| Malignant pleural effusion (MPE) is one of the late clinical manifestations of manykinds of tumors including lung cancer and breast cancer. Subjectivity and poorsensitivity in cytological examinations hamper early diagnosis of MPE, resulting inthe delay of effective therapy for the disease. On the other hand, chemotherapeuticinfusions have limited curative effect and severe toxicity. Therefore a search fornovel diagnostic and prognostic markers of MPE is of great importance. Severalstudies have demonstrated that macrophages are the most important regulatory cellsin tumor microenvironment and play a critical role in the progression of MPE. Wehypothesized that identification of markers expressed by tumor associatedmacrophage (TAM) may represent potential sensitive diagnostic and therapeutictargets for MPE. In this study, using flow cytometry, we first analyzed themacrophage subtypes in50patients with MPE verified by cytologic examinationand50other cases with non-malignant pleural effusion. And then qRT-PCR wascarried out to detect the expression of macrophage-associated cytokines. A blindedvalidation study was subsequently performed. Student’s t-test, rank sum test andreceiver operating characteristic curve (ROC) analysis were used for statisticalanalysis. The number of CD14+cells were significant different between MPE andNMPE (p<0.05). Anti-inflammatory cytokine was highly expressed by CD14+monocytes from MPE, whereas pro-inflammatory cytokines were mainly expressedby CD14+monocytes from NMPE (p<0.05). More importantly, the subset ofCD14+CD163+cells in MPE was remarkably higher than that in NMPE (p<0.0001).In contrast, CD163expression was almost undetectable in peripheral blood fromcancer or non-cancer patients. Using a cutoff level of3.65%, CD163+TAMsreached a sensitivity of86%and a specificity of100%in the diagnosis of lungcancer patients with MPE. In the blinded validation study, at a specificity of100%, a sensitivity of78.9%was achieved. The results of CD14+CD163+cells proportionsin total140pleural effusions showed that CD14+CD163+cell proportion in MPEwas significant higher than that in NMPE (p<0.0001). More importantly, MPEsamples specifically express high levels of CD163molecules, suggesting CD163may serves as a sensitive diagnostic biomarker for MPE.CD14+CD163+macrophages (M2type TAM) have been found to predominantlyproduce anti-inflammatory cytokines, thus the reversion of M2type TAM topro-inflammatory TAM (M1type) may present a novel strategy for treatment ofMPE. The mannose-sensitive hemagglutination pilus strain of Pseudomonasaeruginosa (PA-MSHA) has been demonstrated to trigger na ve immune responsesthrough the activation of multiple immune cells including macrophages. In this study,we further investigated the influence of PA-MSHA on the phenotype and function ofTAM isolated from MPE. CD14+cells isolated by magnetic microbeads wereincubated with PA-MSHA for4hours in vitro. qRT-PCR results showed thatPA-MSHA treatment dramatically increased expression of pro-inflammatorycytokines such as INOS and TNF-α and significantly decreased expression ofanti-inflammatory cytokines such as arginase-I, TGF-β on CD14+macrophage.Additionally, PA-MSHA also induced expression of toll-like receptor4(TLR4) onMPE-resident macrophages. In summary, these results indicated that PA-MSHAcontributes to reverse the phenotype and function of macrophages in MPE throughTLR4pathway. Accordingly, we propose a preliminary basis for CD163expressedby TAMs as a novel option for diagnosis and treatment of MPE... |
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