Human anisakiasis: Diversity in antibody response profiles to the changing antigens in larval excretions/secretions

Anisakiasis is an infectious parasitic disease contracted by eating third stage larvae of Anisakis simplex (L3) carried by marine fishes. Human anisakiasis was researched for specific IgG with L3 excretory secretory products (ESP). L3ESP were prepared by daily harvesting of culture supernatant from day 2 to day 5, using two kinds culture media of RPMI-1640 and phosphate buffered saline (PBS). When the sera from persons diagnosed with anisakiasis by means of endoscopy were analyzed using indirect ELISA and Western blot, the sera was classified into four groups depending on specific antigen recognition patterns. In addition, the presence of a new antigen for L3, located at less than 13 kDa (AgLT13) was demonstrated in L3ESP with a modified Western blot condition. The production of AgLT13 was mainly found in L3ESP harvested both on day 2 and day 3, and that in PBS was predominant over that in RPMI-1640. Among those sera, the high reactive sera to L3ESP-day two prepared with phosphate buffer in indirect ELISA recognized AgLT13, and 33% of the low reactive sera did so. These results indicate that the binding pattern of human L3 specific antibody is diverse depending on L3ESP preparations and that AgLT13 demonstrated with a Western blot condition is a specific antigen for L3.

Clinical activity of the new triazole drug voriconazole (UK 109, 496) against disseminated hepatosplenic aspergillosis in a patient with relapsed leukemia

There is presently a limited antifungal armamentarium comprising amphotericin and the azoles, fluconazole and itraconazole. In vitro studies have shown efficacy of the new drug, voriconazole, against a wide range of fungi, including most species of Candida and Aspergillus. We review here a case report of a young boy with acute myeloid leukemia who developed disseminated hepatosplenic aspergillosis. He failed therapy with itraconazole, amphotericin B and liposomal amphotericin. As he also had relapsed leukemia, there was a great urgency to control this infection in order to facilitate the administration of cancer chemotherapy. Voriconazole was given with good response resulting in virtual disappearance of all scan evidence of aspergillosis.

Nanoparticle routes to mesoporous titania thin films

Controlled aging of TiO2 nanoparticles blended with diblock copolymers and processed into dip-coated thin films led to ordered mesostructures with cubic and hexagonal symmetries that can be transformed into mesoporous TiO2 by calcination.

Molecular cloning and disruption of a novel gene encoding UDP-glucose: tetrahydrobiopterin alpha-glucosyltransferase in the cyanobacterium Synechococcus sp. PCC 7942

The gene encoding UDP-glucose:tetrahydrobiopterin alpha-glucosyltransferase (BGluT) was cloned from the genomic DNA of Synechococcus sp. PCC 7942. The encoded protein consisting of 359 amino acid residues was verified in vitro and in vivo to be responsible for the synthesis of tetrahydrobiopterin (BH4)-glucoside produced in the organism. The BGluT gene is the first cloned in pteridine glycosyltransferases and also a novel one cloned so far in UDP-glycosyltransferases. The mutant cells disrupted in the BGluT gene produced only aglycosidic BH4 at a level of 8.3% of the BH4-glucoside in wild type cells and exhibited half of the wild type growth in normal photoautotrophic conditions. These results suggest that the glucosylation of BH4 is required for the maintenance of the high cellular concentration of the compound, thereby supporting the normal growth of Synechococcus sp. PCC 7942.

Purification and characterization of UDP-glucose:tetrahydrobiopterin glucosyltransferase from Synechococcus sp. PCC 7942

Tetrahydrobiopterin (BH4)-glucoside was identified from Synechococcus sp. PCC 7942 by HPLC analysis and the enzymatic activity of a glycosyltransferase producing the compound from UDP-glucose and BH4. The novel enzyme, named UDP-glucose:BH4 glucosyltransferase, has been purified 846-fold from the cytosolic fraction of Synechococcus sp. PCC 7942 to apparent homogeneity on SDS-PAGE. The native enzyme exists as a monomer having a molecular mass of 39.2 kDa on SDS-PAGE. The enzyme was active over a broad range of pH from 6.5 to 10.5 but most active at pH 10.0. The enzyme required Mn(2+) for maximal activity. Optimum temperature was 42 degrees C. Apparent K(m) values for BH4 and UDP-glucose were determined as 4.3 microM and 188 microM, respectively, and V(max) values were 16.1 and 15.1 pmol min(-1) mg(-1), respectively. The N-terminal amino acid sequence was Thr-Ala-His-Arg-Phe-Lys-Phe-Val-Ser-Thr-Pro-Val-Gly-, sharing high homology with the predicted N-terminal sequence of an unidentified open reading frame slr1166 determined in the genome of Synechocystis sp. PCC 6803, which is known to produce a pteridine glycoside cyanopterin.

Characterization of recombinant Dictyostelium discoideum sepiapterin reductase expressed in E. coli

A cDNA clone (SSC801) putatively encoding sepiapterin reductase (SR) was obtained from the expressed sequence tag clones of Dictyostelium discoideum. The cDNA sequence of 878 nucleotides constituted an ORF of 265 amino acid residues but was missing a few N-terminal residues. The deduced amino acid sequence showed 29.8% identity with mouse SR sequence and a molecular mass of 29,969 Da. The coding sequence was cloned in E. coli expression vector and overexpressed. The purified His-tag recombinant enzyme was confirmed to have the genuine activity of SR to produce tetrahydrobiopterin from 6-pyruvoyltetrahydropterin in a coupled assay with 6-pyruvoyltetrahydropterin synthase as well as dihydrobiopterin from sepiapterin. However, dictyopterin was not observed in our assay condition. The enzyme was also inhibited by N-acetylserotonin and to a lesser extent by melatonin. Km values for NADPH and sepiapterin were 51.8+/-2.7 microM and 40+/-2 microM, respectively. Vmax was determined as 0.14 micromol/min/mg of protein.

