Colorectal cancer (CRC) is a common malignant tumor in the digestive tract, and 30%-85% of CRCs express epidermal growth factor receptors (EGFRs). Recently, treatments using cetuximab, also named C225, an anti-EGFR monoclonal antibody, for CRC have been demonstrated to cause an S492R mutation in EGFR. However, little is known about the biological function of S492R EGFR. Therefore, we attempted to elucidate its biological function in CRC cells and explore new treatment strategies for this mutant form. Our study indicated that EGFR and S492R EGFR accelerate the growth of CRC cells in vitro and in vivo and monoclonal antibody CH12, which specifically recognizes an EGFR tumor-specific epitope, can bind efficiently to S492R EGFR. Furthermore, mAb CH12 showed significantly stronger growth suppression activities and induced a more potent antibody-dependent cellular cytotoxicity effect on CRC cells bearing S492R EGFR than mAb C225. mAb CH12 obviously suppressed the growth of CRC xenografts with S492R EGFR mutations in vivo. Thus, mAb CH12 may be a promising therapeutic agent in treating patients with CRC bearing an S492R EGFR mutation.
Animals ; Antibodies, Monoclonal ; pharmacology ; Antineoplastic Agents, Immunological ; pharmacology ; Caco-2 Cells ; Cell Proliferation ; drug effects ; Colorectal Neoplasms ; therapy ; ErbB Receptors ; genetics ; immunology ; Female ; HT29 Cells ; Humans ; Mice ; Mice, Inbred BALB C ; Mutation ; Xenograft Model Antitumor Assays

OBJECTIVETo investigate the effects of inhibiting TIM-4 function in Kupffer cells (KCs) on liver graft rejection in mice and explore the underlying mechanism.

METHODSMouse models of orthotopic liver transplantation were treated with a control mAb group and TIM-4 mAb. The activated KCs were assayed with immunohistochemistry after operation. The expression of TIM-4 in KCs were assayed with Western blotting and RT-PCR and the levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 were assayed detected. The expression of TIM-4 in KCs was observed with laser confocal microscopy. HE staining was used to observe the microstructure of the liver tissues, and the number of CD25Foxp3T cells was determined using with flow cytometry; the proteins levels of p-P65and p-P38 were assayed with Western blotting. The donor mice were treated with clodronate liposomes to destroy the KCs in the liver before transplantation, and the liver grafts were examined for graft rejection.

RESULTSThe number of activated KCs in the liver graft increased progressively over time. Compared with the sham-operated group, the liver graft showed significantly increased TIM-4 protein and mRNA levels at 1, 3, and 7 days after transplantation (P<0.05) and increased levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 at 7 days (P<0.05). The graft in TIM-4 mAb group showed mild pathological changes with a mean RAI score of 2.67∓0.75, which was significantly lower than that in control mAb group (P<0.05). The mean survival time of the recipient mice was 53.8∓6.4 days in TIM-4 mAb group, significantly longer than that in the control mAB group (14.5∓2.9 days, P<0.05). Donor treatment with clodronate liposomes resulted in comparable RAI scores in TIM-4 mAb and control mAb groups (8.01∓0.64 vs 7.93∓0.56, P>0.05). The protein levels of p-P65 and p-P38 in TIM-4 mAb group were significantly lower than those in control mAb group (P<0.05), and CD25Foxp3T cells in the liver graft increased significantly in TIM-4 mAb group.

CONCLUSIONInhibition of TIM-4 function in KCs reduces the production of inflammatory factors after liver transplantation possibly by inhibiting the NF-κB and MAPK signaling pathways and promoting the proliferation of Foxp3Treg cells to induce allograft tolerance.

