scholarly journals Concanavalin A-mediated binding and sphering of human red blood cells by homologous monocytes.

1976 ◽  
Vol 144 (6) ◽  
pp. 1695-1700 ◽  
Author(s):  
D Guerry ◽  
M A Kenna ◽  
A D Schrieber ◽  
R A Cooper

Human red blood cells sensitized with concanavalin A became bound to homologous peripheral blood monocytes. Binding occured at a concentration of 10(5) molecules of tetrameric Con A per red blood cell (RBC) and increased with additional Con A. RBC binding began within 5 min and was maximal at 90 min. Phagocytosis of sensitized RBCs was minimal. RBC attachment was prevented by 0.01 M alpha-methyl-D-mannopyranoside, and, once the RBC-monocyte rosette was established, bound RBCs were largely removed with this specific saccharide inhibitor of Con A. RBCs attached to monocytes became spherocytic and osmotically fragile. The recognition of concanavalin A (Con A)-coated RBCs was not mediated through the monocyte IgG-Fc receptor. These studies demonstrate that, like IgG and C3b, Con A is capable of mediating the binding of human RBCs to human monocytes. Red cells so bound are damaged at the monocyte surface.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ratnasekhar Ch ◽  
Guillaume Rey ◽  
Sandipan Ray ◽  
Pawan K. Jha ◽  
Paul C. Driscoll ◽  
...  

AbstractCircadian clocks coordinate mammalian behavior and physiology enabling organisms to anticipate 24-hour cycles. Transcription-translation feedback loops are thought to drive these clocks in most of mammalian cells. However, red blood cells (RBCs), which do not contain a nucleus, and cannot perform transcription or translation, nonetheless exhibit circadian redox rhythms. Here we show human RBCs display circadian regulation of glucose metabolism, which is required to sustain daily redox oscillations. We found daily rhythms of metabolite levels and flux through glycolysis and the pentose phosphate pathway (PPP). We show that inhibition of critical enzymes in either pathway abolished 24-hour rhythms in metabolic flux and redox oscillations, and determined that metabolic oscillations are necessary for redox rhythmicity. Furthermore, metabolic flux rhythms also occur in nucleated cells, and persist when the core transcriptional circadian clockwork is absent in Bmal1 knockouts. Thus, we propose that rhythmic glucose metabolism is an integral process in circadian rhythms.


1998 ◽  
Vol 275 (5) ◽  
pp. H1726-H1732 ◽  
Author(s):  
Randy S. Sprague ◽  
Mary L. Ellsworth ◽  
Alan H. Stephenson ◽  
Mary E. Kleinhenz ◽  
Andrew J. Lonigro

Recently, it was reported that rabbit and human red blood cells (RBCs) release ATP in response to mechanical deformation. Here we investigate the hypothesis that the activity of the cystic fibrosis transmembrane conductance regulator (CFTR), a member of the ATP binding cassette, is required for deformation-induced ATP release from RBCs. Incubation of rabbit RBCs with either of two inhibitors of CFTR activity, glibenclamide (10 μM) or niflumic acid (20 μM), resulted in inhibition of deformation-induced ATP release. To demonstrate the contribution of CFTR to deformation-induced ATP release from human RBCs, cells from healthy humans, patients with cystic fibrosis (CF), or patients with chronic obstructive lung disease (COPD) unrelated to CF were studied. RBCs of healthy humans and COPD patients released ATP in response to mechanical deformation. In contrast, deformation of RBCs from patients with CF did not result in ATP release. We conclude that deformation-induced ATP release from rabbit and human RBCs requires CFTR activity, suggesting a previously unrecognized role for CFTR in the regulation of vascular resistance.


Blood ◽  
1992 ◽  
Vol 80 (3) ◽  
pp. 801-808 ◽  
Author(s):  
F Turrini ◽  
H Ginsburg ◽  
F Bussolino ◽  
GP Pescarmona ◽  
MV Serra ◽  
...  

