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1.
Clin Exp Immunol ; 202(2): 249-261, 2020 11.
Article in English | MEDLINE | ID: mdl-32578199

ABSTRACT

While donor-specific human leukocyte antigen (HLA) antibodies are a frequent cause for chronic antibody-mediated rejection in organ transplantation, this is not the case for antibodies targeting blood group antigens, as ABO-incompatible (ABO-I) organ transplantation has been associated with a favorable graft outcome. Here, we explored the role of CD4 T cell-mediated alloresponses against endothelial HLA-D-related (DR) in the presence of anti-HLA class I or anti-A/B antibodies. CD4 T cells, notably CD45RA-memory CD4 T cells, undergo extensive proliferation in response to endothelial HLA-DR. The CD4 T cell proliferative response was enhanced in the presence of anti-HLA class I, but attenuated in the presence of anti-A/B antibodies. Microarray analysis and molecular profiling demonstrated that the expression of CD274 programmed cell death ligand 1 (PD-L1) increased in response to anti-A/B ligation-mediated extracellular signal-regulated kinase (ERK) inactivation in endothelial cells that were detected even in the presence of interferon-γ stimulation. Anti-PD-1 antibody enhanced CD4 T cell proliferation, and blocked the suppressive effect of the anti-A/B antibodies. Educated CD25+ CD127- regulatory T cells (edu.Tregs ) were more effective at preventing CD4 T cell alloresponses to endothelial cells compared with naive Treg ; anti-A/B antibodies were not involved in the Treg -mediated events. Finally, amplified expression of transcript encoding PD-L1 was observed in biopsy samples from ABO-I renal transplants when compared with those from ABO-identical/compatible transplants. Taken together, our findings identified a possible factor that might prevent graft rejection and thus contribute to a favorable outcome in ABO-I renal transplantation.


Subject(s)
ABO Blood-Group System/immunology , B7-H1 Antigen/immunology , Endothelial Cells/immunology , HLA-DR Antigens/immunology , Isoantibodies/immunology , Organ Transplantation , T-Lymphocytes, Regulatory/immunology , Endothelial Cells/pathology , Graft Rejection/immunology , Graft Rejection/pathology , Humans , T-Lymphocytes, Regulatory/pathology
2.
Phys Chem Chem Phys ; 22(46): 27191-27205, 2020 Dec 07.
Article in English | MEDLINE | ID: mdl-33226053

ABSTRACT

Domain-based local pair natural orbital (DLPNO) coupled cluster single and double (CCSD) with triple perturbation (T) correction methods were performed to elucidate the relative stabilities of ten different intermediate structures of the CaMn4Ox cluster in the S0 state of the oxygen evolving complex (OEC) of photosystem II (PSII). Full geometry optimizations of all the S0 intermediates were performed by the UB3LYP-D3/Def2-TZVP methods, providing the assumed geometrical structures and starting natural orbitals (UNO) for DLPNO-CCSD(T)/Def2TZVP calculations. The effective exchange integrals (J) for the spin Hamiltonian models for the ten intermediates were obtained by the UB3LYP/Def2-TZVP calculations followed by the general spin projections. DLPNO-CCSD(T) calculations followed by the CBS extrapolation procedure elucidated that the (II, III, IV, IV) and (III, III, III, IV) valence states in the CaMn4O5 cluster of the OEC of the PS II were nearly degenerated in energy in the S0 state, indicating an important role of dynamical electron correlation effects for the valence and spin fluctuations in strongly correlated electron systems (SCESs) consisting of 3d transition metals.


