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C Agostini

Publications and source records attributed to C Agostini.

At least 19 recordsLinked to original sources
PubMed1999

Antibodies to the IL-12 receptor beta 2 chain mark human Th1 but not Th2 cells in vitro and in vivo.

Great attention has been placed on the possibility of distinguishing Th1 from Th2 cells on the basis of differential expression of surface receptors. We have recently shown that the differential expression of the IL-12R beta 2 chain in Th1 and Th2 cells, as measured at the mRNA level, accounts for an important regulatory mechanism in the differentiation of the two cell subsets. In this study, we identify IL-12R expression at the protein level. We have generated an anti-IL-12R beta 2-specific mAb and analyzed IL-12R beta 2 expression on polarized Th cell populations generated in vitro and on T cells derived from patients with Th1- or Th2-mediated inflammatory conditions. Although IL-12R beta 2 was absent in freshly isolated PBMC and in cord blood cells, we were able to detect IL-12R beta 2 expression selectively in differentiated Th1 and T cytotoxic 1, but not Th2 or T cytotoxic 2 cells. In the presence of IL-12, cell surface expression of the IL-12R beta 2 subunit was readily detected on T cells after 24 h, reached the maximum at day 5, and declined thereafter. Most importantly, the anti-IL-12R beta 2 mAb recognizes lung T cells from patients with sarcoidosis, a disease characterized by a typical cell-mediated, Th1-type inflammatory response. In contrast, IL-12R beta 2 was absent in lung T cells from patients with allergic asthma, a disease characterized by a Th2-type inflammatory response. The mAb reported in this study should represent a powerful tool to investigate the role of Th1 and Th2 cells in inflammatory conditions and to monitor therapies aimed at altering the balance of Th cell subsets.

Adult↗
PubMed1999

CD8 T-cell infiltration in extravascular tissues of patients with human immunodeficiency virus infection. Interleukin-15 upmodulates costimulatory pathways involved in the antigen-presenting cells-T-cell interaction.

Interleukin (IL)-15 regulates the proliferative activity of the CD8(+) T-cell pool in human immunodeficiency virus (HIV)-infected patients, thereby contributing to the maintenance of the CD8(+) T-cell-mediated immune response against HIV in extravascular tissues, including the lung. However, the effects of IL-15 on antigen-presenting cells (APC) during HIV infection are still unclear. In this study, we evaluated whether IL-15 regulates the macrophage stimulatory pathways governing inflammatory events that take place in the lung of patients with HIV infection. As a first step we evaluated the in vitro effects of IL-15 on lung macrophages retrieved from the respiratory tract of eight normal subjects. Although macrophages from uninfected individuals expressed the IL-15 binding proteins (IL-15Ralpha and the common gammac) at resting conditions, they did not express IL-15 messenger RNA (mRNA). However, a 24-hour stimulation with IL-15 induced the expression of interferon-gamma (IFN-gamma) and IL-15 itself, suggesting a role for this cytokine in the activation of the pulmonary macrophage pool during inflammation. As a confirmation of the role of IL-15 in this setting, at resting conditions, alveolar macrophages of patients with HIV infection and T-cell alveolitis expressed IL-15, IFN-gamma, and IL-15 binding proteins; showed an upmodulation of costimulatory molecules, B7 and CD72, which are involved in the APC of macrophages; and behaved as effective accessory cells because they elicited a strong proliferation of T cells. The accessory effect was inhibited by pretreatment with anti-CD72, anti-B7 (CD80 and CD86), and anti-IL-15 monoclonal antibodies (MoAb). We then investigated the relationship between IL-15 and the expression of costimulatory molecules by macrophages. A 24-hour stimulation of IL-15Ralpha+/gammac+ macrophages with IL-15 upregulated the expression of CD80 and CD86. The evidence that IL-15 upregulates the expression of coligands that favor the contact between T cells and APC, per se, triggers T-cell activation and proliferation and acts as a chemoattractant for T cells, suggests that IL-15 plays a key role in Tc1-mediated defense mechanisms taking place in extravascular tissues of patients with HIV disease.

Adult↗
PubMed1998

Involvement of the IP-10 chemokine in sarcoid granulomatous reactions.

