This study was purposed to establish the method of quantifying RhD antigen on red blood cells (RBC) by flow cytometry (FCM) and to explore the expression of D antigen on RBC of different RhD serotype. RhD(+) RBCs and RhD(-) RBCs were mixed in 1:1 ratio. Cells were stained by the indirect method (IgG anti-D as the first antibody, FITC-anti-IgG F(ab')2 as the second antibody), and the ratio of RhD(+) on RBCs was quantified by FCM. The optimal dosage of IgG anti-D was defined. Expression of RhD antigen on RBC of RhD(+), weak D, RhDel and RhD(-) type were detected by FCM. The results showed that optimal dilution of IgG anti-D monoclonal antibody was 1:4, 1x10(6) cells/50 microl. The percentage of D(+) RBC of RhD(+), weak D, RhDel and RhD(-) type were 96.8+/-2.97%, 79.5+/-9.88%, 47.8+/-11.43%, 3.7+/-2.96%, respectively. The mean fluorescence intensity (MFI) of RhD antigen expression of RhD(+), weak D, RhDel and RhD(-) type were 33.3+/-6.21 Dal, 18.6+/-5.39 Dal, 7.10+/-1.17 Dal, 0.79+/-0.55 Dal, respectively. In conclusion, there are significant differences of RhD antigen expressions among RBC of different RhD serotypes. The level of antigen on RhD(+) RBC is the highest and then weak D the next, while the level of antigen on RhDel RBC is the lowest level.
Blood Donors ; Erythrocytes ; immunology ; metabolism ; Flow Cytometry ; methods ; Humans ; Rh-Hr Blood-Group System ; immunology ; metabolism

This study was aimed to explore impact of removal of cell membrane G alalpha1-3Gal beta1-4Glc NAc epitopes (called alpha-Gal) and chemical modification of other xenoantigen on bovine red blood cell (bRBC) and porcine red blood cell (pRBC) antigenicity and to compare their modified erythrocytes, in order to provide basis for development of human blood substitute with rich source, high safety and efficacy. bRBC and pRBC were subjected to both enzymatic removal of membrane alpha-Gal with recombinant coffee bean alpha-galactosidase (rC alpha-GalE) and covalent attachment of benzotriazole carbonate-linked methoxypolyethylene glycol (mPEG-BTC, MW = 20 kD). The effects of treatment were measured by hemagglutination, flow cytometric assay of IgG binding and clinical cross-match testing to human sera. The results showed that although alpha-galactosidase treatment reduced hemagglutination titers to levels similar to negative control, the combination of the treatments was most effective. Clinically used cross-match tests between bRBC, pRBC and human sera demonstrated increased compatibility. Bovine RBC were more robust than pRBC, and had less xenoantigens, and had longer half life than pRBC in vivo. These characteristics suggested that bRBCs were more suitable to investigation as an alternatives to hRBC in clinical transfusion than pRBC. These data suggested that strategies to remove or mask xenoantigens on bRBC reduce antigenicity sufficiently to allow in vitro cross-match compatibility to human sera, and therefore bRBC following modification may be considered as human blood substitute.
Animals ; Antigens, Heterophile ; immunology ; Blood Substitutes ; Cattle ; Disaccharides ; immunology ; Epitopes ; immunology ; Erythrocyte Membrane ; immunology ; Erythrocyte Transfusion ; methods ; Erythrocytes ; immunology ; metabolism ; Humans ; Swine ; alpha-Galactosidase ; immunology