Subject(s)
Calcium/chemistry , Manganese/chemistry , Oxygen/chemistry , Photosystem II Protein Complex/chemistry , Bacterial Proteins/chemistry , Density Functional Theory , Models, Chemical , Protein Domains , Protons , Thermodynamics , Thermosynechococcus/enzymology
4.
Kyobu Geka ; 65(8): 692-6, 2012 Jul.
Article in Japanese | MEDLINE | ID: mdl-22868430

ABSTRACT

The incidence of thoracic surgery for patients with arteriosclerosis has increased with the aging of society. Pulmonary resection is generally indicated for patients with coronary artery or aortic disease, following careful preoperative evaluations of cardiopulmonary function and oncological resectability. When preoperative coronary revascularization is required, percutaneous coronary intervention with a bare metal stent might be effective, due to the intermission of antiplatelet therapy during surgery. Furthermore, a" non-dissecting" technique that preserves mediastinal adhesion and divides the lung parenchyma is an option for pulmonary resection in patients who previously underwent coronary arterial bypass grafting (CABG) using the ipsilateral internal thoracic artery. Perioperative analgesic management with epidural anesthesia is quite important to stabilize hemodynamics and avoid the use of nonsteroidal anti-inflammatory drugs, which may influence potential renal dysfunction. Postoperative arterial fibrillation, which reduces blood flow in the coronary artery with low cardiac output, can be predicted based on preoperative serum brain natriuretic peptide level, and prevented by prophylactic atrial natriuretic peptide infusion and immediately controlled with an ultrashort-acting beta-blocker. Thus, special attention is required for surgical interventions that include pulmonary resection in patients with coronary artery or aortic disease.


Subject(s)
Aortic Diseases/complications , Coronary Disease/complications , Pneumonectomy/methods , Aged , Humans , Lung Neoplasms/surgery , Male
5.
J Small Anim Pract ; 63(8): 635-641, 2022 08.
Article in English | MEDLINE | ID: mdl-35067937

ABSTRACT

We describe a surgical technique to re-establish urine flow in a 3-year-old Scottish Fold cat. A ureteral stent and subcutaneous urinary bypass failed after their placement due to rapid mineralisation of the lumen. Direct pelvicocystostomy anastomosis using a modified tube cystoplasty technique was performed. A wide rectangular apex-based full-thickness flap was created from the ventral aspect of the urinary bladder, which was sutured longitudinally to form a large-diameter tube. The resulting tube-shaped portion of the bladder was then directly anastomosed to the renal pelvis. No major postoperative complications were observed and no further recurrence of obstruction of the upper urinary tract was noted during follow-up. The cat died at home 481 days postoperatively from an undetermined cause. A pelvicocystostomy technique can be considered as an alternative salvage surgical technique for obstructive ureteral disease in cats.


Subject(s)
Cat Diseases , Ureter , Ureteral Obstruction , Anastomosis, Surgical/veterinary , Animals , Cat Diseases/surgery , Cats , Stents/veterinary , Ureter/surgery , Ureteral Obstruction/surgery , Ureteral Obstruction/veterinary , Urologic Surgical Procedures/methods , Urologic Surgical Procedures/veterinary
6.
Am J Transplant ; 11(7): 1509-16, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21672149

ABSTRACT

Living-donor lobar lung transplantation (LDLLT) is one of the final options for saving patients with pulmonary complications after hematopoietic stem cell transplantation (HSCT). We retrospectively investigated 19 patients who had undergone LDLLT after HSCT in Japan. Eight patients underwent LDLLT after HSCT in which one of the donors was the same living donor as in HSCT (SD group), while 11 received LDLLT from relatives who were not the HSCT donors (non-SD group). In the SD group, three patients underwent single LDLLT. The 5-year survival rate was 100% and 58% in the SD and non-SD groups, respectively. In the SD group, postoperative immunosuppression was significantly lower than in the non-SD group. Two patients died of infection and one died of post-transplant lymphoproliferative disease (PTLD) in the non-SD group, while only one patient died of PTLD 7 years after LDLLT in the SD group. Hematologic malignancy relapsed in two patients in the non-SD group. For the three single LDLLTs in the SD group, immunosuppression was carefully tapered. In our study, LDLLT involving the same donor as for HSCT appeared to have advantages related to lower immunosuppression compared to LDLLT from relatives who were not the HSCT donors.


