The erythrocyte surface antigen GP.Mur (also known as Miltenberger subtype III, or Mi.III) is one... more The erythrocyte surface antigen GP.Mur (also known as Miltenberger subtype III, or Mi.III) is one of the most clinically important red blood cell (RBC) antigens in the eld of transfusion in Southeast Asia. GP.Mur is a hybrid membrane protein based on the structure of glycophorin B, inserted with a piece of glycophorin A. The incidence of GP.Mur is rare in Caucasians +/+ +/− 3 − 2 +/+ +/− Conclusion From these findings, elevated blood pressure and expedited CO respiration are likely both resulted from GP.Mur-assisted higher band 3 expression on the RBC membrane. Further, the biochemical and physiologic di erences between GP.Mur and GP.Mur could be due to their variations in the structural organizations of band 3 complexes on the red cell membrane.
Glycophorin A and glycophorin B are structural membrane glycoproteins bound in the band 3 multipr... more Glycophorin A and glycophorin B are structural membrane glycoproteins bound in the band 3 multiprotein complexes on human red blood cells (RBCs). Band 3 is an erythroid-specific anion exchanger (AE1). AE1-mediated HCO 3 − transport provides the substrate for the enzyme-catalyzed conversion HCO 3 − (aq) # CO 2(g) , which takes place inside the RBCs. Bicarbonate transport via AE1 supports intravascular acid-base homeostasis and respiratory excretion of CO 2. In the past decade, we conducted several comparative physiology studies on Taiwanese people having the glycophorin variant GPMur RBC type (which accompanies greater AE1 expression). We found that increased anion transport across the erythrocyte membrane not only enhances gas exchange and lung functions but also elevates blood pressure (BP) and reduces nitric oxide (NO)dependent vasodilation and exhaled NO fraction (FeNO) in healthy individuals with GP.Mur. Notably, in people carrying the GPMur blood type, the BP and NOdependent, flow-mediated vasodilation (FMD) are both more strongly correlated with individual hemoglobin (Hb) levels. As blood NO and nitrite (NO 2 −) are predominantly scavenged by intraerythrocytic Hb, and NO 2 − primarily enters RBCs via AE1, could a more monoanion-permeable RBC membrane (i.e., GPMur/ increased AE1) enhance NO 2 − /NO 3 − permeability and Hb scavenging of NO 2 − and NO to affect blood pressure? In this perspective, a working model is proposed for the potential role of AE1 in intravascular NO availability, blood pressure, and clinical relevance.
Psychiatry and Clinical Neurosciences, Jun 14, 2018
Running head: Anti-NMDAR encephalitis mislabeled schizophrenia Schizophrenia (SCZ) is a heterogen... more Running head: Anti-NMDAR encephalitis mislabeled schizophrenia Schizophrenia (SCZ) is a heterogeneous disease with approximately 10% of patients initially diagnosed with schizophrenia having autoantibodies binding to the NMDA receptor and presenting as anti-NMDAR encephalitis. 1 Therefore, immune modulating therapy may frequently respond well and timely for treating patients with anti-NMDAR encephalitis characterized by psychosis. 2 In this paper we detail a series of seven cases where anti-NMDAR encephalitis was misidentified as SCZ (Table 1). The research protocol was approved by the Mackay Memorial Hospital Institutional Review Board (IRB). Written informed
The GP.Mur red cell phenotype is characterized by the unique presence of glycophorin B-A-B hybrid... more The GP.Mur red cell phenotype is characterized by the unique presence of glycophorin B-A-B hybrid protein on the erythrocyte membrane which promotes band 3 expression. Band 3, or anion exchanger-1, transports HCO3 - across the erythrocyte membrane by exchange of Cl-; this function of band 3 works in concert with intraerythrocytic carbonic anhydrase II (CAII) to facilitate blood CO2 transport. People with the GP.Mur blood type express 10-20% more band 3 protein than those without the special blood type. We thus hypothesized that respiration in people with the GP.Mur blood type might be distinctly different when being challenged. In this study, we recruited 36 age-matched male elite athletes (13 GP.Mur and 23 without GP.Mur [control]) for an incremental running test to exhaustion. While running on a treadmill, the subjects were continuously monitored using a Quark CPET (cardiopulmonary exercise testing) unit (COSMED, Italy). Two statistical methods were employed for data analysis: (1) unpaired t-test for comparison at individual timepoints; and (2) linear mixed modeling for serial cardiopulmonary measurements collected during the running test. We found that their running abilities were similar. However, the subjects with GP.Mur showed higher respiratory rates and smaller inspiratory/expiratory (I/E) ratios than the control subjects throughout the entire exhaustive running test. That is, GP.Mur+ subjects spent a larger fraction of the respiratory cycle time on CO2 excretion than inspiration; their respiration also appeared to respond faster to the same level of workload. These resulted in lower end-tidal CO2 pressure in the running GP.Mur subjects compared to the controls. In conclusion, we presented direct evidence that band 3-mediated HCO3 -/CO2 exchange at the erythrocyte level could impact the respiratory pattern of CO2 excretion. Taiwan National Science and Technology Council; MacKay Memorial Hospital This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
American Journal of Physiology-lung Cellular and Molecular Physiology, Jun 1, 2023
Higher expression of the Cl−/[Formula: see text] transporter band 3 anion exchanger-1 (AE1) on th... more Higher expression of the Cl−/[Formula: see text] transporter band 3 anion exchanger-1 (AE1) on the red blood cell membrane, as in people with the GP.Mur blood type, increases the rate of CO2 excretion during exercise.
