Mario Di Gioacchino

IL-10, an inflammatory/inhibitory cytokine, but not always.

IL-10 has been previously called cytokine synthesis inhibiting factor, produced mostly by Th2 cells, macrophages and CD8+ cell clones. IL-10 is capable of inhibiting the synthesis of several cytokines from different cells, antigen or mitogen activated. IL-10 exerts its inhibition at the mRNA transcriptional and translational level. In addition, IL-10 is a co-stimulatory cytokine on activated T cells. For example, IL-10 inhibits NK cell activity, the production of Th1 cytokines, cytokines generated by peripheral blood mononuclear cells, and macrophage activity. On the other hand, IL-10 exerts immunostimulatory effects on B cells, cytotoxic T cell development and thymocytes. In mast cells derived from CD4+/CD133+ cells, IL-10 inhibits IL-6 and TNFalpha, and prostaglandin E(1) and E(2) induced by IL-6. Here, we report for the first time that IL-10 fails to inhibit tryptase and IL-6 from human mast cell-1 (HMC-1) and human umbilical cord blood-derived mast cells.

Chemokines, sTNF-Rs and sCD30 serum levels in healthy aged people and centenarians.

Several lines of evidence point to a profound remodelling of the cytokine network in healthy elderly subjects, with decreased type-1 cytokine production (IL 2) and a shift to type 0 and 2. We have also observed an increase of proinflammatory cytokines (IL-1, IL-6, TNF-alpha) in vitro, and an increase of circulating stem cell factor in vivo. In this setting, we studied changes of chemokines (MCP-1 and RANTES) with aging, as well as other molecules, namely, sTNF-RI and sTNF-RII, and the soluble form of the CD30 molecule (sCD30), involved in the pro- and antiinflammatory cytokine balance. The subjects enrolled in the study belonged to three different selected healthy groups of young, aged and centenarians. The presence of rheumatoid factor (RF) and antinuclear antibodies (ANA) was simultaneously assessed. The results show that MCP-1 serum levels were higher in the healthy aged and lowest in the young, while RANTES increased exclusively in centenarians. Only centenarians had autoantibodies (ANA and RF). sTNF-RI and sTNF-RII were significantly elevated in healthy old subjects compared to the young, and even higher in selected centenarians compared to the other age groups. sCD30 serum levels were significantly raised in centenarians compared to the young, despite absence of circulating CD30+ cells in the peripheral blood of the whole study population. No relationship among serum values of these different members of the TNF-R family was found, despite a strong correlation for sTNF-RI and sTNF-RII in all groups. We hypothesize that the increased chemokine levels in aged people, and raised sCD30 levels in centenarians, may reflect a general shift towards type 0/2 cytokines in normal aging, which may be responsible, at least in part, for the appearance of circulating autoantibodies without definite clinical consequences at advanced age.

Catcholamine and nitric oxide systems as targets of chronic lead exposure in inducing selective functional impairment

Rats were exposed for ten months to 60 ppm of lead (Pb, as acetate) in drinking water to further assess cardiovascular effects of chronic Pb exposure. At the end of the treatment, mean blood Pb was 3.1+/-0.3 microg/dL in the control rats and 22.8+/-1.2 microg/dL in the Pb-exposed rats (means+/-SE, n=12 in each group); these values were not comparable to those of humans. Pb greatly increased plasma levels of noradrenaline (NA) and adrenaline (A), but not those of L-DOPA and dopamine; monoaminoxidase activity was augmented by Pb, mostly in the aorta and in the liver; the aorta, liver, heart and kidney showed discrete histopathological alterations in the Pb-exposed rats, in which plasma levels of nitric oxide (NO, determined as L-citrulline) were reduced. Pb was able to induce blood hypertension, resulting from increase of cardiac inotropism and, mostly, total peripheral resistance. These data were discussed also in relation to those obtained in our previous studies carried out in rats exposed to Pb in drinking water (15-60 ppm) for periods ranging from five to eighteen months. Pb appeared to increase both sympathetic nerve activity by central mechanisms (thus increasing plasma NA and A) and cyclic adenosine monophosphate (cAMP)-dependent availability of calcium ions (Ca++) for contractile mechanisms in the vascular and cardiac myocells (also through an increased vascular alpha2- and myocardial beta1-adrenoreceptor reactivity). The reduction of plasma NO, contributing to increase vascular resistance and cardiac inotropism, was explained as a result of actions of Pb on enzyme activities concerned with the kallikrein-kinin (KK) and renin-angiotensin-aldosterone (RAA) systems. It was concluded that chronic Pb exposure is able to affect selective neuroendocrine (i.e., catecholamine), au- tacoidal (i.e., KK and RAA) and transductional pathways (i.e., cAMP, NO, Ca++) involved in the cardiovascular function.