Subject(s)
Hematopoietic Stem Cell Transplantation/adverse effects , Immunosuppression Therapy/methods , Living Donors , Lung Transplantation , Adolescent , Adult , Child , Child, Preschool , Female , Graft vs Host Disease/etiology , Graft vs Host Disease/therapy , Hematologic Neoplasms/therapy , Humans , Japan , Lymphoproliferative Disorders/etiology , Male , Postoperative Complications , Retrospective Studies , Treatment Outcome
7.
Clin Exp Immunol ; 166(2): 164-70, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21985362

ABSTRACT

Thymoma-associated multi-organ autoimmunity is a rare, autoimmune disease that causes colitis, liver dysfunction and cutaneous graft-versus-host (GVH)-like skin damage. This paraneoplastic autoimmune disorder may be due to inadequate T cell selection in the tumour environment of the thymus. Although sporadic case reports have revealed its clinical features, little is known about its pathological mechanism. By comparing the skin-infiltrating T cell subsets with those of GVH disease (GVHD) and other inflammatory skin diseases, we sought to elucidate the pathological mechanism of thymoma-associated multi-organ autoimmunity. Histopathological and immunohistochemical analysis of skin biopsies was performed for three patients with thymoma-associated multi-organ autoimmunity. Histopathological findings of thymoma-associated multi-organ autoimmunity were indistinguishable from those of patients with acute GVHD, although the aetiologies of these diseases are completely different. The frequency of regulatory T cells (T(regs)) is reduced in cutaneous lesions and CD8+ cytotoxic T lymphocytes that massively infiltrate into the epidermis of patients with thymoma-associated multi-organ autoimmunity. Additionally, the ratio of T helper type 17 (Th17) cells to CD4+ cells in patients with thymoma-associated multi-organ autoimmunity and acute GVHD was higher than that in healthy controls, but similar to that in psoriasis vulgaris patients. Similarity of the skin-infiltrating T cell subsets with those of acute GVHD suggested that skin damage in patients with thymoma-associated multi-organ autoimmunity might be induced by self-reactive cytotoxic T lymphocytes under the diminished suppressive capacity of T(regs).


Subject(s)
Autoimmunity/immunology , T-Lymphocytes, Regulatory/immunology , Thymoma/immunology , Thymoma/pathology , Adult , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Female , Graft vs Host Disease/immunology , Graft vs Host Disease/pathology , Humans , Lymphocyte Count , Psoriasis/immunology , Psoriasis/pathology , Skin/immunology , Skin/pathology , Skin Diseases/immunology , Skin Diseases/metabolism , Skin Diseases/pathology , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Regulatory/metabolism , Th17 Cells/immunology , Thymus Gland/immunology , Thymus Gland/pathology , Tumor Microenvironment
8.
Prenat Diagn ; 31(12): 1120-5, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21905053

ABSTRACT

OBJECTIVE: To review a single center's experience in the management of twin pregnancies with conjoined fetuses. METHODS: Retrospective study describing prenatal findings, delivery details, surgical treatment and perinatal outcome. RESULTS: The study included 36 twin pregnancies with conjoined twins seen over a period of 12 years in a single tertiary hospital: 69.4% were thoracopagus, 13.9% parapagus, 8.3% omphaloischiopagus 5.6% omphalopagus and 2.8% cephalopagus. Cardiac defects were present in 91.6% of twin pairs and associated malformations were present in 61.8% of the cases: limb abnormalities in 36.1%, abdominal wall defects in 25.0%, cleft lip and/or palate in 13.9% and congenital diaphragmatic hernia in 5.5%. Surgical separation was considered not feasible and prognosis lethal in 30 (83.3%) cases. Termination of pregnancy was performed in 12 pregnancies of poor prognosis. Cesarean section was performed in all remaining cases. Five sets of twins underwent surgical separation and six children survived. Overall survival in our series was 8.3% and, among the livebirths, 13.6%. CONCLUSION: Conjoined twin pregnancies should be referred to tertiary centers for detailed fetal anomaly and echocardiographic assessment to evaluate prognosis and determine the possibility of postnatal surgical separation.


