Recent advances in neonatal Fc receptor targeted drug delivery systems / 药学学报

The neonatal Fc receptor (FcRn) was first found to be a membrane protein that maternal antibodies transmitted to fetuses and newborns, and also expressed in multiple organs and tissues for whole life in adults. It plays a significant role to central regulate the lifespan of immunoglobulin G and serum albumin, as well as its involvement in innate and adaptive immune responses. In modern biopharmaceuticals, FcRn is a great potential drug delivery target and a highlighted subject for current research. This paper briefly describes the basic biological properties and action mechanism of FcRn, as well as the commonly used drug carrier design strategies of FcRn, especially the functional applications of prolonging half-life, targeted drug delivery, transmembrane and antigen presentation and so on. We propose that these distribution in different tissues and the diverse biological activities may have significant implications of targeting FcRn for novel drug delivery systems and immunotherapy.

Therapy of myasthenia gravis: looking forward to the era of targeted immunotherapy / 中华神经科杂志

Myasthenia gravis is mainly acetylcholine receptor antibody-mediated, T cells-dependent and complement participated acquired autoimmune disease characterized by impairment of the neuromuscular transmission. The main clinical feature of the disease is the presence of fatigability or muscle weakness. Most patients can be successfully managed with nonspecific immunotherapies such as corticosteroid and non-steroidal immunosuppressants. However, the side effects caused by long-term corticosteroid therapy are still a hurdle in the treatment of myasthenia gravis (MG). Oral non-steroidal immunosuppressants, as add-on therapy, can greatly reduce the relapse of the disease, but some drugs have a slow onset of action and the potential for significant toxicity, and even increase the risk of infection and neoplasms with long-term treatment. Despite these therapies, a minority of patients can be refractory because of incompletely responding or not well tolerated to available therapies. Thus, the need to avoid the use of corticosteroids, or at least reduce their use as much as possible should concern all patients with MG. Targeted immunotherapy is a therapeutic monoclonal antibody or antibody fragment targeting immune cells, complement, neonatal Fc receptor and cytokines. Recently, targeted immunotherapy has completed phase Ⅱ and Ⅲ clinical trials in patients with MG, and some of them have been approved by Food and Drug Administration. These promising biologics showed efficacy in symptoms persistent improvement, steroids reduction and were well tolerated, now evolving into powerful tools changing the algorithm of MG. This paper summarizes the results of clinical trials of new biologics in MG and looks forward to the prospect of MG treatment.

Effect of FcRn on in vivo pharmacokinetics of a novel monoclonal antibody against West Nile virus MIL94 / 中国药理学通报

Aim To investigate the effects of different species Fc receptors (FcRn) on pharmacokinetic characteristics of MIL94, a monoclonal antibody against West Nile virus developed by Academy of Military Sciences, which has a neutralizing effect on West Nile virus and whose maintenance time in vivo is closely related to its antiviral effect. Methods The pharmacokinetic characteristics of MIL94 in mice expressing FcRn of different species (wild-type mice, hFcRn mice and FcRn knockout mice) were compared-. Wild-type mice and FcRn knockout mice were injected intravenously with MIL94 respectively. HFcRn mice were randomly divided into four groups. Two groups were injected intravenously with MIL94, and the other two groups were injected intravenously with intravenous immunoglobulin (IVIG) and then intravenously with MIL94. Indirect ELISA was used to determine the MIL94 concentration in mouse serum. WinNonlin software was used to calculate the pharmacokinetic parameters. Results After intravenous injection with MIL94, the in vivo pharmacokinetics were basically linear. The distribution volume of MIL94 in animals was related to FcRn. The half-life in vivo varied greatly between different groups. Conclusions FcRn can affect the half-life of MIL94 in different species mainly via alternation of its elimination and distribution. It is expected that the half-life of FcRn in human will be longer than that in preclinical animals.

IgG Fc engineering to modulate antibody effector functions

Therapeutic monoclonal antibodies are among the most effective biotherapeutics to date. An important aspect of antibodies is their ability to bind antigen while at the same time recruit immune effector functions. The majority of approved recombinant monoclonal antibody therapies are of the human IgG1 subclass, which can engage both humoral and cellular components of the immune system. The wealth of information generated about antibodies has afforded investigators the ability to molecularly engineer antibodies to modulate effector functions. Here, we review various antibody engineering efforts intended to improve efficacy and safety relative to the human IgG isotype. Further, we will discuss proposed mechanisms by which engineering approaches led to modified interactions with immune components and provide examples of clinical studies using next generation antibodies.

