Percentage Of Myeloid Dendritic Cells Research Articles

17th International Conference on Malignant Lymphoma, Palazzo dei Congressi, Lugano, Switzerland, 13 - 17 June, 2023.

Introduction: FL is characterized by a heterogeneous clinical course. The biologic importance of the tumour microenvironment in FL pathogenesis is well established. However, detailed information on the immune profile in PB has not been previously investigated, which becomes very relevant in the current era of the immunotherapy. The aim of this study was to characterise the PB immune profile of FL patients at diagnosis, first relapse (R1) and subsequent relapses (>R2) and compare them with healthy controls. Moreover, R1 was also analysed according to histological transformation (HT) and POD24 status. Methods: We collected PB samples of FL patients at diagnosis (n = 42), R1 (n = 22) and >R2 (n = 16) from April 2019 to August 2022 (median age at diagnosis: 65 years [30–82]; 22M/20F). 15 PB samples from healthy donors were also obtained (median age: 31 years [28–65]; 5M/10F). All individuals signed informed consent. The identification of major subsets of T-cells, B-cells, NK cells, monocytes, neutrophils, eosinophils, basophils, dendritic cells (DC) and myeloid suppressor cells (MSC) was performed by multiparameter flow cytometry. Euroflow methodology was used to set up the Omnicyt™ flow cytometer and acquired at least 150.000 events. All data were analysed using Infinicyt™ software version 2.0 (Cytognos, Salamanca, Spain). Results: Compared with healthy controls, FL patients showed a lower CD4+/CD8+ ratio due to an increase in CD8+ lymphocytes and a decrease in total CD4+ lymphocytes. In addition, FL patients had a significantly lower percentage of naïve T lymphocytes, a higher percentage of effector memory and effector lymphocytes, both CD4+ and CD8+. Of note, regulatory T lymphocytes (Treg) and Th1 cells were increased in FL patients, while NK-cells were diminished. Interestingly, differences in DC and MSC were also found between healthy controls and FL patients (Figure). These differences remained when comparing the immune populations between diagnosis and relapse and deepened with each relapse. No differences were observed between groups in the percentage of neutrophils, monocytes, eosinophils, or total B lymphocytes. A subanalysis performed in R1 samples according to HT and POD24 status revealed that HT-R1 presented significantly a smaller CD8+ central memory population compared with non HT-R1. POD24 patients displayed a lower CD4+/CD8+ ratio and a higher proportion of Th1 cells (p < 0.05). In both adverse prognostic groups, the percentage of myeloid DC and neutrophils was significantly lower. The research was funded by: This study has been funded by Instituto de Salud Carlos III (ISCIII) through the projects PI19/00887 to A.L.-G. and E.G., and PI19/00925 to L.M. Andrea Rivero was supported by a grant from Hospital Clinic de Barcelona during the conduct of the study. Keywords: indolent non-Hodgkin lymphoma, microenvironment No conflicts of interests pertinent to the abstract.

Percentage of Myeloid Dendritic Cells in Peripheral Venous Blood Is Negatively Related to Incidence of Graves’ Orbitopathy

The aim of the study was to evaluate the distribution of blood dendritic cells (DCs) in patients with Graves' orbitopathy (GO) and to assess the influence of methylprednisolone therapy on subsets of peripheral blood mononuclear cells (PBMCs). Peripheral blood DC subsets were analyzed by flow cytometry in patients with active GO (n = 17), inactive GO (n = 8), and Graves' disease (GD) without GO (n = 8) and controls (n = 15); additionally, in patients with active GO (n = 17), analyses were done at three time points, i.e., before methylprednisolone treatment and after 6 weeks and after 12 weeks of the treatment. Percentage of myeloid DCs (mDCs) in PBMC fraction was significantly lower in patients with both active and inactive GO, compared to patients with GD without GO and controls (p < 0.05). In addition, mDCs were also documented to be an independent factor negatively associated with GO, however without essential differences between active and inactive phases. On the other hand, we did not observe any changes in the percentage of DCs after methylprednisolone therapy (p > 0.05). In the present study, we have succeeded to firstly demonstrate—according to our knowledge—that blood mDCs are negatively related to GO incidence.