Subject(s)
Twins, Conjoined/pathology , Adult , Brazil , Delivery, Obstetric , Female , Humans , Male , Pregnancy , Retrospective Studies , Twins, Conjoined/surgery , Young Adult
9.
Rev Sci Instrum ; 92(1): 014102, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33514236

ABSTRACT

A new instrument dedicated to the kinetic study of low-temperature gas phase neutral-neutral reactions, including clustering processes, is presented. It combines a supersonic flow reactor with vacuum ultra-violet synchrotron photoionization time-of-flight mass spectrometry. A photoion-photoelectron coincidence detection scheme has been adopted to optimize the particle counting efficiency. The characteristics of the instrument are detailed along with its capabilities illustrated through a few results obtained at low temperatures (<100 K) including a photoionization spectrum of n-butane, the detection of formic acid dimer formation, and the observation of diacetylene molecules formed by the reaction between the C2H radical and C2H2.

10.
Ultrasound Obstet Gynecol ; 36(2): 249-51, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20069561

ABSTRACT

Epithelioid trophoblastic tumor is a distinctive but rare trophoblastic tumor. It derives from intermediate trophoblastic cells of the chorion laeve and is usually associated with a previous gestational event. We report the case of a patient who had undergone dilatation and curettage for a missed miscarriage. Three months later gestational trophoblastic disease was suspected because of persistent vaginal bleeding and high levels of beta-human chorionic gonadotropin (beta-hCG). Transvaginal ultrasound revealed irregular echolucent lacunae within the myometrium, some of them filled with low-resistance, turbulent blood flow on Doppler examination, emphasizing the diagnosis of gestational trophoblastic disease. The patient was treated with 12 courses of multiagent chemotherapy. After a 2-year remission, a low rise in serum beta-hCG was observed. Transvaginal ultrasound revealed a well-circumscribed echogenic lesion with a diameter of 1.8 cm in the uterine fundus, with no detectable blood flow on Doppler imaging. A diagnosis of tumor of intermediate trophoblastic cells was suspected and total hysterectomy was performed. On pathological examination, the histological and immunohistochemical features were characteristic of epithelioid trophoblastic tumor. Most reported cases of epithelioid trophoblastic tumor have solitary nodules with sharp margins, which is consistent with our ultrasound findings. Ultrasound may be helpful in differentiating epithelioid trophoblastic tumor from placental-site trophoblastic tumor, another tumor of intermediate trophoblastic cells, which shows infiltrative growth insinuating between muscle fibers.


Subject(s)
Gestational Trophoblastic Disease/diagnostic imaging , Trophoblastic Neoplasms/diagnostic imaging , Uterine Neoplasms/diagnostic imaging , Chorionic Gonadotropin, beta Subunit, Human/metabolism , Dilatation and Curettage , Female , Gestational Trophoblastic Disease/surgery , Humans , Hysterectomy , Pregnancy , Trophoblastic Neoplasms/surgery , Ultrasonography , Uterine Neoplasms/surgery , Young Adult
11.
J Phys Chem A ; 114(26): 6983-95, 2010 Jul 08.
Article in English | MEDLINE | ID: mdl-20524693

ABSTRACT

The self-reactions and cross reactions of the peroxy radicals C2H5O2 and HO2 were monitored using simultaneous independent spectroscopic probes to observe each radical species. Wavelength modulation (WM) near-infrared (NIR) spectroscopy was used to detect HO2, and UV absorption monitored C2H5O2. The temperature dependences of these reactions were investigated over a range of interest to tropospheric chemistry, 221-296 K. The Arrhenius expression determined for the cross reaction, k2(T) = (6.01(-1.47)(+1.95)) x 10(-13) exp((638 +/- 73)/T) cm3 molecules(-1) s(-1) is in agreement with other work from the literature. The measurements of the HO2 self-reaction agreed with previous work from this lab and were not further refined. The C2H5O2 self-reaction is complicated by secondary production of HO2. This experiment performed the first direct measurement of the self-reaction rate constant, as well as the branching fraction to the radical channel, in part by measurement of the secondary HO2. The Arrhenius expression for the self-reaction rate constant is k3(T) = (1.29(-0.27)(+0.34)) x 10(-13)exp((-23 +/- 61)/T) cm3 molecules(-1) s(-1), and the branching fraction value is alpha = 0.28 +/- 0.06, independent of temperature. These values are in disagreement with previous measurements based on end product studies of the branching fraction. The results suggest that better characterization of the products from RO2 self-reactions are required.

