Human BDCA-1 Positive Blood Dendritic Cells in Immunosuppressed Patients: Phenotype, Function and Maturation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2231-2231
Author(s):  
Kathrin Sebelin ◽  
Antje Meier ◽  
Carola Beier ◽  
Bernd Dörken ◽  
Antonio Pezzutto ◽  
...  

Abstract Immunosuppressive drugs used in patients (pts) after stem cell / organ transplantation (Tx) as well as in pts with autoimmune disease are known to impair the cellular immune response. This results in an increased incidence of viral infections and viral associated malignancies which has been ascribed to the effect of immunosuppressive drugs on lymphocytes. However, in vitro data indicate that immunosuppressive drugs also target Dendritic Cells (DCs), the most potent antigen-presenting cells and initiators of lymphocyte responses. So far, most studies are based on in vitro data obtained with DC culture in the presence of different concentrations of single immunosuppressive drugs. To investigate the effect of immunosuppression on DC phenotype and function in vivo, we quantitatively and qualitatively analyzed freshly isolated human BDCA-1(CD1c) positive DCs from 15 solid organ transplant (SOT) recipients under immunosuppressive treatment. The percentage of BDCA-1 positive cells among total PBMCs was not statistically different in pts vs ctrls (0,52 vs 0,65, p<0,18). BDCA-1 positive DCs were analyzed for expression of HLA class I and II, CD14, costimmulatory molecules and chemokine expression. Interestingly, CD14 was found to be significantly higher expressed on pt-DCs vs ctrl-DCs suggesting a more immature DC-phenotype. We observed a trend toward a reduced expression of HLA-DR and CD86 on pts-DCs as compared to ctrls-DCs (p=0,059). Surface profile of BDCA-1 positive DCs was also analyzed after 48h of LPS and CD40L stimulation. Here we found a marked upregulation of HLA-DR and CD86 in pts- DCs as well as ctrl-DCs. Supernatant of stimulated DCs was analyzed with cytokine capture beads for secretion of inflammatory cytokines. High secretion of IL-6, IL-1 beta and partially of TNF-alpha by stimulated DCs was observed in both groups. Other Th2 type cytokines (IL-10, IL-4, IL-5) and Th1 type cytokines like IFN-gamma and Il-2 were not significantly secreted. We additionally addressed the question if mature and functionally competent DCs could be generated ex vivo from this pts cohort. After 9 days of culture with GM-CSF, IL-4, IL-1, IL-6, TNF-alpha and PGE2 fully mature DCs could be generated. Co-culture of EBV-peptide-pulsed DCs with autologous T-cells resulted in significant expansion of EBV-specific T cells in pts and ctrls. These T cells were fully functional as shown by IFN-γ secretion detected by ELISPOT. In summary, this is the first analysis of freshly isolated BDCA-1 positive DCs from immunosuppressed pts. Our data support the notion that immunosuppressive drugs target DCs and contribute to a maturation defect of circulating blood DCs which may help to understand the mechanism of impaired cellular immune responses in immunosuppressed pts. However, ex vivo generated DCs from immunosuppressed pts do not show an impairment in phenotype and function, suggesting that they could be efficiently be used in immunotherapeutic strategies.

2012 ◽  
Vol 129 ◽  
pp. S170
Author(s):  
E. Napoleone ◽  
A. Cutrone ◽  
D. Cugino ◽  
R. Tambaro ◽  
A. De Curtis ◽  
...  

2008 ◽  
Vol 76 (10) ◽  
pp. 4538-4545 ◽  
Author(s):  
William W. Kwok ◽  
Junbao Yang ◽  
Eddie James ◽  
John Bui ◽  
Laurie Huston ◽  
...  

ABSTRACT Cellular immune responses against protective antigen (PA) of Bacillus anthracis in subjects that received the anthrax vaccine adsorbed (AVA) vaccine were examined. Multiple CD4+ T-cell epitopes within PA were identified by using tetramer-guided epitope mapping. PA-reactive CD4+ T cells with a CD45RA− phenotype were also detected by direct ex vivo staining of peripheral blood mononuclear cells (PBMC) with PA-specific tetramers. Surprisingly, PA-specific T cells were also detected in PBMC of nonvaccinees after a single cycle of in vitro PA stimulation. However, PA-reactive CD4+ T cells in nonvaccinees occurred at lower frequencies than those in vaccinees. The majority of PA-reactive T cells from nonvaccinees were CD45RA+ and exhibited a Th0/Th1 cytokine profile. In contrast, phenotyping and cytokine profile analyses of PA-reactive CD4+ T cells from vaccinees indicated that vaccination leads to commitment of PA-reactive T cells to a Th2 lineage, including generation of PA-specific, pre-Th2 central memory T cells. These results demonstrate that the current AVA vaccine is effective in skewing the development of PA CD4+ T cells to the Th2 lineage. The data also demonstrated the feasibility of using class II tetramers to analyze CD4+ cell responses and lineage development after vaccination.


