A boy, aged 6 years, attended the hospital due to global developmental delay for 6 years and recurrent fever and convulsions for 5 years. The boy was found to have delayed mental and motor development at the age of 3 months and experienced recurrent fever and convulsions since the age of 1 year, with intermittent canker sores and purulent tonsillitis. During the fever period, blood tests showed elevated white blood cell count, C-reactive protein, and erythrocyte sedimentation rate, which returned to normal after the fever subsides. Electroencephalography showed epilepsy, and genetic testing showed compound heterozygous mutations in the GPAA1 gene. The boy was finally diagnosed with glycosylphosphatidylinositol biosynthesis deficiency 15 (GPIBD15) and periodic fever. The patient did not respond well to antiepileptic treatment, but showed successful fever control with glucocorticoid therapy. This article reports the first case of GPIBD15 caused by GPAA1 gene mutation in China and summarizes the genetic features, clinical features, diagnosis, and treatment of this disease, which provides a reference for the early diagnosis and treatment of GPIBD15.
Humans ; Male ; Fever ; Glycosylphosphatidylinositols/genetics* ; Membrane Glycoproteins/genetics* ; Mutation ; Rare Diseases ; Seizures ; Child

Inflammation, an innate immune response mediated by macrophages, forms the first line of defence to protect our body from the invasion of various pathogens. Although inflammation is a defensive response, chronic inflammation has been regarded as the major cause of many types of human diseases such as inflammatory/autoimmune diseases, cancers, neurological diseases, and cardiovascular diseases. Folate receptor (FR) is a cell surface glycosylphosphatidylinositol (GPI)-anchored glycoprotein, and its three isoforms, FR-α, FR-β, and FR-γ, are found in humans. Interestingly, FRs are highly expressed on a variety of cells, including cancer cells and activated macrophages, whereas their expression on normal cells is undetectable, indicating that FR-targeting could be a good selective strategy for the diagnosis and therapeutic treatment of cancers and activated macrophage-mediated inflammatory diseases. Previous studies successfully showed FR-targeted imaging of many types of cancers in animal models as well as human patients. Recently, a number of emerging studies have found that activated macrophages, which are critical players for a variety of inflammatory diseases, highly express FRs, and selective targeting of these FR-positive activated macrophages is a good approach to diagnose and treat inflammatory diseases. In this review, we describe the characteristics and structure of FRs, and further discuss FR-targeted diagnostics and therapeutics of human diseases, in particular, activated macrophage-mediated inflammatory diseases.
Cardiovascular Diseases ; Diagnosis ; Folic Acid* ; Glycoproteins ; Glycosylphosphatidylinositols ; Humans ; Immunity, Innate ; Inflammation ; Macrophages ; Models, Animal ; Protein Isoforms

OBJECTIVETo prepare IL-2-anchored and tumor-derived exosomes vaccine, and investigate the antitumor efficiency of the special cytotoxic T-lymphocytes induced by Ex/GPI-IL-2.

METHODSTo construct pEGFP-N1-IL2gpi plasmid coding a fusion gene of a DNA oligo encoding GPI-anchor signal sequence attaching to human IL-2 cDNA. Then T24 cell lines stably expressing GPI-IL-2 proteins (T24/GPI-IL-2) were established. Ex/GPI-IL-2 were isolated and purified by ultrafiltration and sucrose gradient centrifugation, and the morphology and molecule markers were analyzed. The mixed lymphocyte reaction study and cytotoxic study were performed to determine the proliferative effect of T lymphocytes and the cytotoxicity induced by Ex/GPI-IL-2.

RESULTSThe pEGFP-N1-IL2gpi plasmid was successfully constructed, and cell lines stably expressing GPI-IL-2 fusion proteins were established. Ex/GPI-IL-2 were small vesicular and saucer-shaped in diameter of 30-90 nm, containing heat shock protein 70, intercellular adhesion molecule-1, MAGE-1 and GPI-IL-2. Ex/GPI-IL-2-pulsed could dendritic cells induce proliferation of T cells and cytotoxic immune response more efficiently (P<0.05).

CONCLUSIONSGPI-IL-2 gene-modified tumor cells can make the exosomes containing GPI-IL-2 with an increased anti-tumor effect. Our study provides a feasible approach for exosome-based tumor immunotherapy of bladder transitional cell tumors.

Cancer Vaccines ; immunology ; Carcinoma, Transitional Cell ; immunology ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Exosomes ; genetics ; metabolism ; Glycosylphosphatidylinositols ; metabolism ; HSP70 Heat-Shock Proteins ; metabolism ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Interleukin-2 ; metabolism ; Melanoma-Specific Antigens ; metabolism ; Plasmids ; Recombinant Fusion Proteins ; metabolism ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Urinary Bladder Neoplasms ; immunology ; metabolism ; pathology

OBJECTIVETo prepare a vaccine of IL-12-anchored exosomes derived from renal cancer cells and to evaluate its antitumor effect in vitro.

