1β and IFN-γ.Vaccine-induced CD8+ T cells are usually central memory T cells (TCM) or effector memory T cells (TEM). These two subsets of CD8+ T cells differ in function and surface markers (23). Repeated boosting drives CD8+ T cells toward the TEM subset (23). We therefore determined whether a rBCG prime followed by a rYF17D/SIVGag45-269 boost induced TCM or TEM CD8+ T cells. Staining of PBMC obtained on day 30 postvaccination revealed that the SIV-specific CD8+ T cells were largely TEM cells since the majority of them were CD28 negative (Fig. (Fig.4A).4A). Furthermore, these cells persisted with the same phenotype until day 60 after vaccination (Fig. (Fig.4B).4B). It was recently suggested that TEM cells residing in the mucosae can effectively control infection after a low-dose challenge with SIVmac239 (16).Open in a separate windowFIG. 4.rYF17D/SIVGag45-269 vaccination of animal r01056 induced effector memory Gag181-189CM9-specific CD8+ T cells that suppressed viral replication in CD4+ targets. (A and B) Frequency and memory phenotype of tetramer-positive Gag181-189-specific CD8+ T cells in animal r01056 on day 30 (A) and day 60 (B) after rYF17D/SIVGag45-269 vaccination. CD28 and CD95 expression profiles of tetramer-positive cells show a polarized effector memory phenotype. Cells were gated on CD3+ CD8+ lymphocytes. (C) Ex vivo Gag181-189CM9-specific CD8+ T cells from animal r01056 inhibit viral replication from SIVmac239-infected CD4+ T cells. Gag181-189CM9-specific CD8+ T cells from three SIV-infected Mamu-A*01-positive animals and rYF17D/SIVGag45-269-vaccinated animal r01056 were tested for their ability to suppress viral replication from SIV-infected CD4+ T cells (39). Forty-eight hours after the incubation of various ratios of SIV-infected CD4+ T cells and Gag181-189CM9-specific CD8+ T cells, the supernatant was removed and measured for viral RNA (vRNA) copies per ml by Q-PCR. We observed no suppression when effectors were incubated with CD4+ targets from Mamu-A*01-negative animals (data not shown). Animal rh2029 was infected with SIVmac239 (viral load, ∼105 vRNA copies/ml) containing mutations in 8 Mamu-B*08-restricted epitopes as part of another study (37). Animal r01080 was vaccinated with a DNA/Ad5 regimen expressing Gag, Rev, Tat, and Nef and later infected with SIVmac239 (viral load, ∼103 vRNA copies/ml) (42). Animal r95061 was vaccinated with a DNA/MVA regimen containing Gag181-189CM9 and was later challenged with SIVmac239 (undetectable viral load) (2).We then assessed whether rYF17D/SIVGag45-269-induced CD8+ T cells could recognize virally infected CD4+ T cells. We have shown that these vaccine-induced CD8+ T cells stain for tetramers and produce cytokines after stimulation with synthetic peptides (Fig. (Fig.3).3). None of these assays, however, tested whether these SIV-specific CD8+ T cells recognize SIV-infected cells and reduce viral replication. We therefore used a newly developed assay (39) to determine whether vaccine-induced CD8+ T cells can reduce viral replication in CD4+ T cells. We sorted tetramer-positive (Gag181-189CM9-specific) lymphocytes directly from fresh PBMC and incubated them for 48 h with SIVmac239-infected CD4+ T cells expressing Mamu-A*01. We assessed the percentage of CD4+ T cells that expressed SIV Gag p27 (data not shown) and the quantity of virus in the culture supernatant (Fig. (Fig.4C).4C). Vaccine-induced CD8+ T cells reduced viral replication to the same extent as that seen with Gag181-189CM9-specific CD8+ T cells purified from three SIVmac239-infected rhesus macaques, including an elite controller rhesus macaque, animal r95061 (Fig. (Fig.4C4C).The most encouraging aspect of this study is that rBCG primed a high-frequency CD8+ T-cell response after boosting with rYF17D/SIVGag45-269. These CD8+ T cells reached frequencies that were similar to those induced by an rBCG prime followed by an Ad5 boost (11). Even without the benefit of the rBCG prime, the levels of CD8+ T cells induced by a single rYF17D/SIVGag45-269 vaccination were equivalent to those induced by our best SIV vaccine, SIVmac239ΔNef. Recombinant YF17D generated an average of 195 SFCs/106 PBMC (range, 100 to 750 SFCs/106 PBMC) (n = 6), whereas SIVmac239ΔNef induced an average of 238 SFCs/106 PBMC (range, 150 to 320 SFCs/106 PBMC) (n = 3) (32). It is also possible that any YF17D/HIV recombinants would likely replicate better in humans than they have in rhesus macaques and thus induce more robust immune responses. Also, rBCG was shown previously to be effective in humans (5, 17, 33, 34) and may be more useful at priming T-cell responses in humans than it has been in our limited study with rhesus macaques. These two vectors have long-distinguished safety and efficacy histories in humans and may therefore be well suited for HIV vaccine development.  相似文献   
47.