Background: Human cytomegalovirus (CMV) is a lifelong, often asymptomatic infection, with the vir... more Background: Human cytomegalovirus (CMV) is a lifelong, often asymptomatic infection, with the virus maintained in latently infected myeloid cells. Patients receiving chemotherapy for cancer are at high risk of reactivation of latent CMV, which may further contribute to host immune exhaustion, ultimately leading to a poor antitumor response. Pre-emptive anti-CMV medication may, therefore, serve as an adjunct therapy, preventing deterioration of the patient's immunity during treatment for cancer. The present study evaluated ganciclovir treatment's in vitro effects on CMV-associated T cell exhaustion and the antitumor capacity of cells from cancer patients. Methods: Peripheral blood mononuclear cells from patients with various types of cancers were treated with or without ganciclovir. Cells were then analyzed for T cell subpopulations and activation markers using flow cytometry, and their antitumor capacity was tested after exposure to dendritic celleA549 fusion cells. Results: Following ganciclovir treatment, there was a redistribution of T cell subpopulations which was clearly distinct from the baseline pattern of T cell exhaustion. Treatment resulted in increases in early differentiated proportions, including naive (untreated control cells vs. ganciclovir treated cells, p < 0.001), interleukin (IL)-7Ra þ (p < 0.01), and CD28 þ CD8 þ (p < 0.05) T cells, and a decrease in the proportion of effector memory (p < 0.001) T cells in cancer patients. Ganciclovir treatment significantly improved tumor-killing capacity (p < 0.001), with a concomitant downregulation of T cell exhaustion marker programmed death-1 (PD-1) (p < 0.001). Conclusion: These findings demonstrate that ganciclovir treatment in vitro directly affects immune function by partially reconstituting T cell subsets and restoring the T cell antitumor response.
Frontiers in Cardiovascular Medicine, Nov 29, 2021
GP.Mur, a red blood cell (RBC) hybrid protein encoded by glycophorin B-A-B, increases expression ... more GP.Mur, a red blood cell (RBC) hybrid protein encoded by glycophorin B-A-B, increases expression of erythroid band 3 (Anion Exchanger-1, SLC4A1). GP.Mur is extremely rare but has a prevalence of 1-10% in regions of Southeast Asia. We unexpectedly found slightly higher blood pressure (BP) among healthy Taiwanese adults with GP.Mur. Since band 3 has been suggested to interact with hemoglobin (Hb) to modulate nitric oxide (NO)-dependent hypoxic vasodilation during the respiratory cycle, we hypothesized that GP.Mur red cells could exert differentiable effects on vascular tone. Here we recruited GP.Mur-positive and GP.Mur-negative elite male college athletes, as well as age-matched, GP.Mur-negative non-athletes, for NO-dependent flow-mediated dilation (FMD) and NO-independent dilation (NID). The subjects were also tested for plasma nitrite and nitrate before and after arterial occlusion in FMD. GP.Mur+ and non-GP.Mur athletes exhibited similar heart rates and blood pressure, but GP.Mur+ athletes showed significantly lower FMD (4.8 ± 2.4%) than non-GP.Mur athletes (6.5 ± 2.1%). NO-independent vasodilation was not affected by GP.Mur. As Hb controls intravascular NO bioavailability, we examined the effect of Hb on limiting FMD and found it to be significantly stronger in GP.Mur+ subjects. Biochemically, plasma nitrite levels were directly proportional to individual band 3 expression on the red cell membrane. The increase of plasma nitrite triggered by arterial occlusion also showed small dependency on band 3 levels in non-GP.Mur subjects. By the GP.Mur comparative study, we unveiled comodulation of NO-dependent vasodilation by band 3 and Hb, and verified the long-pending role of erythroid band 3 in this process.
Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the most frequently encoun... more Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the most frequently encountered autoimmune encephalitis. The pathogenesis of both anti-NMDAR encephalitis and schizophrenia involve down-regulation of NMDA receptors. Whether autoantibody-mediated destruction of neuronal NMDA receptors is associated with schizophrenia or first-episode psychosis (FEP) remains unclear, as the current findings from different groups are inconsistent. The main culprits are likely due to heterogeneity of autoantibodies (autoAbs) in a patient's blood or cerebrospinal fluid (CSF), as well as due to limitation of the current detection methods for anti-NMDAR autoAbs. Here, we optimized the current diagnostic method based on the only commercially-available anti-NMDAR test kit. We first increased detection sensitivity by replacing reporter fluorophore fluorescein isothiocyanate (FITC) in the kit with Alexa Fluor 488, which is superior in resisting photobleaching. We also found that using an advanced imaging system could increase the detection limit, compared to using a simple fluorescence microscope. To improve test accuracy, we implemented secondary labeling with a well-characterized mouse anti-NR1 monoclonal antibody (mAb) after immunostaining with a patient's sample. The degree of colocalization between mouse and human antisera in NMDAR-expressing cells served to validate test results to be truly anti-NMDAR positive or false-positive. We also incorporated DNA-specific DAPI to simultaneously differentiate autoAbs targeting the plasma membrane from those targeting cell nuclei or perinuclear compartments. All the technical implementation could be integrated in a general hospital laboratory setting, without the need of specialized expertise or equipment. By sharing our experience, we hope this may help improve sensitivity and accuracy of the mainstream method for anti-NMDAR detection.
Human CO2 respiration requires rapid conversion between CO2 and HCO3(-) Carbonic anhydrase II fac... more Human CO2 respiration requires rapid conversion between CO2 and HCO3(-) Carbonic anhydrase II facilitates this reversible reaction inside red blood cells, and band 3 [anion exchange (AE)-1] provides a passage for HCO3(-) flux across the cell membrane. These 2 proteins are core components of the CO2 transport metabolon. Intracellular H2O is necessary for CO2/HCO3(-) conversion. However, abundantly expressed aquaporin (AQP)-1 in erythrocytes is thought not to be part of band 3 complexes or the CO2 transport metabolon. To solve this conundrum, we used Förster resonance energy transfer (FRET) measured by fluorescence lifetime imaging (FLIM-FRET) and identified interaction between aquaporin-1 and band 3 at a distance of 8 nm, within the range of dipole-dipole interaction. Notably, their interaction was adaptable to membrane tonicity changes. This suggests that the function of AQP1 in tonicity response could be coupled or correlated to its function in band 3-mediated CO2/HCO3(-) exchange. By demonstrating AQP1 as a mobile component of the CO2 transport metabolon, our results uncover a potential role of water channel in blood CO2 transport and respiration.-Hsu, K., Lee, T.-Y., Periasamy, A., Kao, F.-J., Li, L.-T., Lin, C.-Y., Lin, H.-J., Lin, M. Adaptable interaction between aquaporin-1 and band 3 reveals a potential role of water channel in blood CO2 transport.
BACKGROUND: GP.Mur (Mi.III) is a glycophorin B-A-B hybrid sialoglycoprotein expressing several po... more BACKGROUND: GP.Mur (Mi.III) is a glycophorin B-A-B hybrid sialoglycoprotein expressing several potent immunogens, including Mi a , Mur, and Hil. GP.Mur is considered one of the most important red blood cell (RBC) phenotypes in blood banking in Southeast Asia. However, there are no antibodies commercially available for the screening of GP.Mur RBCs. STUDY DESIGN AND METHODS: To develop a direct blood polymerase chain reaction (PCR) approach for the screening of GP.Mur cells, we first confirmed the genomic sequence differences among four GP.Mur and three Mi(a-) samples by sequencing their GYP.Mur and GYPB genes. With these data, we designed PCR primers that best discriminate GYPB and GYP.Mur. Our primer design also allows the detection of other Hil+ glycophorin variants. We also constructed two plasmids-pGBi2i3 and pMiIIIi2i3-which serve as the negative and positive control DNA, respectively, for the PCR procedure. Additionally, we designed a control PCR to be run side by side with the typing PCR. RESULTS: Because of the high specificity of our primers, we found it unnecessary to extract DNA from blood samples for PCR. We have tested this PCR method on 379 fresh and frozen blood samples. The results were further validated by serology and DNA sequencing and were shown to be completely accurate in our hand. We also found that the rapid genotyping method-high-resolution melting-can be a timesaving alternative for DNA sequencing. CONCLUSION: This direct blood PCR approach for determination of GP.Mur and related Hil+ phenotypes is reliable and economical and is expected to be useful for blood banking in Southeast Asia. T he antigens expressed on the glycophorin variant GP.Mur appear to be potent immunogens and as such are important antigens in many Southeast Asian countries. GP.Mur, previously known as Miltenberger Type III or Mi.III, is a glycophorin B-A-B hybrid protein expressed on the red blood cell (RBC) membrane. 