METHODSA mammalian co-expression plasmid of glycolipid-anchor-IL-12 (GPI-IL-12) was constructed by subcloning IL-12A chain gene (P35 subunit) and a fusion gene containing GPI-anchor signal sequence and IL-12B chain gene (P40 subunit) in pBudCE4.1. Confocal laser scanning microscopy and flow cytometry were used to analyze the expression of the fusion proteins. Transmission electron microscopy and Western blot were used to identify the morphology and characteristic molecules of exosomes separated by ultrafiltration and sucrose gradient centrifugation. The function of IL-12-anchored exosomes was determined by IFN-gamma release assay.

RESULTSMammalian co-expression plasmids were successfully constructed. Confocal laser scanning microscopy and flow cytometric analysis of the RC-2-GPI-IL-12 transfectants showed the expression of IL-12 on the cell surface. Exosomes were purified by ultrafiltration and sucrose gradient centrifugation, which were 30-80 nm in diameter, typically saucer-shaped, and expressing HSP70, ICAM-1, G250 and GPI-IL-12. (80.0 +/- 9.6) pg/ml of IL-12 was detected in 10 microg/ml exosomes and it significantly induced the release of IFN-gamma. Stimulation with EXO-IL-12 could efficiently induce antigen-specific cytotoxic T lymphocytes (CTL), resulting in more significant cytotoxic effects in vitro.

CONCLUSIONA vaccine of exosomes-GPI-IL-12 can be obtained from the culture supernatant of renal cancer cells modified to express anchored IL-12. This vaccine expressing IL-12 and tumor associated antigen G250 may become a new strategy for the treatment of renal cancer.

Antigens, Neoplasm ; metabolism ; Cancer Vaccines ; immunology ; Carbonic Anhydrase IX ; Carbonic Anhydrases ; metabolism ; Cell Line, Tumor ; Cytotoxicity, Immunologic ; Exosomes ; genetics ; metabolism ; Glycosylphosphatidylinositols ; genetics ; metabolism ; HSP70 Heat-Shock Proteins ; metabolism ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Interferon-gamma ; secretion ; Interleukin-12 ; genetics ; metabolism ; Kidney Neoplasms ; metabolism ; pathology ; Plasmids ; T-Lymphocytes, Cytotoxic ; cytology ; immunology ; Transfection

Trypanosoma brucei, a protozoan parasite, causes sleeping sickness in humans and Nagana disease in domestic animals in central Africa. The trypanosome surface is extensively covered by glycosylphosphatidylinositol (GPI)-anchored proteins known as variant surface glycoproteins and procyclins. GPI anchoring is suggested to be important for trypanosome survival and establishment of infection. Trypanosomes are not only pathogenically important, but also constitute a useful model for elucidating the GPI biosynthesis pathway. This review focuses on the trypanosome GPI biosynthesis pathway. Studies on GPI that will be described indicate the potential for the design of drugs that specifically inhibit trypanosome GPI biosynthesis.
Animals ; Biosynthetic Pathways ; Glycosylphosphatidylinositols/*biosynthesis/chemistry ; Humans ; Protozoan Proteins/genetics/metabolism ; Trypanosoma brucei brucei/chemistry/genetics/*metabolism ; Trypanosomiasis, African/*parasitology

Trypanosoma brucei, a protozoan parasite, causes sleeping sickness in humans and Nagana disease in domestic animals in central Africa. The trypanosome surface is extensively covered by glycosylphosphatidylinositol (GPI)-anchored proteins known as variant surface glycoproteins and procyclins. GPI anchoring is suggested to be important for trypanosome survival and establishment of infection. Trypanosomes are not only pathogenically important, but also constitute a useful model for elucidating the GPI biosynthesis pathway. This review focuses on the trypanosome GPI biosynthesis pathway. Studies on GPI that will be described indicate the potential for the design of drugs that specifically inhibit trypanosome GPI biosynthesis.
Animals ; Biosynthetic Pathways ; Glycosylphosphatidylinositols/*biosynthesis/chemistry ; Humans ; Protozoan Proteins/genetics/metabolism ; Trypanosoma brucei brucei/chemistry/genetics/*metabolism ; Trypanosomiasis, African/*parasitology

