An analytical review of vector- and pathogen-based transmission-blocking vaccine for malaria control

Malaria is a vector borne disease, considered to be one of the most serious public health problems. The present review focused on the blocking of parasite development in mosquito vectors; one broad strategy for achieving this is Transmission Blocking Vaccines (TBV). The TBVs usually rely on immunization of vertebrate hosts with molecules derived from the vector or pathogen to reduce pathogen transmission from infected to uninfected hosts. Most of the studies on the TBVs are based on the antibodies targeted against the surface antigens of sexual stages of malaria parasite, but it is meagre to develop mosquito-based vaccine in this regard. Vector-based TBVs include surface proteins that are expressed by the mosquito midgut digestive enzymes which are induced upon blood-feeding, and receptors expressed on the epithelial line of the tissue. Many proteins are reported that can act as candidates for transmission-blocking vaccines. This review aims to summarize the vector midgut-based proteins identified till date, that can block the development and maturity of sexual stages of the parasite within mosquitoes as targets for transmission-blocking vaccine development. The TBVs intervention can block transmission of different malaria parasite species in various species of mosquitoes with future application perspective worldwide.

APN/CD13 inhibitor Ubenimex: A molecular chaperone of antineoplastic chemotherapeutic drugs / 中国药理学通报

Cytotoxic anti-neoplastic drugs are a kind of chemotherapeutic drugs that directly kill or inhibit the growth and proliferation of tumor cells, and it is one of the main drugs for the treatment of malignant tumors. These drugs may have toxic side effects on normal cells of human body (especially those with strong division and proliferation) when they are used to kill tumor cells. And patients may usually have adverse reactions even at a normal dose when using this kind of drugs. Due to the strong toxic side effects of cytotoxic chemotherapeutic drugs, their clinical application is limited. In recent years it has been found that aminopeptidase N inhibitor Ubenimex has a significant synergistic effect with anti-neoplastic chemotherapeutic drugs, which has the advantages of enhancing the therapeutic effect of drugs and reducing the toxic side effects of chemotherapeutic drugs. This review enumerates that the combination of Ubenimex and a variety of cytotoxic drugs can enhance the anti-tumor effect of cytotoxic drugs and reduce the occurrence of adverse reactions. In addition, the mechanism of combined use of Ubenimex in reversing drug resistance is also introduced. At the same time, is is further confirmed the clinical value of Ubenimex as an effective adjuvant in the treatment of malignant tumors, so as to provide a basis for clinical application.

Genome-wide analysis of various paralogs of aminopeptidase N (APN) gene in Anopheles gambiae (Diptera: Culicidae)

Malaria continues to be a life threatening infectious disease throughout the tropical region of the world.aminopeptidase N1 (APN1) is one of the best choices for developing new Malaria Transmission-blockingvaccines. In this study an attempt has been made to overview genome-wide identification of APN genes inAnopheles gambiae. A total of eighteen A. gambiae APN sequences were found that contain conserved HEXXHand GAMEN signature sequences, indicate that large numbers of APN isomers present in mosquitoes. MultipleAPN paralogs exist as a gene cluster may propose that huge synthesis of APNs is required for rapid digestion ofpeptides over a brief period. Gene structure study shows high sequence variations among them. Protein–proteininteractions show that APN1 is highly connected protein, supporting their role as hub with other five types ofAPNs involved in glutathione metabolism, act as hub protein and disruption of one of these proteins may affectthe whole pathway

Interaction of Bombyx mori aminopeptidase N and cadherin-like protein with Bacillus thuringiensis Cry1Ac toxin / 生物工程学报

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.

A preliminary study on the interaction between Asn-Gly-Arg (NGR)-modified multifunctional nanoparticles and vascular epithelial cells

Previously developed Asn-Gly-Arg (NGR) peptide-modified multifunctional poly(ethyleneimine)-poly(ethylene glycol) (PEI-PEG)-based nanoparticles (TPIC) have been considered to be promising carriers for the co-delivery of DNA and doxorubicin (DOX). As a continued effort, the aim of the present study was to further evaluate the interaction between TPIC and human umbilical vein endothelial cells (HUVEC) to better understand the cellular entry mechanism. In the present investigation, experiments relevant to co-localization, endocytosis inhibitors and factors influencing the internalization were performed. Without any treatment, there was no co-localization between aminopeptidase N/CD13 (APN/CD13) and caveolin 1 (CAV1). However, co-localization between CD13 and CAV1 was observed when cells were incubated with an anti-CD13 antibody or TPIC. As compared with antibody treatment, TPIC accelerated the speed and enhanced the degree of co-localization. TPIC entered HUVEC not only together with CD13 but also together with CAV1. However, this internalization was not dependent on the enzyme activity of CD13 but could be inhibited by methyl--eyclodextfin (MCD), further identifying the involvement of caveolae-mediated endocytosis (CvME). This conclusion was also verified by endocytosis inhibitor experiments.