The accumulation of T cells and monocytes at sites of ongoing inflammation represents the earliest step in the series of events that lead to granuloma formation in sarcoidosis. In this study, we evaluated the pulmonary production of IFN-inducible protein 10 (IP-10), a CXC chemokine that stimulates the directional migration of activated T cells. Striking levels of IP-10 were demonstrated in the bronchoalveolar lavage (BAL) fluid of 24 patients with pulmonary sarcoidosis and lymphocytic alveolitis, as compared with patients with inactive disease or control subjects. A positive correlation was demonstrated between IP-10 levels and the number of sarcoid CD45R0+/CD4+ cells in the BAL. Immunochemistry, performed with an anti-human IP-10 polyclonal Ab in lymph nodes displaying prominent sarcoid granulomas, showed that cells bearing IP-10 were mainly epithelioid cells and CD68+ macrophages located inside granulomatous areas. Macrophages recovered from the BAL of sarcoid patients stained positive for IP-10 protein. Furthermore, alveolar macrophages isolated from sarcoid patients with T cell alveolitis and cultured for 24 h in presence of IFN-gamma secreted definite levels of IP-10 capable of inducing T cell chemiotaxis. Interestingly, alveolar lymphocytes recovered from patients with active sarcoidosis were CD4+ T cells expressing Th1 cytokines (IL-2 and IFN-gamma) and high levels of CXCR3. Taken together, these data suggest the potential role of IP-10 in regulating the migration and activation of T cells toward sites of sarcoid inflammatory process and the consequent granuloma formation.

Adult↗
PubMed1998

Induction of NADPH-diaphorase activity in the rat periaqueductal gray matter after nociceptive visceral stimulation.

Nitric oxide (NO) is a neuronal messenger that it is thought to be involved in the nociceptive transmission modulation. The activity of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) was shown to be identical to NOS activity in the brain. Since the periaqueductal gray matter (PAG) plays an important role in pain perception and antinociception this study was carried out to monitor the expression of NADPH-d in PAG after nociceptive visceral stimulation. Our data showed that the noxious visceral stimulation significantly increased NADPH-d positive neurons and that these neurons were localized in the ventrolateral areas of the PAG. These findings suggest that NO in the PAG may play a role in pain modulation and antinociception.

Acetic Acid↗
PubMed1998

Impaired cytokine production by neutrophils isolated from patients with AIDS.

OBJECTIVES: To determine the ability of neutrophils isolated from HIV-seropositive patients to produce proinflammatory cytokines. DESIGN: The in vitro responsiveness of polymorphonuclear neutrophils (PMN) and peripheral blood mononuclear cells (PBMC) to lipopolysaccharide (LPS), used in the presence or absence of interferon (IFN)gamma, was determined in 47 HIV-positive patients with advanced stages of virus infection. METHODS: Cytokines in cell-free supernatants were measured by enzyme-linked immunosorbent assay or radioimmunoassay. RESULTS: Cell-free supernatants from PMN isolated from the peripheral blood of HIV-positive patients and stimulated with LPS contained increased amounts of tumour necrosis factor (TNF)-alpha and interleukin (IL)-8 with respect to supernatants obtained from PMN of normal donors. In contrast, release of IL-1beta and IL-1ra (IL-1 receptor antagonist) in response to LPS, or LPS plus IFNgamma, was found to be lower in PMN from HIV-positive patients than in PMN from controls, but was significant only in the case of IL-1ra. Furthermore, the release of IL-12 induced by LPS or LPS plus IFNgamma did not significantly differ between PMN from HIV-positive patients and healthy donors. Concerning PBMC, the production of TNF-alpha and IL-12 in response to LPS, or LPS plus IFNgamma, was found to be significantly higher in cells isolated from HIV-positive patients, whereas the release of IL-1beta was significantly lower. In the case of IL-8, no statistically significant difference was found between PBMC isolated from HIV-positive patients and healthy donors. CONCLUSIONS: Collectively, the data suggest that in HIV-positive patients with advanced stages of disease, the ability of PMN to produce specific cytokines in response to LPS is significantly altered. Alterations in this ability might contribute to the evolution of HIV disease.

Adolescent↗
PubMed1998

HIV load in highly purified CD8+ T cells retrieved from pulmonary and blood compartments.