The effect of pH and ligand density on the endocytosis and exocytosis process of FcBP decorated PEG-PCL micelles on Caco-2 cells / 药学学报

The difference in pH between apical and basolateral side of intestinal epithelial and pH dependence character of the combination of FcRn (neonatal Fc receptor) and ligand might improve the delivery of hydrophobic drugs by facilitating the transcytosis of nanocarriers. Here we designed FcBP (IgG Fc domain-binding peptides) decorated coumarin 6 (C6) loaded poly(ethyl ethylene phosphate)-co-poly(ε-caprolactone) (PEG-PCL) micelles with different ligand densities to study the effect of pH and ligand density on the endocytosis and exocytosis process of micelles on human colon adenanocaricinoma cell lines (Caco-2). Active micelles with different ligand densities and passive micelles were prepared using the thin-film hydration method. The size of the micelles was characterized by dynamic light scattering analysis and the morphology was observed by transmission electron microscope. The endocytosis and exocytosis of the micelles at pH 7.4 and pH 6.0, as well as the effect of FcRn on the endocytosis, were investigated by flow cytometry. The results showed that the size of micelles was about 30 nm, which was not affected by FcBP decoration. We found that pH and ligand density could both influence the endocytosis. The uptake of active micelles was higher at pH 6.0 than at pH 7.4, and an optimal ligand density of endocytosis was appeared in both pH environment. Then we proved that FcBP decorated micelles could be endocytosed at pH 6.0 and exocytosed at pH 7.4, and the exocytosis process was also related to ligand density. Micelles with 10% ligand density had the largest exocytosis, showing the potentiality to deliver drugs through the intestinal epithelial. In addition, the competitive inhibition experiments illustrated that the interaction between FcRn and FcBP were essential to endocytosis. The results will enhance the understanding on the FcBP decorated PEG-PCL micelles for transmemberane drug delivery.

Immunosuppression mediated by porcine FcγRⅢin PRRSV infection to PAMS / 中国免疫学杂志

Objective:To study immunosuppression mediated by the porcine FcγRⅢ in porcine reproductive and respiratory syndrome virus ( PRRSV ) infection to pulmonary alveolar macrophages ( PAMS ).Methods: In this study pulmonary alveolar macrophages cells were treated with containing 200 TCID50 PRRSV,lipopolysaccharide (LPS) (100 ng/ml) and purified mouse anti-pig FcγRⅢIgG (550 μg/ml) separately,simultaneously,PAM cells treated with purified mouse anti-pig FcγRⅢIgG (550 μg/ml) was infected by 200 TCID50 PRRSV ,untreated PAM cells as the control group.Each group were post-cultured 12,24,36,48,60,72 h, the cells and the supernatant were collected.The dynamic variation of PRRSV RNA copies in inoculation group were detected by using real-time fluorescence quantitative PCR method.mRNA level of IFN-αand TNF-αin each group were detected by using relative fluorescence quantitative PCR.Results:The result showed that mRNA level of IFN-αwas improved during PRRSV infection to PAMS 12-24 h,and mRNA level of IFN-αwas inhibited during 36-72 h,then mRNA level of IFN-αrecovered normally; mRNA level of TNF-αwas increased slightly post-infection 12-72 h.IFN-αand TNF-αmRNA levels of PAM cells treated with LPS were both up-regu-lated,using the purified mouse anti-pig FcγRⅢ IgG to treat the PAM cells,selective activation of porcine FcγRⅢ in the PAM cells down-regulated significantly mRNA levels of IFN-αand TNF-α.PRRSV infection assay mediated by selective activation FcγRⅢof the PAM cells inhibited antiviral cytokine ( IFN-αand TNF-α) mRNA levels.Conclusion:The results show selective activation of FcγRⅢinhibited significantly mRNA levels of the antiviral cytokine IFN-αand TNF-αof host cells,and innate antiviral immune response to PRRSV infection.

