The Experts below are selected from a list of 394530 Experts worldwide ranked by ideXlab platform
Jeanphilippe Girard - One of the best experts on this subject based on the ideXlab platform.
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dendritic cells control lymphocyte entry to lymph nodes through high endothelial venules
Nature, 2011Co-Authors: Christine Moussion, Jeanphilippe GirardAbstract:Christine Moussion and Jean-Philippe Girard report that dendritic cells in the immune system have an unexpected immune surveillance role in lymphocyte recirculation during homeostasis. Lymphotoxin ligands derived from dendritic cells promote the growth of high endothelial venules — blood vessels specialized in lymphocyte recruitment — which control the entry of naive Lymphocytes from the blood into lymph nodes. While patrolling the body in search of foreign antigens, naive Lymphocytes continuously circulate from the blood, through the lymph nodes, into the lymphatic vessels and back to the blood1,2. This process, called lymphocyte recirculation, provides the body with effective immune surveillance for foreign invaders and for alterations to the body’s own cells. However, the mechanisms that regulate lymphocyte recirculation during homeostasis remain incompletely characterized. Here we show that dendritic cells (DCs), which are well known for their role in antigen presentation to T Lymphocytes3, control the entry of naive Lymphocytes to lymph nodes by modulating the phenotype of high endothelial venules (HEVs), which are blood vessels specialized in lymphocyte recruitment2,4,5. We found that in vivo depletion of CD11c+ DCs in adult mice over a 1-week period induces a reduction in the size and cellularity of the peripheral and mucosal lymph nodes. In the absence of DCs, the mature adult HEV phenotype reverts to an immature neonatal phenotype, and HEV-mediated lymphocyte recruitment to lymph nodes is inhibited. Co-culture experiments showed that the effect of DCs on HEV endothelial cells is direct and requires lymphotoxin-β-receptor-dependent signalling. DCs express lymphotoxin, and DC-derived lymphotoxin is important for lymphocyte homing to lymph nodes in vivo. Together, our results reveal a previously unsuspected role for DCs in the regulation of lymphocyte recirculation during immune surveillance.
Christine Moussion - One of the best experts on this subject based on the ideXlab platform.
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dendritic cells control lymphocyte entry to lymph nodes through high endothelial venules
Nature, 2011Co-Authors: Christine Moussion, Jeanphilippe GirardAbstract:Christine Moussion and Jean-Philippe Girard report that dendritic cells in the immune system have an unexpected immune surveillance role in lymphocyte recirculation during homeostasis. Lymphotoxin ligands derived from dendritic cells promote the growth of high endothelial venules — blood vessels specialized in lymphocyte recruitment — which control the entry of naive Lymphocytes from the blood into lymph nodes. While patrolling the body in search of foreign antigens, naive Lymphocytes continuously circulate from the blood, through the lymph nodes, into the lymphatic vessels and back to the blood1,2. This process, called lymphocyte recirculation, provides the body with effective immune surveillance for foreign invaders and for alterations to the body’s own cells. However, the mechanisms that regulate lymphocyte recirculation during homeostasis remain incompletely characterized. Here we show that dendritic cells (DCs), which are well known for their role in antigen presentation to T Lymphocytes3, control the entry of naive Lymphocytes to lymph nodes by modulating the phenotype of high endothelial venules (HEVs), which are blood vessels specialized in lymphocyte recruitment2,4,5. We found that in vivo depletion of CD11c+ DCs in adult mice over a 1-week period induces a reduction in the size and cellularity of the peripheral and mucosal lymph nodes. In the absence of DCs, the mature adult HEV phenotype reverts to an immature neonatal phenotype, and HEV-mediated lymphocyte recruitment to lymph nodes is inhibited. Co-culture experiments showed that the effect of DCs on HEV endothelial cells is direct and requires lymphotoxin-β-receptor-dependent signalling. DCs express lymphotoxin, and DC-derived lymphotoxin is important for lymphocyte homing to lymph nodes in vivo. Together, our results reveal a previously unsuspected role for DCs in the regulation of lymphocyte recirculation during immune surveillance.