The pulmonary microenvironment can be HIV infected from the asymptomatic period of HIV infection and it has been demonstrated that HIV presence elicits a discrete virus-specific CTL immune response in the lungs. In this study we analyzed T cell subsets and compared the proportion of CD8+ T cells harboring HIV in the lung and in the circulation of HIV-seropositive patients with T cell alveolitis. Proviral load was assessed using the DNA-polymerase chain reaction technique on highly purified CD8+ T cells isolated from peripheral blood and bronchoalveolar lavage. The proviral load of pulmonary CD8+ T cells showed an upward trend with respect to corresponding samples isolated from the peripheral blood of the same patients.

Adult↗
PubMed1998

Sarcoidosis news: immunologic frontiers for new immunosuppressive strategies.

Although the etiology of sarcoidosis is still unknown, it is now clear that the formation of the sarcoid granuloma is keenly regulated by a cascade of cytokines. Furthermore, several experimental data indicate a direct association between the release of cytokines and the development of lung fibrosis. In a recent meeting over 300 investigators convened to assess current knowledge in the field of sarcoidosis, vasculitis, and diffuse lung diseases. The meeting provided an overview on the complex networks between immunocompetent cells, cytokines, and mesenchymal cells setting the stage for the pathogenesis of granulomatous and vasculitic disorders. However, emphasis was given to the possibility of using innovative immunotherapies to target relevant cytokines or molecules involved in granuloma formation and the remodelling of lung tissue.

Adjuvants, Immunologic↗
PubMed1998

Cells and molecules involved in the development of sarcoid granuloma.

Although the etiology of sarcoidosis is still unknown, characteristic morphologic aspects and immunohistological patterns of sarcoid granulomatous lesions suggest that they are the consequence of an exaggerated immunological response against an undefined antigen which persists at different sites of disease involvement. This article reviews the newly emerging hypothesis regarding the molecular bases which drive the development of sarcoid granulomas. The accumulation of Th1 cells represents the pivotal step along the series of events that lead to the formation of granuloma; furthermore, a set of biological mediators of the immune response define immune regulatory networks that may contribute to tissue damage. It is also thought that shifts of the Th1/Th2 networks and alterations in the complex networks between immunocompetent cells and mesenchymal cells may set the stage for the remodeling of tissues surrounding granulomatous lesions.

Animals↗
PubMed1998

Cytokines in sarcoidosis.

Although the cause of sarcoidosis is still unknown, the combination of the characteristic morphologic aspect and the immunohistologic pattern of the sarcoid granulomatous lesions suggest that they are the result of an antigen-driven process. In particular, sarcoid granuloma is considered to be the consequence of an exaggerated immunological response against an undefined antigen which has persisted at the sites of disease involvement. Taking advantage of the availability of pure recombinant cytokines and molecular probes for cytokines and their receptors, in the last few years it has been possible to keenly study the involvement of several cytokines in the pathologic changes associated with sarcoidosis. The purpose of this review is to summarize the interactions between cytokines and their receptors which define regulatory networks ultimately contributing to the sarcoid granuloma formation at sites of disease activity. After a concise overview of the main cytokines involved in the sarcoid inflammatory response, we will briefly discuss the biological effects of Th1 and Th2 cytokines in sarcoid lung and then concentrate on the importance of the local production of those molecules whose release has been recently shown within the lung of patients with sarcoidosis, such as interleukin-12, interleukin-15, and chemokines. Furthermore, we will focus the discussion on the cytokines which, pivotal to the activation of the host defenses, may contribute to lung damage and the consequent lung fibrosis. The final section of this article reviews the lung release of cytokines in the context of recent hypotheses claiming microbial pathogens as putative causative agents of sarcoidosis.

Cytokines↗
PubMed1997

B lymphocytes from patients with chronic lymphoproliferative disorders are equipped with different costimulatory molecules.