This study was purposed to investigate the efficacy of different whole flow lysis reagents for lysis of red blood cells in flow cytometric analysis. The expression of immunocytes was detected by flow cytometry after lysis of red blood cells using commercial reagents (Optilyse C, FACS Lysing Solution) and self-made red blood cell lysis reagents (RBC Lysis Buffer), the detection results were analyzed comparatively. The results showed that there was no significant difference in the percentage of CD3e(+), CD3e(+)CD4(+), CD3e(+)CD8a(+), CD3e(-)CD19(+), CD3e(-)NK1.1(+) and Gr-1(+) cells between 3 different lysis reagent groups. However OptiLyse C solution was suitable to Gr-1(+) cell detection, but did not suit to Foxp3(+) Treg detection. The self-made RBC Lysis Buffer and FACS Lysing Solution were suited to Foxp3(+) Treg detection. It is concluded that the use of self-made RBC Lysis Buffer for flow cytometry can get the lysis efficiency of commercially available lysis solutions when samples are prepared in accordance with standardized procedure. The self-made RBC Lysis Buffer not only can satisfy experimental requirements, but also can reduce the experimental costs.
Animals ; Erythrocyte Count ; Erythrocytes ; immunology ; metabolism ; Flow Cytometry ; instrumentation ; methods ; Immune System ; immunology ; Indicators and Reagents ; analysis ; Mice ; Mice, Inbred C57BL

BACKGROUND: Validation of hemagglutination inhibition (HI) assays is important for evaluating antibody responses to influenza virus, and selection of erythrocytes for use in these assays is important. This study aimed to determine the correlation between receptor binding specificity and effectiveness of the HI assay for detecting antibody response to pandemic influenza H1N1 (pH1N1) virus. METHODS: Hemagglutination (HA) tests were performed using erythrocytes from 6 species. Subsequently, 8 hemagglutinating units of pH1N1 from each species were titrated by real-time reverse transcription-PCR. To investigate the effect of erythrocyte binding preference on HI antibody titers, comparisons of HI with microneutralization (MN) assays were performed. RESULTS: Goose erythrocytes showed most specific binding with pH1N1, while HA titers using human erythrocytes were comparable to those using turkey erythrocytes. The erythrocyte binding efficiency was shown to have an impact on antibody detection. Comparing MN titers, HI titers using turkey erythrocytes yielded the most accurate results, while those using goose erythrocytes produced the highest geometric mean titer. Human blood group O erythrocytes lacking a specific antibody yielded results most comparable to those obtained using turkey erythrocytes. Further, pre-existing antibody to pH1N1 and different erythrocyte species can distort HI assay results. CONCLUSIONS: HI assay, using turkey and human erythrocytes, yielded the most comparable and applicable results for pH1N1 than those by MN assay, and using goose erythrocytes may lead to overestimated titers. Selection of appropriate erythrocyte species for HI assay allows construction of a more reliable database, which is essential for further investigations and control of virus epidemics.
Adult ; Animals ; Antibodies, Neutralizing/immunology ; Antibodies, Viral/*analysis/immunology ; Chickens ; Erythrocytes/*metabolism ; Female ; Geese ; *Hemagglutination Inhibition Tests ; Horses ; Humans ; Influenza A Virus, H1N1 Subtype/genetics/immunology/*metabolism ; Influenza, Human/epidemiology/immunology/virology ; Male ; Middle Aged ; Neutralization Tests ; Pandemics ; Swine ; Turkeys

In order to meet the demand for safe transfusion in special conditions and to utilize the donated blood supply efficiently, technology has been developed to convert erythrocytes from type A, B, or AB to "universal donor" blood. Conversion of blood type B to O was performed by means of recombinant alpha-galactosidase digestion. The results showed that blood type B to O was converted successfully, 1 transfusion unit of red cells of group B (100 ml totally) could converted to universal blood cells in the optimal conditions including pH 5.6, 26 degrees C, 2 hours, obturation and sterilization. It is concluded that the universal red blood cells converted from group B to group O are conformed to demand of identification rules of biological products, no harmful effects of alpha-galactosidase on cell structure and function are observed. The converted red cells can stored in 4 degrees C for 21 days.
ABO Blood-Group System ; classification ; immunology ; Blood Group Incompatibility ; prevention & control ; Blood Transfusion ; methods ; Coffee ; enzymology ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Erythrocytes ; immunology ; metabolism ; Humans ; Isoantigens ; drug effects ; metabolism ; Recombinant Proteins ; metabolism ; pharmacology ; alpha-Galactosidase ; genetics ; metabolism ; pharmacology