Animals ; Antibodies, Monoclonal ; pharmacology ; Graft Rejection ; Immunohistochemistry ; Kupffer Cells ; drug effects ; metabolism ; Liver ; surgery ; Liver Transplantation ; Male ; Membrane Proteins ; antagonists & inhibitors ; Mice ; NF-kappa B ; metabolism ; T-Lymphocytes, Regulatory ; immunology

The biological activity of ADCC by anti-CD20 monoclonal antibody was determined by BioGlo™ Luciferase Assay System using Jurkat/NFAT-luc+FcγRIIIa cell line as effector cell and WIL2-S cell line as target cell. The developed method was verified for specificity, precision and accuracy. Anti-CD20 monoclonal antibody showed a dose-response mode by the developed method, and the determination result complied with the following four-parameter equation: y = (A-D)/[1 + (X/C)(B)] + D. The optimized parameters of the method were determined including the antibodies diluted concentration (18,000 ng·mL(-1)), dilution rate (1:5), the ratio of effector cell and target cell (6:1), and induction time (6 h). The values of eight independent tests have passed a statistical test for curve regression analysis, linear or parallelism, which showed the method possessed good specificity. Four different dilute groups of recovery rates sample were determined for 3 times, and the result showed mean relative potencies of (44.39±3.93)%, (72.74±2.78)%, (128.28±7.01)% and (168.19±2.70)% respectively, with a variation coefficient of less than 10%, and the recoveries of (88.78±7.85)%, (96.99±3.70)%, (102.63±5.61)% and (112.12±1.80)% respectively. A novel reporter gene method for determination of biological activity of ADCC by anti-CD20 monoclonal antibody was successfully developed, which showed strong specificity, good reproducibility and high accuracy, and might be used routinely.
Antibodies, Monoclonal, Murine-Derived ; pharmacology ; Antibody-Dependent Cell Cytotoxicity ; Antigens, CD20 ; immunology ; Genes, Reporter ; Humans ; Reproducibility of Results ; Rituximab

OBJECTIVETo study the inhibitory effect of CD133 monoclonal antibody labeled with ¹³¹I (¹³¹I-CD133mAb) on Huh-7 human liver cancer cell line overexpressing CD133 antigen in vitro and in mouse models bearing the tumor cell xenograft.

METHODS¹³¹I-CD133mAb was prepared by chloramines-T method and evaluated for its stability. Flow cytometry and immunohistochemistry were used to detect the expression of CD133 in Huh-7 cells and in Huh-7 cell-derived tumors, respectively. Huh-7 cells treated with ¹³¹I-CD133mAb plus cisplatin (DDP), ¹³¹I -CD133mAb, DDP, or no treatment (blank control) were examined for cell proliferation suppression by MTT assay with the IC₅₀ calculated. BALB/c mice bearing subcutaneous Huh-7 cell xenograft in the right forelegs were treated with ¹³¹I -CD133mAb, DDP, or both every two days for two weeks. The tumor size and volume were measured twice a week, and pathological examination of the tumor was carried out after the treatments. The tumor inhibition rate was calculated and tumor cell apoptosis observed with HE staining.

RESULTSThe labeling ratio of ¹³¹I-CD133mAb was 90.25% and the radiochemical purity was 97.78%. Huh-7 cells showed obviously higher CD133 expression than HepG2 cells. ¹³¹I-CD133mAb combined with DDP group resulted in a significantly higher tumor inhibition rate than other treatments in the tumor-bearing mice.

CONCLUSION¹³¹I-CD133mAb can inhibit the growth of liver cancer cells with a high CD133 expression both in vivo and in vitro.

AC133 Antigen ; Animals ; Antibodies, Monoclonal ; pharmacology ; Antigens, CD ; immunology ; Apoptosis ; Carcinoma, Hepatocellular ; drug therapy ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Cisplatin ; pharmacology ; Glycoproteins ; immunology ; Hep G2 Cells ; Humans ; Liver Neoplasms ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Peptides ; immunology ; Xenograft Model Antitumor Assays

