Immunomodulatory effects of pidotimod in adults with community-acquired pneumonia undergoing standard antibiotic therapy.

The morbidity and mortality of community-acquired pneumonia (CAP) are still elevated and two aspects seem to contribute to a worse outcome: an uncontrolled inflammatory reaction and an inadequate immune response. Adjuvants, including corticosteroids and intravenous immunoglobulins, have been proposed to counterbalance these effects but their efficacy is only partial. We examined the immunomodulatory activity of Pidotimod (PDT), a synthetic dipeptide molecule in adult patients hospitalized for CAP. Sixteen patients with a diagnosis of CAP and a PSI score III or IV and/or a CURB-65 0-2 were randomized to receive either levofloxacin 500 mg b.i.d. alone or levofloxacin plus PDT (800mg, 2 daily doses). Blood samples were drawn at baseline (T0), before initiation of therapy, as well as 3 (T3), and 5 (T5) days after initiation of therapy. Immunologic and clinical parameters were analyzed at each time point. Supplementation of antibiotic therapy with PDT resulted in an upregulation of antimicrobial and of immunomodulatory proteins as well as in an increased percentage of Toll like receptor (TLR)2- and TLR4, and of CD80- and CD86-expressing immune cells. Notably, Pidotimod supplementation was also associated with a robust reduction of TNFα-producing immune cells. No significant differences were observed in clinical parameters. These results confirm that supplementation of antibiotic therapy with Pidotimod in patients with CAP results in a potentially beneficial modulation of innate immunity.

Evaluation of Th9 lymphocytes in peripheral blood of rheumatoid arthritis patients and correlation with anti-tumor necrosis factor therapy: results from an in vitro pivotal study.

The aim of this study was to determine the prevalence of T helper 9 (Th9) lymphocytes in rheumatoid arthritis (RA) patients and to identify a possible association between the percentage of Th9 and the discontinuation of a biological treatment with an anti-tumor necrosis factor (TNF) (infliximab). We collected peripheral blood mononuclear cells (PBMCs) from 55 consecutive RA outpatients and 10 healthy controls. Among RA patients, 15 were not receiving any immunosuppressive drug, 20 were successfully treated with infliximab and 20 discontinued infliximab because of adverse events or inefficacy and were treated with other biological agents. PBMCs were cultured with/without infliximab 50 mg/L for 18 h, and the percentage of Th9 cells was assessed by means of flow cytometry. Th9 lymphocytes were identified as interferon gamma, interleukin (IL)4-, IL17-, IL9-secreting cluster of differentiation 4 (CD4)+ T cells. Cytometric analysis revealed no significant decrease in the percentage of Th9 cells after infliximab exposure in any of the groups, although it was lower in healthy controls than RA patients either before and after the infliximab stimulation assay. Th9 cells are IL-9-secreting T helper lymphocytes whose role in RA is still poorly known. IL-9 levels are increased in RA patients, in whom this cytokine plays a crucial role. Th9 cells are the major producers of IL-9, and their prevalence is higher in RA patients than in healthy subjects; however our experiment in vitro does not demonstrate an association between Th9 lymphocytes and the response to infliximab. Further studies are required to evaluate the real involvement of Th9 population in the immunogenicity of anti-TNF agents.

Upregulation of inflammasome activity and increased gut permeability are associated with obesity in children and adolescents.

BACKGROUND: Immune activation contributes to the persistent state of inflammation associated with metabolic dysfunction in obesity. The specific immune receptors that sense metabolic stress signals and trigger inflammation are nevertheless largely unknown, and little is known on inflammatory and immune gene regulation in obesity. METHODS: The study includes a cross-sectional and a longitudinal arm. Forty children and adolescents were enrolled: 22 obese subjects and 18 age-matched normal weight controls. Obese subjects participated in an 18-month therapeutic protocol, based on intensive lifestyle modification (dietary regimen, physical activity and behavioral interventions). Expression of genes involved in the inflammasome pathway, plasma concentration of the inflammasome-associated pro-inflammatory cytokines (interleukin (IL)-1ß and IL-18) and indexes of microbial translocation (lipopolysaccharide (LPS), soluble CD14 (sCD14) and intestinal fatty acid-binding protein) were analyzed at baseline in obese subjects compared with controls, and after 18 months in obese subjects. RESULTS: Cross-sectional analyses showed that the LPS-induced expression of genes involved in inflammasome (NLRP3, caspase 5 and NAIP), Nod-like receptors (NLRX1 and NOD1), downstream signaling (P2RX7, RAGE, RIPk2, TIRAP and BIRC2) and effector molecules (IFN-γ, IL-12ß, IL-1ß, CCL2, CCL5, IL-6 and TNFα) was significantly increased in obese subjects at baseline as compared with normal weight controls. The baseline plasma concentration of inflammasome-related cytokines (IL-1ß and IL-18) and of microbial translocation markers (LPS and sCD14) was augmented in obese subjects as compared with controls as well. Longitudinal analyses indicated that intensive lifestyle modification resulted in a normalization of parameters in subjects with a significant reduction of BMI after 18 months. CONCLUSIONS: In children and adolescents, obesity is characterized by the activation of the inflammasome and by an alteration of gut permeability. Successful lifestyle modification is effective in reducing inflammation, suggesting that inhibition of the inflammasome may be a potential therapeutic strategy in obesity.

