OBJECTIVETo investigate the immunotoxicity of acrylamide (ACR) in female BALB/c mice.

METHODSA total of 200 female mice weighing 18-22 g were randomly divided into four clusters based on body weight, and each weight-based cluster included five groups (10 mice per group): negative control, positive control (cyclophosphamide), low, intermediate, and high dose ACR groups, and all the groups were administered ACR by gavage for 30 days. At the end of the study, the immunotoxicological effects of the ACR were evaluated through immunopathology, humoral immunity, cellular immunity, and non-specific immunity.

RESULTSThe terminal body weight, spleen and thymus weights, lymphocyte counts in the ACR-H group were decreased, pathological changes were observed in lymph glands, thymus and spleen. %T cells in blood lymphocytes were significantly increased in all ACR-treated groups, and a significant reduction of % natural killer(NK) cells and increase of %Th cells were observed in the ACR-H group. interleukin-6(IL-6), Concanavalin A(ConA)-induced splenocyte proliferation and serum half hemolysis value (HC50) were also significantly suppressed in the ACR-H group.

CONCLUSIONACR elicited an inhibitory effect on cellular and humoral immunity of mice after 30 day feeding.

Acrylamide ; toxicity ; Animals ; Body Weight ; drug effects ; CD4-CD8 Ratio ; Cytokines ; blood ; Female ; Immunity, Cellular ; drug effects ; Immunity, Humoral ; drug effects ; Immunophenotyping ; Immunotoxins ; toxicity ; Mice ; Mice, Inbred BALB C ; Organ Size ; drug effects ; Random Allocation ; Spleen ; drug effects ; Thymus Gland ; drug effects ; Toxicity Tests

OBJECTIVE: To investigate the in vitro and in vivo anticancer efficacy of the immunotoxin DTAT and DTATEGF against globlastoma multiforme. METHODS: The in vitro cytotoxicity of DTAT and DTATEGF was measured using MTT assay. In vivo studies were performed in which 18 nude mice were randomly divided into 3 groups and the glioma xenograft intracranial mouse model was constructed with U87-luc cell line of human glioma. Then 1 μg of DTAT, or DTATEGF, or a control protein Bickel3 was delivered intracranially by convection-enhanced delivery (CED) via an osmotic minipump. The brain tumor fluorescence signal intensity was investigated by bioluminescent imaging (BLI). Microvessel density (MVD) was measured by immunchistochemistry SABC method in each group. RESULTS: In vitro DTAT and DTATEGF were found highly potent against U87-luc cell line, with IC(50) <0.01 nmol/L and IC(50)<1 nmol/L, respectively. In vivo BLI monitoring of the control group showed progressively increasing luminescence, while in the two treatment groups, luminescence was reduced on day 8, and increased slowly (P<0.05). The MVD of DTAT (31.6±5.2)/mm(2) and DTATEGF (25.1±6.5)/mm(2) groups had significant difference with that of the control group (51.3±7.4) /mm(2) (P<0.01). CONCLUSION Both DTAT and DTATEGF have potential in clinical application against globlastoma multiforme because of their ability to target the tumor cells and neovasculature simultaneously.
Angiogenesis Inhibitors ; pharmacology ; Animals ; Brain Neoplasms ; drug therapy ; Cell Line, Tumor ; Glioblastoma ; drug therapy ; Glioma ; Humans ; Immunotoxins ; pharmacology ; Mice ; Mice, Nude ; Xenograft Model Antitumor Assays

