No abstract available.
Humans* ; Immunoglobulin G ; Placenta* ; Receptors, Fc ; RNA, Messenger* ; Trophoblasts

Monoclonal antibodies have become the main type of antibody drug because of their high specificity and strong affinity to antigen. However, with the intensive study of the natural monoclonal antibody, many defects have faced, such as the limit times of binding to antigen, the unanticipated antibody clearance and antigen accumulation. Therefore, studies are no longer limited to the natural antibody screening, but rather to improve the efficiency of antibody drugs by engineering. In recent years, the bottlenecks in the development of conventional antibody have been solved effectively since the discovery of a novel recycling antibody. Recycling antibody binds to an antigen in plasma and dissociates from the antigen in endosome, thus maximizing the use of antibody and reducing antigen-mediated antibody clearance and antibody-mediated antigen accumulation. In addition, recycling antibodies can enhance the affinity with Fc receptors through further Fc modification. This paper reviews the research progress of circulating antibodies, including its characteristics, transformation methods and prospects.
Antibodies, Monoclonal ; immunology ; Antigens ; Endosomes ; Protein Binding ; Receptors, Fc

OBJECTIVETo study the regulation of Fc receptor expression by immune complexes (ICs) on neutrophils and U937 cells.

METHODSIgA ICs, IgG1 ICs, IgG2 ICs, IgG3 ICs, IgG4 ICs, and IgM ICs were incubated with neutrophils or U937 cells for 1 h. Then their surface Fc receptors were stained by anti-Fc gammaR I, anti-Fc gammaR II , anti-Fc gammaR III, and anti-Fc alphaR I monoclonal antibodies and analyzed by fluorescent activated cell sorting (FACS).

RESULTSIgG1 ICs and IgG3 ICs up-regulated Fc gammaR II and Fc gammaR III on U937 cells, Fc gammaR I and Fc alphaR I on neutrophils. Almost all ICs down-regulated Fc gammaR II on neutrophils.

CONCLUSIONSICs can regulate Fc receptor expression on neutrophils and U937 cells, among which IgG1 ICs and IgG3 ICs are most effective.

Antibodies, Anti-Idiotypic ; immunology ; Antibodies, Monoclonal ; pharmacology ; Antigen-Antibody Complex ; immunology ; metabolism ; Antigens, CD ; immunology ; Humans ; Immunoglobulin A ; classification ; immunology ; Immunoglobulin G ; chemistry ; classification ; immunology ; metabolism ; Neutrophils ; metabolism ; Receptors, Fc ; biosynthesis ; genetics ; Receptors, IgG ; immunology ; U937 Cells ; immunology

PURPOSE: Fc receptors and Mac-1 play an important role in the protective response of granulocytes and monocytes against microbial infection. FcgammaRl, FcgammaRll, FcgammaRlll as well as CD11b/ CD18 have never been measured in a quantitative way during hemopoiesis. Thus we quantified the expression of Fc Rl, Fc Rll, Fc Rlll, and CD11b/CD18 during hematopoietic differentiation using HL-60 cells, which was induced to differentiate by DMSO, or PMA. METHODS: HL-60 cells (ATCC CCL-240) were induced to differentiate by adding 1.0% DMSO, or 16nM PMA. On the 4th and 7th day after stimulation as well as before stimulation, phenotypic analysis was performed by flow cytometry after staining the cells with PE-conjugated anti- human CD64, CD32, CD16, CD11b, CD18, and isotype controls. And the measured fluorescent intensity was transformed into Molecules of Equivalent Soluble Fluorochromes (MESF). RESULTS: Percent positive cells and MESF of CD11b on HL-60 cells increased upon induction by DMSO, but not by PMA. Percent positive cells of CD18 on HL-60 cells was 99% regardless of differentiation. But MESF of CD18 was increased on the 4th day and decreased on the 7th day by DMSO or PMA. Percent positive cells and MESF of FcgammaRl on HL-60 cells increased upon induction by DMSO or PMA. Percent positive cells of FcgammaRll on HL-60 cells was above 90% regardless of differentiation. MESF of FcgammaRll showed no significant change by DMSO or PMA. CONCLUSION: Quantitative expression of FcgammaRl, FcgammaRll, FcgammaRlll, and CD11b/CD18 of HL-60 cells changed during induction of differentiation by DMSO or PMA. MESF of FcgammaR and CD11b/ CD18 a better indicator than percent positive cells to compare the differentiation of HL-60cells.
Dimethyl Sulfoxide ; Flow Cytometry ; Fluorescent Dyes ; Granulocytes ; HL-60 Cells* ; Humans ; Monocytes ; Receptors, Fc

No abstract available.
Histocompatibility Antigens Class II* ; Interleukin-1* ; Macrophages, Peritoneal* ; Phenol* ; Receptors, Fc*

No abstract available.
Histocompatibility Antigens Class II* ; Interleukin-1* ; Macrophages, Peritoneal* ; Phenol* ; Receptors, Fc*