Mechanisms of action of intravenous immunoglobulin in autoimmune and inflammatory diseases / 国际儿科学杂志

Intravenous immunoglobulin(IVIG) has been increasingly used in autoimmune and inflammatory diseases in the past 30 years.The effect of IVIG is obvious,but its mechanism of action is unclear.This review discusses the progresses in mechanism of action of IVIG in recent years,which include the F(ab) 2 and Fc receptor-mediated mechanisms of IVIG,modulation of adhesion molecules and cytokine production.We also discuss these mechanisms with respect to the different autoimmune and inflammatory diseases for which they might be relevant.

Overexpression of Fc receptor-like 1 associated with B-cell activation during hepatitis B virus infection

The role of B cells in the pathogenesis of hepatitis B virus (HBV) infection has not been explored in depth. In the present study, the activation status of B cells from peripheral blood of healthy controls (N = 20) and patients with acute hepatitis B (AHB, N = 15) or chronic hepatitis B (CHB, N = 30) was evaluated by measuring the expression levels of B-cell activation markers CD69 and CD86, using quantitative real-time PCR and flow cytometry. Moreover, the potential mechanism underlying B-cell activation during HBV infection was further investigated by analyzing the expression profile of FCRL1, an intrinsic activation molecule of B cells. An elevation in the levels of B-cell activation markers including CD69 and CD86 was observed in the AHB patients (44.31 ± 9.27, 27.64 ± 9.26%) compared to CHB patients (30.35 ± 11.27, 18.41 ± 6.56%, P < 0.05), which was still higher than healthy controls (12.23 ± 7.84, 8.22 ± 3.43%, P < 0.05). Furthermore, the expression of FCRL1 was found to be similar to B-cell activation markers, which was highest in AHB patients (70.15 ± 17.11%), lowest in healthy donors (36.32 ± 9.98%, P < 0.05) and half-way between these levels in patients with CHB (55.17 ± 12.03%, P < 0.05). The results were positively associated with aberrant B-cell activation. These data suggest that B cells can play a role in HBV infection, and therefore more effort should be devoted to exploring their functions.

Dexamethasone Induces FcgammaRIIb Expression in RBL-2H3 Cells

Mast cells are involved in allergic responses, protection against pathogens and autoimmune diseases. Dexamethasone (Dex) and other glucocorticoids suppress FcepsilonRI-mediated release of inflammatory mediators from mast cells. The inhibition mechanisms were mainly investigated on the downstream signaling of Fc receptor activations. Here, we addressed the effects of Dex on Fc receptor expressions in rat mast cell line RBL-2H3. We measured mRNA levels of Fc receptors by real-time PCR. As expected, Dex decreased the mRNA levels of activating Fc receptor for IgE (FcepsilonR) I and increased the mRNA levels of the inhibitory Fc receptor for IgG FcgammaRIIb. Interestingly, Dex stimulated transcriptions of other activating receptors such as Fc receptors for IgG (FcgammaR) I and FcgammaRIII. To investigate the mechanisms underlying transcriptional regulation, we employed a transcription inhibitor actinomycin D and a translation inhibitor cycloheximide. The inhibition of protein synthesis without Dex treatment enhanced FcgammaRI and FcgammaRIII mRNA levels potently, while FcepsilonRI and FcgammaRIIb were minimally affected. Next, we examined expressions of the Fc receptors on cell surfaces by the flow cytometric method. Only FcgammaRIIb protein expression was significantly enhanced by Dex treatment, while FcgammaRI, FcgammaRIII and FcepsilonRI expression levels were marginally changed. Our data showed, for the first time, that Dex regulates Fc receptor expressions resulting in augmentation of the inhibitory receptor FcgammaRIIb.

Fc receptor like 3 in Han nationality of China patients with ankylosing spondylitis / 中华微生物学和免疫学杂志

