DW MRI at 3.0 T versus FDG PET/CT for detection of malignant pulmonary tumors.

Emerging evidence suggests that diffusion-weighted magnetic resonance imaging (DW MRI) could be useful for tumor detection with N and M staging of lung cancer in place of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). DW MRI at 3.0 T and FDG PET/CT were performed before therapy in 113 patients with pulmonary nodules. Mean apparent diffusion coefficient (ADC), maximal standardized uptake value (SUVmax ) and Ki-67 scores were assessed. Quantitatively, specificity and accuracy of ADC (91.7 and 92.9%, respectively) were significantly higher than those of SUVmax (66.7 and 77.9% respectively, p < 0.05), although sensitivity was not significantly different between them (93.5 and 83.1%, p > 0.05). Qualitatively, sensitivity, specificity and accuracy of DW MRI (96.1, 83.3 and 92.0%, respectively) were also not significantly different from that of FDG PET/CT (88.3, 83.3 and 86.7%, respectively, p > 0.05). Significant negative correlation was found between Ki-67 score and ADC (r = -0.66, p < 0.05), ADC and SUVmax (r = -0.37, p < 0.05), but not between Ki-67 score and SUVmax (r = -0.11, p > 0.05). In conclusion, quantitative and qualitative assessments for detection of malignant pulmonary tumors with DW MRI at 3.0 T are superior to those with FDG PET/CT. Furthermore, ADC could predict the malignancy of lung cancer.

Der p2 recombinant bacille Calmette-Guerin priming of bone marrow-derived dendritic cells suppresses Der p2-induced T helper17 function in a mouse model of asthma.

BACKGROUND AND OBJECTIVE: Previous studies have demonstrated that our recombinant bacille Calmette-Guerin (rBCG), which expresses Der p2 in house dust mite (Der p2 rBCG) suppresses asthmatic airway inflammation by regulating the phenotype and function of dendritic cells (DC) and reprogramming T helper (Th) 0 cell differentiation into different T cell (Th1/Th2/Treg) subtypes. However, the exact role of Der p2 rBCG in reprogramming Th17 differentiation and the relevant mechanisms are not known. The aim of this study was to examine whether Der p2 rBCG-mediated inhibition of allergic airway inflammation is mediated by regulating Th17 differentiation in a murine asthma model. METHODS: Primary mouse bone marrow-derived dendritic cells (BMDC) were infected with Der p2 rBCG and adoptively transferred to Der p2-intranasally sensitized mice. The role of Der p2 rBCG-BMDC on the regulation of airway inflammation and Th17 cell differentiation was assessed. RESULTS: Adoptive transfer of Der p2 rBCG-BMDC suppressed airway inflammation and mucin secretion. Der p2 rBCG-BMDC inhibited excessive Th17 immune responses but not BCG-BMDC. Furthermore, Der p2 rBCG decreased jagged-2 and increased delta-like-4 expressions on BMDC to a greater extent than BCG. CONCLUSIONS: These findings suggest that DC plays a key role in Der p2 rBCG-induced immunoregulation. Der p2 rBCG also displayed a potent inhibitory effect on Th17 differentiation, and these findings increase our understanding of the cellular basis of Der p2 BCG-mediated inhibition of asthma.

Der p 2 recombinant bacille Calmette-Guérin targets dendritic cells to inhibit allergic airway inflammation in a mouse model of asthma.

BACKGROUND: Previous studies showed that a recombinant bacille Calmette-Guérin (rBCG) which expressed the Der p 2 of house dust mites (Der p 2 rBCG) could suppress asthmatic airway inflammation. There are two possible mechanisms: (1) Der p 2 rBCG elicits immune deviation from Th2 to Th1, and (2) Der p 2 rBCG induces antigen-specific regulatory T cells. However, the role of dendritic cell (DC) Der p 2 rBCG in this protective effect and in reprogramming T-cell commitment still needs to be studied. OBJECTIVES: The aim of this study was to determine whether DCs play a central role in the Der p 2 rBCG-mediated inhibition of allergic airway inflammation. METHODS: DCs were collected from Der p 2 rBCG-immunized mice (Der p 2 rBCG-DCs) and adoptively transferred to Der p 2-sensitized mice. The effects of DCs on airway inflammation and immune regulation were analyzed. RESULTS: Adoptive transfer of DCs from Der p 2 rBCG-immunized mice suppressed asthmatic responses, including airway inflammation, mucin secretion and airway responsiveness. Der p 2 rBCG-DCs could effectively inhibit excessive Th2 immune responses and induced a subtype of CD4+CD25+Foxp3+ anti-specific regulatory T cells in this asthma model. Furthermore, Der p 2 rBCG immunization recruited more plasmacytoid DCs in abdominal draining lymph nodes. CONCLUSIONS: These findings suggest that DCs played a key role in Der p 2 rBCG-induced immunoregulation. Compared with BCG, Der p 2 rBCG displayed a more potent inhibitory effect on asthma responses, which may be related to the increase in plasmacytoid DC recruitment. These results improve our understanding of the cellular basis of Der p 2 BCG-mediated inhibition of asthma.

