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

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

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

OBJECTIVETo study the correlation between the expression of Fcgamma receptor II b (FcgammaRII b) on B cells and rheumatoid arthritis (RA) patients of Shen deficiency syndrome (SDS).

METHODSThere were 43 RA patients, including 26 of SDS and 17 of non-SDS. The expression levels of FcgammaRII b on naive B cells, memory B cells, and plasma blasts in the peripheral blood were detected by flow cytometry. The numbers of tender joints, numbers of swollen joints, erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), and disease activity score (DAS28), the correlation between the distribution of B cells and the expression level of FcgammaRII b in RA patients were analyzed. Besides, another 21 healthy volunteers were recruited as the control group.

RESULTSThe expression level of FcgammaRII b was 49.65% +/- 15.86% on memory B cells and 43.69% +/- 22.57% on plasma blasts in RA patients of SDS, significantly down-regulated when compared with those of the control group (64.03% +/- 6.01%, 66.59% +/- 10.18%, P < 0.01). The expression level of FcgammaRII b on memory B cells of RA patients of non-SDS was down-regulated more obviously when compared with that of the control group (52.70% +/- 9.52% versus 64.03% +/- 6.01%, P < 0.01). The expression level of FcgammaRII b on plasma blasts was obviously lower in RA patients of SDS than in RA patients of non-SDS (56.10% +/- 17.05%, P < 0.05). The expression level of FcgammaRII b on memory B cells was not correlated with numbers of tender joints, numbers of swollen joints, ESR, RF, or DAS28.

CONCLUSIONSThe defective immunological tolerance of B cells in RA patients of SDS might be closely correlated with down-regulation of FcgammaRII b on memory B cells and plasma blasts. There might exist genetic abnormality of FcgammaRII b gene in RA patients of SDS, thus inducing loss of autoimmunity tolerance.

Adult ; Arthritis, Rheumatoid ; blood ; diagnosis ; immunology ; B-Lymphocytes ; immunology ; metabolism ; Case-Control Studies ; Female ; Humans ; Male ; Medicine, Chinese Traditional ; Middle Aged ; Receptors, IgG ; immunology ; metabolism

OBJECTIVETo study the clinical value of expression of peripheral blood neutrophil CD64 in adults with measles complicating pneumonia.

METHODS106 patients were divided into two groups by clinical manifestation and bacteria study: measles complicating bacterial pneumonia group and measles complicating viral pneumonia, using flow cytometry determination of CD64, C-reactive protein (CRP) and white blood cell (WBC) count.

RESULTSThe expression of CD64 in the bacterial pneumonia group with eruptive stage was (32.15 +/- 11.07) MFI, which was significantly higher than that in the group of with recovery stage (10.6 +/- 3.23) MFI (P < 0.01) and viral pneumonia (9.55 +/- 3.48) MFI (P < 0.01). These markers were considered positive if CD64 > or = 8.5 MFI, CRP > or = 10 mg/L and WBC > or = 9.05 x 10(9)/L. Their sensitivity was 78.12%, 80.48% and 59.37%. Their specificity was 76.19% ,67.67% and 64.28%. Their accuracy rate was 77.35%, 74.52%, 61.32%; CD64 has a positive relationship with CRP.

CONCLUSIONCompared to CRP, expression of peripheral blood neutrophil CD64 can be a better marker in the early diagnosis of patients with measles complicating bacterial pneumonia and as one of the indicators of disease conditions.

Adult ; Biomarkers ; blood ; metabolism ; C-Reactive Protein ; metabolism ; Female ; Humans ; Leukocyte Count ; methods ; Male ; Measles ; blood ; immunology ; microbiology ; Pneumonia, Bacterial ; blood ; immunology ; virology ; Receptors, IgG ; biosynthesis ; blood ; immunology

OBJECTIVEFunctional defects in NK cells have been proposed to be responsible for the impairment of anti-tumor immune responses. However, it remained unclear whether the function of NK cells were impaired in patients with hepatocellular carcinoma. To address this issue, we analyzed the frequency and function of peripheral NK cell subsets in hepatocellular carcinoma (HCC) patients.