Palladium nanoparticles induce disturbances in cell cycle entry and progression of peripheral blood mononuclear cells: paramount role of ions.

There is concern about the possible toxicity of palladium nanoparticles (Pd-NP), as they are released in the environment through many applications. We previously studied the toxicity of Pd-NP at high concentrations; here we address the possible toxicity of Pd-NP at low, subtoxic doses. In particular, we have exposed normal human PBMC entering into the first in vitro mitotic division to Pd-NP and to Pd(IV) ions to evaluate ROS generation and cell cycle progression. We have measured a statistically significant increase of intracellular ROS in Pd(IV) exposed cells, but not in Pd-NP exposed cells. TEM revealed accumulation of lipid droplets and autophagic and mitophagic vacuoles, which appeared more conspicuous in cells exposed to Pd(IV) ions than to Pd-NP. Pd-NP were visible in the cytoplasm of Pd-NP exposed cells. Pd-NP addition was associated with a significant increase of cells within the G0/G1-phase and a significant reduction in GS- and G2/M-phases. Cells exposed to Pd(IV) ions showed a significant amplification of these cell cycle alterations. These results suggest that ions, per se or released by NPs, are the true inducers of Pd toxicity. It will be essential to verify whether the observed disturbance represents a temporary response or might result in permanent alterations.

Quantitative assessment of the compliance with once‐daily sublingual immunotherapy in children (EASY Project: Evaluation of A novel SLIT formulation during a Year)

Compliance is a major determinant for allergy treatment, especially in children. Sublingual immunotherapy (SLIT) is self‐managed at home, and no quantitative data on pediatric adherence are available. We studied the compliance in a large real‐life setting. A simplified schedule of SLIT was used, consisting of a 10‐day updosing phase followed by maintenance treatment in monodose containers to be taken daily (SLITOne®). Italian specialists throughout Italy assessed the compliance in children who were newly prescribed SLIT according to guidelines. Parents were contacted with unscheduled telephone interviews at the third and sixth month of therapy and asked to count at that moment the remaining vials. Data from 71 children (38 boys, age range 2–13 yr) were enclosed in the database. Thirty had rhinoconjunctivitis, four asthma and 37 rhinoconjunctivitis + asthma. SLIT was prescribed for: mites in 57 (81%) subjects, grasses in 11 (15%) and 3 (4%) grass + olive mixture. Compliance data were available for all children at 3 months, and for 56 at 6 months. At 3 months, 85% of subjects had a compliance rate >75% (69% of them adhered >90%). At 6 months, 84% had a compliance rate >75% (66% of them adhered >90%). In four cases SLIT was discontinued for economical reasons, and in one case (1.4%) for side effects probably related to therapy. These data obtained in a quite large sample of children and in real‐life confirm that the compliance with SLITOne® is good, despite the therapy managed at home.

Autophagy as an ultrastructural marker of heavy metal toxicity in human cord blood hematopoietic stem cells

Stem cells are a key target of environmental toxicants, but little is known about their toxicological responses. We aimed at developing an in-vitro model based on adult human stem cells to identify biomarkers of heavy metal exposure. To this end we investigated the responses of human CD34+ hematopoietic progenitor cells to hexavalent chromium (Cr[VI]) and cadmium (Cd). Parallel cultures of CD34+ cells isolated from umbilical cord blood were exposed for 48 h to 0.1 microM and 10 microM Cr(VI) or Cd. Cultures treated with 10 microM Cr(VI) or Cd showed marked cell loss. Ultrastructural analysis of surviving cells revealed prominent autophagosomes/autophagolysosomes, which is diagnostic of autophagy, associated with mitochondrial damage and replication, dilatation of the rough endoplasmic reticulum and Golgi complex, cytoplasmic lipid droplets and chromatin condensation. Treated cells did not show the morphologic hallmarks of apoptosis. Treatment with 0.1 microM Cr(VI) or Cd did not result in cell loss, but at the ultrastructural level cells showed dilated endoplasmic reticulum and evidence of mitochondrial damage. We conclude that autophagy is implicated in the response of human hematopoietic stem cells to toxic concentrations of Cr(VI) and Cd. Autophagy, which mediates cell survival and death under stress, deserves further evaluation to be established as biomarker of metal exposure.

