The function of regulatory immunological cell in xenotransplantation immunity / 器官移植

Xenotransplantation is the most promising method to resolve the organ shortage problem in the future. In recent years, the advances in gene editing and immunological technique have driven the rapid development of xenotransplantation. However, there are still many insurmountable obstacles in the clinical application of xenotransplantation, among which the rejection is the most important cause of the xenotransplantation failure. Regulatory immunological cells are a group of immunological cells with the negative regulation function in the body, which can inhibit allotransplantation rejection and prolong the survival time of the graft. This paper summarized the research progress of regulatory immunological cells in the xenotransplantation application in recent years, providing reference for the prevention and treatment of xenotransplantation rejection.

Effects of total flavones of rhododendra on transient receptorpotential vanilloid receptor 4 in cerebral basilar arteries ofrats subjected to ischemia/reperfusion injury / 中国药理学通报

Aim To research the effects of total flavones of rhododendra(TFR)on transient receptor potential vanilloid receptor 4(TRPV4)in cerebral basilar arteries(CBA)of rats subjected to ischemia/reperfusion(IR)injury.Methods The model of total brain IR was established by four-artery occlusion(4-VO)method in rats.Arterial pressure perfusion and cell membrane potential recording methods were used for surveying the dilatation and hyperpolarization of TFR and ruthenium red(RR,an inhibitor of TRPV4)in the KCl-preconstricted CBA ex vivo in rats subjected to IR.Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blot were utilized to investigate the TRPV4 mRNA and protein expressions of TFR and RR in cerebrovascular endothelial cells of CBA in vivo in rats subjected to IR.Results 11～2 700 mg·L-1 TFR significantly induced concentration-dependent hyperpolarization and dilatation in the KCl-preconstricted CBA in rats subjected to IR.TFR still produced degenerative hyperpolarization and dilatation by removal of endothelium in CBA,which was remarkably attenuated as compared with endothelium-intact group(P<0.01).After removal of NO and PGI2 vasodilatation,TFR obviously elicited the hyperpolarization and dilatation that were further decreased by RR(an inhibitor of TRPV4)in IR CBAs.TFR pretreatment apparently increased the level of TRPV4 mRNA and protein expressions in IR CBAs.These effects were restrained by RR,an inhibitor of TRPV4.Conclusions TFR could mediate endothelium-dependent and endothelium-independent effects.The endothelium-derived dilatation may be related to the increase of endothelium activity and endothelium-derived hyperpolarizing factor(EDHF)generation and release that have been promoted by TFR,and secondarily activating TRPV4,which results in Ca2+ inflow and subsequent hyperpolarization of vascular smooth muscle cell membrane and vasorelaxation.

Expressions and clinical significance of CD146 and TfR1 in ovarian epithelial cancer / 西安交通大学学报(医学版)

ABSTRACT:Objective To evaluate the expressions of cell adhesion molecules CD146 and transferrin receptor 1 (TfR1)in ovarian epithelial cancer and investigate their relationship with clinical pathological features of patients with ovarian epithelial cancer (OEC ) so as to further explore the pathogenesis of OEC. Methods Immunohistochemistry was employed to determine the expressions of CD146 and TfR1 in normal,benign and ovarian cancer tissues.Results The immunohistochemical results showed that the positive expressions of CD146 and TfR1 gradually increased with the changes of normal,benign and malignant tissues in OEC.There were significant differences between all the groups (P0.05).There was a significant correlation between expressions of CD146 and TfR1 in OEC (P<0.05,rs=0.532).Combined detection sensitivity and specificity were 82.4% and 75.0%.Conclusion The high expressions of CD146 and TfR1 may play a key role in the occurrance,progression and metastasis of OEC.They may be used as potential markers for diagnosis,postoperative follow-up and targeted therapy.

Enforced Expression of CXCR5 Drives T Follicular Regulatory-Like Features in Foxp3⁺ T Cells

CXCR5⁺ T follicular helper (Tfh) cells are associated with aberrant autoantibody production in patients with antibody-mediated autoimmune diseases including lupus. Follicular regulatory T (Tfr) cells expressing CXCR5 and Bcl6 have been recently identified as a specialized subset of Foxp3+ regulatory T (Treg) cells that control germinal center reactions. In this study, we show that retroviral transduction of CXCR5 gene in Foxp3⁺ Treg cells induced a stable expression of functional CXCR5 on their surface. The Cxcr5-transduced Treg cells maintained the expression of Treg cell signature genes and the suppressive activity. The expression of CXCR5 as well as Foxp3 in the transduced Treg cells appeared to be stable in vivo in an adoptive transfer experiment. Moreover, Cxcr5-transduced Treg cells preferentially migrated toward the CXCL13 gradient, leading to an effective suppression of antibody production from B cells stimulated with Tfh cells. Therefore, our results demonstrate that enforced expression of CXCR5 onto Treg cells efficiently induces Tfr cell-like properties, which might be a promising cellular therapeutic approach for the treatment of antibody-mediated autoimmune diseases.

