CD64 (Fc gamma RI) is the one of the three Fc gamma receptors on monocytes and represents a high affinity immunoglobin G receptor. CD64 is rapidly upregulated on monocyte in response to gamma interferone. X-linking of CD64 triggers an oxidative burst as well as antibody dependent cytotoxicity. In this experiments, peripheral blood mononuclear cells (PBMC) were separated and incubated with or without gamma interferone and PG E1. The samples were divided into four groups, the first was PBMC alone, the second was PBMC with gamma interferone 100 U/ml, the third was PBMC with gamma interferone 100 U/ml and Prostaglandin E1 1 micro M/L, and the fourth was PBMC with gamma interferone 100 U/ml and Prostaglandin E1 10 micro M /L. Flow cytometric measurements of CD64 on monocyte were performed at 0, 3, 6, and 9 hours after incubation and the mean fluorescence intensities (MFI) and the mean percentages of CD64(+) cell in monocytic gated area were obtained. After 6 hours of incubation, although there is no statistical significance, all gamma interferone added groups show the higher mean fluorescence intensity than PBMC alone group. Furthermore, at 6 and 9 hours of incubation, the mean percentages of CD64(+)cells between the PBMC with gamma interferone group and the PBMC with gamma interferone and PG E1 10 micro M/L group showed 74.83 +/- 9.72% vs. 34.07 +/-12.98%, 80.04 +/- 11.30% vs. 29.42 +/- 19.86% respectively, and there are statistical significances, p=0.05, p=0.05 respectively. It appears that PG E1 inhibits the expression of CD64 on monocyte.
Alprostadil* ; Fluorescence ; Interferons ; Monocytes* ; Receptors, IgG ; Respiratory Burst

Hematologic Neoplasms ; therapy ; Humans ; Immunotherapy, Adoptive ; Receptors, Antigen, T-Cell ; Receptors, IgG ; immunology ; T-Lymphocytes

Objective To investigate the relationship between disease courses and severity and monocyte subsets distribution and surface CD31 intensity in patients of hemorrhagic fever with renal syndrome (HFRS). Methods Peripheral blood samples from 29 HFRS patients and 13 normal controls were collected. The dynamic changes of classical monocyte subsets (CD14⁺⁺CD16^-), intermediated monocyte subsets (CD14⁺⁺CD16⁺) and non-classical monocyte subsets (CD14⁺CD16⁺⁺) and the mean fluorescent intensity (MFI) of CD31 on monocyte subsets were detected by multiple-immunofluorescent staining and flow cytometry. Results In acute phase of HFRS, the ratio of classical monocyte subsets to total monocytes was dramatically decreased compared to convalescent phase and normal control. It was still much lower in convalescent phase compared to normal controls. The ratio of classical monocyte subsets to total monocytes were decreased in HFRS patients compared to that in normal control, whereas there was no difference between severe/critical groups and mild/moderate groups. On the contrary, the ratio of intermediate monocyte subsets to total monocytes in acute phase of HFRS was significantly increased compared to convalescent phase and normal control. The ratio of intermediate monocyte subsets to total monocytes were increased in HFRS patients compared to that in normal control, whereas no difference was found between severe/critical groups and mild/moderate groups. Phases or severity groups had no difference in ratio of non-classical monocyte subsets to total monocytes. Additionally, the ratio of classical monocyte subsets had a tendency to decline and that of intermediate monocyte subsets showed an increase both to total monocytes between the acute and convalescent phases in 11 HFRS patients with paired-samples. Moreover, in acute phase of HFRS, the mean fluorescent intensity (MFI) of CD31 on three monocyte subsets all decreased, specifically classical monocyte subsets showed the highest MFI of CD31 while the normal control reported the highest MFI of CD31 in non-classical monocyte subsets. In convalescent phase, the MFI of CD31 on classical and intermediated monocyte subsets were both lower than that of normal control, while MFI of CD31 was still significantly lower than normal control on non-classical monocyte subsets. Finally, MFI of CD31 on classical and intermediated monocyte subsets in severe/critical group were both lower than those in mild/moderate group, showing no statistical difference in MFI of CD31 on non-classical monocyte subset across groups of different disease severity. Conclusion The ratio of classical and intermediated monocyte subsets to total monocytes are correlated with the course of HFRS, and so are the surface intensity of CD31 on these monocyte subsets with the disease course and severity. The surface intensity of CD31 on non-classical monocyte subsets, however, is correlated only with the course of the disease. Together, the underlying mechanisms for the observed changes in monocyte subsets in HFRS patients should be further investigated.
Humans ; Monocytes ; Lipopolysaccharide Receptors ; Hemorrhagic Fever with Renal Syndrome ; Receptors, IgG ; Disease Progression