Abstract The stage-dependent phagocytosis of Plasmodium falciparum-infected erythrocytes (IRBC) opsonized with nonimmune serum has been investigated. An average of 2.9 red blood cell (RBC) harboring ring- forms (RIRBC) and 7.5 RBC infected with trophozoites (TIRBC) or schizonts (SIRBC) were ingested per monocyte, in comparison with 0.8 noninfected RBC (NRBC) or 5 RBC oxidatively damaged with diamide. Abrogation of generation of complement component C3b or blockage of its binding to the phagocyte inhibited phagocytosis of RIRBC by 78% to 95% and of TIRBC by 25% to 50%. Blockage of immunoglobulin G (IgG) binding reduced phagocytosis of both RIRBC and TIRBC nonsignificantly by 14%. Preincubation of monocytes with phosphatidylserine (PS)-containing liposomes reduced phagocytosis of TIRBC by 22%, but had little effect on RIRBC. Residual, noncomplement, non-IgG-, and non-PS-dependent phagocytosis amounted to 6% to 18% of total phagocytosis in RIRBC and TIRBC, respectively. RIRBC bound 2.5 times more protein A and 3.1 times more anti-C3c (a stable derivative of C3b) antibodies, and TIRBC bound 20 times more protein A and 6.8 times more anti-C3c antibodies than NRBC. Phagocytosis of oxidatively damaged RBC and RIRBC are similar, whereas a higher portion of phagocytosis appears to be noncomplement- dependent and PS-suppressible in TIRBC. It is concluded that RIRBC generate recognition signals similar to those present in oxidatively damaged or senescent RBC. Extensive membrane modifications in TIRBC produce additional, hitherto undefined signals that induce much higher and qualitatively distinct phagocytosis.


1989 ◽  
Vol 93 (2) ◽  
pp. 321-342 ◽  
Author(s):  
P A King ◽  
R B Gunn

Na- and Cl-dependent glycine transport was investigated in human red blood cells. The effects of the carrier substrates (Na, Cl, and glycine) on the glycine transport kinetics were studied with the goal of learning more about the mechanism of transport. The K1/2-gly was 100 microM and the Vmax-gly was 109 mumol/kg Hb.h. When cis Na was lowered (50 mM) the K1/2-gly increased and the Vmax-gly decreased, which was consistent with a preferred order of rapid equilibrium loading of glycine before Na. Na-dependent glycine influx as a function of Na concentration was sigmoidal, and direct measurement of glycine and Na uptake indicated a stoichiometry of 2 Na:1 glycine transported. The sigmoidal response of glycine influx to Na concentration was best fit by a model with ordered binding of Na, the first Na with a high K1/2 (greater than 250 mM), and the second Na with a low K1/2 (less than 10.3 mM). In the presence of low Cl (cis and trans 5 mM), the K1/2-gly increased and the Vmax-gly increased. The Cl dependence displayed Michaelis-Menten kinetics with a K1/2-Cl of 9.5 mM. At low Cl (5 mM Cl balanced with NO3), the glycine influx as a function of Na showed the same stoichiometry and Vmax-Na but a decreased affinity of the carrier for Na. These data suggested that Cl binds to the carrier before Na. Experiments comparing influx and efflux rates of transport using red blood cell ghosts indicated a functional asymmetry of the transporter. Under the same gradient conditions, Na- and Cl-dependent glycine transport functioned in both directions across the membrane but rates of efflux were 50% greater than rates of influx. In addition, the presence of trans substrates modified influx and efflux differently. Trans glycine largely inhibited glycine efflux in the absence or presence of trans Na; trans Na largely inhibited glycine influx and this inhibition was partially reversed when trans glycine was also present. A model for the binding of these substrates to the outward-facing carrier is presented.


2020 ◽  
pp. 32-37
Author(s):  
О.А. Гусева ◽  
И.С. Мельников ◽  
Е.С. Зубкова ◽  
С.Г. Козлов ◽  
Ю.Н. Автаева ◽  
...  

