In vitro effects of aminobisphosphonates on Vgamma9Vdelta2 T cell activation and differentiation.

In this study we have evaluated the in vitro effects of four different aminobisphosphonates, alendronate, risedronate, neridronate and zoledronate, on Vgamma9Vdelta2 T cell activation and differentiation. All tested aminobisphosphonates induce an IL-2-dependent activation and expansion of Vgamma9Vdelta2 T lymphocytes in primary PBMC cultures of healthy donors. Most notably, they also determine a different distribution of Vgamma9Vdelta2 T cell subsets, with decrease of T(naive) and T(CM) cells and increase of T(EM) and T(EMRA) Vgamma9Vdelta2cells, indicating that in vitro treatment with aminobisphosphonates induces Vgamma9Vdelta2 T lymphocytes to differentiate towards an effector/cytotoxic phenotype. Accordingly, Vgamma9Vdelta2 T lymphocytes cultured with aminobisphosphonates and IL-2 showed a major content of IFN-gamma and acquired the ability to kill tumor target cells.

Production of cytokines at the operation site.

BACKGROUND AND AIM: Cytokines are part of a family of molecules involved in the initiation, control and termination of the events that occurs in wound healing process. Aim of this study was to evaluate the production of some cytokines [interleukin (IL)-6, IL-10, IL-1alpha, IL-1ra, interferon (IFN)-gamma] in the drainage wound fluid from patients undergoing incisional hernia repair. METHODS: Ten female patients with abdominal midline incisional hernia undergoing to surgical repair were included in this study. In all cases a closed suction drain was placed in the wound below the fascia and it was removed on the 4th postoperative day. Wound fluid was collected on the 1st, 2nd, 3rd and 4th day and its amount in each time was recorded. The production of IL-6, IL-10, IL-1alpha, IL-1ra and IFN-gamma were evaluated as quantity produced in 24 hour. RESULTS: In all patients the amount of drain fluid from surgical wound was highest on the 1st day after surgery, afterwards there is a significant reduction. The production of all cytokines evaluated was highest on the 1st day decreasing on the 2nd day except for IL-1alpha that not show any modification. The produciton of IL-1ra, IL-6, IL-1alpha and IL-10 was significantly reduced on the 3rd and 4th postoperative day in comparison with the respectively values recorded on the 1st day, whereas IFN-gamma levels were similar. CONCLUSIONS: The dosage of cytokines in the drain fluid led us to better evaluated the events that follow surgical wound and their analysis offers further information in the role of cytokines in healing process, with the goal to get supportive treatments to promote the best evolution.

Effects of chemically modified tetracyclines (CMTs) in sensitive, multidrug resistant and apoptosis resistant leukaemia cell lines.

Recently discovered chemically modified tetracyclines (CMTs) have shown in vitro and in vivo anti-proliferative and anti-tumour activities. Here, we evaluated in vitro the anti-proliferative and apoptotic activity of six different dedimethylamino chemically modified tetracyclines (CMT-1, CMT-3, CMT-5, CMT-6, CMT-7 and CMT-8) in sensitive and multidrug resistant myeloid leukaemia cells (HL60 and HL60R) in vitro. Three of these compounds (CMT-5, CMT-6, CMT-7) showed low cytotoxic activity both in sensitive and in resistant cells, CMT-3 was endowed with a high anti-proliferative activity only in sensitive cells and was moderately effective as apoptosis inducing agent, with an activity similar to that shown by doxycycline. On the contrary, CMT-1 and CMT-8 were very effective as programmed cell death inducing agents. The apoptotic pathway activated by these compounds involved the activation of caspases, especially caspase-9 and, for CMT-1, also the activation of FAS: Interestingly CMT-8, but not CMT-1, was able to induce apoptosis in multidrug resistant HL60R and in Fas-ligand resistant HUT78B1 cell lines. These properties, together with others previously described (e.g. anti-metastatic and anti-osteolytic activities), suggest that CMT-8 may have important applications in the clinical management of cancer. The comparative analysis of structure-activity relationship of CMT-8 and doxycycline suggests that the C-5 hydroxy moiety may play an important role in conferring activity in multidrug resistant cells. These findings appear to support the hypothesis that CMT-8 may represent an interesting lead for the development of a new class of potent apoptosis inducer agents active in multidrug resistant and Fas-ligand resistant malignancies.

Anti-inflammatory effects of chemically modified tetracyclines by the inhibition of nitric oxide and interleukin-12 synthesis in J774 cell line.