PURPOSE: Receptors for the Fc of IgG(FcvR) and a beta2 integrin molecule, CD11c/CD18 are important in clearance of microbes by granulocytes. We performed an in vitro study on the effect of recombinant human granulocyte colony-stimulating factor(rhG-CSF), or granulocyte-macrophage colony-stimulating factor(rhGM-CSF) on the expression of Fc R II, Fc R III, CD11c and CD18 and respiratory burst function of granulocytes. METHODS: Peripheral blood was collected from six healthy adults. The isolated granulocytes were stimulated with rhG-CSF, 250mg/mL, rhGM-CSF, 100ng/mL or both of them for 1, 3, 9, 24, and 48 hours. Using flow cytometry, we compared the expression of the Fc R II, Fc R III, CD11c and CD18 of granulocytes before and after stimulation. We also the studied respiratory burst of granulocytes with chemiluminescence assay. RESULTS: Fc R II and CD18 expression were not changed significantly after stimulation. Fc R III expression was decreased significantly after stimulation with rhG-CSF, rhGM-CSF, or both of them. CD11c expression was increased initially but was found to decrease significantly after 9 hours of stimulation. Granulocytes treated with rhG-CSF, rhGM-CSF, or both displayed enhanced respiratory burst. Our results suggest that exposure of granulocyte to growth factor results in granulocyte activation. CONCLUSION: We have shown that rhG-CSF and rhGM-CSF resulted in an activation of peripheral blood granulocytes immunophenotypically and functionally.
Adult ; Antigens, CD18* ; Flow Cytometry ; Granulocytes* ; Humans* ; Luminescence ; Receptors, IgG* ; Respiratory Burst*

OBJECTIVETo investigate the effect of FCGR3A polymorphisms on the antibody-dependent cell-mediated cytotoxicity (ADCC) activity induced by cetuximab against A549 cells.

METHODSA549 cell line was used as target cells and NKTm cells as effector cells. FCGR3A polymorphisms were detected by direct sequencing. The ADCC activity mediated by cetuximab was assessed by CCK-8 assay.

RESULTSThree genotypes of FCGR3A were detected:V/V,V/F,and F/F. The ADCC activity of NKTm cells with these three different genotypes mediated by cetuximab were significantly different (P=0.0015). NKTm cells with FCGR3A-158V/V genotypes had significantly higher ADCC activity than FCGR3A-V/F or F/F genotypes (P<0.01),whereas the ADCC activity between V/F and F/F genotype showed no statistical significance(P>0.05).

CONCLUSIONFCGR3A polymorphisms have an impact on ADCC activity mediated by cetuximab in NKTm cells.

Antibody-Dependent Cell Cytotoxicity ; Cell Line, Tumor ; Cetuximab ; Genotype ; Humans ; Polymorphism, Genetic ; Receptors, IgG

OBJECTIVE: To improve the method for detecting the neutrophil CD64 (nCD64) index and to enhance the detection rate and accuracy of nCD64 index in patients with hematologic malignancies. METHODS: The nCD64 index in peripheral blood of patients with hematologic malignancies combined with suspicious bacterial infection (255 cases-time) was detected by using array method. When the detection of nCD64 index in samples was interfered with abnormal cells in detection process of enrolled patients, the antibodies CD45, CD15 and CD10 were added into samples on the basis of routine detection by using the primary detection kit, in order to more accurately distinguish the neutrphils and obtain the nCD64 index. The nCD64 index as well as the efficiency of nCD64 index, PCT and CRP for diagnosis of sepsis before and after the improvement of deteation method were compared. RESULTS: The samples of 60 cases were interfered with abnormal cells in detection process, out of which the samples of 18 cases failed in detection, but these samples of 18 cases all got the effective results of detection after the detection method was improved. The detection showed that the nCD64 index before and after the improvement as well as the PCT and CRP levels in sepsis group were higher than those in non-sepsis group(P＜0.05). After improvement of method, the efficiency of nCD64 index for diagnosis of sepsis was suprior to the PCT and CRP, the nCD64 index obtained after the improvement of method possessed the diagnosis efficiency same as the efficiency obtained before improvement of method, moreover the detection results were more reliable. CONCLUSION For the samples of patients with hematologic malignancies interfered with abnormal cells in the process of detecting the nCD64 index, the corresponding antibodies are added into detected samples according to the kinds of hemotologic diseases of patients, in order to more accurately gate the neutrophils in paripheral blood of patients, there by the detection rate and accuracy for detecting the nCD64 index are enhanced by accurately distinguishing the neutrophils.
Biomarkers ; C-Reactive Protein ; Hematologic Neoplasms ; Humans ; Neutrophils ; Receptors, IgG ; Sepsis