Several costimulatory molecules play a key role in the differentiation of B lymphocytes and in T-B-cell interactions. In this study, we addressed the question of whether different receptors and counter-receptors may be expressed on malignant B lymphocytes from chronic B-cell malignancies. Using flow cytometry and reverse transcription PCR analyses, the expression of molecules belonging to the tumor necrosis factor receptor (TNFR) and tumor necrosis factor ligand (TNFL) families, as well as the expression of CD80 and CD86 molecules, was analyzed in normal B cells and in different chronic lymphoproliferative disorders of B-cell type, including B-cell chronic lymphocytic leukemia (CLL), mantle cell lymphoma, hairy cell leukemia (HCL), and HCL variant. Different patterns of expression of TNFR and TNFL superfamily molecules were demonstrated among B-cell malignancies. In particular, CD40 was commonly observed on all B cells (both tumor and normal), whereas its ligand (CD40L), which is usually undetectable on resting normal B lymphocytes, was expressed in CLL and HCL but not in other chronic lymphoproliferative disorders. CD27 was not shown in normal B cells, although it was present in all malignancies and with particularly high density in mantle cell lymphoma. CD70 was widely distributed on tumor B lymphocytes, but not on the CD5+ normal counterpart. CD30 was strongly expressed in HCL variant and weakly in B-cell CLL, whereas its ligand showed a wide pattern of expression, including all neoplastic and normal B cells. TNFR II (CD120b) and CD80 were distributed on neoplastic B cells from all groups, usually at an intermediate to high degree of intensity, whereas the CD86 molecule was present at lower intensity than CD80. Finally, reverse transcription PCR analysis confirmed the presence of CD40L, CD30, and CD30L mRNAs in those B cells expressing the corresponding membrane-bound proteins at low density. Our data indicate that TNFR and TNFL molecules are of use clinically both in differentiating B-cell malignancies from the normal counterpart (i.e., CD27, CD70, CD40L, CD30, and CD80) and in defining different chronic B-cell disorders (i.e., CD40L, CD27, and CD30). Interestingly, the observation that several receptors and their ligands (i.e., CD40/CD40L, CD30/CD30L, and CD27/CD70) can be expressed on the same cell suggests that these molecules play a role in initiating and maintaining the neoplastic process by mediating B-T and B-B interactions.

Adult↗
PubMed1997

Interleukin-15 triggers activation and growth of the CD8 T-cell pool in extravascular tissues of patients with acquired immunodeficiency syndrome.

The impairment of interleukin-2 (IL-2) production occurs very early after human immunodeficiency virus (HIV) infection as a consequence of the quantitative depletion of Th1 cells. Despite the shift in cytokine production, most individuals develop an oligoclonal expansion of major histocompatibility complex restricted, HIV-specific CD8+ cytotoxic T lymphocytes (CTL) in different organs, suggesting that other cytokines replace IL-2 in initiating the tissue infiltration of CD8+ T cells. In this study we show that IL-15, a product of monocyte-macrophages and non-T cells and which has overlapping biological activities with IL-2, is involved in local cell networks accounting for the activation and expansion of CD8+ T-cell pools in a highly affected organ, ie, the lung. IL-15 induced proliferation of T cells obtained from the lower respiratory tract of HIV-infected patients with T-cell alveolitis and severe depletion of CD4+ T cells. Lung lymphocytes were CD45R0+/CD8+ T cells spontaneously expressing activation markers (CD69 and HLA-DR) and equipped with the receptorial subunits which bind IL-15, notably the beta and gamma chains of the IL-2 receptor (IL-2R) and the recently identified IL-15 binding-protein termed IL-15R alpha. Similar phenotypic findings were obtained after incubation of normal T cells with IL-15, which induced CD8+ T cells to express activation markers and to proliferate. The block of the IL-2R beta/IL-2R gamma complex with specific monoclonal antibodies abolished the T-cell stimulatory activity of IL-15 while the combination of IL-15 and tumor necrosis factor-alpha upregulated the proliferative response of lung T lymphocytes. The hypothesis that the tissue growth of lung CD8+ lymphocytes may involve cytokines produced from cells other than T lymphocytes was confirmed by the evidence that pulmonary macrophages expressed high levels of IL-15 and that anti-IL-15 antibodies inhibited the accessory function of alveolar macrophages on mitogen-induced CD8+ T-cell proliferation. Together, these results suggest that macrophage-derived cytokines produced at sites of T-cell infiltration play a role in the activation of HIV-specific CD8+ T-cell-mediated immune response.

AIDS-Related Opportunistic Infections↗
PubMed1997

Interleukin-15 triggers the proliferation and cytotoxicity of granular lymphocytes in patients with lymphoproliferative disease of granular lymphocytes.

