Project description:CD163, a haptoglobin-hemoglobin (Hp-Hb) scavenger receptor, expressed by monocytes and macrophages, is important in resolution of inflammation. Age-related non-AIDS co-morbidities in HIV-infected individuals, particularly dementia and cardiovascular disease, result in part from effects of HIV-1 infection on monocyte and macrophage biology. CD163 co-expression on CD14+CD16++ monocytes has been proposed as a useful biomarker for HIV-1 disease progression and the presence of HIV associated dementia. Here we investigated CD163 expression on monocyte subsets ex vivo, on cultured macrophages, and soluble in plasma, in the setting of HIV-1 infection. Whole blood immunophenotyping revealed CD163 expression on CD14++CD16- monocytes but not on CD14+CD16++ monocytes (P?=?0.004), supported by CD163 mRNA levels. Incubation with M-CSF induced CD163 protein expression on CD14+CD16++ monocytes to the same extent as CD14++CD16- monocytes. CD163 expression on CD14++CD16+ monocytes from HIV-infected subjects was significantly higher than from uninfected individuals, with a trend towards increased expression on CD14++CD16- monocytes (P?=?0.019 and 0.069 respectively), which is accounted for by HIV-1 therapy including protease inhibitors. Shedding of CD163 was shown to predominantly occur from the CD14++CD16- subset after Ficoll isolation and LPS stimulation. Soluble CD163 concentration in plasma from HIV-1 infected donors was similar to HIV-1 uninfected donors. Monocyte CD163 expression in HIV-1 infected patients showed a complicated relationship with classical measures of disease progression. Our findings clarify technical issues regarding CD163 expression on monocyte subsets and further elucidates its role in HIV-associated inflammation by demonstrating that CD163 is readily lost from CD14++CD16- monocytes and induced in pro-inflammatory CD14+CD16++ monocytes by M-CSF. Our data show that all monocyte subsets are potentially capable of differentiating into CD163-expressing anti-inflammatory macrophages given appropriate stimuli. Levels of CD163 expression on monocytes may be a potential biomarker reflecting efforts by the immune system to resolve immune activation and inflammation in HIV-infected individuals.
Project description:During acute heart transplant rejection, infiltration of lymphocytes and monocytes is followed by endothelial injury and eventually myocardial fibrosis. To date, no information is available on monocyte-macrophage-related cellular shifts and their polarization status during rejection. Here, we aimed to define and correlate monocyte-macrophage endomyocardial tissue profiles obtained at rejection and time points prior to rejection, with corresponding serial blood samples in 25 heart transplant recipients experiencing acute cellular rejection. Additionally, 33 healthy individuals served as control.Using histology, immunohistochemistry, confocal laser scan microscopy, and digital imaging expression of CD14, CD16, CD56, CD68, CD80, and CD163 were explored to define monocyte and macrophage tissue profiles during rejection. Fibrosis was investigated using Sirius Red stainings of rejection, non-rejection, and 1-year biopsies. Expression of co-stimulatory and migration-related molecules on circulating monocytes, and production potential for pro- and anti-inflammatory cytokines were studied using flow cytometry.At tissue level, striking CD16+ monocyte infiltration was observed during rejection (p?<?0.001). Significantly more CD68+CD163+ M2 macrophages were documented during rejection compared to barely present CD68+CD80+ M1 macrophages. Rejection was associated with severe fibrosis in 1-year biopsies (p?<?0.001). Irrespective of rejection status, decreased frequencies of circulating CD16+ monocytes were found in patients compared to healthy individuals. Rejection was reflected by significantly increased CD54 and HLA-DR expression on CD16+ monocytes with retained cytokine production potential.CD16+ monocytes and M2 macrophages hallmark the correlates of heart transplant acute cellular rejection on tissue level and seem to be associated with fibrosis in the long term.