Immunomodulating activity of Pidotimod in children with Down syndrome.

Acute respiratory tract infections (ARTIs) are the most frequent illnesses in pediatric age, frequently experienced in children with Down Syndrome (DS) due to the associated immune defects of both specific and non-specific immunity. Pidotimod, a synthetic immunostimulant, was shown to reduce the rates of ARTIs in children with DS, however the mechanisms associated with this effect is currently unknown. We analyzed immune parameters in DS children who received the seasonal 2011–2012 virosomal-adjuvanted influenza vaccine. Eighteen children aged 3-10 years (mean age 7.1+/-2.6 years) were randomly assigned (1:1 ratio) to receive Pidotimod 400 mg, administered orally once a day for 90 days or placebo. At the recruitment (T0) all children received a single dose of virosomal-adjuvanted influenza vaccine (Flu). Blood samples were collected at T0 and 3 months after the recruitment (T3) in order to evaluate innate and adaptative immune responses pathway. Flu-specific IgG1 and IgG3 levels in plasma samples were determined at pre-vaccination (T0), and 1 (T1) and 3 months (T3) post-vaccination. The use of Pidotimod was associated with the upregulation of a number of genes involved in the activation of innate immune responses and in antimicrobial activity. Interestingly the ratio of Flu-specific IgG1/IgG3 was skewed in pidotimod-treated individuals, suggesting a preferential activation of complement-dependent effector mechanisms. Although preliminary these data suggest that Pidotimod can potentiate the beneficial effect of immunization, possibly resulting in a stronger activity of both innate and adaptive immune responses.

The PD-1/PD-L1 pathway in human pathology.

T-cell activation is dependent on signals delivered through the antigen-specific T-cell receptor and accessory receptors on T-cells. Integration of signals through this family of costimulatory and inhibitory receptors and their ligands regulates the balance between T-cell activation, tolerance, and immunopathology. Programmed death 1 (PD-1) and its ligands, PD-L1 and PD-L2, deliver inhibitory signals and exert a vital and diverse range of immunoregulatory roles in T-cell activation, tolerance, and immune-mediated tissue damage. In this review, we revisit current understanding of the immunoregulatory functions of PD-1 and its ligands and their involvement in immune-mediated diseases.

OS048 Mitochondrial content and function in placental cells and tissuesof preeclampsia and IUGR.

INTRODUCTION: Early onset placenta Preeclampsia (ePE) with Intrauterine Growth Restriction (IUGR) is associated with insufficient placental function, leading to decreased nutrient and oxygen (O2) availability for the fetus [1]. Mitochondria (mt) are the cell energy producers. Mt dysfunctions could be involved in altered placental metabolism leading to ePE and IUGR. We previously demonstrated higher levels of mtDNA in human IUGR placentas [2]. OBJECTIVES: Here we investigate mtDNA levels in ePE and PE without IUGR placentas, and we present an innovative technique, High Resolution Respirometry (HRR), on cytotrophoblast cells (CTC) from PE, IUGR and control placentas (C), measuring cell O2 consumption which represents respiratory chain efficiency. METHODS: mtDNA was measured by Real-Time PCR in 20 PE placentas, with (n=14) or without (n=6) IUGR, and 45 C. CTC were isolated from 4 PE, 4 IUGR and 6 C and characterized by flow cytometry, staining samples with anti-cytokeratin-7 and anti-vimentin antibodies. Cells were located in chambers with atmospheric O2levels; 2 different protocols were used, with or without digitonin permeabilization, allowing to measure the O2 consumption of the respiratory chain complexes singularly or all together. Substrates and inhibitors of different respiratory chain complexes were sequentially administered (succinate, ADP, oligomycin, FCCP, rotenone, antimycin A, glutamate, malate, myxothiazol, TMPD, ascorbate, pyruvate, cytochrome C, differently combined depending on the protocol) and O2 consumption levels were recorded. Data were normalized by Citrate Synthase (CS) activity and CTC mtDNA content. RESULTS: PE placentas: mtDNA content was significantly increased in ePE+IUGR (p=0.02) vs C; opposite to this, mtDNA was decreased in PE without IUGR (p=0.03). CTC: single mt O2 consumption (obtained by normalizing data both by CS activity and mtDNA) was slightly increased both in PE and IUGR. The global cell respiration was increased, though not significantly. The trend towards higher O2 consumption studied on permeabilized cells  was confirmed for all the respiratory chain complexes. CONCLUSION: Our study showed that mtDNA is increased also in ePE with IUGR and added the novel observation that mtDNA is decreased in PE without IUGR. In both conditions placental mitochondria present an altered respiratory chain activity, with a trend to a higher respiratory capacity. This could lead to higher ATP production likely as an attempt to compensate for other aspects of placental disease due to small or inefficient exchange capabilities. Further data are needed to confirm these preliminary results, together with specific enzymatic assays to asses the respiratory chain complexes functionality. Supported by Fondazione Giorgio Pardi, Associazione Studio Malformazion(ASM) and by a Grant COFIN (Italian Ministry of Research) on: New markers for preterm deliveries.