The recently cloned cytokine interleukin-15 (IL-15) shares several functional activities with IL-2 in different cell systems. Although IL-15 does not show sequence homology with IL-2, it uses components of the IL-2 receptor (IL-2R) for binding and signal transduction, namely, p75 (beta) and the p64 (gamma) chains of IL-2R. To evaluate whether IL-15 is involved in the activation of granular lymphocytes (GL) in patients with lymphoproliferative disease of granular lymphocytes (LDGL), we evaluated the ability of IL-15 to stimulate GL proliferation, cytotoxic function, and the role of IL-2R beta and gamma molecules on relevant cells. Our results show that IL-15 stimulates cell proliferation and cytotoxic activity of GL in LDGL patients. Reverse-transcriptase polymerase chain reaction (RT-PCR) and phenotypic analyses using the anti-IL-2R gamma-chain-specific TUGh4 monoclonal antibody (MoAb) indicate that both CD3+ and CD3- GL express the p64 IL-2R, a result previously unknown. IL-15 activity was inhibited by antibodies against p75 and p64 IL-2R chains, while no inhibitory effects are detectable with anti-p55 IL-2R antibody. The association of anti-p75 and anti-p64 IL-2R MoAbs resulted in a nearly complete (95%) inhibition of IL-15-induced GL proliferation. Using RT-PCR analysis, we demonstrated that highly purified CD3+ and CD3- GL did not express mRNA for IL-15 or IL-2. By contrast, a clear-cut IL-15 mRNA signal was detected by RT-PCR in patients' peripheral blood mononuclear cells, with monocytes likely accounting for the source of IL-15 in LDGL patients. However, even in concentrated supernatants from enriched monocyte populations, we could not demonstrate the presence of IL-15 protein. Using anti-IL-15 specific MoAbs, a membrane-bound form of this cytokine was demonstrated both on CD3+ and CD3- LDGL cells. By RT-PCR analysis, purified GL from these patients were found to express the message for IL-15 receptor alpha chain. Taken together, these results indicate that both CD3+ and CD3- GL are stimulated by IL-15 and that this cytokine mediates its activity through the beta and gamma chains of the IL-2R, providing further suggestions for the interpretation of the mechanisms that lead to cell expansion in patients with LDGL.

Adult↗
PubMed1997

Spontaneous resolution of p58/EB6 antigen restricted NK-type lymphoproliferative disease of granular lymphocytes: role of Epstein Barr virus infection.

We describe a patient with a CD3- lymphoproliferative disease of granular lymphocytes (LDGL) characterized by proliferation of CD3-CD16+ GL, restricted to the expression of p58/EB6 antigen and lacking the p58/GL183 antigen. Using PCR analysis we demonstrated the presence of EBV DNA in the peripheral blood mononuclear cells and purified CD16+ GL from the patient; a monoclonal episomic configuration of the virus could not be demonstrated with Southern blot analysis. The presence of EBV DNA was also detected by PCR in the serum; this finding was associated with a serological pattern consistent with a previous, already seroconverted, EBV infection. During a 4-year follow-up the lymphocytosis spontaneously disappeared; interestingly, in terms of the p58 antigen expression, we provided evidence of the reconstitution of a normal pattern of circulating NK subsets (i.e. p58/EB6+ p58/GL183-, p58/EB6+ p58/GL183+, p58/EB6- p58/GL183-, p58/EB6-p58/GL183+). At the time of resolution of lymphocytosis, EBV-PCR analysis still demonstrated the persistence of EBV DNA in peripheral blood mononuclear cells, but not in the patient's serum. By indicating that inciting agents (in this case EBV) are involved in inducing the GL proliferation, our data contribute insights into the pathogenetic mechanisms accounting for in vivo GL accumulation in LDGL. It appears that a second, still unknown, event is required to determine the neoplastic transformation.

Aged↗
PubMed1997

Immune effector cells in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a poorly understood immunomediated disorder that is characterized by three major features; influx of inflammatory cells into the lower respiratory tract, alveolar epithelial or capillary cell injury, and release of cytokines that stimulate proliferation of fibroblasts and type II pneumocytes along with deposition of extracellular matrix proteins, notably collagen. In the past few years interest in the pathogenetic mechanisms taking place in IPF has focused on immune effector cells that are involved in pulmonary inflammatory pathways, cell-specific injury, and fibroblast activation. In particular, accumulating evidence indicates that a complex relationship exists between the macrophage/lymphocyte/neutrophil cellular axis and the local network of cytokines that, through paracrine and autocrine interactions, coordinate inflammation and fibrogenesis in the respiratory tract.