Antibody-mediated targeting of the transferrin receptor in cancer cells / Anticuerpos que reconocen el receptor de transferrina en células tumorales

Abstract: Iron is essential for cell growth and is imported into cells in part through the action of transferrin (Tf), a protein that binds its receptor (TfR1 or CD71) on the surface of a cell, and then releases iron into endosomes. TfR1 is a single pass type-II transmembrane protein expressed at basal levels in most tissues. High expression of TfR1 is typically associated with rapidly proliferating cells, including various types of cancer. TfR1 is targeted by experimental therapeutics for several reasons: its cell surface accessibility, constitutive endocytosis into cells, essential role in cell growth and proliferation, and its overexpression by cancer cells. Among the therapeutic agents used to target TfR1, antibodies stand out due to their remarkable specificity and affinity. Clinical trials are being conducted to evaluate the safety and efficacy of agents targeting TfR1 in cancer patients with promising results. These observations suggest that therapies targeting TfR1 as direct therapeutics or delivery conduits remain an attractive alternative for the treatment of cancers that overexpress the receptor.

Resumen: El hierro es esencial para el crecimiento celular. Es transportado dentro de las células con la ayuda de la transferrina (Tf), proteína que se une a su receptor (TfR1 o CD71) en la superficie celular y libera el hierro dentro de los endosomas. El TfR1 es una proteína de membrana tipo II que se sobreexpresa en muchos tejidos debido al requerimiento de las células para importar hierro unido a Tf. La sobreexpresión de TfR1 se ha asociado con células que proliferan rápidamente, incluyendo los diferentes tipos de cáncer. El TfR1 se ha empleado como blanco terapéutico por diversos motivos: su accesibilidad a la superficie celular, su capacidad de internalizarse constitutivamente en las células, su papel esencial en el crecimiento y la proliferación celular, así como por su sobreexpresión en las células tumorales proliferantes. Entre los agentes terapéuticos dirigidos contra el TfR1 destacan los anticuerpos, por su alta especificidad, estabilidad y propiedades estructurales. Se han realizado diversos ensayos clínicos para evaluar la seguridad y la eficacia de los anticuerpos que reconocen el TfR1 en pacientes con cáncer y se han obtenido resultados prometedores. Estas observaciones sugieren que las terapias con fundamento en el reconocimiento de TfR1, ya sea como terapia directa o empleados como acarreadores, representan una alternativa muy atractiva de tratamiento contra los diferentes tipos de cáncer que sobreexpresan este receptor.

Changes of circulating Tfr and Tfh cells in children with myasthenia gravis / 中华微生物学和免疫学杂志

Objective To investigate the changes of follicular regulatory T cells ( Tfr cells) and follicular T helper cells ( Tfh cells) in peripheral blood of children with myasthenia gravis ( MG) . Methods We recruited 28 MG patients and 20 healthy subjects in this study. The percentages of Tfh and Tfr cells in peripheral blood samples were measured by flow cytometry. Real-time PCR was performed to detect the ex-pression of transcription factors and regulatory factors of Bcl-6, c-MAF, Blimp-1 and PD-1 at mRNA level. ELISA was used to detect the levels of IL-2, IL-6, IL-10 and IL-21 in plasma samples and the titers of Ach-Rab and PsMab. Results Compared with the healthy subjects, the MG patients showed higher percentages of Tfh cells and lower percentages of Tfr cells before receiving treatment. The expression of Bcl-6 and c-MAF on CD4+T lymphocytes cells at transcriptional level were significantly enhanced, while the expression of Blimp-1 on CD4+T cells and the expression of PD-1 on Treg cells at transcriptional level were inhibited in the MG patients in comparison with those in healthy subjects. Moreover, decreased levels of IL-2 and increased levels of IL-21 were found in plasma samples collected from the MG patients. Conclusion The decreased percentages of Tfr cells and increased percentages of Tfh cells in patients with MG resulted in abnormal ratios of Tfr/Tfh cells, which might be involved in the immunological pathogenesis of MG. Several changes in the patients with MG might be responsible for the imbalanced ratio of Tfr/Tfh cells, which included changes of IL-2 and IL-21 in microenvironment, enhanced expression of Bcl-6 and c-MAF at mRNA level and inhibited expression of Blimp-1 at mRNA level on CD4+T cells as well as over-expression of PD-1 at mRNA level on Treg cells.