Suppression of allergic airway inflammation in a mouse model by Der p2 recombined BCG.

Allergic asthma is a chronic inflammatory disease mediated by T helper (Th)2 cell immune responses. Currently, immunotherapies based on both immune deviation and immune suppression, including the development of recombinant mycobacteria as immunoregulatory vaccines, are attractive treatment strategies for asthma. In our previous studies, we created a genetically recombinant form of bacille Calmette-Guerin (rBCG) that expressed Der p2 of house dust mites and established that it induced a shift from a Th2 response to a Th1 response in naive mice. However, it is unclear whether rBCG could suppress allergic airway inflammation in a mouse model. In this article we report that rBCG dramatically inhibited airway inflammation, eosinophilia, mucus production and mast cell degranulation in allergic mice. Analysis of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) levels in bronchoalveolar lavage fluid (BALF) and lung tissue revealed that the suppression was associated with a shift from a Th2 response to a Th1 response. At the same time, rBCG induced a CD4(+) CD25(+) Foxp3(+) T-cell subtype that could suppress the proliferation of Th2 effector cells in vitro in an antigen-specific manner. Moreover, suppression of CD4(+) CD25(+) T cells could be adoptively transferred. Thus, our results demonstrate that rBCG induces both generic and specific immune responses. The generic immune response is associated with a shift from a Th2 to a Th1 cytokine response, whereas the specific immune response against Der p2 appears to be related to the expansion of transforming growth factor-beta (TGF-beta)-producing CD4(+) CD25(+) Foxp3(+) regulatory T cells. rBCG can suppress asthmatic airway inflammation through both immune deviation and immune suppression and may be a feasible, efficient immunotherapy for asthma.

[Expression in E.coli and bioactivity assay of Micrococcus luteus resuscitation promoting factor domain and its mutants].

OBJECTIVE: To express Micrococcus luteus resuscitation promoting factor (Rpf) domain and its mutants in prokaryotic cells, and to investigate their bioactivity. METHODS: The gene of Rpf domain and its mutants (E54K, E54A) were amplified by polymerase chain reaction (PCR) from the genome of Micrococcus luteus and cloned into pMD18-T vector. After sequenced, the Rpf domain and its mutant gene were subcloned into expression vector PGEX-4T-1, and transfected into E. coli DH5alpha. The expressed product was purified by affinity chromatography using GST Fusion Protein Purification bead. The aim proteins were identified by SDS-PAGE analysis and by Western blot with monoclonal antibodies against Rpf domain (mAb). The bioactivity of the proteins was analyzed by stimulating the resuscitation of Mycobacterium smegmatis. RESULTS: The sequences of the PCR products were identical to those of the Rpf domain and its mutant gene in GenBank. The relative molecular mass identified by SDS-PAGE analysis was consistent with that had been reported, which was also confirmed by Western blot analysis that there were specific bindings at 32 000 with Rpf domain mAb. The purified GST-Rpf domain could stimulate resuscitation of Mycobacterium smegmatis. Replacements E54A and especially E54K resulted in inhibition of Rpf resuscitation activity. CONCLUSIONS: Rpf domain and two kinds of its mutant protein were obtained, and its effects on the resuscitation of dormant Mycobacterium smegmatis were clarified.

[The effects of rBCG expressing Der p2 in the form of lipoprotein on murine immune response].

