Biomedical subjects

M Bocchino

Publications and source records attributed to M Bocchino.

At least 19 recordsLinked to original sources

PubMed2006

Lysophosphatidic acid enhances antimycobacterial activity both in vitro and ex vivo.

Lysophosphatidic acid (LPA) is a polar lipid metabolite which is involved in a wide range of biological processes, including cell proliferation and migration, wound healing, and increase of endothelial permeability. The present study reports evidences showing that LPA is able to enhance the antimicrobial activity of human macrophages and of bronchoalveolar lavage cells from tuberculosis patients leading to intracellular growth control of Mycobacterium tuberculosis. Such antimicrobial activity is mediated by the activation of phospholipase D which in turn induces acidification of M. tuberculosis containing phagosomes and is associated with the enhanced expression of Cathepsin D. These results suggest the possible protective role of this lysophospholipid in the activation of innate antimycobacterial response.

Adjuvants, Immunologic↗

PubMed2006

Cost determinants of tuberculosis management in a low-prevalence country.

SETTING: Division of respiratory medicine in a specialised infectious disease hospital in Rome, Italy. OBJECTIVE: Retrospective evaluation of tuberculosis (TB) care associated costs in an integrated in- and out-patient management programme. DESIGN: Review of the medical records of 92 human immunodeficiency virus negative TB cases admitted between September 2000 and May 2003. RESULTS: Length of in-hospital stay (45 +/- 35 days) was the major cost determinant, as hospitalisation accounted for almost 80% of the total costs of the case, with fixed bed-per-day charges amounting to 76% of hospital costs. Factors associated with higher costs were chest X-ray score, fever, sputum bacterial load and multidrug resistance (P < 0.05). Cure/treatment completion was achieved in 82% of patients entering the out-patient programme (63% of all cases). Homelessness, age and comorbidities were associated with unfavourable outcomes. CONCLUSIONS: A closely followed hospital-centred protocol carried out in a high-resource setting may produce acceptable cure/completion treatment rates. As a too high fraction of resources invested in TB control goes toward hospital costs, out-patient treatment strategies should be implemented.

Adult↗

PubMed2005

Role of mycobacteria-induced monocyte/macrophage apoptosis in the pathogenesis of human tuberculosis.

Apoptosis is a physiological programmed cell death process whose dysregulation plays an important role in different human infectious diseases. An increasing number of intracellular pathogens are known to induce target cell apoptosis, while some other parasites inhibit it. Unlike necrosis, apoptosis is a silent immunological event occurring without inflammation. Infection-induced target cell apoptosis may be a successful strategy to eliminate pathogens and assure host survival. Conversely, apoptosis inhibition could represent an adaptive mechanism for pathogen survival, while it may be beneficial for the host to initiate an effective immune response. The worldwide increase in tuberculosis has stimulated more research aimed at defining the interaction between Mycobacterium tuberculosis and the immune system. M. tuberculosis possesses sophisticated strategies to circumvent its fate within target monocytic cells. Apoptosis of alveolar macrophages and monocytes has been described as a consequence of M. tuberculosis infection. Moreover, the observation that mycobacterial lipoproteins activate macrophages through Toll-like receptor (TLR) 2 suggests that innate immune receptors contribute to defence against M. tuberculosis. There is evidence that TLR-induced apoptosis modulates inflammation and immune activation during M. tuberculosis infection. Finally, the role of apoptotic-infected cells as a source of microbial antigens for cross-priming of effector T-cells is also discussed.

Apoptosis↗

PubMed2004

Expansion of CCR5+ CD4+ T-lymphocytes in the course of active pulmonary tuberculosis.

Nonsyncytium inducing, macrophage tropic HIV strains predominate in the course of active tuberculosis (TB). The present study assesses the expression of CCR5 in CD4+ T-lymphocytes from blood and bronchoalveolar lavage (BAL) of TB patients, non-TB lung disease controls and healthy controls. Memory (CD45RO+), recently activated (CD69+), proliferating (Ki67+) CCR5+ or CCR3+ CD4+ T-lymphocytes were determined by multiparametric flow cytometry analysis. Results show that BAL CD4+ T-lymphocytes expressing CCR5 or CCR3 were significantly increased when compared to peripheral blood both in patients and in healthy controls. However, the data show that the proportions of peripheral blood CCR5+ CD4+ and CCR3+ CD4+ T-lymphocytes and BAL CCR5+ CD4+ T-lymphocytes, but not BAL CCR3+ CD4+ T-lymphocytes, were significantly increased in TB patients. Furthermore, the observation that BAL CCR5+ CD4+ T-lymphocytes from TB patients expressed early activation markers, were not proliferating and showed down-regulation of CCR5 expression suggests recruitment and trapping at the site of disease. Altogether, these results suggest that the lower respiratory tract mucosa may provide cellular targets accessible for efficient transmission of macrophage tropic HIV-1 variants and that tuberculosis may enhance this phenomenon.