FcγRIIB, the only inhibitory IgG Fc receptor, functions to suppress the hyper-activation of immune cells. Numerous studies have illustrated its inhibitory function through the ITIM motif in the cytoplasmic tail of FcγRIIB. However, later studies revealed that in addition to the ITIM, the transmembrane (TM) domain of FcγRIIB is also indispensable for its inhibitory function. Indeed, recent epidemiological studies revealed that a non-synonymous single nucleotide polymorphism (rs1050501) within the TM domain of FcγRIIB, responsible for the I232T substitution, is associated with the susceptibility to systemic lupus erythematosus (SLE). In this review, we will summarize these epidemiological and functional studies of FcγRIIB-I232T in the past few years, and will further discuss the mechanisms accounting for the functional loss of FcγRIIB-I232T. Our review will help the reader gain a deeper understanding of the importance of the TM domain in mediating the inhibitory function of FcγRIIB and may provide insights to a new therapeutic target for the associated diseases.
Autoimmune Diseases ; drug therapy ; genetics ; immunology ; Humans ; Protein Domains ; Receptors, IgG ; chemistry ; immunology

Neutrophils play an important role in the human immune system for protection against such microorganisms as a protozoan parasite, Trichomonas vaginalis; however, the precise role of neutrophils in the pathogenesis of trichomoniasis is still unknown. Moreover, it is thought that trichomonal lysates and excretory-secretory products (ESP), as well as live T. vaginalis, could possibly interact with neutrophils in local tissues, including areas of inflammation induced by T. vaginalis in humans. The aim of this study was to investigate the influence of T. vaginalis lysate on the fate of neutrophils. We found that T. vaginalis lysate inhibits apoptosis of human neutrophils as revealed by Giemsa stain. Less altered mitochondrial membrane potential (MMP) and surface CD16 receptor expression also supported the idea that neutrophil apoptosis is delayed after T. vaginalis lysate stimulation. In contrast, ESP stimulated-neutrophils were similar in apoptotic features of untreated neutrophils. Maintained caspase-3 and myeloid cell leukemia-1 (Mcl-1) in neutrophils co-cultured with trichomonad lysate suggest that an intrinsic mitochondrial pathway of apoptosis was involved in T. vaginalis lysate-induced delayed neutrophil apoptosis; this phenomenon may contribute to local inflammation in trichomoniasis.
Animals ; *Apoptosis ; Cells, Cultured ; Female ; Humans ; Membrane Potentials ; Mitochondrial Membranes/physiology ; Neutrophils/chemistry/*immunology ; Receptors, IgG/analysis ; Trichomonas vaginalis/*immunology

To investigate the distribution of variant genotypes of Fc gamma receptor IIIa (Fc gamma R IIIa) in healthy Chinese population of Zhengzhou city, genomic DNA was extracted from peripheral blood of healthy donators. The genotypes of Fc gamma R IIIa-158 were determined by nested polymerase chain reaction (PCR) in 137 healthy people in Zhengzhou city. The results showed that frequencies of variant genotypes FF, VV and VF were 42.3%, 48.9% and 8.8% respectively. The distribution of Fc gamma R IIIa-158 in healthy Chinese population of Zhengzhou city was polymorphic and different from that of African Americans (AA) and Caucasian Americans (CA).
Asian Continental Ancestry Group ; European Continental Ancestry Group ; Genetic Variation ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Receptors, IgG ; genetics

OBJECTIVETo review and summarize literature regarding stimulatory and inhibitory signaling pathways from different types of Fc gamma receptors (FcgammaRs).

DATA SOURCEArticles were obtained from Medline from January 1991 to April 2002.

STUDY SELECTIONOver 100 English language papers and reviews published over the last 11 years were selected.

RESULTS AND CONCLUSIONSStimulatory Fcgamma receptors include FcgammaRI, FcgammaRIIA, FcgammaRIIC, and FcgammaRIII A. They transduce signals through the immunoreceptor tyrosine-based activation motif (ITAM) in subunits or in the cytoplasmic domain. Inhibitory Fcgamma receptors, such as FcgammaRIIB, are single chain receptors, transducing signals through an immunoreceptor tyrosine-based inhibitory motif (ITIM) in cytoplasmic domains. Stimulatory signals include protein phosphorylation, increase in intracellular free calcium, the production of 1,4,5-triphosphate inositol (IP(3)) and diacylglycerol (DAG) mainly through the Src-family kinases, phosphoinositide 3-kinase (PI3-K) and phospholipase C (PLC). Inhibitory signaling has been implicated in the repression of the above activities as well as inhibition of B cell responses through Src homology 2-containing inositol phosphatase (SHIP).

Amino Acid Motifs ; Animals ; Blood Platelets ; physiology ; Humans ; Phagocytes ; physiology ; Receptors, IgG ; chemistry ; physiology ; Signal Transduction ; physiology