Project description:Human and mouse monocytes can be divided into 2 different sub-populations, using CD14-CD16 and Ly6C-CX3CR1 respectively. We investigated the pig monocytes sub-populations and found that all porcine monocyte express CD16 and CD172α but can be divided into 2 subpopulation using CD14 and the scavenger receptor CD163. The CD14hi-CD163low population resemble to the inflammatory monocytes whereas the CD14low-CD163hi display more a resident monocyte type. Pig monocyte can be differentiated into macrophages when cultured with rhCSF-1 and show an increase in size, granularity and autofluorescence, and express the common macrophage markers CD14, CD16 and CD172α. Gene expression in these 2 sub-populations was profiled using the newly-developed and annotated pig whole genome snowball microarray, showing a distinct pattern between inflammatory and resident monocytes but this difference would be more a maturation process instead of two separate subsets. Furthermore, the expression of certain genes such as CD36, CLEC4E or TREM-1 proved to share the same pattern as human monocytes, quite different from mouse monocytes. These results emphasize the potential role of the pigs as a model for human inflammatory disease and will improved our knowledge on the mononuclear phagocyte system development. Porcine PBMCs were isolated from the blood of three seperate pigs, FACS sorted on expression of CD14 and CD163 and RNA isolated from each sample, a total of 6 microarrays were hybridised
Project description:Antibody-dependent cellular cytotoxicity (ADCC) is exerted by immune cells expressing surface Fc? receptors (Fc?Rs) against cells coated with antibody, such as virus-infected or transformed cells. CD16, the Fc?RIIIA, is essential for ADCC by NK cells, and is also expressed by a subset of human blood monocytes. We found that human CD16- expressing monocytes have a broad spectrum of ADCC capacities and can kill cancer cell lines, primary leukemic cells and hepatitis B virus-infected cells in the presence of specific antibodies. Engagement of CD16 on monocytes by antibody bound to target cells activated ?2-integrins and induced TNF? secretion. In turn, this induced TNFR expression on the target cells, making them susceptible to TNF?-mediated cell death. Treatment with TLR agonists, DAMPs or cytokines, such as IFN?, further enhanced ADCC. Monocytes lacking CD16 did not exert ADCC but acquired this property after CD16 expression was induced by either cytokine stimulation or transient transfection. Notably, CD16+ monocytes from patients with leukemia also exerted potent ADCC. Hence, CD16+ monocytes are important effectors of ADCC, suggesting further developments of this property in the context of cellular therapies for cancer and infectious diseases.
Project description:Immune thrombocytopenia (ITP) results from decreased platelet production and accelerated platelet destruction. Impaired CD4(+) regulatory T-cell (Treg) compartment and skewed Th1 and possibly Th17 responses have been described in ITP patients. The trigger for aberrant T-cell polarization remains unknown. Because monocytes have a critical role in development and polarization of T-cell subsets, we explored the contribution of monocyte subsets in control of Treg and Th development in patients with ITP. Unlike circulating classic CD14(hi)CD16(-) subpopulation, the CD16(+) monocyte subset was expanded in ITP patients with low platelet counts on thrombopoietic agents and positively correlated with T-cell CD4(+)IFN-?(+) levels, but negatively with circulating CD4(+)CD25(hi)Foxp3(+) and IL-17(+) Th cells. Using a coculture model, we found that CD16(+) ITP monocytes promoted the expansion of IFN-?(+)CD4(+) cells and concomitantly inhibited the proliferation of Tregs and IL-17(+) Th cells. Th-1-polarizing cytokine IL-12, secreted after direct contact of patient T-cell and CD16(+) monocytes, was responsible for the inhibitory effect on Treg and IL-17(+)CD4(+) cell proliferation. Our findings are consistent with ITP CD16(+) monocytes promoting Th1 development, which in turn negatively regulates IL-17 and Treg induction. This underscores the critical role of CD16(+) monocytes in the generation of potentially pathogenic Th responses in ITP.
