Impact of heavy polypropylene mesh and composite light polypropylene and polyglactin 910 on the inflammatory response.

The aim of the study was to analyze the acute inflammatory response after implantation of a heavyweight mesh of polypropylene (PP) compared with a composite mesh of light PP and polyglactin 910 (PG) in patients undergoing inguinal hernioplasty. A total of 30 male patients with inguinal hernia were included in the study and divided into 2 groups (PP and PP-PG) according to the mesh used. Changes of leukocytes, cytokines, growth factors, and acute phase proteins were evaluated in the sera. Leukocytes and acute phase proteins were significantly increased postoperatively in both groups, and the values were slightly higher in the PP group. Cytokine levels were significantly increased postoperatively in both groups; a slight increase was observed in the PP-PG group, especially for the proinflammatory cytokine. Growth factors decreased significantly in both groups immediately after surgery. The authors found that the use of the mesh is a stimulator of inflammatory response, and the 2 types of mesh induce a similar inflammatory response.

Modifications in the production of cytokines and growth factors in drainage fluids following mesh implantation after incisional hernia repair.

BACKGROUND: The aim of this study was to evaluate changes in the production of some cytokines (interleukins [ILs]-6, -10, -1, and -1ra), vascular endothelial growth factor, and beta-fibroblast growth factor after polypropylene mesh implantation. METHODS: Twenty female patients were divided into 2 groups. In 1 group, hernia repair was performed with conventional sutures (CR), whereas in the other group polypropylene mesh (MR) was used. Growth factors and cytokines production was analyzed in wound drain fluids based on the amount produced during 24 hours. RESULTS: IL-1 increased substantially in MR patients on postoperative days 1 and 2. IL1-ra and IL-10 production was always significantly higher in CR patients. IL-6 production did not show any considerable difference between the 2 groups. Vascular endothelial growth factor production was significantly higher in the MR than the CR group at all time points, whereas beta-fibroblast growth factor production was higher in the MR than the CR group only on postoperative day 1. COMMENTS: Our data suggest that different surgical procedures induce various levels of inflammation and that implantation of prostheses significantly stimulates the inflammatory response.

Production of VEGF and b-FGF in drainage fluid from patients undergoing incisional hernia repair.

Wound healing is a complex process involving interaction between different cell types, such as growth factors. Among these, vascular endothelial growth factors (VEGF) and basic fibroblast growth factors (b-FGF) are the most important. The aim of this study was to assess the production of VEGF and b-FGF in wound drainage fluid from patients undergoing incisional abdominal hernia repair. Ten female patients with abdominal midline incisional hernia undergoing surgical repair were included in this study. In all cases a closed suction drain was placed in the wound below the fascia and removed on postoperative day 4. Wound fluid was collected on the I, II, III and IV day and its amount at each time was recorded. VEGF and b-FGF production were evaluated as the quantity produced in 24 hours. In all patients the amount of drainage fluid from the surgical wound was highest on the I day after surgery, after which there was a significant reduction. VEGF production increased progressively after the operation proving significantly higher only on the IV day. The amount of b-FGF, in contrast, was higher on the I day, decreasing thereafter on the following postoperative days. Analysis of the production of growth factors in the drainage fluid has enabled us to better assess the events that occur following surgical wounds and has confirmed the physiology of the healing process and the possible use of these factors in modulating positive healing.

Association between the HLA-DR alleles and longevity: a study in Sardinian population.

Human longevity may be correlated with optimal functioning of the immune system, suggesting that genetic determinants of longevity also resides in those polymorphisms for the immune system genes that regulate immune responses as histocompatibility (HLA) antigens. However, conflicting results have been obtained. Some well planned and designed association studies performed in Caucasians suggest that longevity is associated with positive selection of alleles (i.e. HLA-DR11) or haplotypes (i.e. HLA-B8,DR3) that confer resistance to infectious diseases, respectively, via peptide presentation or via antigen non-specific control of immune response. Association studies are subjected to a number of possible confounding factors, the homogeneity of the population in term of geographical origin among others. Because of the lack of large-scale heterogeneity, the Sardinians represent a suitable population for association studies addressed to dissect the complex traits as longevity. Thus, we have evaluated, by the amplification refractory mutation system/polymerase chain reaction, HLA-DR frequencies in 120 centenarians (79 women and 41 men) and 86 controls (53 women and 33 men) from Sardinia, to validate, in this very homogeneous population, the associations between HLA alleles or haplotypes and longevity observed in other Caucasoid populations. No significant differences were obtained by analysing the differences between Centenarians and controls except for HLA-DRB1*15 that was increased in centenarians. However, the significance was not maintained by multiplying P values for the number of alleles under study. Thus, in Sardinian centenarians, we were not able to confirm the findings observed in the well planned and designed studies performed in other Caucasoid populations. Besides, HLA HFE gene polymorphisms have been recently demonstrated to be associated with longevity in the Sicilian population but not in Danish one. On the whole these findings clearly show that HLA/longevity associations are population-specific, being heavily affected by the population-specific genetic and environmental history. So, in our opinion, HLA genes might be considered survival genes not longevity genes.