The aim of this study was to evaluate the efficacy of intravenous immunoglobulin treatment for recurrent spontaneous abortion. Immunologic causes in either alloimmune or autoimmune type have been suggested for more than 80% of these patients. Various immunotherapy including paternal leukocyte transfusion has been used, but there is controversy on its efficacy and side-effects. The proposed immunomodulatory mechanism of intravenous immunoglobulin includes passive transfer of blocking or anti-idiotype antibody, blockade of Fc receptors, enhancement of supressor T-cell function, down regulation of B cell function. In this study, we used intravenous immunoglobulin for the prevention of spontaneous abortion. Five patients with a history of two or more spontaneous abortions were enrolled in this study. Other etiologic factors such as anatomical, chromosomal, hormonal factors were excluded. Three of them were positive for anti-cardiolipin antibody (ACA). When the pregnancy was diagnosed at about five weeks of gestation, 30 g intravenous immunoglobulin was administered and continued up to 28 weeks with three weeks. Ongoing pregnancy beyond 20 weeks was considered successful. Four among five patients (80%) was successful in maintaining pregnancy now ongoing 20, 31, 33, 39 weeks. One patient with ACA positive had abartion due to anembryonic pregnancy. No adverse reaction was observed during the treatment. From these preliminary data, it is suggested that intravenous immunoglobulin treatment may be effective in maintaining pregnancy in patients with unexplained recurrent spontaneous abortion, Further studies are needed to clarify the its immunomodulatory mechanism and establish a more simplified protocol limiting the use at certain critical period of time.
Abortion, Spontaneous* ; Critical Period (Psychology) ; Down-Regulation ; Female ; Humans ; Immunoglobulins* ; Immunotherapy ; Leukocyte Transfusion ; Pregnancy ; Receptors, Fc ; T-Lymphocytes

This study investigated the presence of nucleic acids of various Rickettsial agents in ticks collected in Jeju Island, Korea from June 2007 to August 2008, through the nested polymerase chain reaction (PCR) and sequencing analysis of partial citrate synthase (gltA), Rickettsial outer membrane protein B (ompB), and 17-kDa genes. Examination of the 1,584 ticks showed that the subspecies distribution of Haemaphysalis longicornis was 99.81% (n=1,581) and H. flava was 0.19% (n=3). A total 224 out of 250 pools from one to 15 ticks were found to be positive in ompB-PCR assay (minimal infection rate 141 ticks/1,000 tested). From the positive samples, 26 were analyzed by gltA- and 17-kDa-PCR assays. The nucleotide sequences of the ompB- and gltA-PCR products showed a high degree of similarity with those of the Rickettsia japonica (98.7~99.2% and 98.7~99.3%, n=25) and R. monacensis (99% and 99.7%, n=1). However, analysis of the nucleotide sequences of the 17-kDa-PCR amplicons showed that the sequences of the 25 PCR amplicons were more close to R. marmionii (99.4~100%) than R. japonica (98.6~99.1%). These findings suggest that various rickettsial diseases could be transmitted via the bite of tick vectors in Jeju Island, Korea.
Base Sequence ; Bites and Stings ; Citrate (si)-Synthase ; Fever ; Korea ; Membrane Proteins ; Nucleic Acids ; Polymerase Chain Reaction ; Receptors, Fc ; Rickettsia ; Ticks

OBJECTIVE: Immune hemolytic jaundice is caused by the destruction of antibody-sensitized erythrocytes and is associated with antibody-dependent cellular cytotoxic effects mediated by Fc receptor-bearing cells of the reticuloendothelial system. Intravenous immune globulin(IVIG) may have exerted its effect through Fc receptor blockade. We studied the effect of high-dose intravenous immune globulin(HDIVIG) in neonatal hemolytic jaundice unresponsive to phototherapy. METHODS: We selected only those with Coombs test(+) immune hemolytic jaundice who had admittcd at the NICU of the Dcpartment of Pediatzics of Dongsan Medical Center, Keimyung University between January 1995 and December 1998. They were unresponsive to phototherapy. Ten newborn infants(9 ABO incomplatibilities, l minor group incompatabillity due to anti-E) received HDIVIG therapy combined with phototherapy. IVIG was given as a dose of lg/kg for 6 hours, and serial hemoglobin, reticulocyte count, and bilirubin levels were evaluated. If the serum bilirubin level went up and reached the level above 22mg/dl, we conducted exchange transfusion for the patient. RESULTS: HDIVIG induced a significant decrease of serum billirubin levels in 8(80%, group I, HDIVIG responsive poup) of 10 cases and only 2 cases(group II, HDIVIG unreponsive group) required exchange tnnsfusions. No side effect was observed after HDIVIG therapy. CONCLUSION: We suggest HDIVIG may be effective in the treatment of phototherapy-resistant hyperbilirubinemia due to blood group incompatibility. More studies are needed to confirm the optimal dosage and therapeutic indication of HDIVIG in the therapy of neonatal immune hemolytic jaundice.
Bilirubin ; Blood Group Incompatibility ; Erythrocytes ; Humans ; Hyperbilirubinemia ; Immunoglobulins, Intravenous ; Infant, Newborn ; Jaundice* ; Mononuclear Phagocyte System ; Phototherapy* ; Receptors, Fc ; Reticulocyte Count

BACKGROUND: The FcgammaRII receptor, the only kind of Fc receptor in the platelet, plays important role for immune-complex mediated platelet activation, which occurs in Heparin induced thrombocytopenia(HIT) or antiphospholipid syndrome. The purpose of this research is to find out the role of gamma-subunit in FcgammaRII signal transduction of platelets. METHODS: After cross-linking the FcgammaRII receptors with IV.3 anti FcgammaRII specific antibody and Rabbit anti mouse antibody, we made the platelet lysate in the RIPA EDTA lysis buffer condition, and performed anti gamma-subunit immunoprecipitation. After polyacylamide gel electrophoresis and Western transfer, we probed the nitrocellulose membrane of gamma-subunit immunoprecipitate with anti gamma-subunit antibody. RESULTS: The mobility shift of gamma-subunit was observed upon FcgammaRII cross-linking. CONCLUSION: The gamma-subunit is activated upon FcgammaRII cross-linking, which means the gamma-subunit is involved in FcgammaRII signal transduction of platelet.
Animals ; Antiphospholipid Syndrome ; Blood Platelets ; Collodion ; Edetic Acid ; Electrophoresis ; Heparin ; Immunoprecipitation ; Membranes ; Mice ; Platelet Activation ; Receptors, Fc ; Signal Transduction*