1 Various glycophorin hybrid proteins were initially termed Miltenberger variants and were classified in the Miltenberger series of the MNS system by their serologic reactivities with these antisera: Mi a (MNS7), Vw (MNS9), Hut (MNS19), MUT (MNS 35), Mur (MNS10), Hil (MNS20), Hop (MNS26), Nob (MNS27), DANE (MNS32), TSEN (MNS33), and MINY(MNS34). 2,3 Most of the antisera listed here react with more than one glycophorin variant, indicating that the structures of these variants are associated. GP.Mur is believed to evolve from gene recombination events between homologous glycophorin A (GYPA) and glycophorin B (GYPB). 1 Because the
Background and Objectives Miltenberger blood group antigen subtype III (Mi.III) is characterized ... more Background and Objectives Miltenberger blood group antigen subtype III (Mi.III) is characterized by expression of a glycophorin B-A-B hybrid (Gp.Mur) on the erythrocyte surface. The two alleles of glycophorin B are substituted with the B-A-B hybrid alleles in homozygous Mi.III (Mi.III + ⁄ +), and thus, Mi.III + ⁄ + erythrocytes lack glycophorin B (GPB) and express Gp.Mur only. Because GPB is a major component of the Rh complex on RBCs, in this study, we explored how the absence of GPB might affect Rh expression in Mi.III RBCs. Materials and Methods (1) Mi.III+ RBCs were serologically identified and further differentiated their homozygosity or heterozygosity by immunoblot or direct sequencing. (2) RhD and RhCcEe mRNA was cloned, and their sequences analysed. (3) The expression levels of Rh antigen, Rh-associated glycoprotein (RhAG) and the U antigen in MI.III vs. non-Mi.III RBCs were assessed by flow cytometry and Western blot. Results Compared with the non-Mi.III samples, the surface expression of the Rh antigen was reduced to 76AE4% in Mi.III + ⁄ + RBCs and 93AE6% in Mi.III + ⁄). RhAG expression was also significantly reduced in Mi.III + ⁄ + , but not in Mi.III + ⁄). The U antigen expression in Mi.III + ⁄) was only 14AE9% relative to the control RBCs, while GPB was half the level of the controls. The mRNA sequences of Rh polypeptides from Mi.III+ samples were identical to the NCBI reference sequences. Conclusion Substitution of GPB with Gp.Mur significantly reduced the expression of Rh antigen and RhAG on the Mi.III + ⁄ + erythrocyte membrane. The Mi.III phenotype is predicted to induce considerable structural variations within the band 3 ⁄ Rhassociated macrocomplexes.
BAFF supports B-cell survival and homeostasis by activating the NF-κB pathway. While NF-κB is als... more BAFF supports B-cell survival and homeostasis by activating the NF-κB pathway. While NF-κB is also involved in the priming signal of NLRP3 inflammasome, the role of BAFF in NLRP3 inflammasome regulation is unknown. Here we report BAFF engagement to BAFF receptor elicited both priming and activating signals for NLRP3 inflammasomes in primary B cells and B lymphoma cell lines. This induction of NLRP3 inflammasomes by BAFF led to increased NLRP3 and IL-1β expression, caspase-1 activation, IL-1β secretion, and pyroptosis. Mechanistically, BAFF activated NLRP3 inflammasomes by promoting the association of cIAP-TRAF2 with components of NLRP3 inflammasomes, and by inducing Src activity-dependent ROS production and potassium ion efflux. B-cell receptor (BCR) stimulation on the Lyn signaling pathway inhibited BAFF-induced Src activities and attenuated BAFF-induced NLRP3 inflammasome activation. These findings reveal an additional function of BAFF in B-cell homeostasis that is associated with BCR activities.
plays multiple roles during HIV-1 infection: support of virus release (Klimkait et al., 1990; Str... more plays multiple roles during HIV-1 infection: support of virus release (Klimkait et al., 1990; Strebel et al., 1989) and promotion of CD4 degradation (Willey et al., 1992).
The erythrocyte surface antigen GP.Mur (also known as Miltenberger subtype III, or Mi.III) is one... more The erythrocyte surface antigen GP.Mur (also known as Miltenberger subtype III, or Mi.III) is one of the most clinically important red blood cell (RBC) antigens in the eld of transfusion in Southeast Asia. GP.Mur is a hybrid membrane protein based on the structure of glycophorin B, inserted with a piece of glycophorin A. The incidence of GP.Mur is rare in Caucasians +/+ +/− 3 − 2 +/+ +/− Conclusion From these findings, elevated blood pressure and expedited CO respiration are likely both resulted from GP.Mur-assisted higher band 3 expression on the RBC membrane. Further, the biochemical and physiologic di erences between GP.Mur and GP.Mur could be due to their variations in the structural organizations of band 3 complexes on the red cell membrane.