12.
Vet Pathol ; 47(5): 806-18, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20551474

ABSTRACT

Encephalitic flaviviruses are important arthropod-borne pathogens of humans and other animals. In particular, the recent emergence of the West Nile virus (WNV) and Japanese encephalitis virus (JEV) in new geographic areas has caused a considerable public health alert and international concern. Among the experimental in vivo models of WNV and JEV infection, mice and other laboratory rodents are the most thoroughly studied and well-characterized systems, having provided data that are important for understanding the infectious process in humans. Macaca monkeys have also been used as a model for WNV and JEV infection, mainly for the evaluation of vaccine efficacy, although a limited number of published studies have addressed pathomorphology. These animal models demonstrate the development of encephalitis with many similarities to the human disease; however, the histological events that occur during infection, especially in peripheral tissues, have not been fully characterized.


Subject(s)
Encephalitis Virus, Japanese/immunology , Encephalitis, Japanese/immunology , West Nile Fever/immunology , West Nile virus/immunology , Animals , Disease Models, Animal , Encephalitis, Japanese/pathology , Encephalitis, Japanese/virology , Humans , Mice , West Nile Fever/pathology
13.
Science ; 216(4550): 1127-8, 1982 Jun 04.
Article in English | MEDLINE | ID: mdl-17808500

ABSTRACT

Direct spherical agglomeration of salicylic acid crystals during crystallization is described. The needle-like salicylic acid crystals simultaneously form and agglomerate in a mixture of three partially miscible liquids, such as water, ethanol, and chloroform, with agitation. The agglomerates can be made directly into tablets because of their excellent flowability. Spherical crystallization could eliminate the usual separate agglomeration step after crystallization and may be adaptable to other pharmaceutical and chemical systems.

14.
Science ; 258(5086): 1342-5, 1992 Nov 20.
Article in English | MEDLINE | ID: mdl-17778361

ABSTRACT

Chlorine nitrate photolysis has been investigated with the use of a molecular beam technique. Excitation at both 248 and 193 nanometers led to photodissociation by two pathways, CIONO(2) --> CIO + NO()2 and CIONO(2) --> Cl + NO3, with comparable yields. This experiment provides a direct measurement of the CIO product channel and consequently raises the possibility of an analogous channel in CIO dimer photolysis. Photodissociation of the CIO dimer is a critical step in the catalytic cycle that is presumed to dominate polar stratospheric ozone destruction. A substantial yield of CIO would reduce the efficiency of this cycle.

15.
J Phys Chem A ; 113(52): 15281-97, 2009 Dec 31.
Article in English | MEDLINE | ID: mdl-19908878

ABSTRACT

Symmetry and broken symmetry in the molecular orbital description of spin frustration systems have been investigated in relation to the resonating valence bond (RVB) theory of the spin liquid state and non-BCS superconductivity. Broken symmetry (BS) and resonating BS (RBS) molecular orbital (MO) methods have been employed to obtain resonating valence bond (RVB)-type explanations of spin frustrated systems. RBS MO solutions are expanded using the localized molecular orbitals (LMO) to elucidate a universal MO-VB description. The BS and RBS MO descriptions of triangular spin frustrated systems corresponding to transition structures for exchange-forbidden radical insertions were investigated in comparison with the RVB-type explanations of such systems. The BS and RBS calculations by the use of three different axial (SDW) solutions or three noncollinear GSO (helical SDW) solutions of a triangular hydrogen cluster were performed to obtain potential curves with and without resonance (quantum) effects. The resonating GSO (noncollinear) state responsible for short-range correlation was found to be the most stable for the system. The reliability of the approximate spin projection (AP) procedure to eliminate the high-spin component was also elucidated, comparing with the AP BS and RBS potential curves. The BS GSO (GHF) computations of several triangular systems, N(CH(2))(3), (CH(2))(3), and Mn(II)(3)O(4), were performed to obtain total energies and total spin angular momentums and effective exchange integrals (J) between local spins, which are crucial for construction of effective spin Hamiltonian models. The exact diagonalization of the Heisenberg models was also performed to depict the energy levels and magnetic susceptibility curves for triangular and kagome lattices to elucidate spin frustration effects and related quantum spin behaviors. Implications of the computational results have been discussed in relation to magnetic properties of several triangular and kagome systems synthesized recently and the superconductivity of triangular systems discovered recently.


