Aspargine-glycine-arginine (NGR)-containing peptides are targeted peptides which can be integrated with CD13 receptors on tumor vascular endothelial cells. NGR peptides are connected to liposomes to obtain NGR peptide-modified liposomes. By intravenous injection of these liposomes, NGR peptides can be combined with CD13 receptors on tumor vascular endothelial cells, position liposomes in tumor tissues, and concentrate drug in liposomes in tumor, so as to enhance the antitumor effect. The article starts with NGR peptides, summarizes definition of NGR, NGR peptide-modified liposomes, strengths and weaknesses of NGR peptide-modified liposomes in antitumor and the latest study orientation of NGR peptide-modified liposomes, and looks into the future of studies on NGR peptide-modified liposomes.
Animals ; Antineoplastic Agents ; pharmacology ; CD13 Antigens ; administration & dosage ; pharmacology ; Humans ; Liposomes ; Oligopeptides ; administration & dosage ; pharmacology

To clone and express the gene encoding chicken aminopeptidase N (chAPN), and analysis the biological function of chAPN expressed in Escherichia coli (E. coli). The chAPN gene was amplified by RT-PCR from the kidney cells of chicken embryo and then cloned into the prokaryotic expression vector pCOLD-TF. Recombinant expression plasmid of pCOLD-TF-chAPN was constructed and then transformed into the competent E. coli BL21(DE3) cells for expression under different conditions such as induction time and inductor concentrations. Purified soluble recombinant chAPN was obtained by Ni-NTA His Bind Resin affinity chromatography and identified by SDS-PAGE gel and Western blotting assay. Its biological function was detected by its reaction with Leu-PNA and Enzyme-Linked Immunosorbent Assay (ELISA). The results showed that the expression product of chAPN gene in E. coli was soluble. It was able to bind infectious bronchitis virus (IBV) dose-dependently. In conclusion, chAPN gene has been successfully cloned and expressed in E. coli, which will establish a basis for further research the enzymatic activity and antiviral function.
Animals ; CD13 Antigens ; biosynthesis ; genetics ; metabolism ; Chickens ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism

Bacillus thuringiensis (Bt) produces Cry toxins that are widely used as insecticides in agriculture and forestry. Receptors are important to elucidate the mode of interaction with Cry toxins and toxicity in lepidopteran insects. Here, we purified the Cry toxin from Bt and identified this toxin by flight mass spectrometry as Cry1Ac, and then recombinantly expressed aminopeptidase N (BmAPN6) and repeat domains of cadherin-like protein (CaLP) of B. mori. Using co-immunoprecipitation (co-IP), Far-Western blotting, and enzyme-linked immunosorbent assays (ELISAs), we identified the interaction between Cry1Ac and BmAPN6. Furthermore, analysis of the cytotoxic activity of Cry1Ac toxin in Sf9 cells showed that BmAPN6 directly interacted with Cry1Ac toxin to induce morphological aberrations and cell lysis. We also used co-IP, Far-Western blotting and ELISAs to analyze the interactions of Cry1Ac with three binding sites corresponding to cadherin repeat (CR) 7 CR11, and CR12 of CaLP. Notably, the three repeat domains were essential Cry1Ac binding components in CaLP. These results indicated that BmAPN6 and CaLP served as a functional receptor involved in Bt Cry1Ac toxin pathogenicity. These findings represent an important advancement in our understanding of the mechanisms of Cry1Ac toxicity and provide promising candidate targets for gene editing to enhance resistance to pathogens and increase the economic value of B. mori.
Animals ; Bacillus thuringiensis ; Bacterial Proteins ; metabolism ; Bombyx ; enzymology ; CD13 Antigens ; metabolism ; Cadherins ; metabolism ; Endotoxins ; metabolism ; Hemolysin Proteins ; metabolism ; Larva

OBJECTIVE: To investigate the expressions of CD33 and CD13 in newly diagnosed multiple myeloma (MM) patients and its relationship with prognosis. METHODS: It was retrospectively observed that the expression of CD33 and CD13 in 121 MM patients who were newly diagnosed from January 2014 to January 2020, and the relationship between the expressions of CD33 and CD13 and patients prognosis was analyzed. RESULTS: Among the 121 newly diagnosed MM patients, there were 30 patients (24.8%) in the CD33⁺ group and 12 patients (9.9%) in the CD13⁺ group. Kaplan-Meier analysis showed that, compared with the CD33^- group, the progression-free survival (PFS) time and overall survival (OS) time were significantly shortened in MM patients in CD33⁺ group (PFS 17.5 vs 23 months, P=0.000; OS 18.5 vs 25 months, P=0.000); and the PFS time and OS time of MM patients in the CD13⁺ group were also significantly shortened than those in CD13^- group (PFS 21 vs 22 months, P=0.012; OS 25 vs 26 months, P=0.006). Cox regression analysis showed that CD33 and CD13 were independent adverse prognostic factors in MM patients (CD33: P=0.000;CD13: P=0.003). CONCLUSION CD33 and CD13 are prognostic risk factors in patients with MM.
CD13 Antigens ; Cell Count ; Humans ; Kaplan-Meier Estimate ; Multiple Myeloma ; Prognosis ; Retrospective Studies ; Sialic Acid Binding Ig-like Lectin 3

OBJECTIVETo screen and identify the peptides that specifically bind to CD13 on monocytes.