Specific prebiotics modulate gut microbiota and immune activation in HAART-naive HIV-infected adults: results of the "COPA" pilot randomized trial.

Intestinal mucosal immune system is an early target for human immunodeficiency virus type 1 (HIV-1) infection, resulting in CD4(+) T-cell depletion, deterioration of gut lining, and fecal microbiota composition. We evaluated the effects of a prebiotic oligosaccharide mixture in highly active antiretroviral therapy (HAART)-naive HIV-1-infected adults. In a pilot double-blind, randomized, placebo-controlled study, 57 HAART-naive HIV-1-infected patients received a unique oligosaccharide mixture (15 or 30 g short chain galactooligosaccharides/long chain fructooligosaccharides/pectin hydrolysate-derived acidic oligosaccharides (scGOS/lcFOS/pAOS) daily) or a placebo for 12 weeks. Microbiota composition improved significantly with increased bifidobacteria, decreased Clostridium coccoides/Eubacterium rectale cluster, and decreased pathogenic Clostridium lituseburense/Clostridium histolyticum group levels upon prebiotic supplementation. In addition, a reduction of soluble CD14 (sCD14), activated CD4(+)/CD25(+) T cells, and significantly increased natural killer (NK) cell activity when compared with control group were seen in the treatment group. The results of this pilot trial highly significantly show that dietary supplementation with a prebiotic oligosaccharide mixture results in improvement of the gut microbiota composition, reduction of sCD14, CD4(+) T-cell activation (CD25), and improved NK cell activity in HAART-naive HIV-infected individuals.

Immunological effects of omalizumab in chronic urticaria: a case report.

We describe a case of chronic idiopathic urticaria in which symptoms improved dramatically after treatment with omalizumab. This drug, which is approved for the treatment of asthma, has been studied in other allergic conditions and a number of reports have described its efficacy as an immunomodulator in chronic and physical urticaria. Immunopathologic mechanisms are poorly understood. In chronic autoimmune urticaria, it has been postulated that this monoclonal antibody against immunoglobulin (Ig) E might reduce FcepsilonRI expression on the surface of basophils, thus preventing IgG antibody-mediated crosslinking and the release of mast cell mediators. We analyzed activation and homing molecules of B cells and type 1 and type 2 cytokine production by T cells and document a new immunomodulator mechanism characterized by a reduction in B-cell activation and homing and in tumor necrosis factor-alpha and interleukin 4 production and an increase in interferon-gamma synthesis.

Immune modulation by lactoferrin and curcumin in children with recurrent respiratory infections.

The clinical and immunologic effects of lactoferrin and curcumin (LC) oral supplementation were examined in healthy children with recurrent respiratory tract infections. Infections were reduced in children receiving LC. Immunologic analyses showed that LC supplementation resulted in a significant skewing of CD8+T lymphocytes maturation. Additionally: 1) CD14+, toll like receptor (TLR) 2-expressing cells augmented (p= 0.005) whereas CD14+/TLR4+ diminished (p= 0.004); and 2) IL10 production by CD14+ cells was reduced in children receiving LC. LC supplementation results in immune modulation and could be clinically beneficial.

Immunomodulatory effects of 1,25-dihydroxyvitamin D3 on TH1/TH2 cytokines in inflammatory bowel disease: an in vitro study.