Anti-inflammatory effects of annexin-1: stimulation of IL-10 release and inhibition of nitric oxide synthesis.

Annexin-1 (ANX-1) is an anti-inflammatory protein induced by glucocorticoids. Like glucocorticoids, ANX-1 and derived peptides inhibit eicosanoid synthesis, block leukocyte migration and induce apoptosis of inflammatory cells. Cytokines may possess either pro-inflammatory, i.e. interleukin(IL)-1beta, tumor necrosis factor (TNF)-alpha, IL-12 or anti-inflammatory properties, i.e. IL-4, IL-10. The experiments described in the present study have been performed to answer the question whether the anti-inflammatory action of ANX-1 may be mediated, at least in part, by the release of IL-10. In macrophage (J774) cell line cultures primed with lipolysaccharide (LPS), recombinant ANX-1 stimulated IL-10 release in a dose- and time-dependent manner. In the same cells, the protein and its derived N-terminal peptide (amino acids 2-26) dose-dependently inhibited the release of nitric oxide (NO). Furthermore, both the whole protein and the peptide down-regulated the mRNA expression of the inducible nitric oxide sythase (iNOS). The peptide was also able to inhibit the expression of IL-12 mRNA. These results suggest that some of the anti-inflammatory effects of ANX-1 may be mediated by the release of IL-10, which, in turn, inhibits iNOS mRNA expression and, hence, NO release. In addition, ANX-1-stimulated IL-10 release may also be responsible for the inhibition of IL-12 mRNA expression and, consequently, IL-12 synthesis.

Chemically modified tetracyclines induce cytotoxic effects against J774 tumour cell line by activating the apoptotic pathway.

Here, we have studied the effects of chemically modified tetracyclines (CMTs) on apoptosis both at the level of the cytoplasmic proteolytic caspase cascade, and on Bcl-2 and c-myc mRNA expression in the J774 macrophage cell line. The results indicate that CMTs induce morphological changes consistent with apoptotic events, as clearly demonstrated both by the acridine orange and ethidium bromide staining, and by TUNEL and fragmentation ELISA assays. Furthermore, the analysis of the cell cycle by flow cytometry shows an evident apoptotic sub-G0G1 peak, without important modifications in the cell cycle distribution. CMTs induce programmed cell death (PCD) in a dose-dependent manner and CMT-8 is the strongest among them. CMT-1 and CMT-8 activate mainly caspase-8 as attested by the inhibitory effects of Z-VAD-fmk and Z-IEDT-fmk on CMT-induced apoptosis. Part of CMT-induced PCD is due to the activation of caspase-9, since it is reduced by the specific caspase-9 inhibitor, Z-LEHD-fmk. Besides, CMTs increase Bcl-2 and c-myc mRNA expression. Collectively, these data indicate that CMTs are potentially anti-tumour agents, since they strongly trigger apoptosis both activating the proteolytic system of the caspase family and modulating genes involved in PCD regulation.

Cytokines and growth factors in wound drainage fluid from patients undergoing incisional hernia repair.

Knowing the dynamics of growth factor and cytokine secretion within the site of a surgical operation is important, as they play a crucial role in the pathophysiology of wound healing and are a target for modifying the repair response. The aim of this study was to evaluate the production of several cytokines and growth factors in the drainage wound fluid from patients undergoing incisional hernia repair: namely, interleukin (IL)-6, IL-10, IL-1alpha, IL-1 ra, interferon-gamma, vascular endothelial growth factors and basic fibroblast growth factor. Ten female patients with abdominal midline incisional hernia undergoing surgical repair were included in this study. In all cases, a closed-suction drain was inserted in the wound below the fascia and removed on postoperative day 4. Wound fluid was collected on postoperative days 1-4 and the amount was recorded each time. Growth factors and cytokines production was evaluated as the whole amount produced over a 24-hour period. In all patients, the amount of drain fluid from surgical wounds was more copious the first day after surgery, it decreased significantly afterward. The presence of all cytokines was highest on postoperative day 1, decreasing over the following days. More specifically, the production of IL-1 ra, IL-6, IL-1alpha, and IL-10 on postoperative day 1 fell sharply on postoperative days 3 and 4, whereas, after an initial reduction, interferon-gamma showed an increase from day 2 onward. Vascular endothelial-derived growth factor production increased progressively after the operation reaching statistical significance only on day 4. As for basic fibroblast growth factor, it showed an opposite pattern: it was higher on postoperative day 1 decreasing thereafter. This analysis of cytokine and growth factor production in the drain fluid will lead us to a better evaluation of the events that follow a surgical wound and to a better understanding of the healing process.

Differential requirements for antigen or homeostatic cytokines for proliferation and differentiation of human Vgamma9Vdelta2 naive, memory and effector T cell subsets.