The adoption of oligonucleotide aptamer is well on the rise, serving an ever increasing demand for versatility in biomedical field. Through the SELEX (Systematic Evolution of Ligands by EXponential enrichment), aptamer that can bind to specific target with high affinity and specificity can be obtained. Aptamers are single-stranded nucleic acid molecules that can fold into complex threedimensional structures, forming binding pockets and clefts for the specific recognition and tight binding of any given molecular target. Recently, aptamers have attracted much attention because they not only have all of the advantages of antibodies, but also have unique merits such as thermal stability, ease of synthesis, reversibility, and little immunogenicity. The advent of novel technologies is revolutionizing aptamer applications. Aptamers can be easily modified by various chemical reactions to introduce functional groups and/or nucleotide extensions. They can also be conjugated to therapeutic molecules such as drugs, drug containing carriers, toxins, or photosensitizers. Here, we discuss new SELEX strategies and stabilization methods as well as applications in drug delivery and molecular imaging.
Antibodies ; Drug Delivery Systems ; Immunotoxins ; Ligands ; Methods* ; Molecular Imaging ; Photosensitizing Agents ; Sensitivity and Specificity

OBJECTIVE: To investigate the in vitro and in vivo anticancer efficacy of the immunotoxin DTATEGF against human NSCLC brain metastatic tumor PC9-BrM3 cell line. METHODS: The effect of the immunotoxin DTATEGF was tested for its ability to inhibit the proliferation of PC9-BrM3 cells in vitro by MTT assay. The cell cycle and the apoptosis of cells with 1 pmol/L DTATEGF were examined by flow cytometry. In vivo, 2 μg of DTATEGF or control Bickel3 was given intratumor to nude mice with established PC9-BrM3 xenografts on their hips, and tumor volumes were measured and tumor samples were investigated by immunchistochemistry SABC method. The microvessel density (MVD) was measured in each group. RESULTS: In vitro, DTATEGF killed PC9-BrM3 cells and showed an IC50 of 1 pmol/L. The apoptotic rate in the 1 pmol/L DTATEGF group was (64.0±0.5)% , significantly higher than that in the control group (1.5±0.4)% (P<0.01). The cell cycle was obviously inhibited by DTATEGF in a dose-dependent manner. The percentage of cells treated with 1 pmol/L DTATEGF in SubG0/G1 phase was (32.0±1.5)%, significantly higher than that in the control group (2.0±0.4)% (P<0.01). In vivo, DTATEGF significantly inhibited the growth of PC9-BrM3 hip tumors (P<0.05). The MVD of the DTATEGF group was (15.6±4.6)/mm2, significantly lower than that of the control group (31.2±5.4)/mm2 (P<0.01). CONCLUSION DTATEGF inhibits the growth of the PC9-BrM3 cell line and induces its apoptosis. It is highly efficacious against human metastatic NSCLC brain tumor and against neovascularization.
Animals ; Antibodies, Bispecific ; pharmacology ; Apoptosis ; Brain Neoplasms ; drug therapy ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; Cell Cycle ; Cell Line, Tumor ; Humans ; Immunotoxins ; pharmacology ; Mice ; Mice, Nude ; Neovascularization, Pathologic ; prevention & control ; Xenograft Model Antitumor Assays

Human epidermal growth factor receptor 2 (HER2) belongs to the transmembrane glycoprotein receptor family. Overexpression of HER2 could directly lead to tumorigenesis and metastasis. This phenomenon could be observed in the breast cancer, ovarian cancer, gastric cancer, lung cancer and prostate cancer. Compared with the conventional chemotherapy, the targeted treatment of antibody is more specific and has lower side effects. This review describes the current status of monotherapy and combination therapies of anti-HER2 antibodies, trastuzumab and pertuzumab, with chemotherapeutic drugs. The development trends of new formats of anti-HER2 antibody drugs such as bispecific antibody, immunotoxin are also discussed.
Antibodies, Monoclonal, Humanized ; therapeutic use ; Antineoplastic Agents ; therapeutic use ; Drug Delivery Systems ; Humans ; Immunoconjugates ; therapeutic use ; Immunotoxins ; therapeutic use ; Neoplasms ; metabolism ; therapy ; Receptor, ErbB-2 ; antagonists & inhibitors ; metabolism ; Trastuzumab