Project description:BACKGROUND:Monocytes play a central role in HIV neuropathogenesis, but there are limited data on monocyte subsets and markers of monocyte activation in perinatally HIV-infected children. OBJECTIVE:To determine the relationship between monocyte subsets, the sCD163 monocyte activation marker, and neuropsychological performance among perinatally HIV-infected children initiating antiretroviral therapy (ART). METHODS:ART-naïve children from the PREDICT study were categorised into two groups: those on ART for ?24 weeks (ART group, n =201) and those untreated (no ART group, n =79). This analysis used data from the baseline and week 144 including sCD163 and frequencies of activated monocytes (CD14+/CD16+/HLA-DR+), perivascular monocytes (CD14+/CD16+/CD163+ and CD14low/CD16+/CD163+), and neuropsychological testing scores: Verbal and Performance Intelligence Quotient (VIQ and PIQ), Beery Visuomotor Integration (VMI) and Children's Color Trails 2 (CT2). RESULTS:Baseline demographic and HIV disease parameters were similar between groups. The median age was 6 years, CD4 was 20% (620 cells/mm3), and HIV RNA was 4.8 log10. By week 144, the ART vs the no ART group had significantly higher CD4 (938 vs 552 cells/mm3) and lower HIV RNA (1.6 vs 4.38 log10 copies/mL, P <0.05). sCD163 declined in the ART vs no ART group (median changes -2533 vs -159 ng/mL, P <0.0001). Frequencies of all monocyte subsets declined in the treated but not the untreated group (P <0.05). Higher CD14+/CD16+/HLA-DR+ percentage was associated with higher VIQ, Beery VMI and CT2 scores. Higher percentages of CD14+/CD16+/CD163+ and CD14low/CD16+/CD163+ were associated with higher CT2 and VIQ, respectively. CONCLUSION:ART significantly reduced sCD163 levels and frequencies of activated and perivascular monocytes. Higher frequencies of these cells correlated with better neuropsychological performance suggesting a protective role of monocyte-macrophage immune activation in perinatal HIV infection in terms of neuropsychological function.
Project description:Hemodialysis (HD) patients exhibit chronic inflammation and leukocyte activation. We investigated the surface-marker profile of monocytes by flow cytometry to assess the chronic effect of uremia and the acute effect of dialysis on their phenotypical and functional features in 16 healthy controls (CON) and 15 HD patients before and after a polysulfone-based dialysis session. Median fluorescence intensities were analyzed indicating expression of CD14, CD16, integrins (CD11b, CD18), chemokine receptors (CCR2, CX3CR1), scavenger receptors (CD36, CD163) and Toll-like receptor-2 (TLR2). Before and after dialysis, HD patients harbour 0.9-fold less CD14++CD16- (Mo1), 1.8-fold more CD14++CD16+ (Mo2) and CD14+CD16++ (Mo3) monocytes than CON. HD patients' Mo1 showed elevated expression of CD11b (1.7-fold), CD18 (1.2-fold) and CD36 (2.1-fold), whereas CD163 expression was reduced in Mo1 and Mo2 (0.6-fold) compared to CON. These markers remained unaffected by dialysis. CX3CR1 expression on Mo2 and Mo3 was lower in HD patients before (0.8-fold) and further diminished after dialysis (0.6-fold). Stimulation of monocytes resulted in diminished responses in HD patients compared to CON. In conclusion, a systematic analysis of the expression of particular surface markers on distinct monocyte subsets may help to distinguish between uremia and/or dialysis induced effects and to evaluate the functionality of monocytes and biocompatibility of HD.
