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

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

Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.
Antibodies, Bacterial/immunology ; Antigens, CD11c/metabolism ; Antigens, CD14/metabolism ; Antigens, CD18/metabolism ; Apoptosis/*immunology ; Biological Assay ; Cell Differentiation ; Cell Line, Tumor ; Cholecalciferol/pharmacology ; Dimethylformamide/pharmacology ; Flow Cytometry ; HL-60 Cells ; Humans ; Phagocytosis/*immunology ; Pneumococcal Vaccines/*immunology ; Receptors, IgG/metabolism ; Receptors, Immunologic/*biosynthesis ; Respiratory Burst/immunology ; Streptococcus pneumoniae/*immunology ; Tretinoin/pharmacology

Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.
Antibodies, Bacterial/immunology ; Antigens, CD11c/metabolism ; Antigens, CD14/metabolism ; Antigens, CD18/metabolism ; Apoptosis/*immunology ; Biological Assay ; Cell Differentiation ; Cell Line, Tumor ; Cholecalciferol/pharmacology ; Dimethylformamide/pharmacology ; Flow Cytometry ; HL-60 Cells ; Humans ; Phagocytosis/*immunology ; Pneumococcal Vaccines/*immunology ; Receptors, IgG/metabolism ; Receptors, Immunologic/*biosynthesis ; Respiratory Burst/immunology ; Streptococcus pneumoniae/*immunology ; Tretinoin/pharmacology

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

This study was aimed to investigate the correlation of FcγR polymorphisms with the susceptibility, severity and efficacy of immunotherapy for patients with immune thrombocytopenia (ITP). PCR and DNA sequencing were used to determine the polymorphisms of FcγRIIA, FcγRIIIA and FcγRIIB in 44 ITP patients, and in 97 healthy control subjects. The results indicated that FcγRIIIA-158V/F polymorphisms between patients and controls were statistically significantly different (P = 0.015); among FcγRIIIA genotypes, the frequency of 158V/V homotype was higher in ITP (P = 0.005). However, the FcγRIIA-131H/R or FcγRIIB-232T/I polymorphisms were not significantly different between patients and controls; there were no correlation of FcγRIIA, FcγRIIIA and FcγRIIB genotype frequencies with the platelet counts or the courses of ITP; among the 38 ITP patients who received treatments, the complete response (CR) rate was 42% (16/38), and partial response (PR) rate was 34% (13/38). The therapeutic response was significantly different between FcγRIIIA-158V/V homotype and 158F/V heterotype (P = 0.034). The CR of patients with 158V/V homotype was obviously lower than that of patients with 158F/V, but the frequencies of FcγRIIA and FcγRIIB genotypes not correlated with the responsiveness to treatment. The CR rate of 6 patients treated with rituximab was 67%, and PR rate was 17%. The overall response rate was as high as 84%, the adverse reactions were not observed. It is concluded that the polymorphism of FcγRIIIA-158V/F, but not FcγRIIA-131H/R or FcγRIIB-232T/I, correlates with the patient susceptibility and therapeutic response of ITP.
Adult ; Aged ; Aged, 80 and over ; Antibodies, Monoclonal, Murine-Derived ; therapeutic use ; Case-Control Studies ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Purpura, Thrombocytopenic, Idiopathic ; drug therapy ; genetics ; immunology ; Receptors, IgG ; genetics ; Risk Factors ; Rituximab ; Young Adult

Establishing Epstein-Barr virus(EBV)-specific cytolytic T lymphocytes(EBV-CTLs) from peripheral blood mononuclear cells(PBMCs) for adoptive immunotherapy has been reported in EBV-associated malignancies including Hodgkin's lymphoma and nasopharyngeal carcinoma(NPC). In the current study, we performed ex vivo expansion of tumor-infiltrating lymphocytes(TILs) obtained from NPC biopsy specimens with a rapid expansion protocol using anti-CD3 monoclonal antibody(OKT3), recombinant human interleukin(IL)-2, and irradiated PBMCs from healthy donors to initiate the growth of TILs. Young TIL cultures comprised of more than 90% of CD3+ T cells, a variable percentage of CD3+CD8+ and CD3+CD4+ T cells, and less than 10% of CD3-CD16+ natural killer cells, a similar phenotype of EBV-CTL cultures from PBMCs. Interestingly, TIL cultures secreted high levels of the Th1 cytokines, interferon gamma (IFNγ) and tumor necrosis factor-alpha (TNF-α), and low levels of the Th2 cytokines, IL-4 and IL-10. Moreover, young TILs could recognize autologous EBV-transformed B lymphoblast cell lines, but not autologous EBV-negative blast cells or allogeneic EBV-negative tumor cells. Taken together, these data suggest that ex vivo expansion of TILs from NPC biopsy tissue is an appealing alternative method to establish T cell-based immunotherapy for NPC.
Biopsy ; CD3 Complex ; analysis ; CD4 Antigens ; analysis ; CD8 Antigens ; analysis ; Cells, Cultured ; Herpesvirus 4, Human ; immunology ; Humans ; Immunotherapy, Adoptive ; Interferon-gamma ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-2 ; pharmacology ; Interleukin-4 ; metabolism ; Lymphocytes, Tumor-Infiltrating ; immunology ; virology ; Monocytes ; pathology ; Muromonab-CD3 ; pharmacology ; Nasopharyngeal Neoplasms ; immunology ; pathology ; therapy ; virology ; Receptors, IgG ; analysis ; T-Lymphocytes, Cytotoxic ; immunology ; virology ; Tumor Necrosis Factor-alpha ; metabolism

Tyrosine kinases are one of the most important regulators for intracellular signal transduction related to inflammatory responses. However, there are no reports describing the effects of tyrosine kinases on neutrophil apoptosis induced by Entamoeba histolytica. In this study, isolated human neutrophils from peripheral blood were incubated with live trophozoites in the presence or absence of tyrosine kinase inhibitors. Entamoeba-induced receptor shedding of CD16 and PS externalization in neutrophils were inhibited by pre-incubation of neutrophils with the broad-spectrum tyrosine kinase inhibitor genistein or the Src family kinase inhibitor PP2. Entamoeba-induced ROS production was also inhibited by genistein or PP2. Moreover, genistein and PP2 blocked the phosphorylation of ERK and p38 MAPK in neutrophils induced by E. histolytica. These results suggest that Src tyrosine kinases may participate in the signaling event for ROS-dependent activation of MAPKs during neutrophil apoptosis induced by E. histolytica.
*Apoptosis ; Cells, Cultured ; Entamoeba histolytica/*immunology/*pathogenicity ; GPI-Linked Proteins/metabolism ; Genistein/metabolism ; Humans ; Neutrophils/*immunology ; Protein Kinase Inhibitors/metabolism ; Pyrimidines/metabolism ; Reactive Oxygen Species/metabolism ; Receptors, IgG/metabolism ; src-Family Kinases/antagonists & inhibitors/*metabolism

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

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