Lymphocyte subset changes in blood and gastrointestinal mucosa after oral nickel challenge in nickel‐sensitized women

This study investigates lymphocyte subsets in both the gastrointestinal mucosa and blood, in patients with nickel allergic contact dermatitis, after 10 mg oral nickel challenge (double‐blind, placebo‐controlled). 6 such patients with cutaneous symptoms induced only by skin contact with nickel (group A), 6 with a flare‐up of cutaneous symptoms after food nickel ingestion (group B) and 6 healthy controls (group C) were enrolled. Blood lymphocyte subsets (CD4, CD45RO, CD8) were analyzed before and after 4 and 24 h from the challenge (test 1, 2, and 3), and intestinal biopsies were performed 2 days later. Challenges were positive in group B and negative in group A and controls. Serum and urine nickel levels significantly increased after nickel ingestion, with no differences between the 3 groups. At test 3, a significant decrease of the all CDs studied was found in group B. Biopsies of this group showed higher levels of CD45RO+ cells in the lamina propria and in the epithelium and lower levels of epithelial CD8+ lymphocytes. This study confirms that ingested nickel may induce flare‐up of cutaneous reactions in some nickel‐allergic patients, independently of the degree of sensitization and the intake of metal. In these patients, oral nickel stimulates the immune system, inducing maturation of T lymphocytes from virgin into memory cells; these latter cells seem to accumulate in the intestinal mucosa. The immunoreaction also involves CD8+ cells, whose role is not yet clear.

Engineered metal based nanoparticles and innate immunity

Almost all people in developed countries are exposed to metal nanoparticles (MeNPs) that are used in a large number of applications including medical (for diagnostic and therapeutic purposes). Once inside the body, absorbed by inhalation, contact, ingestion and injection, MeNPs can translocate to tissues and, as any foreign substance, are likely to encounter the innate immunity system that represent a non-specific first line of defense against potential threats to the host. In this review, we will discuss the possible effects of MeNPs on various components of the innate immunity (both specific cells and barriers). Most important is that there are no reports of immune diseases induced by MeNPs exposure: we are operating in a safe area. However, in vitro assays show that MeNPs have some effects on innate immunity, the main being toxicity (both cyto- and genotoxicity) and interference with the activity of various cells through modification of membrane receptors, gene expression and cytokine production. Such effects can have both negative and positive relevant impacts on humans. On the one hand, people exposed to high levels of MeNPs, as workers of industries producing or applying MeNPs, should be monitored for possible health effects. On the other hand, understanding the modality of the effects on immune responses is essential to develop medical applications for MeNPs. Indeed, those MeNPs that are able to stimulate immune cells could be used to develop of new vaccines, promote immunity against tumors and suppress autoimmunity.

Prevalence of sensitization to Cupressus sempervirens : a 4-year retrospective study

In the last few years Cupressus sempervirens has been identified as the cause of an increasing number of cases of late winter-early spring pollinosis in Mediterranean countries. We conducted a 4-year retrospective study of a large group of subjects with documented allergic respiratory disease in order to determine the prevalence, clinical significance and annual rate of sensitization to C. sempervirens pollen. Anamnestic data and skin prick tests (SPT) with common aeroallergens and C. sempervirens extract were collected from 1397 subjects (712 male and 685 female) resident in Latium, a region in central Italy, with complaints related to upper- or lower-respiratory-tract disorders or conjunctival disease. Two hundred and forty-three subjects (17.4%) showed positive results to C. sempervirens extract: 47 (19.3%) of them were monosensitized. The annual sensitization rate of SPT positivity to C. sempervirens varied from 7.2% in 1995 to 22% in 1998. All the subjects monosensitized to cypress pollen had symptoms from January through April. Our study suggests that sensitivity to C. sempervirens is responsible for respiratory symptoms in an increasing percentage of subjects. Further studies are needed to determine its frequency at the national level.

Interaction with culture medium components, cellular uptake and intracellular distribution of cobalt nanoparticles, microparticles and ions in Balb/3T3 mouse fibroblasts

Abstract The mechanistic understanding of nanotoxicity requires the physico-chemical characterisation of nanoparticles (NP), and their comparative investigation relative to the corresponding ions and microparticles (MP). Following this approach, the authors studied the dissolution, interaction with medium components, bioavailability in culture medium, uptake and intracellular distribution of radiolabelled Co forms (CoNP, CoMP and Co2+) in Balb/3T3 mouse fibroblasts. Co2+ first saturates the binding sites of molecules in the extracellular milieu (e.g., albumin and histidine) and on the cell surface. Only after saturation, Co2+ is actively uptaken. CoNP, instead, are predicted to be internalised by endocytosis. Dissolution of Co particles allows the formation of Co compounds (CoNP-rel), whose mechanism of cellular internalisation is unknown. Co uptake (ranking CoMP > CoNP > Co2+) reached maximum at 4 h. Once inside the cell, CoNP spread into the cytosol and organelles. Consequently, massive amounts of Co ions and CoNP-rel can reach subcellular compartments normally unexposed to Co2+. This could explain the fact that the nuclear and mitochondrial Co concentrations resulted significantly higher than those obtained with Co2+.