Monoclonal antibody-targeted therapy has been a hot spot in current clinical cancer treatment. As current antibody drugs have large molecule sizes leading to poor tissue penetration, and high dosage in clinical application leading to high cost, to overcome the problems, the development of new antibody drugs with miniaturization and high potency has become a new trend. In recent years, the conjugates of monoclonal antibodies and cytotoxins, called antibody-drug conjugates (ADCs), have entered the arsenal of anti-cancer drugs, becoming a new format of antibody drugs and attracting extensive attentions. The ADC molecule usually consists of antibody, linker and effector molecule. According to different effector molecules, ADCs can be divided into three categories as chemo-conjugates, immunotoxins and radio-conjugates. When ADC molecules are internalized into cancer cells, cytotoxins will be released by chemical, enzyme degradation or by action of lysosomal proteases, then kill targeted cells by inhibiting protein synthesis, depolymerizing microtubules or breaking double-strand DNA. Recently, two ADC drugs have been approved by the US FDA and more ADC drug candidates are in clinical phase II or III trials which show significantly clinical effects and attracting much attention and competition of pharmaceutical enterprises. In this review, antibody conjugates in the past and present will be summarized and the future development trends and challenges of this type of antibody drugs will be discussed.
Antigens, CD ; metabolism ; Hematologic Neoplasms ; metabolism ; therapy ; Humans ; Immunoconjugates ; chemistry ; therapeutic use ; Immunotherapy ; methods ; Immunotoxins ; chemistry ; therapeutic use ; Radioimmunotherapy ; methods

OBJECTIVEThe aim of this study was to explore the possibility of creating a toxin, C-CPE-ETA', by fusing C-terminal high affinity binding domain of CPE (C-CPE) with a truncated form of Pseudomonas aeruginosa exotoxin A (ETA') and to examine whether C-CPE-ETA' could specifically target CLDN-3, 4 molecule and the targeted toxin was cytotoxic against CLDN-3,4-overexpressing ovarian cancer.

METHODSCLDN-3 and CLDN-4 expressions were analyzed at the mRNA level in three ovarian cancer cell lines and epithelial ovarian cancer tissues from 20 patients. After transforming an expression plasmid of C-CPE-ETA' into E. coli BL21 (DE3) plysS strain, the recombinant protein was purified using His-Bind resin chromatography column and analyzed by Western blot and Coomassie blue staining. The specific binding, proapoptotic and cytolytic activities were evaluated by flow cytometry, fluorescence microscopy with the JC-1 probe and MTT assay in CLDN-3,4-overexpressing ovarian cancer cells.

RESULTSQuantitive RT-PCR results showed there existed high levels of CLDN-3 and CLDN-4 in ovarian cancer cells, CAOV3, OVCAR3 and SKOV3. Moreover, high expressions of CLDN-3 and CLDN-4 were observed in 90.0% (18/20) and 60.0% (12/20) of ovarian cancer tissues, with an expression level 10-fold higher than that in the normal ovarian tissue. A 58 000 recombinant protein C-CPE-ETA' was demonstrated by Western blot and Coomassie blue staining. Purified and recombinant C-CPE-ETA' was bound with high affinity to CLDN-3,4-overexpressing ovarian cancer cells, CAOV3, OVCAR3 and SKOV3 cells. C-CPE-ETA' was strongly proapoptotic and cytotoxic towards the CLDN-3,4-overexpressing ovarian cancer cells. The concentration of IC(50) was 7.364 ng/ml for CAOV3 cells, 8.110 ng/ml for OVCAR3 cells and 22.340 ng/ml for SKOV3 cells, respectively. However, control CLDN-3,4-deficient cell line HUVEC was not susceptible to the recombinant C-CPE-ETA' at a concentration up to 10 µg/ml.

CONCLUSIONSThe C-CPE-ETA' protein exhibits remarkably specific cytotoxicity for CLDN-3,4-overexpressing ovarian cancer cells. Its therapeutic potential warrants further development for ovarian cancer molecular targeted therapy.