2021 ◽  
Vol 12 ◽  
Author(s):  
Molly Javier Uyeda ◽  
Robert A. Freeborn ◽  
Brandon Cieniewicz ◽  
Rosa Romano ◽  
Ping (Pauline) Chen ◽  
...  

Type 1 regulatory T (Tr1) cells are subset of peripherally induced antigen-specific regulatory T cells. IL-10 signaling has been shown to be indispensable for polarization and function of Tr1 cells. However, the transcriptional machinery underlying human Tr1 cell differentiation and function is not yet elucidated. To this end, we performed RNA sequencing on ex vivo human CD49b+LAG3+ Tr1 cells. We identified the transcription factor, BHLHE40, to be highly expressed in Tr1 cells. Even though Tr1 cells characteristically produce high levels of IL-10, we found that BHLHE40 represses IL-10 and increases IFN-γ secretion in naïve CD4+ T cells. Through CRISPR/Cas9-mediated knockout, we determined that IL10 significantly increased in the sgBHLHE40-edited cells and BHLHE40 is dispensable for naïve CD4+ T cells to differentiate into Tr1 cells in vitro. Interestingly, BHLHE40 overexpression induces the surface expression of CD49b and LAG3, co-expressed surface molecules attributed to Tr1 cells, but promotes IFN-γ production. Our findings uncover a novel mechanism whereby BHLHE40 acts as a regulator of IL-10 and IFN-γ in human CD4+ T cells.


2019 ◽  
Vol 28 (12) ◽  
pp. 1603-1613 ◽  
Author(s):  
Marcus Bergström ◽  
Malin Müller ◽  
Marie Karlsson ◽  
Hanne Scholz ◽  
Nils Tore Vethe ◽  
...  

Adoptive transfer of autologous polyclonal regulatory T cells (Tregs) is a promising option for reducing graft rejection in allogeneic transplantation. To gain therapeutic levels of Tregs there is a need to expand obtained cells ex vivo, usually in the presence of the mTOR inhibitor Rapamycin due to its ability to suppress proliferation of non-Treg T cells, thus promoting a purer Treg yield. Azithromycin is a bacteriostatic macrolide with mTOR inhibitory activity that has been shown to exert immunomodulatory effects on several types of immune cells. In this study we investigated the effects of Azithromycin, compared with Rapamycin, on Treg phenotype, growth, and function when expanding bulk, naïve, and memory Tregs. Furthermore, the intracellular concentration of Rapamycin in CD4+ T cells as well as in the culture medium was measured for up to 48 h after supplemented. Treg phenotype was assessed by flow cytometry and Treg function was measured as inhibition of responder T-cell expansion in a suppression assay. The concentration of Rapamycin was quantified with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Azithromycin and Rapamycin both promoted a FoxP3-positive Treg phenotype in bulk Tregs, while Rapamycin also increased FoxP3 and FoxP3+Helios positivity in naïve and memory Tregs. Furthermore, Rapamycin inhibited the expansion of naïve Tregs, but also increased their suppressive effect. Rapamycin was quickly degraded in 37°C medium, yet was retained intracellularly. While both compounds may benefit expansion of FoxP3+ Tregs in vitro, further studies elucidating the effects of Azithromycin treatment on Tregs are needed to determine its potential use.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5102-5102
Author(s):  
Don J. Diamond ◽  
Zhongde Wang ◽  
Simon F. Lacey ◽  
Corinna La Rosa

Abstract Adoptive transfer of ex vivo expanded CMV-specific T cells is an effective approach, and an attractive alternative to using anti-virals to manage CMV infection for HSCT recipients. We recently published a robust approach to expanding CMV-specific CTL based on infection of autologous EBV-LCL with the attenuated poxvirus, Modified Vaccinia Ankara (MVA), expressing CMV pp65, pp150, and IE1 proteins. This approach causes vigorous, up to 500fold expansions in as little as 12–14 days of memory CD8+ T cells specific for these immunodominant antigens. In order to improve the specificity of the expanded T cells, a method was sought to derive effective antigen presenting cells (APC) that avoided the use of EBV-LCL. Of equal importance is to develop an expansion approach that avoids the need to involve virally infected APC in developing a clinical product. Our preliminary observation is that rMVA can infect PBMC in vitro, causing high levels of expression of recombinant CMV antigens. To be permissible for high level expression from rMVA, fresh PBMC were treated with different combinations of single-stranded CpG-containing phosphorothioate backbone oligonucleotides (ODN). A three-day incubation with a combination of two ODN (ODN # 2006 and 2216) which are known to stimulate both plasmacytoid dendritic and B-cells were found to reproducibly generate a highly rMVA infectable population of PBMC. In all five healthy CMV-positive donors tested, CpG ODN treated autologous PBMC, infected with recombinant rMVA, elicited a 20-fold average expansion of CMV-specific CD8+ T cells, in 10 days. Several different rMVA expressing CMV genes were evaluated, including a novel vector expressing the UL44 gene product, an immunodominant target of the host cellular immune response. The expanded T cell populations showed minimal alloreactivity, and exhibited high levels of CMV-specific MHC Class I tetramer binding, epitope-specific cytokine production, and cytotoxic activity. The availability of a source of autologous professional APC that can be used after only 3 days of priming, enhances the attractiveness of using rMVA for adoptive immunotherapy for HSCT recipients or donor vaccination.