OBJECTIVE: This research aims to investaigate the effect of cetuximab and dendritic cells (DCs) to kill the head and neck squamous cell (HNSCC), in order to provide a new way for the patients of HNSCC. METHOD: DCs were induced from peripheral blood monocytes by rhIL-4, rhGM-CSF and TNF-alpha in vitro, 7days later, detecting the surface marks of DCs for example CD83, CD86, and then using MTT and flow cytometry detecting the effect T lymphocytes induced by DCs combining cetuximab to kill HNSCC; EGFR and pEGFR in each group were anlysised by Western blot. RESULT: It is successful to induce DCs in vitro. Mature DCs (mDCs) expressed the suface mark such as CD83, CD86 higher compared with immature DCs (imDCs). Compared with other groups, cetuximab combined with DCs significantly enhanced the cytotoxicty and apoptosis to HNSCC (P < 0.05). pEGFR were gradually reduced as the concenetration of cetuximab increasing (P < 0.05). However, comparing with the group of cetuximab, the group of cetuximab combined with DC has no significant difference at the same concentration of cetuximab. In each group EGFR also has no significant diference (P > 0.05). CONCLUSION Cetuximab and DCs have synergistic effects, which can significantly enhance the killing effect of HNSCC.
Antibodies, Monoclonal, Humanized ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Squamous Cell ; pathology ; Cetuximab ; Dendritic Cells ; immunology ; Head and Neck Neoplasms ; pathology ; Humans ; Squamous Cell Carcinoma of Head and Neck ; Tumor Cells, Cultured

This study was purposed to investigate the molecular mechanism of 4-1BBL reverse signals in the human acute monocytic leukemia cell line of U937. The U937 cell line was used as target cells, and stimulated by the mouse anti-human 4-1BBL monoclonal antibody 1F1. The nuclear translocation of NF-κB and the co-location of 4-1BBL and CD28i molecules in U937 cells were observed with confocal laser scanning microscopy. The protein and m-RNA expression levels of 4-1BBL and CD28i were detected by flow cytometry and RT-PCR respectively. The results showed that the significant nuclear translocation of NF-κB and co-localization of 4-1BBL and CD28i on membrane of U937 cells appeared after being stimulated by mAb1F1. It is concluded that the 4-1BBL reverse signals transduction mediating the growth of U937 cells relates with the nuclear translocation of NF-κB. CD28i may be involved in intracellular 4-1BBL reverse signaling pathways.
4-1BB Ligand ; immunology ; metabolism ; Antibodies, Monoclonal ; pharmacology ; CD28 Antigens ; metabolism ; Coculture Techniques ; Humans ; NF-kappa B ; genetics ; Signal Transduction ; U937 Cells

Adult ; Antibodies, Monoclonal ; pharmacology ; Bronchoalveolar Lavage Fluid ; cytology ; Cells, Cultured ; Cytokines ; biosynthesis ; blood ; secretion ; Fas Ligand Protein ; antagonists & inhibitors ; metabolism ; Humans ; Macrophages, Alveolar ; immunology ; metabolism ; Middle Aged ; Occupational Exposure ; analysis ; Signal Transduction ; Silicon Dioxide ; adverse effects ; Silicosis ; blood ; immunology ; fas Receptor ; antagonists & inhibitors ; metabolism

This study was purposed to investigate the efficacy and feasibility of recombinant humanized anti-CD25 monoclonal antibody for treating steroid-resistant acute graft-versus-host disease (aGVHD ) following allo-hematopoietic stem cell transplantation (allo-HSCT) . Twenty-one cases with II-IV grade steroid-resistant aGVHD after allo-HSCT were treated by intravenous injection of recombinant humanized anti-CD25 monoclonal antibody at a dose of 1 mg/(kg·d) on days 1, 4, 8. Injection was repeated after 1 week for the patients who did not achieve CR. The results indicated that 13 cases (61.9%) got complete response (CR), 4 cases out of them have been still in disease-free survival, 8 cases have been in survival with mild cGVHD, 1 cases died from AML relapse, 6 cases (28.57%) got partial response (PR), 3 cases out of them have been in survival with mild cGVHD, 3 case died from pulmonary infection, 2 cases without response died from GVHD. Overall response rate was 90.5% and long term survival rate was 71.48%. There were no infusion-associated side-effects after treatment with recombinant humanized anti-CD25 monoclonal antibody.It is concluded that recombinant humanized anti-CD25 monoclonal antibody is effective and feasible for treatment of steroid-refractory grade II-IV aGVHD after allo-HSCT.
Adolescent ; Adult ; Antibodies, Monoclonal, Humanized ; immunology ; therapeutic use ; Child ; Child, Preschool ; Drug Resistance, Neoplasm ; Female ; Graft vs Host Disease ; drug therapy ; Hematopoietic Stem Cell Transplantation ; methods ; Hormones ; pharmacology ; Humans ; Interleukin-2 Receptor alpha Subunit ; immunology ; Male ; Middle Aged ; Transplantation, Homologous ; Young Adult