We investigated the effects of chemically modified tetracyclines (CMTs) on the production of nitric oxide (NO) and on the synthesis of some cytokines: tumour necrosis factor alpha (TNF-alpha), interleukin(IL)-10 and IL-12 in lipopolysaccharide (LPS)-treated J774 cell line. Furthermore, we studied the ability of these drugs to modify the viability in LPS-stimulated J774 macrophages. CMTs decreased, in a dose-dependent manner, inducible NO synthase (iNOS) activity and, consequently, nitrite formation in J774 cultures. The CMT-induced decrease in NO production is due to the inhibition of enzyme activity rather than to a direct effect on enzyme expression. The absence of the inhibition in mRNA accumulation indicates that the inhibiting activity is mainly post-transcriptional. CMTs were unable to modulate TNF-alpha and IL-10 synthesis and they were not effective in modifying the transcription of relative mRNA in J774 macrophages. On the contrary, IL-12 mRNA expression was significantly increased by CMT-1 and CMT-8 with LPS activation. Since IL-12 protein secretion was inhibited by CMTs, these compounds interfere in the blocking of post-transcriptional events. The studies on cell viability showed that various CMTs induced a dose-dependent decrease in J774 macrophage viability. The cytotoxic activity was present even though NO production was inhibited by CMTs. These compounds appear to be able to activate apoptosis in aNO-independent way. Altogether, these results indicate that CMTs can exert anti-inflammatory effects by inhibiting NO synthesis, and they are able to modify cell viability by exerting a strong apoptotic activity.

Tension-free hernia repair is associated with an increase in inflammatory response markers against the mesh.

BACKGROUND: The purpose of this study was to evaluate the involvement of inflammatory mediators in patients undergoing Lichtenstein tension-free hernioplasty (LH) using polypropylene prosthetic materials or conventional Bassini hernia repair (BH). METHODS: Thirty patients male with unilateral inguinal hernia without complications or recurrence were included in this study. Randomly, patients underwent LH or BH. Peripheral venous bloods samples were collected 24 hours prior to surgery and then 6, 24, 48 and 168 hours postoperatively. RESULTS: We present evidences that LH patients showed a higher increased serum level of fibrinogen, C-reactive protein, alpha-1-antitrypsin, and interleukin-6 than BH patients. Postoperative visual analogue scales for pain were reduced on mobilization for patients undergoing LH compared with BH. Neutrophils were significantly increased only in LH compared with baseline. Ceruloplasmin, transferrin, and albumin levels were unmodified after BH or LH. CONCLUSIONS: In conclusion our data show that although LH induces less pain and more rapid postoperative recovery, it is associated with an higher inflammatory response compared with BH, likely due to polypropylene mesh.

The acute phase response in Sicilian patients with boutonneuse fever admitted to hospitals in Palermo, 1992-1997.

OBJECTIVES: To study the modifications of some components of the acute phase response (APR) in Sicilian patients with boutonneuse fever (BF) caused by Rickettsia conorii. METHODS: Sera from 500 Sicilian patients with confirmed BF were studied at the time of diagnosis and every week after treatment, and after recovery for the presence of various inflammatory mediators. Tumour necrosis factor alpha (TNFalpha), interleukin(IL)-6, IL-1alpha, IL-8, soluble TNF receptors (sTNF-R) and sIL-6R were assayed by commercially ELISA kits. C3, C4, factor B, C-reactive protein (CRP), fibrinogen, ceruloplasmin (Cp) and alpha(1)-antitrypsin (AAT) were assayed by a rate nephelometry. RESULTS: Interferon gamma (IFNgamma), IL-6, TNFalpha, and IL-10 cytokines were significantly modified, whereas IL-1 and IL-8 were not detectable in the blood in any phase of infection. sTNF-RI, sTNF-RII and sIL-6 were significantly increased in the first 2 weeks of infection, but sTNF-R levels were not related to the plasma levels of TNFalpha, whereas sIL-6 was directly related to serum IL-6 concentrations. C3, C4, factor B and CRP were significantly increased in the first 2 weeks of infection, but afterwards returned to the normal range, even though CRP was still high in the third week and C3 persisted high after the fourth week. Fibrinogen was high only in the first week in relation to the injury to the endothelial cells (ECs). The anti-inflammatory proteins, Cp and AAT, were extremely high in the first 2 weeks of infection acting as a buffer of APR activation. CONCLUSIONS: These results suggest that R. conorii is able to elicit, after invasion and proliferation in the ECs, the activation of APR. Further work is required to establish if active inhibitory mechanisms are operating during APR, or if there is a spontaneous decay in the initiation events.

Interleukin-15, as interferon-gamma, induces the killing of Leishmania infantum in phorbol-myristate-acetate-activated macrophages increasing interleukin-12.

The potential leishmanicidal activity of interleukin-15 (IL-15) was examined while priming with the cytokine phorbol-myristate-acetate (PMA)-activated macrophages and infecting them with Leishmania infantum parasites. The activation of macrophage cultures with IL-15 determined a significant anti-leishmanial activity, comparable with that induced by interferon-gamma (IFN-gamma). The killing of Leishmania in macrophages primed with IL-15, as well as with IFN-gamma, was followed by an increase in the IL-12 synthesis. The neutralization of IL-15 or IFN-gamma, by specific monoclonal antibodies (MoAb) caused a significant reduction in leishmanicidal activity. Furthermore, in PMA-activated macrophages, the neutralization of IL-12 production by a specific anti-IL-12 MoAb reduced leishmanicidal activity induced by IL-15 and IFN-gamma. Data indicate that IL-15 could have a role as an activator of leishmanicidal activity, directly or indirectly, by inducing IL-12 production.