Abnormal Activation of Myeloid Dendritic Cells in JORRP Patients and Associated with Disease Activity

BackgroundRepresenting the first line of host defense against virus infections and an essential link between innate and adaptive immune response, the role of dendritic cells (DCs) in peripheral blood of juvenile-onset recurrent respiratory papillomatosis (JORRP) patients and association with disease activity were still not established. Materials and MethodsIn our present study, 28 JORRP patients and 28 age and sex matched healthy controls were enrolled. The percentage, phenotype and cytokine secretion of DC and was measured by flow cytometry. Plasma cytokine were detected by the enzyme-linked immunosorbent assay (ELISA). ResultsWe found that the percentage of myeloid DC (mDC) was significantly lower in JORRP patients compared to healthy controls and was negatively correlated with interval times, but not surgical times or disease onset. Moreover, the activation marker, CD40 and CD86 was significantly up-regulated on the surfaces of mDC in JORRP patients compared with healthy controls. Neither the percentage nor activation of plasmacytoid DC (pDC) showed statistical difference between JORRP patients and healthy controls. HLA-DR expression on both mDC and pDC was down-regulated in JORRP group and negatively correlated with surgical times. Antigen presenting ability of DC was greatly impaired in JORRP patients of higher number of operations and shorter interval time. Plasma IL-10 as well as IL-10 secreted by mDC was higher in JORRP patients compared with healthy control. Finally, we detected an up-regulated TLR2 and TLR4 expression on mDCs and TLR4 expression was positively correlated with HLA-DR expression on mDC of JORRP patients. ConclusionOur results demonstrate an abnormal TLR2 and TLR4 expression in mDCs may contribute to suppressive immune response to HPV6 or HPV11 infection and associated with disease activity in JORRP patients.

Methadone therapy modulate the dendritic cells of heroin addicts

Evidence from various studies suggests that narcotics abuse may exert adverse immunomodulatory effects on immune responses. The aim of this research was to understand the effects of detoxification with methadone on the percentage of dendritic cells (DCs) and expression of its markers in heroin addicts. In this study, myeloid DCs (CD11c+) and plasmacytoid DCs (CD123+) were examined in two groups. These groups comprised of 20 healthy volunteers and 20 chronic heroin addicts, before and after detoxification with methadone. The percentages of myeloid DCs and plasmacytoid DCs were lower in addict subjects than in the control. The HLA-DR expression on DCs was significantly lower in addict subjects than in the control, whereas CD11c and CD123 expression in DCs subsets were increased in them. Most of these changes were modified after the methadone therapy. Dendritic cells are essential to the initiation of primary immune responses, therefore the disruption of their function can be one of the reasons for the increased prevalence of infections in heroin addicts. The methadone therapy can improve the imposed changes by heroin.

Peripheral Dendritic Cells and CD4+CD25+Foxp3+ Regulatory T Cells in the First Trimester of Normal Pregnancy and in Women with Recurrent Miscarriage.

The development of pregnancy is possible due to initiation of immune response in the body of the mother resulting in immune tolerance. Miscarriage may be caused by the impaired maternal immune response to paternal alloantigens located on the surface of trophoblast and fetal cells. The aim of the study was to compare the population of circulating dendritic cells (DCs) and CD4+CD25+Foxp3+ regulatory T cells (TREGs) in the first trimester of a normal pregnancy and in women with recurrent miscarriage and an attempt to determine the relationship between these cells and the role they may play in human reproductive failures. The study was conducted in a group of 33 first trimester pregnant women with recurrent miscarriage and in a group of 20 healthy pregnant women in the first trimester of normal pregnancy. Among mononuclear cells isolated from peripheral blood, the populations of DCs and TREGs were assessed by flow cytometry. The percentage of myeloid DCs and lymphoid DCs showed no significant difference between study and control group. Older maternal age and obesity significantly reduced the pool of circulating myeloid and lymphoid DCs (R=-0.39, p=0.02). In miscarriages the percentage of circulating TREGs was significantly lower compared to normal pregnancies (p=0.003). Among the analysed factors the percentage of TREGs was the most sensitive and the most specific parameter which correlated with the pregnancy loss. The reduction in the population of circulating TREGs suggests immunoregulatory mechanisms disorder in a pregnancy complicated by miscarriage.