In order to obtain an adequate supply of alpha-galactosidase for research and practical use, the fermentation, purification and identification of the recombinant coffee bean a-galactosidase were carried out. Baffled flasks containing 100mL BMGY were inoculated with the pPIC9K-Gal/GS115 strain and allowed to grow at 30 degrees C, 250- 300r/min until a maximum optical density at 600nm (OD600) between 2.0 to 6.0 was attained. Entire 400 mL seed culture was transferred aseptically to the 5-liter fermenter, which contained 4 liter sterilized basal salts medium and 4% glycerol. The batch culture grew at 30 degrees C, pH 5.0 until the glycerol was completely consumed, and a glycerol feed was initiated to increase the cell biomass prior to induction with methanol. The culture was centrifuged at 8000 x g and the supernatant was collected. Following ultrafiltration, the retentate was balanced in 20 mmol/L sodium formicate buffer, pH 3.8 and loaded onto a cation-exchange column, HiTrap SP. The column was washed with the same buffer and bound proteins were eluted with 1 mol/L NaCl. The fractions containing recombinant a-galactosidase were pooled and concentrated with PEG20 000. Subsequently, the biochemical properties of the enzyme were determined with typical methods. At last, the fresh human blood A and B erythrocytes were incubated with the purified alpha-galactosidase at 26 degrees C for 2 4 hours. Hemagglutinins were assayed by the standard method. After an elapsed fermentation times (EFT) of 18h, the fed-batch phase was initiated to increase the cell biomass. A cellular yield of nearly 200 g/liter wet cells was achieved when induction was initiated. 72h later, the alpha-galactosidase activity against artificial substrate PNPG (PNP-alpha-galactopyranoside) achieved 36 000u per liter culture. The crude fementation supernatant contained few impurities as detected by SDS-PAGE. The supernatant was purified by cation-exchange chromatography, the target alpha-galactosidase was eluted with 40% 1mol/L NaCl and showed a 41kD band on SDS-PAGE. After concentration, the final recovery was about 41%. The Michaelis constant of the recombinant alpha-galactosidase was determined as 0.275 mmol/L, which slightly lower than the nature enzyme and suggested a higher affinity with specific substrate. When human blood type B erythrocytes pretreated with 100u/mL recombinant alpha-galactosidase reacted with bood type B antiserum, no hemagglutination occurred. This suggested that the B antigens had been removed by the enzyme successfully. These results demonstrated that the recombinant alpha-galactosidase could be produced in largescale and made it possible to explore the application of alpha-galactosidase in more fields.
ABO Blood-Group System ; immunology ; Chromatography, Ion Exchange ; Electrophoresis, Polyacrylamide Gel ; Erythrocytes ; drug effects ; Fermentation ; physiology ; Hemagglutination ; drug effects ; Humans ; Pichia ; genetics ; metabolism ; alpha-Galactosidase ; genetics ; metabolism ; pharmacology

OBJECTIVETo study the changes of genomic density polymorphism, quantitative expression and the adhesion activity of complement receptor type 1 (ECR1) on erythrocytes in patients with chronic hepatitis.

METHODSPolymerase chain reaction (PCR) and Hind restriction enzyme digestion, the quantitative assay of ECR1 and the activity of erythrocytes immune adhesion test were applied.

RESULTSThe spot mutation rate (25.0%-30.3%) of ECR1 density gene in patients with chronic hepatitis was not significantly different from that of healthy individuals (28.0%). The amount of ECR1 in patients with chronic hepatitis, except for the diseases with normal liver function, was significantly lower than that of healthy individuals (t=9.87,P<0.000 1). The quantitative expression of ECR1 in decompensated cirrhosis was obviously lower than that of compensated cirrhosis (t=2.21,P<0.05).

CONCLUSIONSDefective expression of ECR1 in chronic hepatitis B may be acquired through central and/or peripheral mechanisms. It is very important to study the quantitative expression in the patients with chronic hepatitis.