Adult↗

PubMed2001

Increased priming for interleukin-12 and tumour necrosis factor alpha in CD64 monocytes in HIV infection: modulation by cytokines and therapy.

BACKGROUND: A key factor leading to impaired immunity in HIV infection is an alteration of the pattern of cytokine response, although its precise nature remains controversial, particularly the in vivo influence of HIV on interleukin (IL)-12 synthesis. DESIGN: A cross-sectional study in 73 HIV-infected persons (28 of them receiving highly active antiretroviral therapy) and 18 HIV-seronegative healthy donors. METHODS: The frequency of monocytes/macrophages (M/M) synthesizing IL-12, IL-10 and tumour necrosis factor alpha (TNF-alpha) was determined in peripheral blood mononuclear cells. The cells were cultured in medium or were stimulated with lipopolysaccharide; proportions of CD64 M/M producing IL-12, TNF-alpha or IL-10 was determined by cytofluorometric analysis. The influence of exogenous interferon gamma (IFN-gamma), IL-10 or IL-15 on IL-12 synthesis was tested. RESULTS: Chronic HIV disease is associated with increased priming of M/M for IL-12 (involving both p40 and p70 molecules) and TNF-alpha synthesis; this was associated with cosynthesis of both cytokines by a fraction of M/M. Priming for IL-12 was physiologically enhanced by IFN-gamma and decreased by IL-10; IL-15 had no effect. The proportion of IL-10-producing CD64 M/M was not altered in patients compared with controls but there was an inverse correlation between IL-10-producing M/M and viral load. IL-12 production was not correlated with viral load but was increased following antiretroviral therapy. Following LPS stimulation, IL-12 and TNF-alpha responses were not altered in HIV-positive patients; however, the IL-10 response was decreased but restored by antiretroviral therapy. CONCLUSION: These observations argue for a preserved intrinsic CD64 M/M of IL-12 production in HIV pathogenesis.

Anti-HIV Agents↗

PubMed2001

Tuberculosis and lung cancer. An interesting case study.

This report describes the case of a patient with lung cancer who completely recovered when he was suffering from tuberculosis. Since bacillus Calmette-Guerin (BCG) has beneficial effects in certain types of cancer, it was hypothesized that infection with Mycobacterium tuberculosis induced an effective response against the tumour. M. tuberculosis-infected blood T-lymphocytes of the patient were cultured with two lung tumour cell lines. T-lymphocytes in vitro remained attached to tumour cells that appeared reduced in number. Moreover, M. tuberculosis isolated from the patient was a strong inducer, in infected macrophages, of the expression of the inducible form of the nitric oxide synthase, that may regulate cytotoxic activity of human macrophages.

Aged↗

PubMed2001

Demographic risk factors and lymphocyte populations in patients with tuberculosis and their healthy contacts.

SETTING: Campania, a southern region of Italy, and the Institute of Respiratory Diseases, Monaldi Hospital, University 'Federico II', Naples. OBJECTIVE: To evaluate clinical and socio-demographic risk factors for tuberculosis (TB) infection and/or disease. Peripheral blood lymphocytes from a sub-cohort of 19 patients and 53 contacts were studied by flow cytometry. DESIGN: A prospective study among patients with newly diagnosed pulmonary tuberculosis and their close contacts. RESULTS: A total of 90 patients and 277 contacts were enrolled. The prevalence of infection was 45% (95%CI 39-51%) among contacts. Age, sex, delay in diagnosis and treatment, cavitation on chest radiograph, cough, unwillingness to cover the mouth, and volume of air shared by close contacts and patients were investigated as potential risk factors for infection. Only delay in diagnosis of cases remained independently associated with an increased risk of infection (P < 0.0002), and hemoptysis was the only factor capable of reducing the delay significantly. The CD8+ CD28+ cytotoxic subset was significantly diminished in the patients (P < 0.001), whereas the CD8+ CD28- and CD8+ CD57+ (suppressor and NK-like subsets) were elevated (P < 0.001 and P = 0.04). CONCLUSIONS: These data show that delay in diagnosis of cases is a crucial factor for tuberculosis and that cytotoxic CD8+ cells play a primary role in immune response to tuberculosis.