Simian hemorrhagic fever virus: Recent advances

The simian hemorrhagic fever virus (SHFV) genome differs from those of other members of the family Arteriviridae in encoding three papain-like one proteases (PLP1α, PLP1β and PLP1γ) at the 5′ end and two adjacent sets of four minor structural proteins at the 3′ end. The catalytic Cys and His residues and cleavage sites for each of the SHFV PLP1s were predicted and their functionality was tested in in vitro transcription/translation reactions done with wildtype or mutant polyprotein constructs. Mass spectrometry analyses of selected autoproteolytic products confirmed cleavage site locations. The catalytic Cys of PLP1α is unusual in being adjacent to an Ala instead of a Typ. PLP1γ cleaves at both downstream and upstream sites. Intermediate precursor and alternative cleavage products were detected in the in vitro transcription/translation reactions but only the three mature nsp1 proteins were detected in SHFV-infected MA104 cell lysates with SHFV nsp1 protein-specific antibodies. The duplicated sets of SHFV minor structural proteins were predicted to be functionally redundant. A stable, full-length, infectious SHFV-LVR cDNA clone was constructed and a set of mutant infectious clones was generated each with the start codon of one of the minor structural proteins mutated. All eight of the minor structural proteins were found to be required for production of infectious extracellular virus. SHFV causes a fatal hemorrhagic fever in macaques but asymptomatic, persistent infections in natural hosts such as baboons. SHFV infections were compared in macrophages and myeloid dendritic cells from baboons and macaques. Virus yields were higher from macaque cells than from baboon cells. Macrophage cultures from the two types of animals differed dramatically in the percentage of cells infected. In contrast, similar percentages of myeloid dendritic cells were infected but virus replication was efficient in the macaque cells but inefficient in the baboon cells. SHFV infection induced the production of pro-inflammatory cytokines, including IL-1β, IL-6, IL-12/23(p40), TNF-α and MIP-1α, in macaque cells but not baboon cells.

Regulatory T cells, dendritic cells and neutrophils in patients with renal cell carcinoma

We evaluated dendritic cells (DC), regulatory T lymphocytes (Treg) and neutrophils in 37 patients with newly diagnosed renal cell carcinoma (RCC) in the tumor and peripheral blood (PB) and correlated these parameters with tumor staging (early-T1, 2, late-T3, 4 and metastatic disease). The number of myeloid and plasmacytoid DC in blood of RCC patients was higher than in healthy controls. The percentage of myeloid dendritic cells (mDC) from CD45+ cells in tumors was higher in comparison with peripheral blood irrespective of disease stage. Higher percentage of these cells expressed a maturation marker in the periphery in the early stage (CD83 expressing cells). The number of plasmacytoid dendritic cells (pDC) in PB was similar in both early and late stage groups, but the early group displayed a significantly higher percentage of pDC in tumor cell suspension. Neutrophil counts in the peripheral blood of RCC patients were higher than in healthy controls, but the counts in both tumor stage groups were similar. The proportion of neutrophils from CD45+ cells was higher in late stage tumors. Higher percentage of Treg from CD4+ cells was detected in renal carcinoma tissue in comparison to PB with no difference between stages of the disease. Our results reflect the complex interplay between various cells of the immune system and the tumor microenvironment. Activation of dendritic cell subpopulations at early stages of the disease course is counterbalanced by the early appearance of T regulatory cells both in the periphery and tumor tissue. Later stages are characterized by the accumulation of neutrophils in the tumor. Appropriate timing of anticancer strategies, especially immunotherapy, should take these dynamics of the immune response in RCC patients into account.