ADP Ribose Transferases ; metabolism ; physiology ; Apoptosis ; Bacterial Toxins ; metabolism ; Cell Line, Tumor ; Claudin-3 ; Claudin-4 ; Claudins ; genetics ; metabolism ; Enterotoxins ; metabolism ; physiology ; Exotoxins ; metabolism ; physiology ; Female ; Humans ; Immunotoxins ; metabolism ; Ovarian Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Recombinant Fusion Proteins ; metabolism ; physiology ; Virulence Factors ; metabolism ; physiology

OBJECTIVELeukemia is the most common hematopoietic malignancies in children. Chemotherapy is currently the primary modality of treatment for this fatal disease. Although chemotherapy is very effective in terms of cell killing, severe side effects such as severe infections, intracranial hemorrhage etc. are frequently encountered due to its poor selective damage between normal and malignant cells or tissues. Thus, a new therapy with highly selective killing of malignant cells which leaves the normal cells unaffected is desperately desired. The aim of this study was to investigate the targeting efficacy in vitro with a new clone of anti-human CD19 antibody immunotoxin 2E8-Genistein on B lineage leukemia cell line Nalm-6 cells and its mechanisms in order to provide the evidence of target therapy on B lineage leukemia and lymphoma.

METHODS2E8-Genistein immunotoxin was generated by conjugating Mab 2E8 with a tyrosine kinase inhibitor, Genistein (Gen) via the Sulfo-SANPAH, an ultra-violet sensitive reagent. Nalm-6, a CD19+ B cell leukemia cell line, was used as target cells, while Molt-3, a CD19-T cell leukemia cell line, was taken as the negative control. The morphology of the cells was observed under the reverted reversed light microscope and the viability was checked with either trypan blue exclusion or MTT methods. Two-color flow cytometry was applied to study the mechanism of cell killing.

RESULTSAfter 24 hours of culture, 2E8-Genistein showed marked target killing on Nalm-6 cells at nine different concentrations from 20 nmol/L through 100 nmol/L with cell survival rates from (71.8 +/- 7.9)% down to (16.6 +/- 12.9)%, respectively (n = 3), which were all significantly lower than that of control group (100 +/- 13.9)% (P < 0.05). The killing effect was even more significant when the concentration was over 80 nmol/L. The growth inhibition rates of this immunotoxin on Nalm-6 cells were 82%, 84% and 94%, respectively at 24, 48 and 72 hours of culture in a time dependent manner. Significant difference was observed between the cell growth curve of Nalm-6 cultured with 100 nmol/L of 2E8-Gen and those of Nalm-6 cultured with medium (blank), PBS (negative control) or the same concentration of pure 2E8 antibody (negative control) groups (F = 152.15, P = 2.15 x 10(-7)), but there was no significant difference among the three control groups (F = 1.51, P = 0.29). When Molt-3 cells were used as target cells, the cell growth curves of Molt-3 cultured with 2E8-Gen (100 nmol/L) and with negative control of blank did not show any significant difference (F = 0.34, P = 0.59). PI/FITC Annexin V double staining analysis with flow cytometry showed that the positive rate (33.45 +/- 8.77)% of early apoptosis on Nalm-6 cells induced by 100 nmol/L of 2E8-Genistein was significantly higher than that of negative control of blank (10.44% +/- 1.28%, t = -4.39, P = 0.001) at 24 hours of culture.

CONCLUSION2E8-Genistein immunotoxin can significantly target the Nalm-6 cells in vitro in a time response manner and the apoptosis induction is involved in the course of this killing effect.