Glycophorin A and glycophorin B are structural membrane glycoproteins bound in the band 3 multipr... more Glycophorin A and glycophorin B are structural membrane glycoproteins bound in the band 3 multiprotein complexes on human red blood cells (RBCs). Band 3 is an erythroid-specific anion exchanger (AE1). AE1-mediated HCO 3 − transport provides the substrate for the enzyme-catalyzed conversion HCO 3 − (aq) # CO 2(g) , which takes place inside the RBCs. Bicarbonate transport via AE1 supports intravascular acid-base homeostasis and respiratory excretion of CO 2. In the past decade, we conducted several comparative physiology studies on Taiwanese people having the glycophorin variant GPMur RBC type (which accompanies greater AE1 expression). We found that increased anion transport across the erythrocyte membrane not only enhances gas exchange and lung functions but also elevates blood pressure (BP) and reduces nitric oxide (NO)dependent vasodilation and exhaled NO fraction (FeNO) in healthy individuals with GP.Mur. Notably, in people carrying the GPMur blood type, the BP and NOdependent, flow-mediated vasodilation (FMD) are both more strongly correlated with individual hemoglobin (Hb) levels. As blood NO and nitrite (NO 2 −) are predominantly scavenged by intraerythrocytic Hb, and NO 2 − primarily enters RBCs via AE1, could a more monoanion-permeable RBC membrane (i.e., GPMur/ increased AE1) enhance NO 2 − /NO 3 − permeability and Hb scavenging of NO 2 − and NO to affect blood pressure? In this perspective, a working model is proposed for the potential role of AE1 in intravascular NO availability, blood pressure, and clinical relevance.
Psychiatry and Clinical Neurosciences, Jun 14, 2018
Running head: Anti-NMDAR encephalitis mislabeled schizophrenia Schizophrenia (SCZ) is a heterogen... more Running head: Anti-NMDAR encephalitis mislabeled schizophrenia Schizophrenia (SCZ) is a heterogeneous disease with approximately 10% of patients initially diagnosed with schizophrenia having autoantibodies binding to the NMDA receptor and presenting as anti-NMDAR encephalitis. 1 Therefore, immune modulating therapy may frequently respond well and timely for treating patients with anti-NMDAR encephalitis characterized by psychosis. 2 In this paper we detail a series of seven cases where anti-NMDAR encephalitis was misidentified as SCZ (Table 1). The research protocol was approved by the Mackay Memorial Hospital Institutional Review Board (IRB). Written informed
The GP.Mur red cell phenotype is characterized by the unique presence of glycophorin B-A-B hybrid... more The GP.Mur red cell phenotype is characterized by the unique presence of glycophorin B-A-B hybrid protein on the erythrocyte membrane which promotes band 3 expression. Band 3, or anion exchanger-1, transports HCO3 - across the erythrocyte membrane by exchange of Cl-; this function of band 3 works in concert with intraerythrocytic carbonic anhydrase II (CAII) to facilitate blood CO2 transport. People with the GP.Mur blood type express 10-20% more band 3 protein than those without the special blood type. We thus hypothesized that respiration in people with the GP.Mur blood type might be distinctly different when being challenged. In this study, we recruited 36 age-matched male elite athletes (13 GP.Mur and 23 without GP.Mur [control]) for an incremental running test to exhaustion. While running on a treadmill, the subjects were continuously monitored using a Quark CPET (cardiopulmonary exercise testing) unit (COSMED, Italy). Two statistical methods were employed for data analysis: (1) unpaired t-test for comparison at individual timepoints; and (2) linear mixed modeling for serial cardiopulmonary measurements collected during the running test. We found that their running abilities were similar. However, the subjects with GP.Mur showed higher respiratory rates and smaller inspiratory/expiratory (I/E) ratios than the control subjects throughout the entire exhaustive running test. That is, GP.Mur+ subjects spent a larger fraction of the respiratory cycle time on CO2 excretion than inspiration; their respiration also appeared to respond faster to the same level of workload. These resulted in lower end-tidal CO2 pressure in the running GP.Mur subjects compared to the controls. In conclusion, we presented direct evidence that band 3-mediated HCO3 -/CO2 exchange at the erythrocyte level could impact the respiratory pattern of CO2 excretion. Taiwan National Science and Technology Council; MacKay Memorial Hospital This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
American Journal of Physiology-lung Cellular and Molecular Physiology, Jun 1, 2023
Higher expression of the Cl−/[Formula: see text] transporter band 3 anion exchanger-1 (AE1) on th... more Higher expression of the Cl−/[Formula: see text] transporter band 3 anion exchanger-1 (AE1) on the red blood cell membrane, as in people with the GP.Mur blood type, increases the rate of CO2 excretion during exercise.
