Proteomic alterations of fibroblasts induced by ovarian cancer cells reveal potential cancer targets.

The common spread pattern of ovarian cancer is peritoneal implantation. The growth of the shed ovarian cancer cells in the peritoneal cavity is closely related to the tumor microenvironment. Cancer-associated fibroblasts are vital in the tumor microenvironment. It is not clearly defined that the protein expression alters during the activating process of fibroblasts. This study detected the protein alterations in fibroblasts induced by ovarian cancer cells and explored the potential biological relevance through two-dimensional gel electrophoresis and mass spectrometry. Our data showed that the level of CENPE, BAG2, SOD2, GDI2, CORO1C, CFL1, DSTN, CALD1, PHGDH, PDHA1, AKR1B1, TST and TBCA proteins were significantly up-regulated in the fibroblasts co-cultured with ovarian cancer cells, whereas HSPB1, P4HB and VIM were significantlydown-regulated. However, only BAG2, SOD2 and CORO1C proteins were confirmed to be significantly increased by western blot analysis. The differentially expressed proteins were mainly involved in metabolic processes, cellular component organization, responses to stimulus, multicellular organismal processes, localization, protein depolymerization, cellular senescence and the mitotic pathway. These data demonstrated that fibroblasts had an altered protein expression pattern after being induced by ovarian cancer cells, and participated in multiple cell processes resulting in tumor progression. The differentially expressed proteins should be considered as targets for cancer treatment.

Transition care readiness among patients in a tertiary paediatric department.

INTRODUCTION: A smooth transition of healthcare for young people with chronic illnesses from paediatric to adult healthcare services is important to ensure optimal outcome. At the moment, there are no standard guidelines to assess a patient's readiness to transfer care. METHODS: A cross-sectional study using a self-administered questionnaire, adapted from UNC (University of North Carolina) TRxANSITION self-assessment tool was conducted to evaluate patients' transition care readiness in paediatric haematology and paediatric diabetes clinic. RESULTS: A total of 80 patients (37 thalassaemia and 43 diabetes) with the mean age of 21.2 (SD±4.3) years, were recruited during the 3-month study period. Majority of the patients have basic knowledge regarding their medications, and were able to comply with their follow-up. The mean total score obtained by the respondents on this questionnaire was 15.3 (SD±3.59). Self-management skills and knowledge on disease were the two poorly scored section; with mean score of 3.78 (SD±1.38) and 4.28 (SD±1.20) respectively. Overall, only 21 (26.2%) respondents obtained high score (score above 75th percentile). Seventy-five percent of the respondents admitted that they were not ready for transfer to an adult healthcare service yet at the time of the study. CONCLUSION: We suggest that patients with high score should be prepared for transition to adult facility whereas those with a low score need to be identified to ensure provision of continuous education.

Antimelanogenic effects of luteolin 7-sulfate isolated from Phyllospadix iwatensis Makino.

BACKGROUND: Abnormal deposition of melanin may cause an aesthetic skin problem; therefore, the control of unwanted excessive melanin synthesis is the major goal of cosmetic research. OBJECTIVES: To identify novel tyrosinase (TYR) inhibitors from marine plants and examine their cellular antimelanogenic effects. METHODS: The extracts of 50 marine plants endemic to Korea were screened against human TYR. Active constituents were then isolated from the selected plant extracts that showed potential and their chemical structures elucidated. Furthermore, their antimelanogenic effects were examined using murine melanoma B16/F10 cells and human epidermal melanocytes (HEM). RESULTS: Among the tested extracts, that of Phyllospadix iwatensis Makino exhibited the strongest human TYR inhibitory activity. The active constituents were purified from the butanol fraction of the P. iwatensis extract and identified as hispidulin 7-sulfate and luteolin 7-sulfate. Luteolin 7-sulfate inhibited human TYR more strongly than hispidulin 7-sulfate, luteolin, hispidulin and arbutin. Furthermore, luteolin 7-sulfate showed lower cytotoxicity than luteolin in both B16/F10 cells and HEM. Luteolin 7-sulfate attenuated cellular melanin synthesis more effectively in B16/F10 cells and HEM stimulated by α-melanocyte-stimulating hormone and l-tyrosine than arbutin. CONCLUSIONS: This study demonstrates that luteolin 7-sulfate isolated from P. iwatensis is a human TYR inhibitor with advantageous antimelanogenic properties, and would be useful for development as a therapeutic agent for the control of unwanted skin pigmentation.

HLA-B*59:09, a novel allele identified by sequence-based typing in a cord blood donated by a Korean woman.

The new allele B*59:09 showed two nucleotide differences with B*59:01:01:01 in exon 3.

A carcinoid tumour arising within a tailgut cyst: a diagnostic challenge.

A 49-year-old man was referred with constipation that had lasted for a few months. On colonoscopy, a subepithelial tumour more than 4 cm in size was seen in the rectum. He underwent endoscopic ultrasound and pelvic magnetic resonance imaging. He was preoperatively diagnosed with a rectal duplication cyst based on imaging studies. However, the final histopathologic diagnosis after transanal excision of the rectal mass was rectal carcinoid tumour with tailgut cyst. Tailgut cysts are very rare congenital lesions in the presacral area and are most often discovered incidentally in middle-aged women. It is difficult to distinguish the imaging appearance of tailgut cysts from that of many other retrorectal cysts. Malignant transformation of tailgut cysts has been estimated to occur in 2 to 13% of cases. We report the diagnostic difficulties encountered in a case of carcinoid tumour arising from a tailgut cyst in a male patient.