Crohn's disease (CD) is associated with a higher type-1-helper T cell (Th1) cytokine expression, whereas ulcerative colitis (UC) appears to express a modified Th2 response. In addition to its classic role in calcium homeostasis, calcitriol, the hormonal active form of vitamin D, exerts immunoregulatory effects such as modulation of Th1/Th2 cytokines. Therefore, calcitriol administration could modify immune dysfunction in CD and UC. Nine patients with UC (M/F: 5/4; mean age 47 years, remission(R)/active(A) disease: 7/2), 8 patients with CD (M/F: 2/6; mean age 36, R/A 5/3) and 6 healthy controls (HC) (M/F: 3/3, mean age 4) were enrolled. Peripheral blood was collected after a drug-washout of 15 days and peripheral blood mononuclear cells were stimulated with mitogens alone or in the presence of physiological concentrations of calcitriol (100 pg/ml). Type 1 (IL-2, TNF-alpha, IFN-gamma) and type 2 (IL-10) cytokine production was assayed on supernatants by ELISA. Compared to HC, TNF-alpha production was significantly higher both in UC (p=0.0002) and CD (p=0.0001) patients, at baseline and after incubation with calcitriol (UC p=0.0003, CD p=0.0009). The effects of calcitriol incubation were: 1) reduced IFN-gamma (p=0.024) and increased IL-10 (p=0.06) production in UC patients; 2) reduced TNF-alpha production in CD (p=0.032); 3) no significant effects in HC. Calcitriol increased, albeit not significantly, IL-10 production in UC compared to CD patients (p=0.09). These results suggest an important modulatory role of vitamin D in the Th1/Th2 immune response. The observation that the effect of this modulation was different in CD compared to UC patients provides an interesting area of research into the pathogenesis and treatment of these inflammatory conditions.

Interferon-gamma and granulocyte-macrophage colony stimulating factor therapy in three patients with pulmonary aspergillosis.

An immune response mediated by type 2 cytokines is thought to contribute to the development and unfavorable outcome of aspergillosis. Adjuvant therapy with interferon-gamma (IFN-gamma) and granulocyte-macrophage colony stimulating factor (GM-CSF) was added to antifungal treatment in three nonneutropenic patients (one HIV-positive and two HIV-negative patients) with culture proven aspergillosis refractory to classical antifungal therapy. Clinical improvement was observed concomitantly with an increase in peripheral blood leukocyte proliferation and type 1 cytokines production. Our findings suggest an association between the improvement in type 1 cytokine production observed during IFN-gamma and GM-CSF administration and a better control of Aspergillus infection in patients with progressive disease despite adequate antifungal therapy.

PIN1 promoter polymorphisms are associated with Alzheimer's disease.

In our study, we analyzed the coding and promoter regions of the PIN1 gene in a group of 111 Alzheimer's disease (AD) patients looking for a possible genotype-phenotype correlation. The presence of SNPs - which could affect and modify the clinical phenotype of AD patients was also investigated. We identified two single nucleotide polymorphisms (SNPs) at positions -842 (G-->C) and -667 (C-->T) in the promoter region of the PIN1 gene. Our results evidenced a significantly higher percentage of -842C allele carriers in AD subjects with respect to healthy controls. We found that this allele significantly raised the risk of developing AD (OR 3.044, CI 1.42-6.52). The -842 and -667 SNPs were in linkage disequilibrium and combined to form haplotypes. The CC haplotype conferred a higher risk of developing AD (OR 2.95, confidence interval 1.31-6.82). Finally, protein expression analyses revealed that subjects carrying the -842 CC genotype or the CC haplotype showed reduced levels of the PIN1 protein in peripheral mononuclear cells.

Contemporary antithrombotic strategies in patients undergoing coronary stent implantation.

The number of annual stenting procedures has been increasing at a rapid pace since coronary stents were first used in clinical practice just over a decade ago. Subacute stent thrombosis, which usually has serious clinical consequences, plagued the stent early experience despite intense anticoagulation therapy. The reduction of stent thrombosis was among the factors that contributed to stent growth and widespread acceptance in recent years. This was the result of improved implantation techniques, advances in adjunctive pharmacotherapy and evolution in stent designs, delivery systems and non-thrombogenic coatings. However, novel designs and materials customized for particular lesion types and newer anti-restenotic treatments could influence stent thrombogenicity. Intravascular brachytherapy and drug-eluting stents have been shown to reduce the incidence of in-stent restenosis preventing cellular proliferation. However, by interfering with the re-endothelization process they may also increase the risk of stent thrombosis. To prevent a recrudescence of this feared complication, future research direction must focus on the hemocompatibility aspects of new technologies, along with further refinement of stent-deployment techniques and antithrombotic strategies.