Cell adhesive molecular P-selectin was cloned, expressed and anchored on CHO cell membrane through GPI for selection specific antibodies. Total human platelet RNA was extracted and the functional segment of P-selectin gene was cloned by RT-PCR. The P-selectin functional segment gene was cloned into a eukaryotic expression vector pMCEw2-GPI containing an attenuated neo gene together with a downstream GPI, which was synthesized by overlapping PCR. The recombinant plasmid pMCEw2-GPI-P-selectin was then transfected to CHO(dhfr-) cells and screened with G418. ELISA, western-blot and immunofluorescence were carried out to detect the stability of P-selection expression on cell membrane. These results provided a necessary basis for the following study of selection the antibodies targeting P-selectin.
Animals ; Antibodies ; metabolism ; CHO Cells ; Cell Membrane ; metabolism ; Cloning, Molecular ; Cricetinae ; Cricetulus ; Epidermal Growth Factor ; metabolism ; Glycosylphosphatidylinositols ; metabolism ; Lectins ; metabolism ; P-Selectin ; biosynthesis ; genetics ; immunology ; RNA ; metabolism ; Transfection

OBJECTIVETo study the antitumor effect GPI-CD80 fusion protein and its mechanisms.

METHODSA tumor vaccine was prepared by culturing HepG2 cells in the presence of purified GPI-CD80 followed by inactivation with mitomycin, with mitomycin-inactivated HepG2 cells as the control group. The two preparations were co-cultured with nude mouse splenic lymphocytes, and the changes of lymphocyte proliferation and the production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were detected by MTT assay. The cytotoxic T-lymphocyte (CTL) activity was evaluated by LDH-release assay, and the changes of gross tumor volume were measured in tumor-bearing nude mice after administration of different vaccines.

RESULTSThe application of GPI-CD80 tumor vaccine resulted in significantly increased optical density, IL-2 and IFN-gamma levels and CTL activity of the nude mouse splenic lymphocytes in comparison with the control groups. The average tumor volume in nude mice treated with GPI-CD80 tumor vaccine was significantly smaller than that in negative control and blank control groups.

CONCLUSIONGPI-CD80 fusion protein may inhibit the tumor growth velocity in nude mice, possibly by promoting lymphocyte proliferation, stimulating the production of the cytokines IL-2 and IFN-gamma, and enhancing of CTL activity.

Animals ; B7-1 Antigen ; biosynthesis ; genetics ; immunology ; isolation & purification ; CHO Cells ; Cancer Vaccines ; biosynthesis ; genetics ; immunology ; isolation & purification ; Cell Proliferation ; Cricetinae ; Cricetulus ; Glycosylphosphatidylinositols ; genetics ; metabolism ; Interferon-gamma ; biosynthesis ; Interleukin-2 ; biosynthesis ; Mice ; Mice, Nude ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; isolation & purification ; Spleen ; cytology ; immunology ; metabolism ; Tumor Burden ; immunology

A glycosylphosphatidylinositol (GPI) anchor is a common but complex C-terminal post-translational modification of extracellular proteins in eukaryotes. Here we investigate the problem of correctly annotating GPI-anchored proteins for the growing number of sequences in public databases. We developed a computational system, called FragAnchor, based on the tandem use of a neural network (NN) and a hidden Markov model (HMM). Firstly, NN selects potential GPI-anchored proteins in a dataset, then HMM parses these potential GPI signals and refines the prediction by qualitative scoring. FragAnchor correctly predicted 91% of all the GPI-anchored proteins annotated in the Swiss-Prot database. In a large-scale analysis of 29 eukaryote proteomes, FragAnchor predicted that the percentage of highly probable GPI-anchored proteins is between 0.21% and 2.01%. The distinctive feature of FragAnchor, compared with other systems, is that it targets only the C-terminus of a protein, making it less sensitive to the background noise found in databases and possible incomplete protein sequences. Moreover, FragAnchor can be used to predict GPI-anchored proteins in all eukaryotes. Finally, by using qualitative scoring, the predictions combine both sensitivity and information content. The predictor is publicly available at [see text].
Amino Acid Sequence ; Computational Biology ; methods ; Databases, Protein ; Eukaryotic Cells ; chemistry ; Glycosylphosphatidylinositols ; chemistry ; isolation & purification ; metabolism ; Humans ; Hydrophobic and Hydrophilic Interactions ; Markov Chains ; Models, Genetic ; Molecular Sequence Data ; Neural Networks (Computer) ; Predictive Value of Tests ; Protein Processing, Post-Translational ; Proteome ; analysis ; Sensitivity and Specificity ; Sequence Analysis, Protein

Biomarkers, Tumor ; CD59 Antigens ; physiology ; Glycosylphosphatidylinositols ; physiology ; Humans ; Membrane Cofactor Protein ; physiology ; Neoplasms ; diagnosis ; therapy