B Cell Development and the Splenic Microenvironment in Dlk-1 Deficient Mice

AbstractAbstract 1251 Background:DLK-1 is a transmembrane and secreted protein that plays a crucial role in normal B cell development and differentiation. In a previous study we showed that DLK-1 knockout mice (Dlk1−/− mice (KO)) have distinct differences in B cell fractions in the spleen and bone marrow compared to wild-type Dlk1+/+ (WT) mice. KO mice showed a decrease in follicular (FO) B cells and an increase in the size of the marginal zone (MZ) and number of MZ B cells in the spleen of 8 week old mice. Furthermore, there was an exaggerated primary T-dependent antigen-specific humoral immune response. The mechanisms underlying the changes in splenic B cell fractions between KO and WT mice are not yet clear. It has been suggested that stromal microenvironmental cells form distinct cellular niches that influence different stages of B cell development. Alterations in these stromal niches due to absence of DLK-1 may be an underlying cause of the observed splenic B cell fraction alterations. It was previously shown that Galectin-1 (GAL1) plays an important role in the bone marrow microenvironment and affects proliferation and differentiation of normal mouse pre-BII cells (Blood April 21, 2011). This study is designed to investigate the splenic stromal cells in DLK-1 deficient mice as a step toward understanding these B cell alterations, and to test whether the stromal cell derived-GAL1 influences splenic B-cell development. Methods:For detection of B cell fractions, a multicolor flow cytometry panel consisting of anti-IgD/IgM/CD23/CD93/CD45R/CD21/CD35 was used. B cell fractions were identified as follows: MZ (CD23neg-low, CD21high), FO (CD23high, CD21intermediate), Tr1 (CD23neg, CD21neg, AA4.1pos, B220pos), Tr2 (CD23pos, AA4.1pos, B220pos). For detection of stromal cell fractions, an anti-CD11c/Ter119/CD19/Gr-1/Tie-2/CD45/CD31/CD117/CD34 panel was used. Stromal cells were identified as follows: CD45neg, lineage− (Ter119, CD19, GR1, CD11c, and CD34), CD117neg, CD34neg, Tie2neg. Two stromal cell fractions were detected: CD31 +and CD31−. Galectin-1 expression was evaluated on CD31+ and CD31−stroma cell fractions. An eight color flow cytometric panel consisting of antibody directed to MHC II, CD11c, Gr-1, CD8a, B220, and CD11b was used to evaluate myeloid, lymphoid and plasmacytoid dendritic cell fractions. Results:Our data showed an increase in MZ B-cells (p<0.005) and a decrease in FO B cells (p<0.005) in the KO mice. When looking at the splenic stromal cells, we found an increase in the CD31+ fraction and a decrease in the CD31- fraction in KO mice compared to WT mice (p<0.005). We observed that the CD31 + stromal cell expressed high galectin-1 (GAL1) levels compared to CD31− stroma cells. Also there was an increased percentage of myeloid dendritic cells in KO compared to WT (p< 0.05). Conclusion:We have shown that absence of DLK-1 leads to alterations in splenic stromal populations and that these may play an important role in altered B cell populations and function observed in DLK-1-deficient mice. We are investigating whether the CD31+ GAL1 +stroma cell is a key stroma cell that plays a critical role in splenic B cell development and is responsible for the B-lineage differences seen in DLK-1-deficient mice. Our observation that there is an increase in the myeloid dendritic cell fraction may explain the exaggerated primary immune response seen in the KO mice. These data show that DLK-1-deficiency leads to several changes in the splenic cellular microenvironment and suggest that these changes contribute to alterations in B-cell development and function. Disclosures:No relevant conflicts of interest to declare.