Background: Human cytomegalovirus (CMV) is a lifelong, often asymptomatic infection, with the vir... more Background: Human cytomegalovirus (CMV) is a lifelong, often asymptomatic infection, with the virus maintained in latently infected myeloid cells. Patients receiving chemotherapy for cancer are at high risk of reactivation of latent CMV, which may further contribute to host immune exhaustion, ultimately leading to a poor antitumor response. Pre-emptive anti-CMV medication may, therefore, serve as an adjunct therapy, preventing deterioration of the patient's immunity during treatment for cancer. The present study evaluated ganciclovir treatment's in vitro effects on CMV-associated T cell exhaustion and the antitumor capacity of cells from cancer patients. Methods: Peripheral blood mononuclear cells from patients with various types of cancers were treated with or without ganciclovir. Cells were then analyzed for T cell subpopulations and activation markers using flow cytometry, and their antitumor capacity was tested after exposure to dendritic celleA549 fusion cells. Results: Following ganciclovir treatment, there was a redistribution of T cell subpopulations which was clearly distinct from the baseline pattern of T cell exhaustion. Treatment resulted in increases in early differentiated proportions, including naive (untreated control cells vs. ganciclovir treated cells, p < 0.001), interleukin (IL)-7Ra þ (p < 0.01), and CD28 þ CD8 þ (p < 0.05) T cells, and a decrease in the proportion of effector memory (p < 0.001) T cells in cancer patients. Ganciclovir treatment significantly improved tumor-killing capacity (p < 0.001), with a concomitant downregulation of T cell exhaustion marker programmed death-1 (PD-1) (p < 0.001). Conclusion: These findings demonstrate that ganciclovir treatment in vitro directly affects immune function by partially reconstituting T cell subsets and restoring the T cell antitumor response.
Frontiers in Cardiovascular Medicine, Nov 29, 2021
GP.Mur, a red blood cell (RBC) hybrid protein encoded by glycophorin B-A-B, increases expression ... more GP.Mur, a red blood cell (RBC) hybrid protein encoded by glycophorin B-A-B, increases expression of erythroid band 3 (Anion Exchanger-1, SLC4A1). GP.Mur is extremely rare but has a prevalence of 1-10% in regions of Southeast Asia. We unexpectedly found slightly higher blood pressure (BP) among healthy Taiwanese adults with GP.Mur. Since band 3 has been suggested to interact with hemoglobin (Hb) to modulate nitric oxide (NO)-dependent hypoxic vasodilation during the respiratory cycle, we hypothesized that GP.Mur red cells could exert differentiable effects on vascular tone. Here we recruited GP.Mur-positive and GP.Mur-negative elite male college athletes, as well as age-matched, GP.Mur-negative non-athletes, for NO-dependent flow-mediated dilation (FMD) and NO-independent dilation (NID). The subjects were also tested for plasma nitrite and nitrate before and after arterial occlusion in FMD. GP.Mur+ and non-GP.Mur athletes exhibited similar heart rates and blood pressure, but GP.Mur+ athletes showed significantly lower FMD (4.8 ± 2.4%) than non-GP.Mur athletes (6.5 ± 2.1%). NO-independent vasodilation was not affected by GP.Mur. As Hb controls intravascular NO bioavailability, we examined the effect of Hb on limiting FMD and found it to be significantly stronger in GP.Mur+ subjects. Biochemically, plasma nitrite levels were directly proportional to individual band 3 expression on the red cell membrane. The increase of plasma nitrite triggered by arterial occlusion also showed small dependency on band 3 levels in non-GP.Mur subjects. By the GP.Mur comparative study, we unveiled comodulation of NO-dependent vasodilation by band 3 and Hb, and verified the long-pending role of erythroid band 3 in this process.
Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the most frequently encoun... more Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the most frequently encountered autoimmune encephalitis. The pathogenesis of both anti-NMDAR encephalitis and schizophrenia involve down-regulation of NMDA receptors. Whether autoantibody-mediated destruction of neuronal NMDA receptors is associated with schizophrenia or first-episode psychosis (FEP) remains unclear, as the current findings from different groups are inconsistent. The main culprits are likely due to heterogeneity of autoantibodies (autoAbs) in a patient's blood or cerebrospinal fluid (CSF), as well as due to limitation of the current detection methods for anti-NMDAR autoAbs. Here, we optimized the current diagnostic method based on the only commercially-available anti-NMDAR test kit. We first increased detection sensitivity by replacing reporter fluorophore fluorescein isothiocyanate (FITC) in the kit with Alexa Fluor 488, which is superior in resisting photobleaching. We also found that using an advanced imaging system could increase the detection limit, compared to using a simple fluorescence microscope. To improve test accuracy, we implemented secondary labeling with a well-characterized mouse anti-NR1 monoclonal antibody (mAb) after immunostaining with a patient's sample. The degree of colocalization between mouse and human antisera in NMDAR-expressing cells served to validate test results to be truly anti-NMDAR positive or false-positive. We also incorporated DNA-specific DAPI to simultaneously differentiate autoAbs targeting the plasma membrane from those targeting cell nuclei or perinuclear compartments. All the technical implementation could be integrated in a general hospital laboratory setting, without the need of specialized expertise or equipment. By sharing our experience, we hope this may help improve sensitivity and accuracy of the mainstream method for anti-NMDAR detection.