We have compared four human subsets of Vgamma9Vdelta2 T cells, naive (T(naive), CD45RA(+)CD27(+)), central memory (T(CM), CD45RA(-)CD27(+)), effector memory (T(EM), CD45RA(-)CD27(-)) and terminally differentiated (T(EMRA), CD45RA(+)CD27(-)), for their capacity to proliferate and differentiate in response to antigen or homeostatic cytokines. Cytokine responsiveness and IL-15R expression were low in T(naive) cells and progressively increased from T(CM) to T(EM) and T(EMRA) cells. In contrast, the capacity to expand in response to antigen or cytokine stimulation showed a reciprocal pattern and was associated with resistance to cell death and Bcl-2 expression. Whereas antigen-stimulated cells acquired a T(CM) or T(EM) phenotype, IL-15-stimulated cells maintained their phenotype, with the exception of T(CM) cells, which expressed CD27 and CD45RA in various combinations. These results, together with ex vivo bromodeoxyuridine incorporation experiments, show that human Vgamma9Vdelta2 memory T cells have different proliferation and differentiation potentials in vitro and in vivo and that T(EMRA) cells are generated from the T(CM) subset upon homeostatic proliferation in the absence of antigen.

Reciprocal stimulation of gammadelta T cells and dendritic cells during the anti-mycobacterial immune response.

Gammadelta T cells and dendritic cells (DC) are two distinct cell types of innate immunity that participate in early phases of immune response against Mycobacterium tuberculosis infection. Here we show that a close functional relationship exists between these cell populations. Using an in vitro coculture system, Vgamma1 T cells from Tcrb(-/- )mice were found to be activated by DC infected in vitro with BCG, as indicated by the elevated CD69 expression, IFN-gamma secretion and cytotoxic activity. This activation process was due to a non-cognate mechanism since it required neither cell to cell contact nor interaction between the TCR and a specific antigen, but was mediated by DC-derived IL-12. Reciprocally, Vgamma1 T cells provided a key cytokine, IFN-gamma, which increased IL-12 production by BCG-infected DC. Moreover, exposure of BCG-infected DC to Vgamma1 T cells conditioned the former to prime a significantly stronger anti-mycobacterial CD8 T cell response. Consequently, stimulation of gammadelta T cells and their non-cognate interaction with DC could be applied as an immune adjuvant strategy to optimize vaccine-induced CD8 T cell immunity.

CD4+ CCR5+ and CD4+ CCR3+ lymphocyte subset and monocyte apoptosis in patients with acute visceral leishmaniasis.

The potential involvement of apoptosis in the pathogenesis of visceral leishmaniasis (VL) was examined by studying spontaneous and Leishmania antigen (LAg)-induced apoptosis using cryopreserved peripheral blood mononuclear cells (PBMC) of Sicilian patients with VL. Results indicate that monocytes and T lymphocytes from acute VL patients show a significantly higher level of apoptosis compared with that observed in healed subjects. The percentage of apoptotic cells was higher in monocytes than in T lymphocytes. T cells involved in programmed cell death (PCD) were mainly of the CD4(+) phenotype. In particular, the T helper 1-type (Th1) subset, as evaluated by chemokine receptor-5 (CCR5) expression, is involved in this process. Cell death in Th1-type uses a CD95-mediated mechanism. Furthermore, Th1-type CCR5(+) cells are prone to cell suicide in an autocrine or paracrine way, as attested by enhanced expression of CD95L in acute VL patients. The reduction in Th1-type cells by apoptosis was confirmed by the decrease in interferon-gamma secretion. In conclusion, apoptosis of monocytes, CD4(+) and CD4(+) CCR5(+) T cells could be involved in the failure of cell mediated immunity that is responsible for severe immune-depression in VL.

Estrogen regulates cytokine production and apoptosis in PMA-differentiated, macrophage-like U937 cells.

We have investigated the effects of sex steroids, estradiol (E2), and testosterone (T) on the synthesis of tumor necrosis factor alpha (TNF-alpha) and interleukin-10 (IL-10) in phorbol-myristate-acetate (PMA)-differentiated human monoblastic U937 cells. The ability of both hormones to modulate the viability and programmed cell death of macrophage-like PMA-differentiated U937 cells was also inspected. E2 increased TNF-alpha synthesis, whereas T had no effect on the production of this cytokine. The combination of E2 and its antagonist tamoxifen or ICI-182,789 completely abolished the induction of TNF-alpha, while combination of T and its antagonist Casodex (CSDX) did not significantly affect TNF-alpha production by U937 cells. Exposure of cells to E2 resulted in a dose-dependent decrease of IL-10 synthesis, while again T did not show any detectable effect. In addition, E2 induced a significant increase of apoptosis in macrophage-like U937 cells and this increase was inhibited by the simultaneous addition of either tamoxifen or ICI-182. In contrast, T alone or in combination with CSDX did not modify apoptotic rates of U937 cells. This evidence, taken together, suggests that estrogens, but not androgens, exert a pro-inflammatory action through the modulation of TNF-alpha and IL-10, and regulate the immune effector cells by the induction of programmed cell death.