Quantitative study of iron metabolism-related genes expression in rat / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the multiple iron metabolism-related genes expression, its regulation by iron and the expression correlation among the genes in rat tissues.</p><p><b>METHODS</b>Two groups (n=30) of Sprague-Dawley female weanling rats were fed with a control diet and an iron deficient diet respectively for 4 weeks. All rats were then sacrificed, and blood and tissue samples were collected. The routine blood examination was performed with a veterinary automatic blood cell analyzer. Elemental iron levels in liver, spleen and serum were determined by atomic absorption spectrophotometry. The mRNA expression of genes was detected by real-time fluorescence quantitative PCR.</p><p><b>RESULTS</b>After 4 weeks, the hemoglobin (Hb) level and red blood cell (RBC) count were significantly lower in the iron deficient group compared with those in the control group. The iron levels in liver, spleen and serum in the iron deficient group were significantly lower than those in the control group. In reference to small intestine, the relative expression of each iron-related gene varied in the different tissues. Under the iron deficiency, the expression of these genes changed in a tissue-specific manner. The expression of most of the genes significantly correlated in intestine, spleen and lung, but few correlated in liver, heart and kidney.</p><p><b>CONCLUSION</b>Findings from our study provides new understandings about the relative expression, regulation by iron and correlation among the mRNA expressions of transferrin receptors 1 and 2, divalent metal transporter 1, ferritin, iron regulation proteins 1 and 2, hereditary hemochromatosis protein, hepcidin, ferroportin 1 and hephaestin in intestine, liver, spleen, kidney, heart, and lung of rat.</p>

HFE gene mutations and iron status of Brazilian blood donors

Mutations of the HFE and TFR2 genes have been associated with iron overload. HFE and TFR2 mutations were assessed in blood donors, and the relationship with iron status was evaluated. Subjects (N = 542) were recruited at the Hemocentro da Santa Casa de São Paulo, São Paulo, Brazil. Iron status was not influenced by HFE mutations in women and was independent of blood donation frequency. In contrast, men carrying the HFE 282CY genotype had lower total iron-binding capacity (TIBC) than HFE 282CC genotype carriers. Men who donated blood for the first time and were carriers of the HFE 282CY genotype had higher transferrin saturation values and lower TIBC concentrations than those with the homozygous wild genotype for the HFE C282Y mutation. Moreover, in this group of blood donors, carriers of HFE 63DD plus 63HD genotypes had higher serum ferritin values than those with the homozygous wild genotype for HFE H63D mutation. Multiple linear regression analysis showed that HFE 282CY leads to a 17.21 percent increase (P = 0.018) and a 83.65 percent decrease (P = 0.007) in transferrin saturation and TIBC, respectively. In addition, serum ferritin is influenced by age (3.91 percent, P = 0.001) and the HFE 63HD plus DD genotype (55.84 percent, P = 0.021). In conclusion, the HFE 282Y and 65C alleles were rare, while the HFE 63D allele was frequent in Brazilian blood donors. The HFE C282Y and H63D mutations were associated with alterations in iron status in blood donors in a gender-dependent manner.

Alterações moleculares associadas à hemocromatose hereditária / Molecular changes associated with hereditary hemochromatosis

A hemocromatose hereditária (HH) é a mais comum doença autossômica em caucasianos e caracteriza-se pelo aumento da absorção intestinal de ferro, o qual resulta em acúmulo progressivo de ferro no organismo. A classificação da HH é realizada de acordo com a alteração genética encontrada, sendo os casos divididos em tipos 1, 2A, 2B, 3 e 4, quando a sobrecarga de ferro for associada aos genes HFE, HJV, HAMP, TFR2 e SLC40A1, respectivamente. Não existem estudos brasileiros que avaliaram a presença de mutações em genes relacionados à fisiopatologia da HH (genes HJV, HAMP, TFR2 e SLC40A1), além da pesquisa das três mutações no gene HFE (C282Y, H63D e S65C). Porém, está descrito, nos estudos realizados no Brasil, que alguns pacientes com sobrecarga de ferro primária não são portadores da HH tipo 1 (associada ao gene HFE). Portanto, é de suma importância a identificação das características genéticas dessa população, uma vez que outras mutações nos genes HJV, HAMP, TFR2 e SLC40A1 podem estar associadas à fisiopatologia da doença, podendo haver interações entre os genes alterados, de forma que possa auxiliar no entendimento da fisiopatologia da HH em pacientes brasileiros.