Adult↗

PubMed2000

P53 immunohistochemistry can identify bronchial dysplastic lesions proceeding to lung cancer: a prospective study.

Dysplasia is an important step in bronchial carcinogenesis and smokers present more dysplastic lesions than nonsmokers. These lesions not always lead to malignancy, so there is a need for additional, preferentially objective, diagnostic markers. To verify whether immunohistochemical overexpression of p53 protein in dysplastic areas could be a predictive marker of the development of lung cancer, we investigated p53 overexpression in 22 bronchial dysplastic lesions obtained by fibrebronchoscopy from heavy smokers who were not diagnosed as having lung cancer and were followed for a 4-yr period. Nine (41%) lesions showed p53-positivity. Seven lung cancers (78%), mostly squamous cell carcinomas, were detected within the follow-up in these patients and 3 in 13 (23%) patients with p53-negative lesions. Lung cancer occurred in all seven patients with dysplastic lesions showing >10% p53 positive nuclei. The positive predictive value of p53 immunostaining for lung cancer was 78%. The negative predictive value of p53 was 77%. p53 staining was not detected in squamous metaplasia lesions without atypia and in normal bronchial epithelium. Our findings provide evidence that p53-overexpression in bronchial dysplastic areas may be a clinically useful marker for identifying patients proceeding to, at least, squamous cell carcinoma and, in addition, may facilitate the detection of occult tumours.

Bronchi↗

PubMed2000

HIV, cytokines and programmed cell death. A subtle interplay.

HIV infection is marked by the progressive destruction of the CD4 T lymphocyte subset, an essential component of the immune system and a vital source of cytokines required for differentiation of natural killer (NK) and gamma delta T cells, for maturation of B lymphocytes into plasmocytes, and for differentiation of CD8+ T cells into virus-specific cytotoxic T lymphocytes. CD4 T lymphocytes are also a source of chemokines which control migration of lymphocytes to the site of infection and which also inhibit HIV entry into CD4-expressing targets. Continuous production of viral proteins leads to an unbalanced immune activation and to the triggering of apoptotic programs, turning mononuclear cells, including CD4 T cells, CD8 T cells and APC, into effectors of apoptosis, leading to fratricidal destruction of healthy uninfected cells expressing the death receptors. Inappropriate PCD is also responsible for the disappearance of T helper cells primed for type-1 cytokine synthesis, thus contributing to the lack of survival factors which could prevent spontaneous lymphocyte apoptosis. Under potent anti-retroviral therapies, a significant decrease in spontaneous, TCR- and CD95-induced lymphocyte apoptosis is observed, concomitant with a partial quantitative and qualitative restoration of the immune system in treated patients. However, owing to the suppressive effect of anti-retroviral drugs on physiological apoptosis, these therapies are associated with alteration of TNF-alpha-regulated T cell homeostasis, leading to an accumulation in the blood of T cells primed for TNF-alpha synthesis, and contributing to the development of a new syndrome associated with these treatments, the lipodystrophy syndrome.

Animals↗

PubMed2000

Mycobacterium tuberculosis and HIV co-infection in the lung: synergic immune dysregulation leading to disease progression.

There is evidence that Mycobacterium tuberculosis (Mtb) impacts on human immunodeficiency virus (HIV) infection and that HIV promotes mycobacterial diseases. Epidemiological and clinical studies demonstrate the detrimental effect of tuberculosis (TB) on the progression of HIV infection, that is an increased risk of death among Mtb-HIV co-infected patients. Pulmonary TB may occur very early during HIV infection, whereas extrapulmonary or atypical manifestations are associated with more profound immunodeficiency, showing features like mycobacteraemia and multi-drug resistance, much more severe than in immunocompetent hosts. During the last decade, many efforts have been focused on the immunological aspects of Mtb-HIV co-infection. The host protective response to TB is mediated by cell immunity, which, mainly supported by interleukin (IL)-12 and interferon (IFN)-gamma production, leads to granuloma formation. Perturbations in the cytokine expression, that is a reduced type-1-like response, have been suggested in HIV-infected patients to contribute to their susceptibility to TB. Indeed, an impaired balance between pro-inflammatory and anti-inflammatory cytokines and apoptosis-induced depletion of immune effector cells account for the dissemination of both the pathogens and for a poor granulomatous reaction in Mtb-HIV co-infected patients. However, the recently elucidated role of chemokines and their receptors in immune regulation opens new questions on the pathogenesis of Mtb-HIV co-infection.

Cytokines↗

PubMed1971