2002 ◽  
Vol 70 (3) ◽  
pp. 1168-1174 ◽  
Author(s):  
Burkhard J. Manfras ◽  
Stefan Reuter ◽  
Thomas Wendland ◽  
Peter Kern

ABSTRACT Alveolar echinococcosis (AE) in humans is a chronic disease characterized by slowly expanding liver lesions. Cellular immunity restricts the spreading of the extracellular pathogen, but functional contributions of CD4+ and CD8+ T cells are not defined. Here we studied ex vivo the phenotype and function of circulating T-cell subsets in AE patients by means of flow cytometry, T-cell receptor spectratyping, and lymphocyte proliferation. AE patients with parasitic lesions displayed a significant increase of activation of predominantly CD8+ T cells compared to healthy controls and AE patients without lesions. In vitro, proliferative T-cell responses to polyclonal stimulation with recall antigens and Echinococcus multilocularis vesicular fluid antigen were sustained during chronic persisting infection in all AE patients. Only in AE patients with parasitic lesions did T-cell receptor spectratyping reveal increased oligoclonality of CD8+ but not CD4+ T cells, suggesting a persistent antigenic drive for CD8+ T cells with subsequent proliferation of selected clonotypes. Thus, our data provide strong evidence for an active role of CD8+ T cells in AE.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5175-5175
Author(s):  
Axel Nogai ◽  
Markus M. Heimesaat ◽  
Marc Thiele ◽  
Stefan Bereswill ◽  
Eckhard Thiel ◽  
...  

Abstract BACKGROUND: Intestinal Graft-versus-Host disease is a frequent and often lethal complication after allogenic stem cell transplantation. Since NOD2 polymorphisms have been recognized as potential triggers of severe intestinal GvHD in humans, we have developed murine transplantation models to investigate the role of different pattern recognition receptors (PRR) in GvHD and GvL. Here we report our results on the role of TLR2 and TLR4 for the induction of GvHD. METHODS: Severity of GvHD in wildtype (wt) C57B/10 (H-2Db), TLR2−/−, TLR4−/−, and combined TLR2−/−TLR4−/− C57B/10 mice was investigated. Mice received treosulfan 2000 mg/kg from day -3 to -1 and cyclophosphamide 200 mg/kg day -1 prior to injection of 10×10^6 H-2Dd BM cells and 5×10^6 splenocytes (SC). Survival and GvHD score were assessed daily. Engraftment was determined every 2 weeks in pB and at the end of the experiments in bone marrow by flow cytometry. T cell alloreactivity in GvH direction was assessed by MLR using splenocytes as stimulators from PRR-deficient mice or wt as control and CFSE-staining as read-out. The relevance of PRR ligands for the enhancement of GvH alloreactivity was determined by addition of lipid A, lipopetides, or CpG. RESULTS: in vivo data: The transfer of 10×10^6 BMC + 5×10^6 SC induced a severe GvHD in all wt recipients, leading to death of 90% of the animals within 20 days. Recipient mice lacking either TLR2 or TLR4 showed only a slightly and not significantly decreased GvHD lethality. In recipients lacking both PPRs, i.e. TLR2 and TLR4, GvHD was generally milder and the majority (60%) of the animals survived until day 20 (p<0.05). However, the long term survival was not significantly improved. Differences in clinical severity of GvHD were confirmed histologically. In vitro data: Stimulation with cells from TLR2−/− and TLR4−/− mice resulted in a decreased alloreactivity in MLR. A median of 2% of Balb/c CD4+ T cells proliferated in response to C57B/10 stimulators. The addition of the TLR2 and TLR4 ligands lipopeptide, Lipid A and CpG significantly (p<0.05) increased the proliferation of CD4+ T cells in a specific manner more than twofold. CONCLUSION: Our in vivo and in vitro data consistantly show that bacterial components are involved in triggering GvH alloreactivity via different types of PPRs. Binding of bacterial substances to TLR2 and TLR4 leads to activation of the immune system and subsequent induction of GvHD. Our data provide an experimental basis for the development of strategies for modulation of the intestinal gut flora by selective gut decontamination and/or probiotic regimens to prevent GvHD in humans.


