Objective To prepare CD318-specific monoclonal antibodies and evaluate their specificity, affinity, and application in immunological detection, laying the foundation for the development of CD318-targeted antibody drugs. MethodsCD318 protein was expressed and purified, and was used as an antigen to immunize mice, then mice with higher antiserum titers were screened. We prepared CD318-specific monoclonal antibodies through cell fusion and monoclonal screening, and the specificity, affinity, and application of the obtained monoclonal antibodies in immunological assays were evaluated. Then we constructed a CD318/CD3-targeting bispecific antibody and assessed its impact on T-cell cytotoxicity. Results Thirteen monoclonal antibodies were successfully generated, with the hybridoma clone 13-8-G2 exhibiting the highest titer, strongest specificity, and broadest applicability. The antibody was identified as an IgG1 isotype with a kappa light chain. The variable region of the light chain measured 318 bp, while the heavy chain variable region was 357 bp, yielding an affinity constant of approximately 7.68×10⁹. The specificity of CD318 was confirmed using flow cytometry and immunofluorescence assays. Additionally, a CD318/CD3-targeting bispecific antibody was constructed using the variable regions of this CD318 monoclonal antibody, which demonstrated enhanced T-cell cytotoxicity. Conclusion High-affinity and highly specific CD318 monoclonal antibodies were successfully prepared, laying a foundation for the development of therapeutic antibodies targeting CD318.
Animals ; Antibodies, Monoclonal/biosynthesis* ; Mice ; Antibodies, Bispecific/immunology* ; Humans ; Mice, Inbred BALB C ; Antibody Specificity/immunology* ; CD3 Complex/immunology* ; Antigens, CD/genetics* ; T-Lymphocytes/immunology* ; Hybridomas/immunology* ; Female

CD96 (Tactile) is an adhesion receptor expressed mainly on activated T cells, NK cells. As a family member of the immunoglobulin-like cell receptor, CD96 consists of three immunoglobulin-like domains (V1, V2/C and C) in the extracellular region. Recent studies have shown that the 1st IgV domain of CD96 (CD96V1) plays an essential role in cell adhesion and NK cell-mediated killing. In this study, the 1st IgV domain of human CD96 (hCD96V1) was cloned and expressed in Escherichia coli (BL21). The soluble protein was obtained by refolding of the hCD96V1 inclusion bodies. From analytical ultracentrifugation, we could predict that CD96 V1 maily exists as dimer with approximate molecular weight of 26.9 kDa. The protein was then successfully crystallized using the sitting-drop vapour-diffusion method. The crystals diffracted to 1.9 angstrom resolution and belonged to space group P21, with unit-cell parameters a = 35.1, b = 69.5, c = 49.6A, alpha=gamma=90 degrees, beta=105.4 degrees.
Antigens, CD ; biosynthesis ; genetics ; Crystallization ; Crystallography ; methods ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunoglobulin Variable Region ; biosynthesis ; genetics ; Protein Structure, Tertiary ; genetics ; Recombinant Proteins ; biosynthesis ; genetics

OBJECTIVETo construct and express human CD96 gene outer membrane domain (hCD96om) in prokaryotic cells and prepare rabbit polyclonal antibody of hCD96om.

METHODShCD96om was amplified by RT-PCR from the peripheral blood of patients with acute myeloid leukemia and inserted into prokaryotic expression vector pET32a(+) to construct the recombinant plasmid pET32-CD96. The expression of hCD96om was induced by IPTG in BL21(DE3) cells, and the expression product was identified by Western blotting. The anti-hCD96 polyclonal antibody was prepared by immunization of rabbits with the fusion protein. The specificity of anti-hCD96 antibody was determined by Western blotting.

RESULTShCD96om protein was expressed in E.coli BL21(DE3) cells in the form of inclusion body, with a relative molecular mass around 37 kD. Western blotting showed a specific reaction of the prepared antiserum with the 70 kD protein extracted from human leukemia cell line HL-60 cells and with the 37 kD hCD96om fusion protein.