Данные крупных проспективных исследований демонстрируют корреляционную связь уровня С-реактивного белка (СРБ) в крови и риска развития неблагоприятных сердечно-сосудистых событий. Однако остаются малоизученными уровень экспрессии СРБ клетками пери- ферической крови и их способность синтезировать СРБ. Цель исследования. Определение уровней экспрессии СРБ циркулирующими клетками периферической крови. Исследование экспрессии мРНК СРБ макрофагами, полученными из моноцитов периферической крови. Материал и методы. Исследовали эритроциты, тромбоциты и лейкоциты периферической крови 6 добровольцев в возрасте от 30 до 60 лет. Для идентификации фенотипа клеток крови применяли метод проточной цитофлюориметрии с использованием панели моноклональных ан- тител, конъюгированных с различными флюорохромами, а именно CD235a-PE-Cy7, CD41-APC, CD45-PerCP-Cy5.5 и CD14-APC-Cy-7. Уровень экспрессии клетками крови СРБ определяли по уровню флюоресценции связанных с целевыми клетками FITC-конъюгированных моноклональ- ных антител к СРБ («ИМТЕК», Россия). Для определения мРНК СРБ применяли метод количественной полимеразной цепной реакции (ПЦР) с последующим анализом специфичности амплификаций с помощью электрофореза в агарозном геле. Об экспрессии СРБ макрофагами, полученными из моноцитов периферической крови, судили по количеству мРНК, выделенной после их активации липополисахаридом (ЛПС). Результаты. Результаты исследования показали, что СРБ экспрессируют 85,0±10,5% моноцитов; лимфоциты, тромбоциты и эритроци- ты — 7,5±0,6, 3,0±0,3 и 4,3±0,5% соответственно. Методом количественной ПЦР в небольших количествах мРНК СРБ была зарегистри- рована в макрофагах, активированных ЛПС. Ее уровень незначительно, в 0,79±0,73 раза (p=0,96, n=6), отличался относительно гена «домашнего хозяйства». Заключение. Обнаружено, что СРБ присутствует на внешней клеточной мембране до 90% циркулирующих моноцитов и до 10% лимфо- цитов, в то время как эритроциты и тромбоциты не несут на своей поверхности СРБ. Установлена возможность синтеза СРБ стимулиро- ванными ЛПС макрофагами, полученными из моноцитов периферической крови. Data from major prospective studies demonstrate a correlation between blood C-reactive protein (CRP) levels and the risk of adverse cardiovascular events. However, the level of expression of CRP by peripheral blood cells and their ability to synthesize CRP remains poorly studied. The purpose of the study. Determination of CRP expression levels by circulating peripheral blood cells. Investigation of expression of CRP mRNA by macrophages obtained from peripheral blood monocytes. Material and methods. erythrocytes, platelets and leukocytes of peripheral blood were studied in 6 volunteers aged 30 to 60 years. To identify the blood cell phenotype, the method of flow cytofluorimetry was used using a panel of monoclonal antibodies conjugated with different fluorophores, namely, CD235a-PE-Cy7, CD41-APC, CD45-PerCP-Cy5.5 and CD14-APC-Cy-7. Blood cell expression level of CRP was determined by fluorescence level of FITC-conjugated monoclonal antibodies to CRP associated with target cells (IMTEK, Russia). The method of quantitative polymerase chain reaction (PCR) with the subsequent analysis of specificity of amplifications by electrophoresis in agarose gel was used for determination of mRNA of CRP. The expression of DRR by macrophages derived from peripheral blood monocytes was judged by the amount of mRNA isolated after their activation by lipopolysaccharide (LPS). The results. The results of the study showed that CRP express 85.0±10.5% monocytes, lymphocytes, platelets and red blood cells — 7.5±0.6, 3.0±0.3 and 4.3±0.5% respectively. The method of quantitative PCR in small amounts of CRP mRNA was registered in macrophages activated by LPS. Its level was insignificant, by 0.79±0.73 times (p=0.96, n=6), differed from the "household" gene. Conclusion. It was found that CRP is present on the outer cell membrane up to 90% of circulating monocytes and up to 10% of lymphocytes, while red blood cells and platelets do not carry CRP on their surface. The possibility of synthesis of CRP by stimulated LPS macrophages obtained from peripheral blood monocytes has been established


2019 ◽  
Vol 8 (11) ◽  
pp. 1918 ◽  
Author(s):  
Daniele Dondossola ◽  
Alessandro Santini ◽  
Caterina Lonati ◽  
Alberto Zanella ◽  
Riccardo Merighi ◽  
...  