2005 ◽  
Vol 79 (21) ◽  
pp. 13412-13420 ◽  
Author(s):  
Eui-Cheol Shin ◽  
Ulrike Protzer ◽  
Andreas Untergasser ◽  
Stephen M. Feinstone ◽  
Charles M. Rice ◽  
...  

ABSTRACT Gamma interferon (IFN-γ) has been shown to inhibit replication of subgenomic and genomic hepatitis C virus (HCV) RNAs in vitro and to noncytolytically suppress hepatitis B virus (HBV) replication in vivo. IFN-γ is also known for its immunomodulatory effects and as a marker of a successful cellular immune response to HCV. Therapeutic expression of IFN-γ in the liver may therefore facilitate resolution of chronic hepatitis C, an infection that is rarely resolved spontaneously. To analyze immunomodulatory and antiviral effects of liver-specific IFN-γ expression in vivo, we intravenously injected two persistently HCV-infected chimpanzees twice with a recombinant, replication-deficient HBV vector and subsequently with a recombinant adenoviral vector. These vectors expressed human IFN-γ under control of HBV- and liver-specific promoters, respectively. Gene transfer resulted in a transient increase of intrahepatic IFN-γ mRNA, without increase in serum alanine aminotransferase levels. Ex vivo analysis of peripheral blood lymphocytes demonstrated enhanced CD16 expression on T cells and upregulation of the liver-homing marker CXCR3. Moreover, an increased frequency of HCV-specific T cells was detected ex vivo in the peripheral blood and in vitro in liver biopsy-derived, antigen-nonspecifically expanded T-cell lines. None of these immunologic effects were observed in the third chimpanzee injected with an HBV control vector. Despite these immunologic effects of the experimental vector, however, IFN-γ gene transfer did not result in a significant and long-lasting decrease of HCV titers. In conclusion, liver-directed IFN-γ gene delivery resulted in HCV-specific and nonspecific activation of cellular immune responses but did not result in effective control of HCV replication.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Willem J Van Der Giessen ◽  
Oana Sorop ◽  
Ilona Krabbendam-Peters ◽  
Yoshinobu Onuma ◽  
Heleen M van Beusekom

Late stent thrombosis and impaired endothelium dependent vasodilation in Cypher and Taxus are often attributed to delayed re-endothelialization. Data to support this hypothesis is scarce and the functional status of endothelium within these drug eluting stents is unknown. We compared 3 DES (Paclitaxel; Sirolimus (-limus via mTOR) and Tacrolimus (-limus via calcineurin)) to BMS in swine coronary arteries with respect to early endothelialization (%EC) at 5 days and function as assessed by immunocytochemistry for eNOS and vWF expression at 28 days (semiquantitative score) and in vitro vasoreactivity at 5 and 28 days. Results. There were no significant differences in %EC between DES and BMS at 5 days (Anova, p=0.7). While vWF expression was similar for all DES, PES showed diminished eNOS expression at 28 days. Microvascular function showed no overt impairment distal to both DES in EC-dependent dilation to bradykinin at 5 and 28 days. However, eNOS blockade by L-NAME uncovered a strongly depressed NO production in both DES at 5 days which recovered at 28 days. Conclusion. DES show no differences in re-endothelialization as compared to BMS. In vitro data showed that both DES induced a temporary reduction in NO production. However, only Paclitaxel showed a prolonged reduction in eNOS expression at 28 days. planimetry of endothelial presence and function


Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1201
Author(s):  
Florian Klomp ◽  
Christoph Wenzel ◽  
Marek Drozdzik ◽  
Stefan Oswald

Cytochrome P450 (CYP) 1A enzymes are considerably expressed in the human intestine and liver and involved in the biotransformation of about 10% of marketed drugs. Despite this doubtless clinical relevance, CYP1A1 and CYP1A2 are still somewhat underestimated in terms of unwanted side effects and drug–drug interactions of their respective substrates. In contrast to this, many frequently prescribed drugs that are subjected to extensive CYP1A-mediated metabolism show a narrow therapeutic index and serious adverse drug reactions. Consequently, those drugs are vulnerable to any kind of inhibition or induction in the expression and function of CYP1A. However, available in vitro data are not necessarily predictive for the occurrence of clinically relevant drug–drug interactions. Thus, this review aims to provide an up-to-date summary on the expression, regulation, function, and drug–drug interactions of CYP1A enzymes in humans.


Sign in / Sign up

Export Citation Format

Share Document