AIM: To investigate the effects of rBCG vaccination containing foreign antigen Der p2 in the form of lipoprotein on murine immune response. METHODS: 6 to 8 weeks old and newborn BALB/c mice were vaccined intraperitoneally with 10(6) CFU rBCG or BCG. At the same time, the control group was injected with saline. Six weeks later, all animals were injected with Der p2 (20 microg). After two weeks later, the concentrations of IL-4 and IFN-gamma in the serum and splenocyte culture supernatant (STLCS) were determined by ELISA, and Th subgroups were determined by double fluorescent staining and flow cytometry. RESULTS: After vaccination, the serum and STLCS from both rBCG-immunized and BCG-immunized group of adult and newborn BALB/c mice had significantly higher level of IFN-gamma and lower level of IL-4 than those from control groups. Besides, there was the larger percentage of CD4 (+) IFN-gamma (+) cells in spleen from rBCG-vaccined and BCG-vaccined mice than that from control group. However, the percentage of CD4 (+) IL-4 (+) cells in spleen cells from rBCG-vaccined and BCG-vaccined group was lower than that from control group. Moreover, the level of IFN-gamma in STLCS from rBCG-immunized was significantly higher, compared with that from BCG-immunized mice. At the same time, the percentage of CD4 (+) IFN-gamma (+) cells in spleen from rBCG-vaccined mice was larger than that from BCG-vaccined group. CONCLUSION: Both rBCG and BCG could stimulate Th1 predominant immune response, when injected intraperitoneally into adult or newborn BALB/c mice, The Der p2 expressed on the cell wall of BCG can work as the component of BCG and be recognized by the immune system of mice, therefore stimulates Der p2-specific Th1 predominant immune response. These data indicate that recombinant BCG-expressing antigens can be used as the antigen-specific vaccines against allergic diseases by regulating the balance of Th1/Th2.

[Using flow cytometry to detect peripheral blood eosinophils and their related molecules].

AIM: To set up an accurate and rapid method to detect the phenotype of peripheral blood eosinophils using flow cytometry. METHODS: 10(-4) mol/L of theophylline, 10(-4) of dexamethasone and 10(-8) mol/L of rhIL-5 were added to peripheral blood sampled from normal human subjects. Anti-CD16-PE mAb and FITC-labelled mAbs to eosinophil's molecules were used to perform double labeling staining. Simultaneously, CD16-FL2 was used to install gating so as to accurately locate eosinophils. And then their molecules were examined and analyzed. RESULTS: The eosinophils were accurately located. Theophylline and dexamethasone effectively inhibited activation of eosinophils and shedding of CD62L on eosinophils caused by IL-5. CONCLUSION: Our method can accurately detect eosinophils in peripheral blood samples and their molecules. In addition, only a tiny amount of blood sample is needed and few artificial factors are involved in the detection. Therefore, this method may be an ideal both in basic immunological research and clinical laboratory examination.

[Constructing shuttle plasmid fusion expressing Ag85B-ESAT-6 on the surface of Mycobacterium].

OBJECTIVE: To construct the E. coli.-BCG (Bacille Calmette-Guerin) shuttle vector expressing Mycobacterium tuberculosis secreted protein Ag85B-ESAT-6 on the surface of Mycobacterium vaccae. METHODS: The gene fragment containing 19 000 antigen (19-ss) were amplified by polymerase chain reaction (PCR) from the Mycobacterium tuberculosis H(37)Ra. We cloned the 19ss gene into the E. coli.-BCG shuttle vector pOLYG and named the pCW, which can shuttle and express exogenous antigen gene on cell wall of Mycobacterium. Then Mycobacterium tuberculosis secret protein Ag85B and ESAT-6 gene were cloned into the vector and determined by indirect immunofluorescence. RESULTS: The sequence of 19-ss gene was identified with Genbank reported by sequencing. The constructed E. coli.-BCG shuttle vector using 19ss gene had the function of shuttle between E. coli. and Mycobacteria. By indirect immunofluorescence technique the secreted protein Ag85B-ESAT-6 can be fused and expressed on surface of Mycobacterium vaccae. CONCLUSION: The E. coli.-BCG shuttle vector is constructed successfully which could express exogenous antigen gene as a chimeric exported membrane.

[Construction and identification of the E.coli-BCG shuttle vector expressing lipoprotein Der p2 on cell wall of mycobacterium vaccae].

AIM: To construct the E.coli-BCG shuttle vector carrying and expressing dust mite antigen gene Der p2 on cell wall of mycobacterium vaccae. METHODS: The gene fragment encoding 19 kDa antigen and the upstream control element (19-ss) was amplified by PCR from the mycobacteria tuberculosis H37Rv.Subsequently, the 19-ss gene was cloned into the E.coli-BCG shuttle vector pOLYG, which can schlepped and expressed exogenous antigen gene on cell wall of mycobacteria and containing the Der p2 gene. The expression of Der p2 gene in mycobacterium vaccae determined by indirect immunofluorescence staining. RESULTS: Sequencing proved that the cloned sequence of 19-ss gene was correct. The constructed E.coli-BCG shuttle vector (pCW) containing 19-ss gene had function of shuttle between E.coli and mycobacteria, and mediated the expression of antibiotic resistance gene. Indirect immunofluorescence staining indicated that the Der p2 gene was expressed in the form of lipoprotein on surface of the mycobacterium vaccae. CONCLUSION: E.coli-BCG shuttle vector has been constructed successfully, which can express exogenous antigen gene as a chimeric protein on cell wall.