Ex-situ machine perfusion (MP) has been increasingly used to enhance liver quality in different settings. Small animal models can help to implement this procedure. As most normothermic MP (NMP) models employ sub-physiological levels of oxygen delivery (DO2), the aim of this study was to investigate the effectiveness and safety of different DO2, using human red blood cells (RBCs) as oxygen carriers on metabolic recovery in a rat model of NMP. Four experimental groups (n = 5 each) consisted of (1) native (untreated/control), (2) liver static cold storage (SCS) 30 min without NMP, (3) SCS followed by 120 min of NMP with Dulbecco-Modified-Eagle-Medium as perfusate (DMEM), and (4) similar to group 3, but perfusion fluid was added with human RBCs (hematocrit 15%) (BLOOD). Compared to DMEM, the BLOOD group showed increased liver DO2 (p = 0.008) and oxygen consumption ( V O ˙ 2) (p < 0.001); lactate clearance (p < 0.001), potassium (p < 0.001), and glucose (p = 0.029) uptake were enhanced. ATP levels were likewise higher in BLOOD relative to DMEM (p = 0.031). V O ˙ 2 and DO2 were highly correlated (p < 0.001). Consistently, the main metabolic parameters were directly correlated with DO2 and V O ˙ 2. No human RBC related damage was detected. In conclusion, an optimized DO2 significantly reduces hypoxic damage-related effects occurring during NMP. Human RBCs can be safely used as oxygen carriers.


2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Yeni Trianah

ABSTRACT[Lectin activities of kebiul seeds to the red blood cell agglutination speed in pathological condition and its implementation as a chemical learning module]. The purposes of this research were to determine: 1) the relative moleculer mass protein that behaves as a lectin in the seed extract kebiul , 2) the velocity of red blood cell clumping influenced by seed lectin kebiul, 3) know the difference student results on protein taught modules and a without modules taught at the College of Teacher Training and Education Teachers Association of the Republic of Indonesia (STKIP-PGRI) Lubuklinggau. Extraction of seeds Kebiul carried out in the a cold buffer solution with pH 7.4 and plus 60% saturated ammonium sulfat (salting out method), and made in four concentrations, namely : 2%, 4%, 6% and 8%. Then tested the activity of seed lectin kebiul to speed clotting of human red blood cells in pathological conditions. To determine the relative molecular mass protein that behaves as a lectin in the seed extract kebiul SDS PAGE electrophoresis performed 1-D. The experiment were then implemented on the material of protein biochemistry using modules. The results of the research showed that on the concentration of 8% the velocity of the clumping of a human red blood cells hypertension most of the highest, the relative molecular mass which behaves as a lectin protein electrophoresis results of 1-D SDS PAGE obtained by a three protein bands in the range of moleculer weights 80, 128 and 144 kDa. The Results of the implementation of the experimental class showed an average `post test value was 95 and the post test control class 69.41. There are differences in students' learning about protein for students who are taught by module and who are taught without module.Keywords: Lectin; agglutination; blood; 1-D SDS PAGE; learning outcomes.


2018 ◽  
Vol 15 (1) ◽  
pp. 23-29
Author(s):  
Lê Văn Phan ◽  
Nguyễn Thị Trung ◽  
Trương Nam Hải

ABO incompatibility is a potential lethal barrier in tranfusion therapy. ABO blood cell grouping for all of the donors and potential recipients is the unique way for ensuring the highest safety for potential recipients in blood transfusion. ABO blood cell grouping must be performed by both of the serum sample method and erythrocytes sample method. Nowadays, when applying the serum sample method, the monoclonal antibodies are commonly used to identify the antigens on the surface of the red blood cells. In this study, for the first time in Vietnam, the hybridoma technology was successefully developed and screened hybrid cells for producing monoclonal antibody specifically agglutinated with red blood cells B group. After being isolated from spleen and iliac lympho node of the human red blood cells B group immuned BALB/c mice, the lymphocytes B was fused with myeloma sp2/0. As the results, 10 single hybrid cell lines B4D6C6, B4D6E2, B4D10C9, B4D10B6, B4D10D5, B4D10D6, B4D10E4, B4H6C5, B8F6B6, B8F6D4 have been screened by a specific agglutination with sample red blood cells group B. Among them, the hybrid cell line B4D10C9 was the best secreting anti-B monoclonal antibody into culture, that presented by antibody titer reached 1/256, hence it was selected for further studies. The ELISA method helped to isotype the anti-B monoclonal antibody which was produced from B4D10C9 hybridoma. As a result, the anti-B monoclonal antibody contained IgM heavy chains and kappa light chains. The IgM antibody could be able to agglutinate red blood cells 25 times more than IgG antibody. The success of screening B4D10C9 hybridoma producing IgM monoclonal antibody is the most significant result of this study.


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