CONCLUSIONThe CD96 gene of human has been successfully cloned and expressed in BL21(DE3) cells, and its rabbit polyclonal antibody has been obtained.

Animals ; Antibodies ; immunology ; metabolism ; Antigens, CD ; biosynthesis ; genetics ; immunology ; Base Sequence ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Humans ; Immune Sera ; biosynthesis ; Immunization ; Leukemia, Myeloid, Acute ; immunology ; Molecular Sequence Data ; Neoplastic Stem Cells ; immunology ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; immunology

As an essential metal for sustaining life, iron is involved in a number of metabolic processes, including DNA synthesis, electron transport, oxygen delivery, and so on. Iron metabolism involves the absorption, transport, and use of iron and is strictly regulated. Numerous studies have found a positive correlation between iron storage and the risk of tumors, such as colorectal carcinoma, hepatic cancer, renal carcinoma, lung cancer, and gastric cancer. In tumor cells, iron metabolism changes by several mechanisms, such as regulating the growth of tumor cells by transferrin, accelerating the uptake of iron by the overexpressions of transferrin receptors 1 and 2 (TfR1 and TfR2), synthesizing or secreting ferritin by some malignant tumor cells, and upregulating the level of hepcidin in patients with cancer. Some advances on diagnosis and treatment based on iron metabolism have been achieved, such as increasing the transfection and target efficiency of transferrin-polyethylenimine (PEI), inducing cell apoptosis by beta-guttiferin through interacting with TfR1.
Animals ; Antibiotics, Antineoplastic ; pharmacology ; Antigens, CD ; genetics ; metabolism ; Antimicrobial Cationic Peptides ; biosynthesis ; genetics ; Apoptosis ; Cell Proliferation ; Doxorubicin ; pharmacology ; Ferritins ; metabolism ; physiology ; Hepcidins ; Humans ; Interleukin-18 ; pharmacology ; Iron ; metabolism ; physiology ; Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Receptors, Transferrin ; genetics ; metabolism ; Transferrin ; metabolism ; physiology ; Tumor Suppressor Protein p53 ; pharmacology

OBJECTIVETo investigate whether there is an association between the expression of B7-H1 in HBV transgenic mice and the immune tolerance to HBV.

METHODST cells stimulatory capacity of DC was analyzed using mixed lymphocyte reaction. Expression of MHC-II, CD80, CD86, B7-H1 on DC was detected by Flow Cytometry. IL-2, IFNgamma, IL-10 production of T cells were determined by using ELISA. B7-H1 mRNA and protein expression in liver tissue were detected by RT-PCR and Western blotting respectively.

RESULTSThe ability of DC cells from HBV transgenic mice to stimulate T cell proliferation was significantly impaired compared with DC cells from control mice (t = 16.674, 19.674, 21.712, P less than 0.01). Expression of MHC-II, CD80 on DC was markedly decreased in transgenic mice (t = 7.910, 6.413, P less than 0.05). Meanwhile, the expression of CD86 and B7-H1 on DC cells in HBV transgenic mice were not significantly different from that in control mice. The levels of IL-2, IFNgamma, IL-10 in supernatant of T cells was significantly lower compared with controls (t = 18.712, 18.712 and 11.683, P less than 0.05). There was no significant difference in B7-H1 expression at mRNA and protein levels in liver tissue compared with controls.

CONCLUSIONSFunctional defect of DC, partly due to decreased expression of MHC-II, CD80, but not related to B7-H1 expression, is the cause for immune tolerance to HBV in HBV transgenic mice.