Aminopeptidase N: A therapeutic target in human liver cancer stem cells / 国际药学研究杂志

Liver cancer stem cells (LCSC) play the critical role in hepatocellular carcinoma development and maintenance. They are generally dormant or slowly cycling tumor cells that have the ability to reconstitute tumors. LCSC associate closely with tumor resistance to chemo/radiation therapy, tumor relapse and metastasis, and can be identified and separated with some special surface markers from hepatocellular carcinoma, such as CD133, CD90, CD44, CD24 and EpCAM to investigate the biological behaviors of them. Early studies showed that these markers can be regarded as special surface markers of liver cancer stem cells. Recent studies found that aminopeptidase N (APN, CD13+) cells in hepatocellular carcinoma have biological characteristics of stem cells and demonstrated that CD13 is a marker for semiquiescent CSC in human liver cancer cell lines and clinical samples and that targeting these cells might provide a way to treat this disease. In this review, we introduce the structure and the main function of CD13, liver cancer stem cells source and identification, CD13+ CSC in hepatocellular carcinoma and combination therapy in the treatment of liver cancer.

Aminopeptidase N:a therapeutic target in human liver cancer stem cells / 国际药学研究杂志

Liver cancer stem cells (LCSC)play the critical role in hepatocellular carcinoma development and maintenance. They are generally dormant or slowly cycling tumor cells that have the ability to reconstitute tumors. LCSC associate closely with tumor resistance to chemo/radiation therapy , tumor relapse and metastasis, and can be identified and separated with some special surface markers from hepatocellular carcinoma, such as CD133, CD90, CD44, CD24 and EpCAM to investigate the biological behaviors of them. Early studies showed that these markers can be regarded as special surface markers of liver cancer stem cells. Recent studies found that aminopeptidase N (APN,CD13+)cells in hepatocellular carcinoma have biological characteristics of stem cells and demonstrated that CD13 is a marker for semiquiescent CSC in human liver cancer cell lines and clinical samples and that targeting these cells might provide a way to treat this disease. In this review,we introduce the structure and the main function of CD13,liver cancer stem cells source and identification,CD13 + CSC in hepatocellular carcinoma and combination therapy in the treatment of liver cancer.

Effect of soluble porcine aminopeptidase N on antibody production against porcine epidemic diarrhea virus

A few members of coronavirus group I which includes porcine epidemic diarrhea virus (PEDV) use porcine aminopeptidase N (pAPN) as a cellular receptor. Cellular receptors play an important role in virus attachment and entry. However, the low permissiveness of PEDV to APN-expressing porcine cell lines has made it difficult to elucidate the role of pAPN in vitro. The purpose of this study was to prove whether the treatment of soluble pAPN could enhance the antibody production against PEDV in guinea pigs, rabbits and sows. The animals (20 guinea pigs, 8 rabbits and 20 sows) were divided into 4 groups. Group A was injected intramuscularly (IM) with soluble pAPN at one hour before intramuscular infection of PEDV on the same site, group B for IM simultaneous injection of pAPN and PEDV, and group C for IM injection of PEDV only. Group D served as a control of pAPN treatment or PEDV infection. Antibody production against PEDV was compared among groups at regular intervals. The results suggested that pAPN could enhance the antibody production against PEDV in guinea pigs and rabbits which are free of pAPN, however, the effect of pAPN treatment in sows was not clearly elucidated.

Identification of a putative cellular receptor 150 kDa polypeptide for porcine epidemic diarrhea virus in porcine enterocytes

Porcine epidemic diarrhea virus (PEDV) causes an acute enteritis in pigs of all ages, often fatality for neonates. PEDV occupies an intermediate position between two well characterized members of the coronavirus group I, human coronavirus (HCoV-229E)and transmissible gastroenteritis virus (TGEV) which uses aminopeptidase N (APN), a 150 kDa protein, as their receptors. However, the receptor of the PEDV has not been identified yet. A virus overlay protein binding assay (VOPBA) was used to identify PEDV binding protein in permissive cells. The binding ability of PEDV to porcine APN (pAPN) and the effects of pAPN on infectivity of PEDV in Vero cells were also investigated. VOPBA identified a 150 kDa protein, as a putative PEDV receptor in enterocytes and swine testicle (ST) cells. Further the PEDV binding to pAPN was blocked by anti-pAPN and pAPN enhanced PEDV infectivity in Vero cells. In conclusion, these results suggested that pAPN may act as a receptor of PEDV.