Cytokines↗
PubMed1997

Selection of T lymphocytes bearing limited TCR-Vbeta regions in the lung of hypersensitivity pneumonitis and sarcoidosis.

Hypersensitivity pneumonitis (HP) and sarcoidosis are interstitial lung disorders (ILD) characterized by a lymphocytic alveolitis that, in the active phase of the disease, is sustained by different T-cell subsets, i.e., CD8+ cells in HP and CD4+ lymphocytes in sarcoid patients. To address the question of whether a bias in T-cell selection occurs in the lung of patients with HP and sarcoidosis, we analyzed the T-cell receptor beta chain variable region (TCR-Vbeta) repertoire by flow cytometry and polymerase chain reaction (PCR) analyses in blood and lung lymphocytes of 14 HP and 25 sarcoid patients. To verify whether these cells can be activated in vitro through the TCR, blood and lung lymphocytes were also assessed for their responsiveness to different superantigenic stimuli represented by staphylococcal enterotoxins, including SEA, SEB, SEC1, SEC2, SED, and SEE. Flow cytometry and PCR analyses demonstrated an overexpression of cells bearing Vbeta2, Vbeta3, Vbeta5, Vbeta6, and Vbeta8 gene segments in the lung of HP patients as compared with the peripheral blood. In sarcoid patients cells bearing Vbeta2, Vbeta5, and Vbeta6 gene segments in the lung of HP patients as compared with the peripheral blood. In sarcoid patients cells bearing Vbeta2, Vbeta5, and Vbeta6 gene segments were overrepresented in the lung rather than in the blood. Both in HP and sarcoid patients almost all T cells bearing the dominant Vbeta segment belonged to the T-cell subset that sustains the alveolitis, i.e., CD8 in HP patients and CD4 in sarcoid subjects. Follow-up studies demonstrated that the recovery of the alveolitis was characterized by the disappearance of cells bearing a limited T-cell repertoire. Interestingly, T-lymphocyte response to different superantigens demonstrated that the proliferation elicited by different staphylococcal toxins was more pronounced in the lung than in the blood. Taken together, our findings indicate a compartmentalization of cells bearing discrete Vbeta gene products in the pulmonary microenvironment and suggest that the expansion of specific Vbeta region subsets occurring in the lung might result from triggering by a specific antigen. In fact, the removal from exposure in HP patients or specific treatment in sarcoidosis resulted in the decrease of the overrepresented cell population accounting for the lymphocytic alveolitis.

Adult↗
PubMed1997

Role of bronchoalveolar lavage in predicting survival of patients with human immunodeficiency virus infection.

In this multicenter study, we investigated the prognostic factors that influence the risk of death in patients with human immunodeficiency virus (HIV) infection. Clinical and laboratory indices obtained from 161 HIV-seropositive patients who underwent a detailed morphologic and immunophenotypic evaluation of bronchoalveolar lavage (BAL) and peripheral blood cell populations were retrospectively analyzed. In 155 patients, death occurred within the 48-mo follow-up (mean follow-up: 14.8 mo; range: 1 to 48 mo). In the univariate analysis, the patient's age (> 30 yr), HIV disease status, HIV transmission category, number of opportunistic pathogens isolated from the BAL, percentage of BAL neutrophils, and low number of BAL CD4 T cells were predictive of increased mortality. In contrast, the presence of an alveolitis or an increase in the numbers of alveolar macrophages and CD3 T cells was associated with a decreased mortality. In the multivariate analysis, significant independent predictors were age, risk factor for HIV, and presence of an alveolitis. Furthermore, patients with a low number of BAL CD4 T cells had a particularly poor prognosis while the CD4 T-cell count in the peripheral blood (< 50 cells/mm3 in the majority of our patients) had a negligible effect on predicting survival. Our findings suggest the clinical utility of BAL analysis in patients infected with HIV.

AIDS-Related Opportunistic Infections↗