Objective To investigate the association between a few single nucleotide polymorphisms(SNPs) in Fc receptor like 3 and ankylosing spondylitis(AS) in Hah nationality of China patients.Methods One hundred and sixty AS patients along with one hundred and seventy healthy controls were included in the study. SNPs of FcRL3-1 (rs0158440), FcRL3-2 ( rs2225828 ), FcRL3-3 ( rs7528684 ),FcRL3-4(rs11284799), FcRL3-5(rs945635), FcRL3-6(rs3761959), FcRL3-7 (rs2210913), FcRL3-8 (ra2282284) and FcRL3-9 (rs2282283) in FcRL3 gene were genotyped by MALDI-TOF technology. Haplotypes were estimated using PHASE v2.1 software. Results The frequency of FcRL3-1-1651C, FcRL3-3-169C, FcRL3-6 Intron3A and FcRL3-7 Intron3A alleles in AS patients were significantly increased and the frequency of FcRL3-2-641C, FcR-L3-4-110A and FcRL3-9 Intron15A were significantly increased compared with healthy controls. The frequency of FcRL3-1→9 CTCGCAAAA, CCCGGGGAA, CCCGCAAAC and CTCGCAAAC haplotypes were significantly increased and the frequency of FcRL3-1→9CCTGGGAA and TCCACAAGA haplotypes were significantly decreased compared with healthy controls. Conclusion These results suggest that FcRL3 may be associated with AS in Han nationality of China.

Intravenous Anti-D immunoglobulin treatment of adult chronic immune thrombocytopenic purpura (ITP) / 대한내과학회지

BACKGROUND/AIMS: Immune thrombocytopenic purpura (ITP) is an autoimmune disease that is mediated by anti-platelet antibodies. Based on the pathogenesis of ITP we evaluated the efficacy of intravenous anti-D immunoglobulin for adult chronic ITP. METHODS: Fourteen patients (4 without splenectomy and 10 with splenectomy) with refractory chronic ITP were treated with 50-70 microgram/kg of intravenous anti-D immunoglobulin only once. Treatment effects were evaluated by measuring the platelet counts and hemoglobin levels. RESULTS: Five patients (36%) showed a response; improvement in the platelet count lasted for on average 7 days (range: 2~24 days). There were no serious adverse effects. CONCLUSION: Anti-D immunoglobulin, which is associated with an Fc receptor blockade, appeared to be safe and effective for the treatment of adults with chronic ITP. Further studies are needed to confirm these findings and define further potentially effective treatment protocols with intravenous anti-D immunoglobulin.

Effect of Inositol-phosphatase on Fc Receptor-mediated Phagocytosis of Macrophages

BACKGROUND: Fc receptor-mediated phagocytosis is a complex process involving the activation of kinases and phosphatases. FcgammaRIIB has been known to transduces inhibitory signals through an immunoreceptor tyrosine-based inhibitory motif (ITIM) in cytoplasmic domains. In this study, we examined the involvement of inositol-phosphatase in the Fc receptor-mediated phagocytosis. METHODS: J774 cells were infected using vaccinia viral vector containing SH2 domain-containing inositol-phosphatase (SHIP) cDNA and stimulated with the sensitized sheep red blood cells. RESULTS: Stimulation of J774 cells induced the tyrosine phosphorylation of SHIP which was maximal at 5 minutes. Phosphatidylinositol-3 (PI-3) kinase inhibitor (wortmannin) inhibits J774 cell phagocytosis of sensitized sheep red blood cells in a dose-dependent manner. Heterologious expression of SHIP in J774 cells inhibits phagocytosis of sensitized sheep red blood cells in a dose-dependency manner, but catalytically dead mutants of SHIP has no effect on phagocytosis. CONCLUSION: These results strongly suggest that the active signals mediated by PI-3 kinase are opposed by inhibitory signals through SHIP in the regulation of Fc receptor-mediated phagocytosis.

Study on targeting therapy of idiopathic thrombocytopenic purpura with MTX-labelled antibody in vitro / 吉林大学学报(医学版)

Objective:To conjugate IVIG and MTX to produce a specific cytotoxicity upon phagocytes.Methods :MTX was conjugated with IVIG by indirect conjugating methods. HSA was used as an intermedi-ary to conjugate MTX with IVIG. The indirect immunofluorescence was adopted to test the binding abilityof Fc fragment. MTT assay was used to measure the cytotoxicity of conjugation on phagocytes. Results:Conjugation showed stronger cytotoxicity upon target cells than free MTX,and it showed only less cyto-toxic effect on Fc receptor negative cells compared with the positive ones. The specific cytotoxicity of IVIG-HSA-MTX was significantly stronger than that of MTX. Conclusion: In vitro the conjugation showed ahighly specific cytotoxicity upon phagocytes.