Functional analysis of HIV-specific cytotoxic T lymphocytes in antiviral-treated- and-naive patients: a preliminary report.

HIV-specific CTL functions were analyzed in HIV-infected individuals who did or did not receive antiretroviral therapy (ART). Results showed that gp 160 (env)-stimulated perforin- and granzyme-expressing CTL, as well as perforin and granzyme-specific mRNA, were reduced in treated patients whereas TNFalpha was increased in ART-treated compared to naive individuals. Reduction of perforin and granzyme-expressing cells was not secondary to impaired IFNgamma production. A defect of CTL is observed in ART-treated individuals; this defect is not dependent on impaired Th cell function. These results reinforce the need for immunomodulants to successfully approach therapy of HIV infection.

Granulocyte/monocyte apheresis induces sustained increases in CD4 T cells in HIV-1 infected patients with poor CD4 T cell restoration after suppression of viral replication by HAART.

Current antiretroviral regimens (HAART) are generally effective in reducing viral replication to undetectable levels and inducing a raise in CD4 T cells. However, in approximately 5 to 15% of patients suppression of viral replication is not followed by an increase in CD4 T cells. Such patients may be at increased risk for opportunistic infections. Here we report the results from a phase II open label randomised trial on 30 patients classified as poor responders to HAART who were either subjected to eight consecutive cycles of selective monocyte apheresis or maintained under HAART alone. The results show that monocyte apheresis results in increased CD4 T cell counts which are maintained for at least 31 weeks after last apheresis. This effect was observed only on patients with complete suppression of viral replication. Other effects of monocyte apheresis included a strong reduction of TNF-alpha production in patients with high baseline levels of this cytokine and activation of resting T cells during the apheresis cycles. In two patients with high cellular HIV DNA load apheresis was followed by a 98% reduction, suggesting purging of infected cells. There was no evidence of increased viral replication during or after the apheresis cycles. The data show that monocyte apheresis is safe, well tolerated and may be indicated in patients who respond poorly to HAART.

Single-cell analysis of cytokine production shows different immune profiles in multiple sclerosis patients with active or quiescent disease.

Peripheral blood mononuclear cells of multiple sclerosis (MS) patients were stimulated with myelin basic protein (MBP) together with anti-CD28 monoclonal antibody and staphylococcal enterotoxin B to optimize cytokine production by antigen-specific cells. Type 1 (IL-2, IL-12, IFNgamma) and pro-inflammatory (TNFalpha, IL-1beta, IL-6) cytokines were augmented in CD4+, CD8+, and CD14+ cells of acute MS patients and of patients undergoing disease reactivation. These cytokines were reduced in IFNbeta-treated and in stable MS patients; type 2 cytokines (IL-4, IL-10) were increased in these patients. Similar immune profiles are seen in MS patients in whom remission is naturally or pharmacologically (IFNbeta) achieved. Cytokine alterations are particularly evident in CD14+ cells, underlying their critical role in the modulation of the immune response.

Evaluation of immune activation in HIV-infected and uninfected African individuals by single-cell analysis of cytokine production.

Immune activation has been observed in HIV-infected and uninfected Africans, among whom it is thought to modify interaction between the immune system and HIV. To characterize this phenomenon accurately, in-depth immunologic analyses were performed in a rural African population. Freshly drawn peripheral blood mononuclear cells (PBMCs) of HIV-infected African (from Gulu, Uganda) and Italian antiviral-naive patients and those of uninfected Ugandan and Italian study subjects were analyzed. Individuals were matched for age and sex and determined to be free from parasitic infections. Intracellular cytokines were measured in mitogen (M)- and gp160 peptides + staphylococcal enterotoxin B and alpha CD28 (env)-stimulated T lymphocytes. Interferon (IFN)-gamma-producing CD8(+) T cells were quantified in an enzyme-linked immunosorbent assay. Results showed that M-stimulated production of interleukin (IL)-10 and tumor necrosis factor (TNF)-alpha increases in CD4(+) and CD8(+) cells of African infected patients and uninfected study subject; and that env-stimulated IL-10 and TNF-alpha production is increased in CD8(+) T lymphocytes of African HIV-infected patients. M- and env-stimulated IFN-gamma-producing CD8(+) T cells were reduced in African participants and not increased by preincubation with alpha IL-10 monoclonal antibody. This is the first set of data that has reported immune activation in rural Africa by single-cell analysis of cytokine production. These results help in defining the immunologic background to be considered in the design of therapeutic and vaccine-based approaches to HIV infection in an African setting.