Animals ; Antigens, CD ; biosynthesis ; genetics ; Cell Proliferation ; Cytokines ; biosynthesis ; Dendritic Cells ; immunology ; metabolism ; Flow Cytometry ; Hepatitis B virus ; genetics ; immunology ; Histocompatibility Antigens Class II ; metabolism ; Immune Tolerance ; Liver ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Transgenic ; RNA, Messenger ; genetics ; metabolism ; Spleen ; immunology ; metabolism ; T-Lymphocytes ; immunology ; metabolism

OBJECTIVETo construct a eukaryotic expression vector of CD99 gene for transfection into Hodgkin lymphoma L428 cells.

METHODSThe full-length cDNA of CD99 gene was amplified from Jurkat cells by RT-PCR and cloned into the pcDNA3.1(+) vector and transfected into L428 cell line using Lipofextamine 2000. The sequence of CD99 mRNA in the transfected cells was confirmed by restriction endonuclease digestion and DNA sequencing, and the expression of CD99 protein was identified using immunocytochemistry.

RESULTSA gene fragment of 558 bp was amplified from the transfected cells and the sequence was verified by DNA sequencing. Immunocytochemistry identified the presence of CD99 expression in the transfected cells.

CONCLUSIONA eukaryotic expression vector pcDNA3.1(+)-CD99 is successfully constructed and stably expressed in L428 cell line.

12E7 Antigen ; Antigens, CD ; biosynthesis ; genetics ; Base Sequence ; Cell Adhesion Molecules ; biosynthesis ; genetics ; Cell Line, Tumor ; Cloning, Molecular ; Genetic Vectors ; genetics ; Hodgkin Disease ; metabolism ; pathology ; Humans ; Jurkat Cells ; Molecular Sequence Data ; Transfection

OBJECTIVETo investigate the expressions of CD1a and CD83 of Langerhans cells (LC) in the lesions of epidermodysplasia verruciformis (EV) patients.

METHODSWe used immunohistochemical method to detect the expressions of CD1a and CD83 in the lesions of 10 patients with EV lesions and in the skins of 10 normal subjects.

RESULTSNo CD83 + LCs was detected in all EV patients and normal controls, but CD1a + LC was found in all cases. The quantity of CD1a + LCs in the lesions of EV patients was significantly lower than that in the normal skin (P < 0.01); furthermore, the distribution of LCs in EV lesions was uneven.

CONCLUSIONThe functions of LCs may be inhibited in EV patients.

Antigens, CD ; biosynthesis ; genetics ; Antigens, CD1 ; biosynthesis ; genetics ; Epidermodysplasia Verruciformis ; immunology ; pathology ; Humans ; Langerhans Cells ; immunology ; Leukocyte Immunoglobulin-like Receptor B1 ; Receptors, Immunologic ; biosynthesis ; genetics ; Skin ; immunology ; pathology

OBJECTIVETo clone human PD-1 gene, construct a prokaryotic expression plasmid and express in E. coli.

METHODSThe human PD-1 cDNA was cloned by RT-PCR from the total RNA, which was extracted from peripheral blood lymphocyte cell of the patient with chronic hepatitis B. Recombinant PD-1 protein was been expressed and purified after the prokaryotic expression plasmid had been constructed. It was identified by SDS-PAGE, DNA sequencing and amino acid sequencing.

RESULTSThe PD-1 gene was cloned and confirmed by DNA sequencing. The recombinant protein was expressed in E. coli. The purified protein was obtained, then been confirmed by amino acid sequencing.

CONCLUSIONThe human PD-1 gene was successfully cloned and expressed in E. coli, which lays the foundation for further study on the function and application of PD-1.