The pandemic of human immunodeficiency virus type one (HIV-1), the major etiologic agent of acquired immunodeficiency disease (AIDS), has led to over 33 million people living with the virus, among which 18 million are women and children. Until now, there is neither an effective vaccine nor a therapeutic cure despite over 30 years of efforts. Although the Thai RV144 vaccine trial has demonstrated an efficacy of 31.2%, an effective vaccine will likely rely on a breakthrough discovery of immunogens to elicit broadly reactive neutralizing antibodies, which may take years to achieve. Therefore, there is an urgency of exploring other prophylactic strategies. Recently, antiretroviral treatment as prevention is an exciting area of progress in HIV-1 research. Although effective, the implementation of such strategy faces great financial, political and social challenges in heavily affected regions such as developing countries where drug resistant viruses have already been found with growing incidence. Activating latently infected cells for therapeutic cure is another area of challenge. Since it is greatly difficult to eradicate HIV-1 after the establishment of viral latency, it is necessary to investigate strategies that may close the door to HIV-1. Here, we review studies on non-vaccine strategies in targeting viral entry, which may have critical implications for HIV-1 prevention.
AIDS Vaccines ; immunology ; therapeutic use ; Antibodies, Monoclonal ; immunology ; therapeutic use ; Antibodies, Neutralizing ; immunology ; therapeutic use ; Genetic Therapy ; HIV Infections ; drug therapy ; prevention & control ; HIV-1 ; drug effects ; immunology ; physiology ; Humans ; Peptides ; chemistry ; immunology ; Small Molecule Libraries ; chemistry ; pharmacology ; therapeutic use ; Virus Internalization ; drug effects

OBJECTIVETo investigate the effect of blocking the inhibitory receptors KIR2DL1 and KIR2DL2/2DL3 with monoclonal antibody on cytotoxic activity of human NK cells.

METHODSHuman peripheral blood NK cells were isolated by Rosettesep NK sorting kit. The cytotoxic activity of NK cells against human leukemia NB4, K-562, Raji cells and allogeneic mature or dendritic cells (DCs) was detected before or after KIR2DL1 and KIR2DL2/2DL3 were blocked. The effect of NK cells on T lymphocyte proliferation was detected by mixed lymphocyte reaction and TGF-β1 concentration in culture supernatant was measured.

RESULTSThe cytotoxicity of NK cells to NB4 cells was augmented with increasing concentration of the antibody. Combination of both antibodies enhanced killing activity of NK cells. NK cells had strong cytotoxicity to K-562 cells, but were not enhanced by the blockade of inhibitory receptors. The cytotoxicity to Raji cells was not evidently augmented. The cytotoxicity of NK cells to mature DC was enhanced remarkably with the increase of concentration of the antibodies (2.20% ±1.10% compared with 37.59% ±5.06%, P<0.05). In mixed lymphocyte reaction, the blockade of two antibodies enhanced the inhibition effect of NK cells on T cell proliferation (77.85% ± 8.31% compared with 43.05% ± 5.95%, P<0.05) and the content of TGF-β1 in the supernatant was increased.

CONCLUSIONThe cytotoxic effects of human NK cells against target cells were significantly enhanced with the blockade of inhibitory KIR receptor; and the cytokine TGF-β1 secreted by NK cells further inhibits T cells proliferation.

Antibodies, Monoclonal ; immunology ; pharmacology ; Cell Line ; Cells, Cultured ; Cytotoxicity, Immunologic ; drug effects ; immunology ; Dendritic Cells ; immunology ; Humans ; Killer Cells, Natural ; drug effects ; immunology ; metabolism ; Lymphocyte Culture Test, Mixed ; Receptors, KIR2DL1 ; drug effects ; immunology ; Receptors, KIR2DL2 ; drug effects ; immunology ; Receptors, KIR2DL3 ; drug effects ; immunology ; T-Lymphocytes ; immunology ; Transforming Growth Factor beta1 ; metabolism