Procaryotic expression of human FceR I a subunit extracellular domain and its binding mechanism with IgE / 第二军医大学学报

Human FceR I a subunit extracellular domain was cloned and expressed with 2 different expressing systems and Dot blot was used to detect its biological activity to bind with IgE,providing reference for binding mechanism of human FceR I a subunit extracellular domain with IgE. It was shown that FceR I a subunit extracellular domain from pBAD/g I A expressing system could bind with IgE, but the one from PQE30 expressing system could not bind with IgE. It is suggested that FceR I a subunit extracellular domain alone is sufficient to bind with IgE without P and Y subunit. The proper space configuration and disulfide bond of FceR I a subunit is necessary for binding with IgE, but its glycosylation is unnecessary.

The Expression of FcRII mRNA in Human Placenta / 대한면역학회지

No abstract available.

The Espression of Fc Receptors and Mac-1 in Cord and Adult Blood Monocytes and Lymphocytes and Production of Interleukin-8 by Cord and Adult Blood Mononeuclear Cells Stimulated by Lipopolysacchride

PURPOSE: The immature neonatal immune system is thought to result in increased risk of infection. Receptors for the Fcmoiety of IgG (Fc R) are important in antibody-mediated clearance of microbes by monocytes/macrophages and immune regulation in lymphocytes. As an approach to understanding their role in neonatal life, we have compared the constitutive expression of the three Fc receptors-Fc RI (CD64), Fc RII (CD32) and Fc RIII (CD16)-by neonatal and adult blood monocytes and lymphocytes. Cells of monocyte lineage produce substances chemotactic for neutrophils, including interleukin-8 (IL-8). Neonatal monocytes have diminished function compared with adult cells. This study was designed as an in vitro evaluation of the hypothesis that LPS would induce IL-8 from monocytes and that neonatal production of this molecule would be impaired. METHODS: Using quantitative immunofluorescence by flow cytometry, we have compared the constitutive expression of the three Fc receptors-Fc RI (CD64), Fc RII (CD32) and Fc RIII (CD16)-and Mac-1 (CD11b/CD18) by neonatal and adult blood monocytes and lymphocytes. The levels of IL-8 released from mononuclear cells after LPS stimulation from adult and cord blood were checked with sandwich ELISA method and compared. RESULTS: The proportions of Fc RI, Fc RII, and Mac-1 positive monocytes were significanly low in cord blood compared to those of adult. However, in lymphocytes, the expression of those molecules were not different between cord blood and adult. Adult mononuclear cell supernatants contained significantly more IL-8 than did neonatal supernatants in response to LPS. CONCLUSION: There were differences in the expression of Fc receptors on monocytes between cord blood and adult peripheral blood and the effects of LPS on the release of IL-8 from mononuclear cells were different in adult and cord. This results suggest that the differences in Fc receptor expression may be contributed to the differences in functional activity and decreased production of IL-8 may contribute to the neonate's poor host response to infection.

The Espression of Fc Receptors and Mac-1 in Cord and Adult Blood Monocytes and Lymphocytes and Production of Interleukin-8 by Cord and Adult Blood Mononeuclear Cells Stimulated by Lipopolysacchride

PURPOSE: The immature neonatal immune system is thought to result in increased risk of infection. Receptors for the Fcmoiety of IgG (Fc R) are important in antibody-mediated clearance of microbes by monocytes/macrophages and immune regulation in lymphocytes. As an approach to understanding their role in neonatal life, we have compared the constitutive expression of the three Fc receptors-Fc RI (CD64), Fc RII (CD32) and Fc RIII (CD16)-by neonatal and adult blood monocytes and lymphocytes. Cells of monocyte lineage produce substances chemotactic for neutrophils, including interleukin-8 (IL-8). Neonatal monocytes have diminished function compared with adult cells. This study was designed as an in vitro evaluation of the hypothesis that LPS would induce IL-8 from monocytes and that neonatal production of this molecule would be impaired. METHODS: Using quantitative immunofluorescence by flow cytometry, we have compared the constitutive expression of the three Fc receptors-Fc RI (CD64), Fc RII (CD32) and Fc RIII (CD16)-and Mac-1 (CD11b/CD18) by neonatal and adult blood monocytes and lymphocytes. The levels of IL-8 released from mononuclear cells after LPS stimulation from adult and cord blood were checked with sandwich ELISA method and compared. RESULTS: The proportions of Fc RI, Fc RII, and Mac-1 positive monocytes were significanly low in cord blood compared to those of adult. However, in lymphocytes, the expression of those molecules were not different between cord blood and adult. Adult mononuclear cell supernatants contained significantly more IL-8 than did neonatal supernatants in response to LPS. CONCLUSION: There were differences in the expression of Fc receptors on monocytes between cord blood and adult peripheral blood and the effects of LPS on the release of IL-8 from mononuclear cells were different in adult and cord. This results suggest that the differences in Fc receptor expression may be contributed to the differences in functional activity and decreased production of IL-8 may contribute to the neonate's poor host response to infection.