Effect of inosine monophosphate dehydrogenase inhibitor on chemotaxis, migration and endocytosis of human peripheral myeloid dendritic cells

Objective To study the effect of inosine monophosphate dehydrogenase inhibitor (IMPDHI) on chemotaxis, migration and endocytosis of human peripheral myeloid dendritic cells (MDCs). Methods Freshly isolated peripheral blood mononuclear cells(PBMC)collected from healthy volunteers (N=15) and the study group were treated with IMPDHI. CC chemokine receptors on MDCs were analyzed by flow cytometry. The study group, control group and different chemokines were added via trans-well approach for different chemokines, stained by Lin-1/CD11c/HLA-DR and counted by flow cytometry. The migration index was calculated as a percentage of MDC migrated in response to the tested chemokine. After isolation of blood dendritic cell antigen-1+ (BDCA-1+ ), mannose receptor-mediated endocytosis was measured as the cellular uptake of FITC-dextran by the flow cytometry. Results (1) Compared to the control group, the expression of CCR1 in the study group was up-regulated significantly(17.02±3.23～30.63±9.13, P＜0.05) and the expressions of CCR3(10.26±2.25～5.81±0.97 P＜0.05) and CCR7 (9.56± 1.84～5.18±0.60 P＜0.05)were downregulated significantly. MDCs in the study group showed enhanced migratory response to inflammatory chemokine CCL2, CCL3, CCL4, CCL7 and CXCL12 (P＜0.05). (2)The endocytosis capacity in the study group was significantly higher than that in control group (P ＜0.05). Conclusion IMPDHI enhances the endocytotic capacity of MDCs and impairs the migratory response of peripheral MDCs to lymphocytic tissue by up-regulating the expression of chemokine receptor in MDCs and enhancing migratory response to inflammatory chemokines. Key words: Inosine monophosphate dehydrogenase inhibitor; Chemokine; Migration; Endocytosis

Significant Decline of Peripheral Myeloid Dendritic Cells Following Multiple Trauma

Dendritic cells (DC) represent an important and integral part of the immune system and are potent initiators of inflammation. Two distinct subsets of DC have been identified: myeloid DC (MDC) and plasmacytoid DC (PDC), which differ widely in many respects. Despite the importance of the DC in the inflammatory response that occurs after severe multiple injury, there is a profound lack of information regarding the distribution and regulation of DC subtypes following multiple trauma. The main goal of this study was to assess whether the normal distribution of circulating DC subpopulations is altered during the first 5 d after multiple trauma. Sixty-three patients with multiple trauma (ISS 31 +/- 15 points) and 11 healthy volunteers (control group) were enrolled. Blood samples were taken on admission (D0) and daily for the following 5 d. The percentages of MDC and PDC were determined by flow cytometry. A significant decline of the MDC concentration was observable on days 3 to 5 after admission in comparison to the values obtained on the day of admission. The ratio of MDC to PDC decreased significantly (3-fold, P < 0.05). This reduction correlated significantly with changes observed in the plasma concentrations of IL-10 (r = 0.5; P < 0.05). Our data demonstrate that multiple trauma is followed by a marked change in the subpopulation composition of the DC compartment, and that these changes are inversely associated with enhanced IL-10 plasma concentrations. This imbalance in the DC compartment favoring PDC concentrations may contribute to the immunological alterations that are observed following multiple trauma.

Dendritic cell subsets in the peritoneal fluid and peripheral blood of women suffering from ovarian cancer

Evaluation of immature myeloid and lymphoid dendritic cells (DCs) in the peritoneal fluid (PF) and peripheral blood (PB) mononuclears of women with ovarian carcinoma (n = 47) and benign ovarian tumors (n = 37). Mononuclear cells were isolated from PF and PB, stained with monoclonal antibodies (mAbs) against DC antigens (anti-BDCA-1, anti-BDCA-2), and estimated using flow cytometry. The percentage of PF myeloid DC (MDC) in mononuclears was significantly lower in patients with ovarian cancer in comparison to the group of nonmalignant ovarian tumors (0.65% and 6.95%). The percentage of PF lymphoid DCs (LDCs) was higher in patients with ovarian cancer than in the reference group (0.64% and 0.09%). The percentage of PB MDCs and LDCs did not differ significantly between studied groups. In women suffering from ovarian cancer the percentage of both MDCs and LDCs was higher in the PF than in the PB. In the reference group the percentage of MDCs was higher but that of LDCs was lower in the PF than in the PB. In women with ovarian cancer, PF MDCs/LDCs ratio was lower in comparison to patients with serous cystadenoma. In PB the ratio of MDCs to LDCs did not differ significantly between studied groups. We concluded that MDCs population may be affected by the presence of malignant disease. LDC subsets may have influence on the local immune response in the PF of women with malignant tumors of the ovary. (c) 2008 Clinical Cytometry Society.