Hereditary Hemochromatosis (HH) is the most common autosomal disease in Caucasians. It is characterized by an increase in intestinal absorption of iron, which results in a progressive accumulation of iron in the body. The classification of HH is carried out according to the genetic alteration found; thus cases of HH are divided into Types 1, 2A, 2B, 3 and 4, when the iron overload is associated to the HFE, HJV, HAMP, TFR2 and SLC40A1 genes, respectively. There is research on the three HFE gene mutations (C282Y, H63D and S65C) in the Brazilian population however there are no Brazilian studies that evaluate the presence of mutations in other genes related to the pathophysiology of HH (HJV, HAMP, TFR2 and SLC40A1 genes). Nevertheless, studies conducted in Brazil have described that some patients with primary iron overload are not carriers of the Type 1 HH (associated with the HFE gene). Hence, it is very important to identify the genetic characteristics of this population, as mutations of the HJV, HAMP, TFR2 and SLC40A1 genes may be associated with the pathophysiology of the disease, and there may be interactions between mutations. These findings will help in understanding the pathophysiology of patients with HH in Brazil.

HUMAN TfR GENE EXPRESSION BEFORE AND AFTER IRON SUPPLEMENTATION IN WHITE BLOOD CELL DETECTED BY FLUORESCENCE QUANTITATIVE POLYMERASE CHAIN REACTION / 营养学报

Objective:To quantitively detect TfR gene expression of human white blood cell before and after iron supplementation. Methods:Before and after iron supplementation,10 healthy women were phlebotomized separately,and the real-time fluorescence quantitative PCR method was used to analyze the expression difference of TfR gene in human white blood cell. Results:TfR gene expression decreased after iron supplementation in 10 women,more evidently in 7 cases,where the expression level was half less than before iron supplementation. Conclusion:TfR gene expression of human white blood cell could be quantitatively measured by FQ-PCR,and was decreased after iron supplementation in 10 women. It explained that the regulative mechanism of TfR mRNA expression by iron is also suitable to white blood cell.

Effects of whole body irradiation with X-rays on the expression of TfR on lymphocytes in spleens of mice / 吉林大学学报(医学版)

Objective: To explore effect of TfR on immune function after ionizing by investigating changes in TfR expression on splenic lymphocytes of mice after whole body irradiation (WBI) with different dose X-rays. Methods: Direct immunoflurescence antibodies and flow cytometry were used to examine the changes of TfR expression. Results: The cell number of TfR positive expression in spleens increased significantly at 24 hours and 72 hours after WBI with 75 mGy X-rays but the cell number of TfR positive expression in spleens decreased significantly at 24 hours after WBI with 1～6 Gy X-rays. The activity of IL-2, meanwhile, demonstrated a parallel change. Conclusion: These results suggest that the TfR enhances immune function in low dose ionizing radiation but suppresses immune function in high dose. The change of TfR expression may be due to the change of IL-2 activity caused by ionizing radiation.

Effects of total flavones of rhododendra (TFR) on bioelectricity of ventricular myocytes in guinea pig / 中国药理学通报

Aim To study the effect of total flavones of Rhododendra(TFR)on bioelectricity changes of ventricular myocytes in guinea pigs. Methods Conventional microelectrode technique was used to record action potentials (AP) , resting potentials (RP) and effective refractory period (ERP). Results TFR 25,50 mg?L-1 decreased the action potential duration at 50%,90% repolarization (APD50,APD90) while TFR 100,200,400 mg?L-1 prolonged APD50 and APD90Significantlg. TFR 200,400 mg?L-1markedly decreased action potentials amplitude (APA) and velocity maximum of depolarization (Vmax). TFR 400 mg?L-1decreased resting potential. TFR 200 mg?L-1 prolonged ERP. Conclusion TFR may antagonize Ca2+ inward flow at lower concentration and block K+ inward flow at higher concentration.