J. J. M. Van Dongen - One of the best experts on this subject based on the ideXlab platform.
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immunophenotyping of blood Lymphocytes in childhood reference values for lymphocyte subpopulations
The Journal of Pediatrics, 1997Co-Authors: Marieke W Comansbitter, Kim Groeneveld, Ronald De Groot, Rene Van Den Beemd, Herbert Hooijkaas, Herman J. Neijens, J. J. M. Van DongenAbstract:Abstract Objective: Immunophenotyping of blood Lymphocytes is an important tool in the diagnosis of hematologic and immunologic disorders. Because of maturation and expansion of the immune system in the first years of life, the relative and the absolute size of lymphocyte subpopulations vary during childhood. Therefore we wished to obtain reference values for the relative and the absolute size of all relevant blood lymphocyte subpopulations in childhood. Study design: We used the lysed whole blood method for analysis of lymphocyte subpopulations in 429 blood samples from neonates (n = 20), healthy children (n = 358), and adults (n = 51). The following age groups were used: 1 week to 2 months (n = 13), 2 to 5 months (n = 46), 5 to 9 months (n = 105), 9 to 15 months (n = 70), 15 to 24 months (n = 33), 2 to 5 years (n = 33), 5 to 10 years (n = 35), and 10 to 16 years (n = 23). Results: Our results show that the absolute number of CD19 + B Lymphocytes increases twofold immediately after birth, remains stable until 2 years of age, and subsequently gradually three-fold decreases 6.5-fold from 2 years to adult age. The CD3 + T Lymphocytes increase 1.5-fold immediately after birth and decrease threefold from 2 years to adult age. The absolute size of the CD3 + /CD4 + T-lymphocyte subpopulation follows the same pattern as the total CD3 + population, but the CD3 + /CD8 + T Lymphocytes remain stable from birth up to 2 years of age, followed by a gradual threefold decrease toward adult levels. In contrast to B and T Lymphocytes, the absolute number of natural killer cells decreases almost threefold in the first 2 months of life and remains stable thereafter. Our study also showed that changes in the absolute size of lymphocyte subpopulations are not always consistent with changes in their relative size. This demonstrates that the relative counts of lymphocyte subsets do not reflect their actual size and are therefore of limited value. Conclusion: On the basis of this study we strongly recommend that immunophenotyping of blood Lymphocytes for the diagnosis of hematologic and immunologic disorders be based on the absolute rather than on the relative size of lymphocyte subpopulations. Our data can be used as age-matched reference values for blood lymphocyte immunophenotyping.
Etienne Garin - One of the best experts on this subject based on the ideXlab platform.
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Lymphocytes and neutrophil to lymphocyte ratio variations after selective internal radiation treatment for hcc a retrospective cohort study
CardioVascular and Interventional Radiology, 2020Co-Authors: Florian Estrade, Celine Lescure, Lea Muzellec, Maud Pedrono, Xavier Palard, Marc Pracht, Samuel Le Sourd, Y Rolland, Thomas Uguen, Etienne GarinAbstract:Selective internal radiation therapy (SIRT) has been proposed for combination with immunotherapy to treat hepatocellular carcinoma (HCC). However, the toxicity of radiation toward Lymphocytes is understudied after SIRT. The aim of this study was to describe variations of Lymphocytes following SIRT and their potential prognostic impact. This is a retrospective cohort study of 164 patients treated with SIRT for HCC. Lymphocyte count and neutrophil-to-lymphocyte (NLR) ratio were evaluated at baseline and at 3 months. Primary endpoint was overall survival (OS). Median baseline lymphocyte count was 1.32 Giga/Liter (G/L) (standard deviation (SD) 0.64) at baseline versus 0.68 G/L (SD 0.41) at 3 months. The mean decrease of lymphocyte count was − 44% (standard deviation 0.24). At 3 months, only 21% of patients had normal (1 G/L or more) lymphocyte count, and 23% had lymphocyte count < 0.5 G/L. NLR at 3 months was significantly and independently associated with OS in multivariate Cox model. Median OS was 9.9 months (95% confidence interval (CI) 6.2–13.5) for patients with NLR at 3 months higher than 7.2 compared to 19.9 months in patients with an NLR lower that the 7.2 threshold (95% CI 16.3–23.3) (p = 0.003). The decrease in Lymphocytes was frequent and deep after SIRT for HCC. NLR increase at 3 months was associated with poor survival.
H F Seigler - One of the best experts on this subject based on the ideXlab platform.
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generation of primary tumor specific cytotoxic t Lymphocytes from autologous and human lymphocyte antigen class i matched allogeneic peripheral blood Lymphocytes by b7 gene modified melanoma cells
Cancer Research, 1997Co-Authors: Sixun Yang, Timothy L Darrow, H F SeiglerAbstract:Expression of B7.1 costimulatory molecules on tumor cells has been shown to elicit antitumor immunity in mice. In the present study, we have developed a human B7.1 retroviral vector system to effectively transduce human melanoma cell lines and investigated the potential role of B7.1 in the generation of tumor-specific CTLs from peripheral blood Lymphocytes (PBLs) in vitro . We have demonstrated that B7.1-modified melanoma cells are able to induce primary CTL activity from autologous, human lymphocyte antigen (HLA) class I-matched allogeneic PBLs and purified CD8+ T cells in the absence of exogenous cytokines. CTLs generated by B7.1 are tumor specific and HLA class I restricted, and CD8+ T cells are primarily responsible for this specific cytotoxicity. Furthermore, CTLs generated from HLA class I-matched PBLs by B7.1 are cytolytic to tumor cells autologous to the stimulated PBLs. These data suggest that B7.1-modified tumor cells can be used as a potent tumor vaccine for both autologous and HLA class I-matched allogeneic patients.