Identification of H-2K(b)-restricted T-cell epitopes within the nucleocapsid protein of Hantaan virus and establishment of cytotoxic T-cell clones

Although neutralizing antibodies against Hantaan virus (HTV) can protect hosts from viral infection, T-cell responses to HTV are also important in host defense against HTV. However, much less is known about cytotoxic T lymphocyte (CTL) responses to HTV. To identify CTL epitopes in the HTV nucleocapsid protein (NP), we selected 7 H-2K(b)-motif-fitting peptides. Of these peptides, 3 peptides (NP3, NP4, and NP7) were recognized by CTL responses derived from HTV-immunized mouse splenocytes. NP3 and NP4 peptides were also recognized by HTV-immunized splenocytes after secondary in vitro stimulation with the relevant peptide, but NP7 could not be recognized after in vitro stimulation. These results agree well with peptide immunization studies showing that peptide-specific CTL responses could be induced with NP3 and NP4 but not with NP7 peptide. Furthermore, CTL activity assay using targets, prepared to express the antigen (NP) endogenously, demonstrated that NP3 and NP4 peptides could be presented endogenously. CTL elicited with NP4 peptide retained some cross-reactivity and was difficult to long-term culture. However, NP3-elicited CTL was very specific for NP3 peptide and was stable enough to be cloned. Among many CTL lines elicited with HTV or HTV NP peptides, 6 NP3-specific CTL clones were established and have been maintained more than 2 years. All 6 CTL clones were characterized to be CD3+, CD4-, CD8+, CD25+, CD62L-, and NK1.1-, and to use TCR Vbeta6. This preferential usage of TCR Vbeta6 indicates that TCR Vbeta6 regions are important for recognition of the HTV NP3 epitope (NP221-228, SVIGFLAL) on H-2K(b) molecule. Our data demonstrate the definition of mouse CTL epitopes in HTV and the generation of HTV-specific mouse CTL clones.

Cell proteins bind to a 67 nucleotide sequence within the 3' noncoding region (NCR) of simian hemorrhagic fever virus (SHFV) negative-strand RNA

The 3'NCR of the SHFV negative-strand RNA [SHFV 3'(-)NCR RNA] is thought to be the initiation site of full-length and possibly also subgenomic positive-strand RNA and so is likely to contain cis-acting signals for viral RNA replication. Cellular and viral proteins may specifically interact with this region to form replication complexes. When in vitro transcribed SHFV 3'(-)NCR RNA was used as a probe in gel mobility shift assays, two RNA-protein complexes were detected with MA104 S100 cytoplasmic extracts. The specificity of thes RNA-protein interactions was demonstrated by competition gel mobility shift assays. Four MA104 protein (103, 86, 55, and 36 kDa) were detected by UV-induced cross-linking assays and three proteins (103, 55, and 36 kDa) were detected by northwestern blotting assays. The binding sites for these proteins were mapped to the region between nucleotides 117 to 184 on the SHFV 3'(-)NCR RNA. Four cellular proteins with identical molecular masses to those of the proteins that bind to the SHFV 3'(-)NCR RNA were detected by the 3'(-)NCR of another arterivirus, LDV-C, suggesting that divergent arteriviruses utilize the same set of conserved cell protein domains.

A 68-nucleotide sequence within the 3' noncoding region of simian hemorrhagic fever virus negative-strand RNA binds to four MA104 cell proteins

The 3' noncoding region (NCR) of the negative-strand RNA [3'(-)NCR RNA] of the arterivirus simian hemorrhagic fever virus (SHFV) is 209 nucleotides (nt) in length. Since this 3' region, designated 3'(-)209, is the site of initiation of full-length positive-strand RNA and is the template for the synthesis of the 5' leader sequence, which is found on both full-length and subgenomic mRNAs, it is likely to contain cis-acting signals for RNA synthesis and to interact with cellular and viral proteins to form replication complexes. Gel mobility shift assays showed that cellular proteins in MA104 S100 cytoplasmic extracts formed two complexes with the SHFV 3'(-)209 RNA, and results from competition gel mobility shift assays demonstrated that these interactions were specific. Four proteins with molecular masses of 103, 86, 55, and 36 kDa were detected in UV-induced cross-linking assays, and three of these proteins (103, 55, and 36 kDa) were also detected by Northwestern blotting assays. Identical gel mobility shift and UV-induced cross-linking patterns were obtained with uninfected and SHFV-infected extracts, indicating that the four proteins detected are cellular, not viral, proteins. The binding sites for the four cellular proteins were mapped to the region between nt 117 and 184 (68-nt sequence) from the 3' end of the SHFV negative-strand RNA. This 68-nt sequence was predicted to form two stem-loops, SL4 and SL5. The 3'(-)NCR RNA of another arterivirus, lactate dehydrogenase-elevating virus C (LDV-C), competed with the SHFV 3'(-)209 RNA in competition gel mobility shift assays. UV-induced cross-linking assays showed that four MA104 cellular proteins with the same molecular masses as those that bind to the SHFV 3'(-)209 RNA also bind to the LDV-C 3'(-)NCR RNA and equine arteritis virus 3'(-)NCR RNA. However, each of these viral RNAs also bound to an additional MA104 protein. The binding sites for the MA104 cellular proteins were shown to be located in similar positions in the LDV-C 3'(-)NCR and SHFV 3'(-)209 RNAs. These data suggest that the binding sites for a set of the cellular proteins are conserved in all arterivirus RNAs and that these cell proteins may be utilized as components of viral replication complexes.