METHODS35 HCC patients and 24 healthy controls (HC) were enrolled in the study. Peripheral NK frequency was analyzed using flow cytometry. In addition, the capacity of NK cells to produce IFN gamma and to lyse K562 cells was evaluated.

RESULTSIn contrast with the healthy controls, the frequency of peripheral NK cells in hepatocellular carcinoma patients was decreased (12.19%+/-10.85% vs 24.01%+/-8.78%, u = 4.01, probability value less than 0.01), while the frequency of CD56(bright)CD16(neg) NK cells was increased (0.62%+/-0.39% vs 0.48%+/-0.28%, u = 1.96, probability value less than 0.05), and the frequency of CD56(dim)CD16(pos) NK cells was significantly decreased (11.59%+/-7.49% vs 22.66%+/-8.84%, u = 3.92, probability value less than 0.01). In addition, peripheral NK cells from HCC patients exhibited decreased capacity to produce IFN gamma (effective cells 13.31%) and to lyse K562 cells (mixed ratio 30:1, 10:1, 1:1, effective cells 16.72%+/-7.33% vs 26.29%+/-12.36%, u = 2.52, P less than 0.05, 8.01%+/-4.40% vs 13.09%+/-5.03%, u = 3.32, probability value less than 0.05, 3.51%+/-2.82% vs 3.42%+/-1.64%, u = 1.56, probability value more than 0.05, respectively) as compared with healthy subjects.

CONCLUSIONAnti-tumor activity of NK cells in HCC patients was impaired.

Adult ; CD56 Antigen ; immunology ; Carcinoma, Hepatocellular ; immunology ; Case-Control Studies ; Cytotoxicity Tests, Immunologic ; Cytotoxicity, Immunologic ; Female ; Flow Cytometry ; Humans ; Interferon-gamma ; metabolism ; K562 Cells ; Killer Cells, Natural ; immunology ; Liver Neoplasms ; immunology ; Lymphocyte Subsets ; immunology ; Male ; Middle Aged ; Receptors, IgG ; immunology

Human polymorphonuclear leukocytes (PMN) migrate into tissues in response to chemoattractants, yet it is not known whether this process alters the functional capabilities of the PMN. Using recombinant human interleukin-8 (rHIL-8, 100 ng/ml) as a stimulus, we compared a population of PMN that migrated through a polyvinylpyrrolidone-coated polycarbonate filter containing 8.0 microns diameter pores with PMN stimulated in suspension. PMN were analyzed by flow cytometry according to functional and phenotypic criteria. CD11b/CD16 expression was unaltered by chemotaxis. In contrast, chemotaxis enhanced phagocytosis of E. coli, independent of opsonization with IgG. Similarly, chemotaxis increased baseline hydrogen peroxide production. We conclude that the chemotactic motion of PMN "primes" the cell for increased oxidative burst activity and augments the ability of PMN to ingest bacteria. This increased functional capability is distinct from rHIL-8 stimulation and appears to be independent of complement-and Fc-receptor expression.
Antigens, CD/analysis ; Chemotaxis, Leukocyte/*physiology ; Escherichia coli/immunology ; Humans ; Neutrophils/physiology ; Phagocytosis/physiology ; Phenotype ; Receptors, IgG/analysis ; Respiratory Burst/physiology