Deficiencies in myeloid antigen‐presenting cells in women with cervical squamous intraepithelial lesions

There is little information on the function of dendritic cells in women with human papillomavirus (HPV)-related cervical squamous intraepithelial lesions (SILs). In the current study the functions of dendritic cells in the development of T-cell immunity in women with cervical SILs were assessed. The percentage of myeloid dendritic cells (MDCs) and plasmacytoid dendritic cells (PDCs) in peripheral blood were enumerated of 44 patients with SIL (low-grade, 19; high-grade, 25), 19 patients with atypical squamous cells of undetermined significance (ASCUS), and 18 controls. The expression of costimulatory receptors was assessed and the ability of monocyte-derived dendritic cells (MDDC) to present HPV16-E6 and HPV16-E7 antigens to autologous T cells. Patients with either low (L)-grade or high (H)-grade SIL had significantly lower median plasma levels of interferon-gamma than did the controls (P = .038 and .031, respectively). Compared with the controls, patients with ASCUS or LSILs had significantly lower median percentages of MDCs (P = .002 and P < .001, respectively), and significantly lower median percentages of MDDCs that expressed CD86 (P < .001 and P = .003, respectively) and major histocompatability complex class-II antigen human leukocyte antigen DR (HLA-DR) (P = .012 and P < .001, respectively). T cells of patients with ASCUS or LSILs proliferated less than those of the controls in response to HPV16-E7 (P = .002 and .046, respectively). Low levels of peripheral blood MDCs and of MDDCs expressing CD86 and HLA-DR suggest that deficiencies in the ability of MDDC to present antigen to autologous T cells may lead to persistent infection with HPV and the development of cervical SILs in HPV-infected women.

Characterization of denritic cell subsets in HCV patients treated with interferon-alpha

Dendritic cells (DC) play a central role in the induction and regulation of an efficient antiviral immune response. The CD11cpos myeloid DC (MDC) including the BDCA–1 and BDCA–3 subpopulations and CD11cneg, CD123pos plasmacytoid DC (PDC) represent the main subsets of circulating DC based on functional and phenotypic differences. We determined the frequency and phenotype of DC subsets in the peripheral blood from 48 patients with chronic hepatitis C (HCV) infection with and without interferon-alpha treatment. Three color flow-cytometric analysis revealed that the percentage of MDC from untreated HCV patients was significantly lower as compared to healthy controls (p<0,01). Antiviral therapy was associated with a further significant decrease of MDC as compared to healthy controls (<0,001) and to untreated HCV patients (p<0,005). The frequency and phenotype of PDC did not reveal a statistically significant difference in both untreated study groups. In contrast, patients receiving IFN-alpha treatment showed a significant decrease of PDC in peripheral blood. The proportions of T cell, B cell and NK cell populations did not differ between patients and controls. The results indicate that chronic HCV infection is associated with reduction of circulating MDC. IFN-alpha treatment correlated with reduced number of both PDC (expressing BDCA–2 and BDCA–4 surface antigens) and MDC including BDCA–1 and BDCA–3 subpopulations. In conclusion, IFN-alpha treatment profoundly influences the number and phenotype of circulating DC subsets and, therefore, may reflect distinct DC homing properties. These findings may indicate novel mechanisms of IFN-alpha-mediated antiviral immune responses.