Amino Acid Sequence ; Antigens, CD ; biosynthesis ; chemistry ; genetics ; isolation & purification ; Apoptosis Regulatory Proteins ; biosynthesis ; chemistry ; genetics ; isolation & purification ; Cloning, Molecular ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; Genetic Vectors ; genetics ; metabolism ; Humans ; Polymerase Chain Reaction ; Programmed Cell Death 1 Receptor ; Prokaryotic Cells ; metabolism ; Sequence Alignment ; Sequence Analysis, DNA

Mitochondrial ferritin (MtF), a new player in iron metabolism, first identified in 2001, is highly homologous to ferritin both structurally and functionally. Preliminary studies have suggested that MtF might play very important roles in the regulation of mitochondrial iron homeostasis. Leukemic cells, just like other malignant cells, demand more iron for their greater proliferation potential. However, little is known about what roles MtF might play in leukemic cell iron metabolism and cell proliferation. The aim of this study was to investigate the expression of MtF, transferrin receptor 1 (TfR1) and ferritin (Fn) mRNAs in K562 leukemic cells during TPA-induced cell differentiation and to explore the interrelationship between the expression levels of these iron metabolism-related molecules. K562 cells cultured with or without TPA (16 nmol/L) were collected at 24, 72 and 120 hours respectively. Cell differentiation toward monocyte lineage was confirmed by microscopic study (Wright's staining) and flow cytometry. Semiquantitative RT-PCR was performed to determine mRNA expression, with house-keeping gene beta-actin as control reference. This study revealed that over 95% of K562 cells showed morphological features of monocyte/macrophage, and the expression of CD64 on cell surface increased significantly at day 5 with TPA treatment. K562 cells could express a certain level of MtF before TPA-induced differentiation. With increase of TPA-induced cell differentiation, MtF mRNA expressions were downregulated progressively. After 5 days of induced cell differentiation, expression levels of MtF and TfR1 mRNA were just 50.3% and 68.2% of that before TPA treatment. While Fn mRNA expression increased to 1.97 folds of that before TPA treatment. It is concluded that MtF expression is downregulated during TPA-induced K562 cell differentiation, with concomitant downregulation of TfR1 and upregulation of Fn. The coordinated expression regulation of these key iron metabolism-related molecules during cell differentiation may in turn inhibit TfR1-mediated iron uptake via endocytosis and thus adversely affect cell proliferation potential.
Antigens, CD ; metabolism ; Cell Proliferation ; Cell Transformation, Neoplastic ; drug effects ; Ferritins ; biosynthesis ; genetics ; Humans ; Iron-Regulatory Proteins ; metabolism ; K562 Cells ; Mitochondria ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, Transferrin ; metabolism ; Tetradecanoylphorbol Acetate ; pharmacology

OBJECTIVE: To evaluate the expression of hCTLA4-Ig and their biological function in newborn porcine islets (NPIs) transfected with AAV-hCTLA4-Ig. METHODS: Cultured NPIs were transfected with AAV-hCTLA4-Ig. The expression of CTLA4-Ig in these NPIs was assayed by RT-PCR and immunocytochemistry. The levels of IL-2, IFN-gamma, and TNF-alpha in the culture medium were assayed by ELISA after these cells the co-cultured with human. The response of glucose-stimulated insulin secretion was observed in the transgene group and the control group. RESULTS: The expressions of CTLA4-Ig mRNA and protein were detected in the transgene group. The levels of cytokines were obviously lower in the transgene group than those in the control group (P<0.01). There was no significant difference in the response of glucose-stimulated insulin release between the transgene group and the control group (P>0.05). CONCLUSION AAV mediated hCTLA4-Ig expression in NPIs could inhibit T lymphocyte to produce cytokines, while the endocrine functions of the NPIs were not significantly affected.
Animals ; Animals, Newborn ; Antigens, CD ; biosynthesis ; genetics ; Antigens, Differentiation ; biosynthesis ; genetics ; CTLA-4 Antigen ; Cells, Cultured ; Dependovirus ; genetics ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; Humans ; Immunoglobulin Fc Fragments ; biosynthesis ; genetics ; Immunohistochemistry ; Interferon-gamma ; analysis ; Interleukin-2 ; analysis ; Islets of Langerhans ; cytology ; immunology ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Swine ; Transfection ; Tumor Necrosis Factor-alpha ; analysis