Association of polymorphism of Fc receptor ? chain gene at position-29 in promoter with the susceptibility to systemic lupus erythematosus in southern Chinese / 中国病理生理杂志

AIM: To detect the association between the polymorphism of Fc receptor ? chain gene at position-29 in promoter and systemic lupus erythematosus(SLE). METHODS: The genotypes at position -29 in promoter of Fc receptor ? chain gene were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 180 patients with SLE and 140 ethnically matched controls in southern China. RESULTS: The frequencies of TT genotype(33.3%) and T allele (54 4%) at position -29 in patients with SLE were significantly higher than those in controls (17 9%, respectively), whereas, the frequencies of GG genotype (24 4%) and G allele (45 6%) in patients with SLE were remarkably lower than those in controls (31 4% and 57 1%, respectively) ( P 0 05) . CONCLUSION: Our results indicate that the T allele at position -29 in promoter of Fc receptor gene probably contributes to the susceptibility to SLE, but does not play a role in the occurrence of lupus nephritis.

Minimum inhibitory concentration of drugs against Mycobacterium leprae as determined by an in vitro assay.

The observations that live Mycobacterium leprae after entry into cultured peritoneal macrophages from mice, reduced the EA rosetting macrophages, have been exploited to determine the minimum inhibitory concentration of diamino diphenyl sulphone and rifampicin. Diamino diphenyl sulphone showed a minimum inhibitory concentration of 0·028 μg/ml and rifampicin 0·11 μg/ml when given externally. However, there was accumulation of diamino diphenyl sulphone inside the macrophages. At an external concentration of 0·028 μg/ml the concentration inside the macrophage was 0·5 μg/ml. The minimum inhibitory concentration for diamino diphenyl sulphone in this assay system is higher by several folds and that for rifampicin is slightly lower, than what is reported earlier with mice foot pad experiments. The minimum inhibitory concentration reported in this assay system is quite close to what is observed for in vitro inhibition of Mycobacterium lufu with both the drugs.

OBSERVATION OF PHAGOCYTOSIS OF MMC-1 MACROPHAGF-LIKE CELL LINE WITH TRANSMISSION ELECTRON MICROSCOPE / 解剖学报

The phagocytosis of opsonic chicken erythrocytes which were engulfed byMMC-1 cells was studied by means of transmission electron microscopy.After incu-bating chicken erythrocytes with the serum of rabbit-anti chicken antibody.MMC-1cells were surrounded by 1 to more than 10 opsonized erythrocytes.The EA rosetteswere formed.At first,opsonized erythrocytes attached to the MMC-1 cells in somepoints.At the site of interaction of opsonized erythrocytes with MMC-1 cells theelectron dense bands which were the specialization of the MMC-1 cell plasma mem-brane appeared.Then many projections of the erythrocytes were engulfed intoMMC-1 cells.When part of the erythrocyte was engulfed by macrophage,a collar-like structure arround the erythrocyte could be seen.Partially engulfed erythrocyteslooked like a dumbbell.The engulfed erythrocytes were irregular in shape.Thedensity of engulfed erythrocytes became faint gradually.The round ring with highelectron density appeared and enlarged in erythrocytes.It was shown that the opso-nized erythrocytes which formed EA rosettes were engulfed by MMC-1 phagocyte.After engulfing many erythrocytes,MMC-1 cells might degenerated or be engulfedby other MMC-1 cells.It was proved that Fc receptors presented on MMC-1 cells.Many mitochondria were easily found in MMC-1 cells,they were responsible forenergy supplies.Extruding of engulfed nuclei from macrophage could be seen too.It was shown that MMC-1 cells had the characteristics of macrophage and it wasestablished by cell fusion of phagocyte and thymoma cell.