CCR4, CCR5, CCR6 expression on BAL lymphocytes and macrophages of patients with bronchiolitis obliterans syndrome.

none5F. Meloni; M. Morsolini; S. Miserere; C. Pellegrini; A.M. FiettaMeloni, Federica; Morsolini, Marco; S., Miserere; Pellegrini, Carlo; A. M., Fiett

Virulence of Mycobacterium tuberculosis affects inteleukin-8, monocyte chemoattractant protein-1 and interleukin-10 production by human mononuclear phagocytes

Microbial virulence and cytokine-mediated immune responses to Mycobacterium tuberculosis infection are important determinants of the pathogenesis of human tuberculosis. To determine the interrelationship between mycobacterial virulence and cytokine induction, human monocytes and monocyte-derived macrophages were infected with attenuated (H37Ra) and virulent (H37Rv and CH306) strains of M. tuberculosis and the amount of proinflammatory [interleukin (IL)-8 and monocyte chemoattractant protein (MCP)- 1] and inhibitory (IL- 10) cytokines was measured in the culture supernatants by enzyme-linked immunosorbent assay (ELISA). Infection with live bacilli induced de novo synthesis of IL-8, MCP-1 and IL-10, since cytokine release was abolished when cells were preincubated with the protein synthesis inhibitor cycloheximide. A differential production of antiinflammatory and inhibitory cytokines was observed. The amount of IL-8 and MCP-1 release was inversely related to strain virulence, the attenuated H37Ra strain being more prone than virulent strains to induce secretion of chemokines. In contrast, virulent strains induced greater amounts of the inhibitory cytokine IL-10. Efficient upregulation of IL-10 synthesis, but not of chemokines, required infection of cells with live bacilli, since heat killing of organisms or challenge with soluble mycobacterial products completely abrogated the effect. Moreover, cells infected with virulent strains produced IL-10 even at a very low bacillus-to-cell ratio and secreted IL-10 continuously during the 96 h that followed infection. The results suggest that the degree of virulence affects host cell responses to M. tuberculosis infection. Continued production of IL-10 may be one of the means by which M. tuberculosis downregulates acute local inflammatory reactions, favoring the development of tuberculosis

A 10-year survey of Mycobacterium tuberculosis isolates in Pavia and their drug resistance: a comparison with other Italian reports

A retrospective review was made of the bacteriological and medical records of patients with culture-confirmed pulmonary tuberculosis who attended the IRCCS San Matteo Polyclinic of Pavia, between 1990 and 2000. Altogether, 279 patients were included in the survey: 220 new cases and 59 prior treatment cases. Resistance to at least one drug, and resistance to both isoniazid and rifampicin (MDR) were more common among previously treated patients than among new cases (86.4% vs. 34.1%, and 44% vs. 5.9%, respectively). While the frequency of resistance to any drug showed no variation in the period examined, a trend toward a progressive decrease in the frequency of primary MDR-TB was observed (from 11.9% in 1990-1992 to 1.3% in 1998-2000). The level of resistance observed in our study suggests that all isolates of Mycobacterium tuberculosis should be tested for drug susceptibility, especially when obtained from patients who report a previous episode of the disease

Foxp3 expressing CD4+ CD25+ and CD8+CD28- T regulatory cells in the peripheral blood of patients with lung cancer and pleural mesothelioma.

The role of T regulatory (Treg) cells in human cancer has not yet been clarified. We assessed the presence and function of CD4+ and CD8+ Treg cell subsets in the peripheral blood of patients with lung cancer (LC) and pleural mesothelioma (PM). We found a low but significant increase in the number of CD4+ T cells with phenotype and functional features of Treg cells in LC patients compared to normal healthy controls (NHC). Furthermore, total CD4+ T cells from LC pa- tients proliferated less than cells from controls, suggesting that the increase in the CD4+ Treg cell pool has func- tional importance. LC patients also showed an expansion of the CD8+CD28- T cell subset and these cells ex- pressed Foxp3 mRNA, as recently observed in alloanti- gen-specific CD8+CD28- T suppressor cells. No varia- tion of peripheral Treg cell subsets was found in patients with PM, a disease with a predominantly localized nature. However, the lack of correlation between cancer stage and the number or the function of peripheral Treg cells in LC patients refuted the hypothesis that these cells are in- volved in tumor spreading. A possible involvement of the peripheral Treg cell pool in cancer development and/or in inducing systemic immunosuppression in LC patients can be hypothesized