Subject(s)
Quantum Theory , Amines/chemistry , Benzene/chemistry , Hydrogen/chemistry , Models, Molecular , Molecular Conformation , Transition Elements/chemistry
16.
Eur Surg Res ; 41(3): 260-6, 2008.
Article in English | MEDLINE | ID: mdl-18580065

ABSTRACT

We investigated the clinical significance of the apoptosis- related molecule expression of tumor cells in patients with advanced esophageal cancer treated with preoperative chemoradiotherapy (CRT). Preoperative CRT reduced Bcl-X(L) expression in a significant proportion of the group responding to CRT but not in the group resisting CRT, although Bcl-2 expression was reduced in both groups. The mean survival time of the patients with cancers that lost Bcl-X(L) following CRT was significantly longer compared to those with cancers expressing Bcl-X(L). These results suggested that CRT reduced Bcl-X(L) expression, and this decrease closely correlated with the prolonged survival of advanced esophageal cancer patients treated with preoperative CRT.


Subject(s)
Esophageal Neoplasms/genetics , Esophageal Neoplasms/therapy , bcl-X Protein/genetics , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Apoptosis/genetics , Base Sequence , Caspase 3/genetics , Caspase 8/genetics , Chemotherapy, Adjuvant , Combined Modality Therapy , DNA Primers/genetics , Docetaxel , Esophageal Neoplasms/pathology , Fas-Associated Death Domain Protein/genetics , Female , Gene Expression , Genes, bcl-2 , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Prognosis , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Neoplasm/genetics , RNA, Neoplasm/metabolism , Radiation-Sensitizing Agents/therapeutic use , Reverse Transcriptase Polymerase Chain Reaction , Taxoids/therapeutic use
17.
Kyobu Geka ; 61(11): 945-9, 2008 Oct.
Article in Japanese | MEDLINE | ID: mdl-18939430

ABSTRACT

A sleeve lobectomy is an established general thoracic surgical procedure. To improve clinical outcomes following the procedure, we reviewed the records of 60 patients who underwent a bronchoplasty procedure in our department from 1992 to 2007. Induction chemotherapy was performed for 20, of whom 10 underwent radiotherapy as well. For all subjects, the postoperative mortality and morbidity rates were 1.7% and 33.3%, respectively. Induction therapy did not significantly affect those rates, though complications related to bronchial anastomoses occurred exclusively in subjects who received that therapy. The overall 5-year survival rate was 51.0%, while subjects with pN0 (67.9%) and pN1 (60.0%) disease, and those in stage I (79.1%) and stage II (59.9%) had better survival as compared with patients with pN2 (16.9%) disease, and those in stage III (21.8%) and stage IV (0%). Furthermore, the survival rate of yp-stage I and II patients was significantly greater than that of those in yp-stage III and IV (59.9% vs. 14.3%, p = 0.0158). We concluded that patients in stages I, II or with pN0-1 disease are good candidates for a bronchoplasty procedure, though induction therapy should be considered thereafter. In addition, due diligence for postoperative complications is necessary.


Subject(s)
Bronchi/surgery , Lung Neoplasms/surgery , Plastic Surgery Procedures/methods , Thoracic Surgical Procedures/methods , Adolescent , Adult , Aged , Combined Modality Therapy , Female , Humans , Lung Neoplasms/pathology , Male , Middle Aged , Neoplasm Staging , Pneumonectomy , Postoperative Complications , Prognosis , Plastic Surgery Procedures/mortality , Retrospective Studies , Survival Rate , Thoracic Surgical Procedures/mortality
18.
Curr Biol ; 7(6): 408-17, 1997 Jun 01.
Article in English | MEDLINE | ID: mdl-9197241