Human CO2 respiration requires rapid conversion between CO2 and HCO3(-) Carbonic anhydrase II fac... more Human CO2 respiration requires rapid conversion between CO2 and HCO3(-) Carbonic anhydrase II facilitates this reversible reaction inside red blood cells, and band 3 [anion exchange (AE)-1] provides a passage for HCO3(-) flux across the cell membrane. These 2 proteins are core components of the CO2 transport metabolon. Intracellular H2O is necessary for CO2/HCO3(-) conversion. However, abundantly expressed aquaporin (AQP)-1 in erythrocytes is thought not to be part of band 3 complexes or the CO2 transport metabolon. To solve this conundrum, we used Förster resonance energy transfer (FRET) measured by fluorescence lifetime imaging (FLIM-FRET) and identified interaction between aquaporin-1 and band 3 at a distance of 8 nm, within the range of dipole-dipole interaction. Notably, their interaction was adaptable to membrane tonicity changes. This suggests that the function of AQP1 in tonicity response could be coupled or correlated to its function in band 3-mediated CO2/HCO3(-) exchange. By demonstrating AQP1 as a mobile component of the CO2 transport metabolon, our results uncover a potential role of water channel in blood CO2 transport and respiration.-Hsu, K., Lee, T.-Y., Periasamy, A., Kao, F.-J., Li, L.-T., Lin, C.-Y., Lin, H.-J., Lin, M. Adaptable interaction between aquaporin-1 and band 3 reveals a potential role of water channel in blood CO2 transport.
BACKGROUND: GP.Mur (Mi.III) is a glycophorin B-A-B hybrid sialoglycoprotein expressing several po... more BACKGROUND: GP.Mur (Mi.III) is a glycophorin B-A-B hybrid sialoglycoprotein expressing several potent immunogens, including Mi a , Mur, and Hil. GP.Mur is considered one of the most important red blood cell (RBC) phenotypes in blood banking in Southeast Asia. However, there are no antibodies commercially available for the screening of GP.Mur RBCs. STUDY DESIGN AND METHODS: To develop a direct blood polymerase chain reaction (PCR) approach for the screening of GP.Mur cells, we first confirmed the genomic sequence differences among four GP.Mur and three Mi(a-) samples by sequencing their GYP.Mur and GYPB genes. With these data, we designed PCR primers that best discriminate GYPB and GYP.Mur. Our primer design also allows the detection of other Hil+ glycophorin variants. We also constructed two plasmids-pGBi2i3 and pMiIIIi2i3-which serve as the negative and positive control DNA, respectively, for the PCR procedure. Additionally, we designed a control PCR to be run side by side with the typing PCR. RESULTS: Because of the high specificity of our primers, we found it unnecessary to extract DNA from blood samples for PCR. We have tested this PCR method on 379 fresh and frozen blood samples. The results were further validated by serology and DNA sequencing and were shown to be completely accurate in our hand. We also found that the rapid genotyping method-high-resolution melting-can be a timesaving alternative for DNA sequencing. CONCLUSION: This direct blood PCR approach for determination of GP.Mur and related Hil+ phenotypes is reliable and economical and is expected to be useful for blood banking in Southeast Asia. T he antigens expressed on the glycophorin variant GP.Mur appear to be potent immunogens and as such are important antigens in many Southeast Asian countries. GP.Mur, previously known as Miltenberger Type III or Mi.III, is a glycophorin B-A-B hybrid protein expressed on the red blood cell (RBC) membrane. 1 Various glycophorin hybrid proteins were initially termed Miltenberger variants and were classified in the Miltenberger series of the MNS system by their serologic reactivities with these antisera: Mi a (MNS7), Vw (MNS9), Hut (MNS19), MUT (MNS 35), Mur (MNS10), Hil (MNS20), Hop (MNS26), Nob (MNS27), DANE (MNS32), TSEN (MNS33), and MINY(MNS34). 2,3 Most of the antisera listed here react with more than one glycophorin variant, indicating that the structures of these variants are associated. GP.Mur is believed to evolve from gene recombination events between homologous glycophorin A (GYPA) and glycophorin B (GYPB). 1 Because the