Erythrocytes ; immunology ; metabolism ; Hepatitis B, Chronic ; genetics ; Humans ; Liver Cirrhosis ; genetics ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Receptors, Complement ; analysis ; genetics ; metabolism ; Tissue Adhesions

The aim of this study is to construct a bifunctional fusion protein, which can conjugate both human red blood cells and antibodies against classical swine fever virus (CSFV). We respectively amplified 2E8ScFv and mE2 genes from different recombinant vectors, in which 2E8ScFv gene is the single chain Fv gene against H antigen of human red blood cells, whereas mE2 gene is the main antigen coding region gene of CSFV E2 protein. We used overlap extension PCR to obtain an artificial fusion gene segment 2E8mE2 containing genes of Both 2E8ScFv and mE2, then ligated into the expression vector pET-DsbA and expressed in Escherichia coli BL21(DE3) PlysS host cells, after induced with IPTG the target fusion protein was successfully expressed and identified in inclusion bodies by SDS-PAGE and Western blotting. We purified the fusion protein and renatured it from inclusion bodies to obtain a native state of well biological activity. The Erythrocyte agglutination test results indicated that the fusion protein can conjugate both human red blood cells and antibodies of CSFV.
Erythrocytes ; immunology ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunoglobulin Fragments ; biosynthesis ; genetics ; immunology ; Immunoglobulin Variable Region ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Single-Chain Antibodies ; biosynthesis ; genetics ; Viral Envelope Proteins ; biosynthesis ; genetics

OBJECTIVETo construct and express anti-human RBC and HIVgp160 fusion protein for rapid detection of antibody to HIV.

METHODSThe gene of the anti human RBC ScFv and HIV antigen were constructed together into expression vector. The fusion protein was expressed in E. coli.

RESULTSThe fusion protein was proved to be able to bind both anti-RBC and HIVgp160. It could cause agglutination of human RBC when HIVgp160 was present.

CONCLUSIONThe fusion protein has the potential in rapid detection of HIV.

Antibodies, Monoclonal ; immunology ; isolation & purification ; Autoantibodies ; immunology ; isolation & purification ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay ; Erythrocytes ; immunology ; Gene Expression ; Genetic Vectors ; genetics ; HIV Antibodies ; blood ; immunology ; HIV Envelope Protein gp160 ; genetics ; immunology ; metabolism ; HIV Seropositivity ; blood ; Hemagglutination Tests ; methods ; Humans ; Recombinant Fusion Proteins ; genetics ; immunology ; metabolism

BACKGROUND: Detection methods for ABO antibody (Ab) titers vary across laboratories, and the results are different depending on the method used. We aimed to compare titer values using different detection methods for the measurement of ABO Ab titers. METHODS: For ABO Ab detection, pooled group A or B red blood cells (RBCs) were reacted with each of 20 sera from blood groups A, B, or O without dithiothreitol treatment. The room-temperature (RT) incubation technique and the indirect antiglobulin test (IAT) were used in the tube test and gel card test. Flow cytometry (FCM) was performed by using anti-IgM and anti-IgG Abs. RESULTS: Regardless of the blood groups tested, the FCM assay with anti-IgM showed the highest titer compared to the tube test and gel card test with RT incubation in both. The tube test with IAT showed a higher titer than the gel card test with IAT (Gel-IAT) or FCM with anti-IgG in blood group A and B, while Gel-IAT showed the highest titer relative to the other tests, only for the anti-A Ab in blood group O. CONCLUSIONS: There were significant differences in the titers depending on the detection method used, and each method showed a different detection capacity for each ABO Ab depending on the ABO blood group tested. Therefore, caution should be exercised in interpreting ABO Ab titer results, taking into consideration the detection method used and the blood group.
ABO Blood-Group System/*immunology ; Adult ; Aged ; Agglutination Tests/instrumentation/*standards ; Antibodies/*analysis ; Antibodies, Anti-Idiotypic/analysis ; Erythrocytes/chemistry/metabolism ; Female ; *Flow Cytometry ; Humans ; Male ; Middle Aged ; Temperature