Modulation of nitric oxide production by tetracyclines and chemically modified tetracyclines.

Chemically modified tetracyclines (CMTs) dose-dependently decreased inducible nitric oxide synthase (iNOS) and, consequently, nitric oxide (NO) formation by the lipopolysaccharide (LPS)-stimulated J774 line. The inhibitory effect was due to a specific reduction in the iNOS protein content in the cells, as attested by Western blot analysis and by the inhibition of iNOS mRNA accumulation. Furthermore, CMTs cause a dose-dependent increase in cell death in the J774 line mediated by the NO-independent apoptotic mechanism.

Interleukin-12 in human boutonneuse fever caused by Rickettsia conorii.

Interleukin (IL)-12 contributes to the resistance against a number of intracellular pathogens. We examined the potential biological role of IL-12 by studying peripheral blood mononuclear cells (PBMC), its production and its effect on cytokine synthesis in 20 Sicilian patients with boutonneuse fever (BF) caused by Rickettsia conorii. Data indicate that PBMC from acute BF patients were able to produce IL-12 in response to in vitro stimulation with rickettsial antigen (Ag): this production was higher than that detected in healed patients. Monocytes were the main source of IL-12 by PBMC from BF patients. IL-12 secretion by in vitro Ag-stimulated PBMC from BF patients was potentiated by recombinant interferon gamma (IFN-gamma) or anti-IL-10 monoclonal antibodies (MoAbs). Furthermore, the treatment with anti-IL-12 MoAbs reduced the IFN-gamma synthesis. These results indicate that treatment of PBMC from acute BF patients with IL-12 shifted the response toward a Th1-type cytokine response. Furthermore, IL-12 and IFN-gamma are interdependent and they may be associated with the immunity against rickettsias.

IL-15 in human visceral leishmaniasis caused by Leishmania infantum.

Interleukin (IL)-15 is a recently discovered cytokine with the ability to stimulate the proliferation activity of Th1 and/or Th2 lymphocytes. Here, we investigated the involvement of IL-15 in the immune response to Leishmania infantum infection by studying patients with visceral leishmaniasis (VL). We found that IL-15 is produced by leishmanial antigen (LAg)-stimulated peripheral blood mononuclear cells (PBMC) from active VL patients at a significantly higher level than those produced by cells from healed VL subjects or healthy controls. A significant increase in IL-15 serum blood levels was also observed in acute VL patients compared with healed ones. Furthermore, recombinant IL-15 had an appreciable effect in vitro in reducing IL-4 and increasing the production of IL-12 in response to LAg, but it was ineffective in altering the production of interferon-gamma (IFN-gamma). The production of endogenous IL-15 in acute VL patients appeared to be insufficient to activate both IFN-gamma and IL-12, as attested by the absence of modification of these two cytokines by neutralization experiments in the presence of anti-IL-15 monoclonal antibodies (MoAB). On the contrary, the neutralization of IL-15 increased IL-4 production. Together, these results indicate that endogenous IL-15 plays a role in the suppression of Th2-type cytokines, even though it does not enhance the production of Th1 cytokines in acute VL patients. Since IL-15, in the presence of anti-IL-4 MoAb, caused a further increase in IL-12 production and led to a significant production of IFN-gamma, one of its indirect effects on Th1 cell activation could be due to the latter's effect on Th2 cytokines such as IL-4. Therefore, our observations indicate that there is a potential for IL-15 to augment the T-cell response to human intracellular pathogens.

Differential up-regulation of circulating soluble selectins and endothelial adhesion molecules in Sicilian patients with Boutonneuse fever.

In 150 patients with Boutonneuse fever (BF), caused by Rickettsia conorii, we studied the plasma levels of soluble L-selectin (sL-selectin), vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1) and E-selectin (sE-selectin) in various phases of disease to clarify their role in disease evolution. Results indicate that during the acute phase of BF there is a significant increase in the serum levels of sL-selectin, sE-selectin, sVCAM-1 and sICAM-1. sL-selectin and sVCAM-1 returned to normal levels in the third week of disease, whereas sE-selectin and sICAM-1 persisted at significantly high levels even after the third week. The secretion of these soluble CAMs in BF is mainly the result of leucocyte expression and endothelial cell activation, but secretion also appears to mediate anti-inflammatory activities, moderating leucocyte adhesion and reducing in particular lymphocyte and monocyte infiltration. Only sL-selectin serum levels were found to correlate with the acute phase of infection characterized by fever.