Frequencies of dendritic cells (myeloid DC and plasmacytoid DC) and their ratio reduced in pregnant women: comparison with umbilical cord blood and normal healthy adults

CD11c + peripheral blood myeloid dendritic cells (MDC), and CD123 bright plasmacytoid cells (PDC), are two human dendritic cell (DC) populations. In the present study, the percentages of MDC [lin −/HLA-DR +/CD123 −/CD11c +] and PDC [lin −/HLA-DR +/CD123 bright] in a peripheral blood (PB) sample obtained from women at the time of delivery and in their umbilical cord blood (UCB) were compared with those in the PB of healthy volunteers. The percentages of MDC and PDC were determined by four-color flow cytometry. The percentages of MDC and PDC were significantly lower in the PB obtained at delivery (MDC, 0.11% ± 0.08%; PDC, 0.06% ± 0.06%) and in the UCB (MDC, 0.15% ± 0.03%; PDC, 0.05% ± 0.05%) than in the PB of the controls (males, 0.28% ± 0.12%, 0.11% ± 0.06%; females, 0.32% ± 0.13%, 0.11% ± 0.07%). Among the pregnant women at delivery, there were significant correlations between the percentage of MDC or percentage of PDC in the PB at delivery and the respective parameter in the UCB. The PB of other pregnant women, at 20–35 weeks of gestational age, also indicated significantly low percentages of MDC and PDC (0.1% ± 0.1%, 0.06% ± 0.07%). The ratio of MDC/PDC was not reduced in the UCB (4.25 ± 2.74), but was reduced in the PB obtained at delivery and the PB obtained during pregnancy (0.79 ± 0.91) in comparison with that in age-matched, nonpregnant females (3.96 ± 2.95). It was assumed that reduction of MDC during pregnancy plays an important role in maintaining immune tolerance against the embryo.

Frequencies of dendritic cells (myeloid DC and plasmacytoid DC) and their ratio reduced in pregnant women: comparison with umbilical cord blood and normal healthy adults

CD11c+ peripheral blood myeloid dendritic cells (MDC), and CD123bright plasmacytoid cells (PDC), are two human dendritic cell (DC) populations. In the present study, the percentages of MDC [lin−/HLA-DR+/CD123−/CD11c+] and PDC [lin−/HLA-DR+/CD123bright] in a peripheral blood (PB) sample obtained from women at the time of delivery and in their umbilical cord blood (UCB) were compared with those in the PB of healthy volunteers. The percentages of MDC and PDC were determined by four-color flow cytometry. The percentages of MDC and PDC were significantly lower in the PB obtained at delivery (MDC, 0.11% ± 0.08%; PDC, 0.06% ± 0.06%) and in the UCB (MDC, 0.15% ± 0.03%; PDC, 0.05% ± 0.05%) than in the PB of the controls (males, 0.28% ± 0.12%, 0.11% ± 0.06%; females, 0.32% ± 0.13%, 0.11% ± 0.07%). Among the pregnant women at delivery, there were significant correlations between the percentage of MDC or percentage of PDC in the PB at delivery and the respective parameter in the UCB. The PB of other pregnant women, at 20–35 weeks of gestational age, also indicated significantly low percentages of MDC and PDC (0.1% ± 0.1%, 0.06% ± 0.07%). The ratio of MDC/PDC was not reduced in the UCB (4.25 ± 2.74), but was reduced in the PB obtained at delivery and the PB obtained during pregnancy (0.79 ± 0.91) in comparison with that in age-matched, nonpregnant females (3.96 ± 2.95). It was assumed that reduction of MDC during pregnancy plays an important role in maintaining immune tolerance against the embryo.

Evaluation of Myeloid and Lymphoid Dendritic Cells in Peritoneal Fluid in Women with Non‐malignant Ovarian Tumors

Identification of myeloid and lymphoid dendritic cells (DCs) in peritoneal fluid (PF) and peripheral blood (PB) of patients with ovarian pathology. PF and PB were collected from 60 patients who underwent laparoscopy because of non-malignant ovarian tumors. Mononuclear cells were separated by gradient centrifugation. The cell surface antigens were determined by flow cytometry using monoclonal antibodies. Both myeloid and lymphoid DCs were detected in PF and PB of women with ovarian tumors. The percentage of myeloid DCs was significantly higher in PF than in PB. The concentration of PF myeloid DCs was the highest (P < 0.05) in patients with dermoid cysts (0.67 x 10(6)/mL PF) in comparison with the other studied groups, excluding patients with normal pelvis. Domination of myeloid and not lymphoid cells in PF may support the hypothesis that local PF immune disturbances may play a role in some non-malignant ovarian pathology.