Cells counteract oxidative stress by altering metabolism, cell cycle and gene expression. However, the mechanisms that coordinate these adaptations are only marginally understood. Here we provide evidence that timing of these responses in yeast requires export of the polyamines spermidine and spermine. We show that during hydrogen peroxide (H2O2) exposure, the polyamine transporter Tpo1 controls spermidine and spermine concentrations and mediates induction of antioxidant proteins, including Hsp70, Hsp90, Hsp104 and Sod1. Moreover, Tpo1 determines a cell cycle delay during adaptation to increased oxidant levels, and affects H2O2 tolerance. Thus, central components of the stress response are timed through Tpo1‐controlled polyamine export.  相似文献   
48.
We have synthesised an extensive series of URB602 analogues as inhibitors of monoacylglycerol lipase (MAGL), which is the major enzyme responsible for metabolising the endocannabinoid 2-arachidonylglycerol. The recently identified crystal structure of MAGL was used in the design strategy and revealed three possible binding sites for URB602 and the proposed analogues. A test series of carbamate analogues were docked into the identified sites to predict the most favourable binding location. The synthesised analogues of URB602 explored the biological effects of isosteric replacement, ring size and substitution, para substitution of the biphenyl moiety and the incorporation of a bicyclic element. The compounds were tested for their ability to inhibit human MAGL. The carbamate analogue 16 displayed the most significant inhibitory activity, reducing MAGL activity to 26% of controls at 100 μM compared to 73% for the parent compound URB602.  相似文献   
49.
In mouse models of influenza, T cells can confer broad protection against multiple viral subtypes when antibodies raised against a single subtype fail to do so. However, the role of T cells in protecting humans against influenza remains unclear. Here we employ a translational nonhuman primate model to show that cross-reactive T cell responses play an important role in early clearance of infection with 2009 pandemic H1N1 influenza virus (H1N1pdm). To "prime" cellular immunity, we first infected 5 rhesus macaques with a seasonal human H1N1 isolate. These animals made detectable cellular and antibody responses against the seasonal H1N1 isolate but had no neutralizing antibodies against H1N1pdm. Four months later, we challenged the 5 "primed" animals and 7 naive controls with H1N1pdm. In naive animals, CD8+ T cells with an activated phenotype (Ki-67+ CD38+) appeared in blood and lung 5-7 days post inoculation (p.i.) with H1N1pdm and reached peak magnitude 7-10 days p.i. In contrast, activated T cells were recruited to the lung as early as 2 days p.i. in "primed" animals, and reached peak frequencies in blood and lung 4-7 days p.i. Interferon (IFN)-γ Elispot and intracellular cytokine staining assays showed that the virus-specific response peaked earlier and reached a higher magnitude in "primed" animals than in naive animals. This response involved both CD4+ and CD8+ T cells. Strikingly, "primed" animals cleared H1N1pdm infection significantly earlier from the upper and lower respiratory tract than the naive animals did, and before the appearance of H1N1pdm-specific neutralizing antibodies. Together, our results suggest that cross-reactive T cell responses can mediate early clearance of an antigenically novel influenza virus in primates. Vaccines capable of inducing such cross-reactive T cells may help protect humans against severe disease caused by newly emerging pandemic influenza viruses.  相似文献   
50.
MiRNAs play a relevant role in regulating gene expression in a variety of physiological and pathological conditions including autoimmune disorders. MiRNAs are also important in the differentiation and function of the mouse intestinal epithelium. Our study was aimed to look for miRNA-based modulation of gene expression in celiac small intestine, and particularly for genes involved in cell intestinal differentiation/proliferation mechanisms. A cohort of 40 children (20 with active CD, 9 on a gluten-free diet (GFD), and 11 controls), were recruited at the Paediatrics Department (University of Naples Federico II). The expression of 365 human miRNAs was quantified by TaqMan low-density arrays. We used bioinformatics to predict putative target genes of miRNAs and to select biological pathways. The presence of NOTCH1, HES1, KLF4, MUC-2, Ki67 and beta-catenin proteins in the small intestine of CD and control children was tested by immunohistochemistry. The expression of about 20% of the miRNAs tested differed between CD and control children. We found that high miR-449a levels targeted and reduced both NOTCH1 and KLF4 in HEK-293 cells. NOTCH1, KLF4 signals and the number of goblet cells were lower in small intestine of children with active CD and in those on a GFD than in controls, whereas more nuclear beta-catenin staining, as a sign of the WNT pathway activation, and more Ki67 staining, as sign of proliferation, were present in crypts from CD patients than in controls. In conclusion we first demonstrate a miRNA mediated gene regulation in small intestine of CD patients. We also highlighted a reduced NOTCH1 pathway in our patients, irrespective of whether the disease was active or not. We suggest that NOTCH pathway could be constitutively altered in the celiac small intestine and could drive the increased proliferation and the decreased differentiation of intestinal cells towards the secretory goblet cell lineage.  相似文献   
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