Project description:HPV infected cervical cells secrete mediators that are gradually changed and have influence on infiltrating M2 phenotypic monocytes in cervical lesions. However, profiles of circulating immune cells in women with cervical lesions and M2 phenotypic monocyte activity in HPV infected cervical lesions are limited. This study aimed to investigate circulating monocyte populations correlated with M2 phenotype density and its activity in HPV infected cervical lesions. HPV DNA was investigated in cervical tissues using PCR. High risk HPV E6/E7 mRNA was detected using in situ hybridization. CD163 immunohistochemical staining was performed for M2 macrophage. CD163 and Arg1 mRNA expression were detected using real-time PCR. Circulating monocyte subpopulations were analyzed using flow cytometry. CD163 and Arg1 mRNA expression were increased according to cervical lesion severity and corresponding with density of M2 macrophage in HSIL and SCC in stroma and peri-tumoral areas. Additionally, the relationship between M2 macrophage infiltration and high risk HPV E6/E7 mRNA expression was found and corresponded with cervical lesion severity. Circulating CD14<sup>+</sup>CD16<sup>+</sup> and CD14<sup>+</sup>CD163<sup>+</sup> monocytes were elevated in No-SIL and cervical lesions. Interestingly, CD14<sup>+</sup>CD64<sup>+</sup> monocyte was greatly elevated in HSIL and SCC, whereas intracellular IL-10<sup>+</sup> monocytes were not significantly different between cervical lesions. The correlation between increasing ratio of circulating CD64<sup>+</sup>/CD163<sup>+</sup> monocyte and density of infiltrating CD163<sup>+</sup> monocytes was associated with severity of HPV infected cervical lesions. The elevated circulating CD64<sup>+</sup>/CD163<sup>+</sup> monocyte ratio correlates to severity of HPV infected cervical lesions and might be a prognostic marker in cervical cancer progression.
Project description:Murine and human peripheral blood monocytes are heterogeneous in size, granularity, nuclear morphology, phenotype and function. Whether and how bovine blood monocytes follow this pattern was analyzed in this study. Flow cytometrically, classical monocytes (cM) CD14?CD16?, intermediate monocytes (intM) CD14? CD16? and nonclassical monocytes (ncM) CD14? CD16? were identified, with cM being the predominant subset (89%). cM showed a significant lower expression of CD172a, intM expressed the highest level of MHC class II molecules, and ncM were low positive for CD163. Compared to cM and intM, ncM showed a significantly reduced phagocytosis capacity, a significantly reduced generation of reactive oxygen species, and reduced mRNA expression of CXCL8, CXCL1 and IL-1? after LPS stimulation. Based on IL-1? secretion after LPS/ATP stimulation, the inflammasome could be activated in cM and intM, but not in ncM. IFN? increased the expression of CD16 selectively on cM and induced a shift from cM into intM in vitro. In summary, bovine CD172a-positive mononuclear cells define three monocyte subsets with distinct phenotypic and functional differences. Bovine cM and intM share homologies with their human counterparts, whereas bovine ncM are not inflammatory monocytes.
Project description:Antigen-presenting cells (APCs) are key players in the induction and regulation of immune responses. In Plasmodium falciparum malaria, determination of which cells and pathways are activated in the network of APCs remains elusive. We therefore investigated the effects of a controlled human malaria infection in healthy, malaria-naive volunteers on the subset composition and activation status of dendritic cells (DCs) and monocytes. While subsets of monocytes increased in frequency during blood-stage infection, DC frequencies remained largely stable. Activation markers classically associated with peptide presentation to and priming of ??T cells, HLA-DR and CD86, were upregulated in monocytes and inflammatory CD16 myeloid DCs (mDCs) but not in the classical CD1c, BDCA2, or BDCA3 DC subsets. In addition, these activated APC subsets showed increased expression of CD1c, which is involved in glycolipid antigen presentation, and of the immune complex binding Fc? receptor III (CD16). Our data show that P. falciparum asexual parasites do not activate classical DC subsets but instead activate mainly monocytes and inflammatory CD16 mDCs and appear to prime alternative activation pathways via induction of CD16 and/or CD1c. Changes in expression of these surface molecules might increase antigen capture and enhance glycolipid antigen presentation in addition to the classical major histocompatibility complex class II (MHC-II) peptide presentation and thereby contribute to the initiation of T-cell responses in malaria. (This study has been registered at Clinicaltrials.gov under registration no. NCT01086917.).