Background and Objectives Miltenberger blood group antigen subtype III (Mi.III) is characterized ... more Background and Objectives Miltenberger blood group antigen subtype III (Mi.III) is characterized by expression of a glycophorin B-A-B hybrid (Gp.Mur) on the erythrocyte surface. The two alleles of glycophorin B are substituted with the B-A-B hybrid alleles in homozygous Mi.III (Mi.III + ⁄ +), and thus, Mi.III + ⁄ + erythrocytes lack glycophorin B (GPB) and express Gp.Mur only. Because GPB is a major component of the Rh complex on RBCs, in this study, we explored how the absence of GPB might affect Rh expression in Mi.III RBCs. Materials and Methods (1) Mi.III+ RBCs were serologically identified and further differentiated their homozygosity or heterozygosity by immunoblot or direct sequencing. (2) RhD and RhCcEe mRNA was cloned, and their sequences analysed. (3) The expression levels of Rh antigen, Rh-associated glycoprotein (RhAG) and the U antigen in MI.III vs. non-Mi.III RBCs were assessed by flow cytometry and Western blot. Results Compared with the non-Mi.III samples, the surface expression of the Rh antigen was reduced to 76AE4% in Mi.III + ⁄ + RBCs and 93AE6% in Mi.III + ⁄). RhAG expression was also significantly reduced in Mi.III + ⁄ + , but not in Mi.III + ⁄). The U antigen expression in Mi.III + ⁄) was only 14AE9% relative to the control RBCs, while GPB was half the level of the controls. The mRNA sequences of Rh polypeptides from Mi.III+ samples were identical to the NCBI reference sequences. Conclusion Substitution of GPB with Gp.Mur significantly reduced the expression of Rh antigen and RhAG on the Mi.III + ⁄ + erythrocyte membrane. The Mi.III phenotype is predicted to induce considerable structural variations within the band 3 ⁄ Rhassociated macrocomplexes.
BAFF supports B-cell survival and homeostasis by activating the NF-κB pathway. While NF-κB is als... more BAFF supports B-cell survival and homeostasis by activating the NF-κB pathway. While NF-κB is also involved in the priming signal of NLRP3 inflammasome, the role of BAFF in NLRP3 inflammasome regulation is unknown. Here we report BAFF engagement to BAFF receptor elicited both priming and activating signals for NLRP3 inflammasomes in primary B cells and B lymphoma cell lines. This induction of NLRP3 inflammasomes by BAFF led to increased NLRP3 and IL-1β expression, caspase-1 activation, IL-1β secretion, and pyroptosis. Mechanistically, BAFF activated NLRP3 inflammasomes by promoting the association of cIAP-TRAF2 with components of NLRP3 inflammasomes, and by inducing Src activity-dependent ROS production and potassium ion efflux. B-cell receptor (BCR) stimulation on the Lyn signaling pathway inhibited BAFF-induced Src activities and attenuated BAFF-induced NLRP3 inflammasome activation. These findings reveal an additional function of BAFF in B-cell homeostasis that is associated with BCR activities.
plays multiple roles during HIV-1 infection: support of virus release (Klimkait et al., 1990; Str... more plays multiple roles during HIV-1 infection: support of virus release (Klimkait et al., 1990; Strebel et al., 1989) and promotion of CD4 degradation (Willey et al., 1992).
Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the most frequently encoun... more Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the most frequently encountered autoimmune encephalitis. The pathogenesis of both anti-NMDAR encephalitis and schizophrenia involve down-regulation of NMDA receptors. Whether autoantibody-mediated destruction of neuronal NMDA receptors is associated with schizophrenia or first-episode psychosis (FEP) remains unclear, as the current findings from different groups are inconsistent. The main culprits are likely due to heterogeneity of autoantibodies (autoAbs) in a patient's blood or cerebrospinal fluid (CSF), as well as due to limitation of the current detection methods for anti-NMDAR autoAbs. Here, we optimized the current diagnostic method based on the only commercially-available anti-NMDAR test kit. We first increased detection sensitivity by replacing reporter fluorophore fluorescein isothiocyanate (FITC) in the kit with Alexa Fluor 488, which is superior in resisting photobleaching. We also found that using an advanced imaging system could increase the detection limit, compared to using a simple fluorescence microscope. To improve test accuracy, we implemented secondary labeling with a well-characterized mouse anti-NR1 monoclonal antibody (mAb) after immunostaining with a patient's sample. The degree of colocalization between mouse and human antisera in NMDAR-expressing cells served to validate test results to be truly anti-NMDAR positive or false-positive. We also incorporated DNA-specific DAPI to simultaneously differentiate autoAbs targeting the plasma membrane from those targeting cell nuclei or perinuclear compartments. All the technical implementation could be integrated in a general hospital laboratory setting, without the need of specialized expertise or equipment. By sharing our experience, we hope this may help improve sensitivity and accuracy of the mainstream method for anti-NMDAR detection.
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Papers by Kate Hsu