Antibodies, Monoclonal ; immunology ; pharmacology ; Antigens, CD19 ; Apoptosis ; drug effects ; Cell Line, Tumor ; Flow Cytometry ; Genistein ; immunology ; pharmacology ; Humans ; Immunotoxins ; immunology ; pharmacology ; Leukemia, B-Cell ; immunology

Traditional chemotherapy has become one of the essential treatments of cancer. However, cytotoxic agents are not tumor specific, which would cause serious side effects. Antibody-drug conjugates (ADCs), also called immunoconjugates, belong to the "targeted chemotherapeutics" category of anti-cancer drugs. ADCs are composed of three components including the cytotoxic drug, the monoclonal antibody, and the linker connecting the drug to the antibody. With the special-binding between antibody and antigen expressed on the surface of targeted cancer cells, ADCs provide a method to achieve excellent localization of the drug at the desired site in the body. The internalization and formation of ADCs are crucial in designing and applying an antibody conjugate to a particular disease model. In this review, we summarize three distinct internalization routes of ADCs and analysis the structure of ADCs. We also discuss in detail the categories and interaction of every component, as well as their influence to targeting property, liability and activity.
Antibodies, Monoclonal ; administration & dosage ; Antineoplastic Agents ; administration & dosage ; Drug Delivery Systems ; Immunotoxins ; chemistry ; therapeutic use

OBJECTIVEMonoclonal antibody (mAb) conjugated with certain toxin to generate immunotoxin bears an important and promising effect as a new therapy for patients with hematopoietic malignancies. However, most toxic moieties conjugated with antibody proteins reported in the literature were toxic proteins which presented immunogenicity to patients capable of inducing anti-toxin antibody. Norcantharidin (NCTD) is a small molecule toxin. It does not have the immunogenicity to human body so that it bears a promising potential for development of new targeting drug. In this study, a new clone of self-made anti-CD19 mAb named ZCH-4-2E8 conjugated with NCTD was used to investigate its targeting efficacy against CD19+ lymphoid malignant Nalm-6 cells in vitro to provide the experimental data for the further development of this new targeting agent.

METHODSA monoclonal antibody named 2E8 was prepared from mouse ascites and purified by gel chromatography. The purity of the antibody protein was checked by SDS-PAGE assay. Immunotoxin 2E8-NCTD was successfully generated through conjugating CD19 mAb protein and Norcantharidin by the activated ester method. The binding activity of the immunoconjugate (2E8-NCTD) against CD19 antigens on cell surface and the expression levels of CD19 antigens on Nalm-6 and K562 cells were examined by flow cytometry. Comparisons of the inhibitory effects among PBS, purified 2E8 antibody, norcantharidin and immunotoxin 2E8-NCTD groups on cell growth of either Nalm-6 cells or K562 cells were made.

RESULTSThe purity of the purified 2E8 antibody was higher than 99.00% demonstrated by SDS-PAGE assay. 2E8 antibody in the supernatant reacted with 99.34% of Nalm-6 cells, while only 0.98% of K562 cells reacted with this antibody. The newly generated immunotoxin (2E8-NCTD) had a positive rate of 99.90% on Nalm-6 cells with little reduction of binding activity. From the in vitro study, both 2E8-NCTD and norcantharidin were shown to have significant inhibitory effects on the growth of CD19+ Nalm-6 cells (P < 0.001), while the purified 2E8 antibody did not show any significant influences on the growth of Nalm-6 cells. Since no significant inhibitory effects were identified among immunotoxin 2E8-NCTD, 2E8 antibody and control groups on CD19(-) K562 cells, a significant targeting effect of the 2E8-NCTD against Nalm-6 cells was confirmed.

CONCLUSIONSThe immunotoxin 2E8-NCTD was successfully synthesized by activated ester method with an excellent targeting killing effect on CD19+ Nalm-6 leukemia cells in vitro, which provides some experimental data for the further development of this new targeting agent.

Animals ; Antibodies, Monoclonal ; biosynthesis ; Antigens, CD19 ; immunology ; Bridged Bicyclo Compounds, Heterocyclic ; chemical synthesis ; immunology ; Electrophoresis, Polyacrylamide Gel ; Humans ; Hybridomas ; Immunotoxins ; immunology ; K562 Cells ; Mice ; Mice, Inbred BALB C