ABSTRACT

BACKGROUND: Adhesion of leukocytes to the extracellular matrix and to other cells is mediated by members of the integrin family of adhesion molecules. Src family kinases are activated upon integrin-mediated adhesion. In lymphocytes, CD45 is a leukocyte-specific transmembrane protein tyrosine phosphatase that activates Src family kinases associated with B-cell and T-cell antigen receptor signaling by constitutive dephosphorylation of the inhibitory carboxy-terminal tyrosine phosphorylation site. Here, we show that CD45 is also important in downregulating the kinase activity of Src family members during integrin-mediated adhesion in macrophages. RESULTS: We found that CD45 colocalized with beta2 integrin and the Src family kinase p53/56(lyn) to adhesion sites in bone marrow-derived macrophages. Macrophages from CD45(-/-) mice were unable to maintain integrin-mediated adhesion. In adherent macrophages, absence of CD45 led to the hyperphosphorylation and hyperactivation of p56/59(hck) and p53/56(lyn), but not of p58(c-fgr). CD45 directly inactivated p59(hck) but not p56(lck) in transient transfection assays. Furthermore, coexpression of CD45 with p59(hck) or p56(lyn) containing a tyrosine to phenylalanine mutation at the carboxy-terminal negative regulatory site resulted in decreased tyrosine phosphorylation of the Src family member kinases due to dephosphorylation of the potentiating tyrosine phosphorylation site within the kinase domain. CONCLUSIONS: Using primary bone marrow macrophages, these studies demonstrate that CD45 regulates Src family kinases and is required to maintain macrophage adhesion. CD45 decreases Src family kinase activity by dephosphorylating the tyrosine residue located within the kinase domain.


Subject(s)
CD18 Antigens/metabolism , Integrins/metabolism , Leukocyte Common Antigens/metabolism , Macrophages/physiology , src-Family Kinases/metabolism , Animals , Cell Adhesion , Down-Regulation , Gene Expression Regulation , Mice , Mice, Mutant Strains , Phosphorylation , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-hck
19.
Curr Opin Immunol ; 7(3): 312-9, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7546394

ABSTRACT

CD45 is a leukocyte transmembrane protein tyrosine phosphatase that functions in lymphocyte activation by increasing the kinase activity of Src family members. In contrast, an intracellular protein tyrosine phosphatase that contains Src homology 2 domains, SHP, is required to inactivate receptors. Recent studies have examined the mechanisms of interaction and regulation of these enzymes.


Subject(s)
Leukocyte Common Antigens/immunology , Protein Tyrosine Phosphatases/immunology , Animals , Humans , Intracellular Signaling Peptides and Proteins , Mice , Models, Immunological , Protein Tyrosine Phosphatase, Non-Receptor Type 11 , Protein Tyrosine Phosphatase, Non-Receptor Type 6 , SH2 Domain-Containing Protein Tyrosine Phosphatases , Signal Transduction/immunology , src Homology Domains/immunology
20.
Mol Cell Biol ; 14(12): 8259-71, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7526155

ABSTRACT

By establishing a unique screening method, we have isolated yeast mutants that die only after differentiating into cells with a mating projection, and some of them are also defective in Ca2+ signaling. The mutants were classified into five complementation groups, one of which we studied extensively. This mutation defines a new gene, designated MID1, which encodes an N-glycosylated, integral plasma membrane protein with 548 amino acid residues. The mid1-1 mutant has low Ca2+ uptake activity, loses viability after receiving mating pheromones, and escapes death when incubated with high concentrations of CaCl2. The MID1 gene is nonessential for vegetative growth. The efficiency of mating between MATa mid1-1 and MAT alpha mid1-1 cells is low. These results demonstrate that MID1 is required for Ca2+ influx and mating.


Subject(s)
Calcium/metabolism , Fungal Proteins/genetics , Gene Expression Regulation, Fungal , Genes, Fungal , Membrane Glycoproteins/genetics , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/genetics , Amino Acid Sequence , Base Sequence , Fungal Proteins/chemistry , Fungal Proteins/metabolism , Ion Channels/chemistry , Ion Channels/genetics , Mating Factor , Membrane Glycoproteins/chemistry , Methylene Blue , Molecular Sequence Data , Mutagenesis, Insertional , Peptides/pharmacology , Phenotype , RNA, Messenger/genetics , Restriction Mapping , Signal Transduction , Solubility , Transcription, Genetic
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