This study was performed to evaluate the effect of granulocyte-colony stimulating factor on neutrophil functions in diabetic patients with active foot infections in vitro. Twelve diabetic patients with foot infections and 12 normal volunteers were enrolled. Neutrophils from peripheral blood were incubated with granulocyte colony-stimulating factor (G-CSF, 50 ng/mL) for 20 min. Superoxide production of neutrophils was measured by the reduction of ferricytochrome C. Neutrophil phagocytosis was assayed using Staphylococcus aureus and the weighted phagocytic index was calculated. Superoxide production of neutrophils in diabetic patients with foot infections was 7.7 (unit: nmol/2 x 10(5) cells/60 min), which was significantly lower than that in controls (12.0) (p<0.05). G-CSF increased neutrophil superoxide production to 12.1 in diabetic patients with foot infections and to 19.8 in controls (p<0.05 for each). Weighted phagocytic index in diabetic patients with foot infections was 0.77, which was not significantly different from that of the controls (0.69). Weighted phagocytic index was increased significantly by G-CSF to 0.88 in diabetic patients with foot infections and to 0.79 in controls (p<0.05 for each). In conclusion, G-CSF significantly enhanced neutrophil functions in diabetic patients with foot infections in vitro.
Adult ; Aged ; Bacterial Infections/immunology* ; Diabetes Mellitus/immunology* ; Female ; Foot Diseases/immunology* ; Granulocyte Colony Stimulating Factor, Recombinant/pharmacology* ; Human ; Male ; Middle Age ; Neutrophils/immunology ; Neutrophils/drug effects* ; Receptors, IgG/analysis ; Superoxides/metabolism

The aim of this study was to establish an efficient method for expansion in vitro of natural killer (NK) cells highly purified from human peripheral blood. The CD3-CD56+CD16+ NK cells purified by the negative sorting method of MACS (magnetic microbeads activated cells sorting) were expanded with the different combinations of IL-2, SCF, IL-15 in SCGM (stem cell growth medium) supplemented with 10% human AB serum for 18 days. Cultures were fed with fresh medium and cytokines every 3 days. The sum of cells was counted for evaluating the efficiency of expansion. Then the purity of the CD3-CD56+CD16+ NK cells were determined by flow cytometry and the cytotoxicity to K562 targets was detected by CCK-8 assay in the end. Furthermore, the same way was used to explore the relationship between the efficiency of expansion, cytotoxicity to K562 targets of NK cells and the dose of IL-2. The results showed that after peripheral blood mononuclear cells (PBMNC) were purified by the negative sorting method of MACS, the purity of CD3-CD56+CD16+ NK cells increased from (12.70±2.66)% to (93.03±1.72)%. The CD3-CD56+CD16+ NK cells purified by MACS were expanded with the different combinations of IL-2, SCF, IL-15 in SCGM supplemented with 10% human AB serum for 18 days. The expanding multiple of IL-2/IL-15/SCF group was significantly higher than other groups (p<0.05). The purity of NK cells in the groups with cytokines was not significantly lower than that before expansion (p>0.05). The cytotoxicity of the groups with cytokines was significantly higher than that before expansion. Especially, the cytotoxicity (%) of NK cells in IL-2/IL-15 group and IL-2/IL-15/SCF group was more than 90%. The expanding multiples of low-dose group, medium-dose group and high-dose group were significantly higher than that of zero-dose group (p<0.05), but no significant difference was found between themselves (p>0.05). The cytotoxicity of the groups with IL-2 was significantly higher than that before expansion. Cytotoxicity to K562 cells in high-dose group was significantly higher than that in others (p<0.05); there was no significant difference between low-dose group and medium-dose group (p>0.05). It is concluded that cytokines in the 4 groups were efficient for expansion and the cytotoxicity of highly purified NK cells in vitro. IL-2/SCF/IL-15 combination is the most efficient one among different combinations, and enhanced significantly the cytotoxicity of NK cells against K562 targets. The efficiency of expansion and the cytotoxicity in vitro of NK cells are not related with the dose of IL-2, when IL-2<1,000 U/ml. It is indicated that IL-2 of high-dose (≥1,000 U/ml) may enhance the cytotoxicity of NK cells in vitro more efficiently.
CD3 Complex ; immunology ; CD56 Antigen ; immunology ; Cell Culture Techniques ; methods ; Cell Separation ; methods ; Cells, Cultured ; Humans ; Immunophenotyping ; Interleukin-2 ; pharmacology ; K562 Cells ; Killer Cells, Natural ; cytology ; immunology ; Receptors, IgG ; immunology