METHODSThe phages capable of specific binding to CD13 were screened in the phage-displayed 12-peptide library. The affinity of the selected phages with CD13 was verified with enzyme-linked immunosorbent assay (ELISA). The sequences of the peptides bound to the phages were deduced according to the phage DNA sequences, and the functional peptides aligned using the BLASTP on the Website NCBI were synthesized. To analyze the biological function of the screened peptides, the location of the peptides bound to THP-1 cells was detected using immunofluorescence assay. The blocking effect of WM15 on the peptide binding to THP-1 cells was assessed by immunofluorescence assay.

RESULTSThe phages that specifically bound to CD13 were effectively enriched to approach saturation after 4 rounds of panning. The recovery rate in the fourth round was 30 times that in the first round. Twenty selected phages were verified by ELISA, and the signals of 10 phages were higher than the control. The sequences of the peptides P9 and P7 showed 83% and 100% identity with those of human cytomegalovirus (HCMV) UL38 and UL105, respectively. The peptides bound to the cell membrane of THP-1 cells as shown by immunofluorescence assay. The binding of the peptides P9 and P7 to THP-1 cells was blocked by CD13-specific monoclonal antibody WM15 at different levels.

CONCLUSIONTwo peptides (P7 and P9) that can specifically bind to CD13 have been screened successfully, and these two peptides show specific binding to CD13 on the membrane of THP-1 cells.

Amino Acid Sequence ; Binding, Competitive ; CD13 Antigens ; analysis ; metabolism ; Cell Line ; Humans ; Molecular Sequence Data ; Peptide Library ; Peptides ; metabolism ; Protein Binding

Porcine epidemic diarrhea virus (PEDV) causes lethal diarrhea in piglets that leads to great economic losses in East Asia. It was reported that aminopeptidase N (APN) was the receptor for Transmissible gastroenteritis virus (TGEV), Human coronavirus 229E (HCoV-229E) and Feline coronavirus (FeCoV) which all belonged to group I coronavirus including PEDV. It was also confirmed previously that porcine aminopeptidase N (pAPN) could bind to PEDV, and anti-pAPN antibodies could inhibit the combination. To investigate whether pAPN was a receptor for PEDV, we transfected MDCK cells with porcine aminopeptidase (pAPN) cDNA and this enabled non-susceptible cells to support PEDV replication and serial viral propagation. Moreover, the infection was blocked by antibodies against pAPN, implying the critical role of pAPN during virus entry. In addition, immunofluorescence assays for detection of pAPN and PEDV antigens, together with neutralization assays using antibodies against pAPN, further confirmed the correlation between pAPN expression and viral replication in pAPN-transfected MDCK cells. These results indicated that pAPN is a functional receptor for PEDV.
Animals ; Antibodies ; pharmacology ; CD13 Antigens ; antagonists & inhibitors ; genetics ; metabolism ; Cell Line ; Coronavirus Infections ; enzymology ; metabolism ; Dogs ; Porcine epidemic diarrhea virus ; enzymology ; Swine

To investigate the effects of interferon alpha-2b on proliferation and apoptosis in HL-60 cells, HL-60 cells were cultured in different concentrations of IFN alpha-2b. The morphologic changes were observed by Wright's and acridine orange (AO) and ethidium bromide (EB) staining respectively. Inhibition of proliferation was detected by MTT. Expression of CD13(+) was checked by indirect fluoroimmunoassay. The results showed that apoptosis rate of HL-60 cells assayed by the above-mentioned two methods was (51 +/- 2)% and (78 +/- 3)% respectively and OD(570) values of proliferation inhibited were 1.8 +/- 0.1 and 1.0 +/- 0.1 respectively when the concentrations of the IFN(alpha-2b) were 500 and 10,000 U/ml in culture for 48 hours. Morphology and count of CD13(+) cells were changed. CD13(+) cell expression rate was (62 +/- 2)% and (30 +/- 3)% respectively when the concentrations of the IFN(alpha-2b) were 500 and 10,000 U/ml in culture for 48 hours. It is concluded that IFN(alpha-2b) can enhance the apoptosis of HL-60 cells, inhibit their proliferation, promote their maturation and differentiation.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; CD13 Antigens ; biosynthesis ; genetics ; Cell Proliferation ; drug effects ; HL-60 Cells ; Humans ; Interferon-alpha ; pharmacology ; Recombinant Proteins

To investigate the immunological and other clinical characteristics in TEL/AML1+ childhood B-acute lymphoblastic leukemia (B-ALL), immunophenotyping was performed with three-color flow cytometry, and the expression of TEL-AML1 fusion gene was detected with nested RT-PCR. Diagnosis was made according to FAB and MIC criteria. The results showed that (1) among 119 children with B-ALL, 22 (18.5%) were TEL-AML1 positive and classified as L2 morphological subtype. In TEL-AML1+ group, positive rate and score of PAS, which were 65% and 121 respectively, were all higher than that of TEL-AML1- group (P < 0.05); (2) compared with TEL-AML1- group, no significant difference was found in age, gender, white cell count and blasts count in peripheral blood of TEL-AML1+; (3) in TEL-AML1+ group, 21 out of 22 (95.5%) were common ALL, as compared with TEL-AML1- group, the positive rate of CD13 was higher (59.1%, 13/22) and the positive rate of CD20 was lower (22.7%, 5/22) than that in TEL-AML1- group, respectively (P < 0.05), and the mean fluorescence index of CD10 and HLA-DR significantly increased to 92.80 and 53.61, respectively (P < 0.05). It is concluded that TEL-AML1 rearrangement is a frequent molecular abnormality in childhood ALL. Leukemic blasts with this anomaly have special immunophenotypic characteristics. These characteristics may be useful in detection of minimal residual leukemia.
Antigens, CD20 ; analysis ; Burkitt Lymphoma ; genetics ; immunology ; CD13 Antigens ; analysis ; Child ; Child, Preschool ; Core Binding Factor Alpha 2 Subunit ; genetics ; Female ; HLA-DR Antigens ; analysis ; Humans ; Immunophenotyping ; Infant ; Male ; Oncogene Proteins, Fusion ; genetics

Severe acute respiratory syndrome (SARS) has recently recognized as a new human infectious disease. A novel coronavirus was identified as the causative agent of SARS. This report summarizes the hematological findings in SARS patients and proposes a hypothesis for the pathophysiology of SARS coronavirus related abnormal hematopoiesis. Hematological changes in patients with SARS were common and included lymphopenia (68% - 90% of adults; 100% of children, n = 10), thrombocytopenia (20% - 45% of adults, 50% of children), and leukopenia (20% - 34% of adults, 70% of children). The possible mechanisms of this coronavirus on blood system may include (1) directly infect blood cells and bone marrow stromal cells via CD13 or CD66a; and/or (2) induce auto-antibodies and immune complexes to damage these cells. In addition, lung damage in SARS patients may also play a role on inducing thrombocytopenia by (1) increasing the consumption of platelets/megakaryocytes; and/or (2) reducing the production of platelets in the lungs. Since the most common hematological changes in SARS patients were lymphopenia and immunodeficiency. We postulate that hematopoietic growth factors such as G-CSF, by mobilizing endogenous blood stem cells and endogenous cytokines, could become a hematological treatment for SARS patients, which may enhance the immune system against these virus.
Adult ; Antigens, CD ; immunology ; Antigens, Differentiation ; immunology ; CD13 Antigens ; immunology ; Cell Adhesion Molecules ; Child ; Hematologic Diseases ; immunology ; physiopathology ; Hematopoiesis ; physiology ; Humans ; SARS Virus ; Severe Acute Respiratory Syndrome ; immunology ; physiopathology ; virology

This study was aimed to investigate the effect of exogenous Wnt5a on directional differentiation of K562 cells. Wnt5a and GFP condition mediums were prepared by recombinant adenoviral vector AdWnt5a and AdGFP transfecting CHO cells. K562 cells were treated with Wnt5a and the GFP condition mediums for 1 - 7 days as Wnt5a treated group and control group respectively. The morphological changes of K562 cells were observed by light microscope and electron microscope; the differentiation phenotypes of K562 cells were identified by the cytochemical staining of POX, PAS, alpha-NAE and immunocytochemistry of CD13, CD14, CD68, and the effect of Wnt5a on cell cycle distribution of K562 cells was detected by flow cytometry. The results showed that the morphology and ultrastructure of K562 cells treated by Wnt5a displayed differentiation mature feature; both POX and PAS staining showed higher positive ratio in Wnt5a treated group than that in control group; the alpha-NAE staining also was positive, but positive intensity in Wnt5a treated group could be inhibited up to 70% by NaF. The expressions of monocytic differentiation antigens of CD14, CD68 in Wnt5a treated group were higher than those in control group, but the expression differences of granulocytic differentiation antigen CD13 between Wnt5a treated group and control group were not significant. The cell cycle in treated group was blocked at G2 phase as compared with control group. It is concluded that exogenous Wnt5a can induce K562 cells to differentiate towards mature and K562 cells treated with Wnt5a displays features of differentiation towards monocytic lineage.
Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; CD13 Antigens ; metabolism ; Cell Cycle ; drug effects ; Cell Transformation, Neoplastic ; drug effects ; Culture Media ; Humans ; K562 Cells ; Lipopolysaccharide Receptors ; metabolism ; Phenotype ; Proto-Oncogene Proteins ; metabolism ; pharmacology ; Wnt Proteins ; metabolism ; pharmacology ; Wnt-5a Protein