HLA-A*02:328, a novel allele identified by sequence-based typing in cord blood from a Korean woman.

The novel allele A*02:328 showed one nucleotide difference with A*02:06:01 in exon 3 resulting in an amino acid change at codon 120 from Gly to Arg.

Influence of chimeric human-bovine fibers on adenoviral uptake by liver cells and the antiviral immune response.

Human adenoviruses (HAdV) are widely used for in vitro and in vivo gene transfer. Viral hepatotropism, inflammatory responses and neutralization by pre-existing antibodies (NAbs) are obstacles for clinical applications of HAdV vectors. Although the multifactorial events leading to innate HAdV toxicity are far from being elucidated, there is a consensus that the majority of intravenously injected-HAdV vectors is sequestered by Kuppfer cells, probably independently of coagulation factors. In this study, we show that the adenoviral-associated humoral and innate cytokine immune responses are significantly reduced when HAdV-5 vector carrying human bovine chimeric fibers (HAdV-5-F2/BAdV-4) is intravenously injected into mice. Fiber pseudotyping modified its interaction with blood coagulation factors, as FIX and FX no longer mediate the infection of liver cells by HAdV-5-F2/BAdV-4. As a consequence, at early time points post-infection, several cytokines and chemokines (IFN-gamma, IL-6, IP-10, MCP-1, RANTES and MP1beta) were found to be present at lower levels in the plasma of mice that had been intravenously injected with HAdV-5-F2/BAdV-4 compared with mice injected with the parental vector HAdV-5. Moreover, genetic modification of the fiber allowed HAdV-5-F2/BAdV-4 to partially escape neutralization by NAbs.

Characterization of naturally occurring parainfluenza virus type 2 (hPIV-2) variants.

BACKGROUND: Human parainfluenza viruses (hPIV) are respiratory pathogens responsible for upper and lower respiratory tract infections. In most labs, the clinical diagnosis of hPIV is routinely done using techniques based on the detection of viral antigens such as immunofluorescence assay or/and viral isolation. STUDY DESIGN: Five hPIV-2 isolated from respiratory samples exhibited unusual phenotypic and antigenic characteristics. These isolates showed important syncytial cytopathic effect and failed to react with one specific monoclonal antibody. These variant strains were subsequently compared with hPIV-2 prototype strain by cellular and molecular techniques. RESULTS: Both variant and prototype strains showed similar growth kinetics. Observation of plaque formation and syncytia assay indicated a more important fusogenic activity for the variant strains. Sequencing of fusion (F) and hemagglutinin-neuraminidase (HN) genes showed differences between the "atypical" hPIV-2 isolates and the Greer hPIV-2 prototype strain. These differences were analyzed with molecular modelling and structure prediction soft wares. A potential new glycosylation site in HN, in addition to minor changes observed in the predicted structure for the variant strains could explain their antigenic variation. Genetic changes in the fusion peptide and the cleavage site of F could also explain the difference observed in the fusion activity. CONCLUSIONS: Continuous global viral surveillance is essential to monitor antigenic changes that may occur in nature particularly with regards to the implementation of diagnostic assays. The differences observed in F and HN between the prototype strain and clinical hPIV-2 variants could also provide new data for the analysis of Paramyxovirus fusion mechanisms and their pathogenesis.

Adenovirus 5 vector genetically re-targeted by an Affibody molecule with specificity for tumor antigen HER2/neu.

In order to use adenovirus (Ad) type 5 (Ad5) for cancer gene therapy, Ad needs to be de-targeted from its native receptors and re-targeted to a tumor antigen. A limiting factor for this has been to find a ligand that (i) binds a relevant target, (ii) is able to fold correctly in the reducing environment of the cytoplasm and (iii) when incorporated at an optimal position on the virion results in a virus with a low physical particle to plaque-forming units ratio to diminish the viral load to be administered to a future patient. Here, we present a solution to these problems by producing a genetically re-targeted Ad with a tandem repeat of the HER2/neu reactive Affibody molecule (ZH) in the HI-loop of a Coxsackie B virus and Ad receptor (CAR) binding ablated fiber genetically modified to contain sequences for flexible linkers between the ZH and the knob sequences. ZH is an Affibody molecule specific for the extracellular domain of human epidermal growth factor receptor 2 (HER2/neu) that is overexpressed in inter alia breast and ovarian carcinomas. The virus presented here exhibits near wild-type growth characteristics, infects cells via HER2/neu instead of CAR and represents an important step toward the development of genetically re-targeted adenoviruses with clinical relevance.

Co-targeting of EGF receptor and neuropilin-1 overcomes cetuximab resistance in pancreatic ductal adenocarcinoma with integrin ß1-driven Src-Akt bypass signaling.

Pancreatic ductal adenocarcinoma (PDAC) cells usually overexpress the epidermal growth factor receptor (EGFR); however, most are resistant to the anti-EGFR monoclonal antibody, cetuximab. In this study, we report that the molecular mechanism of resistance to cetuximab in PDAC cells is mediated by the overexpression of active integrin ß1 with downstream Src-Akt activation; this triggers an EGFR ligand-independent proliferation signaling, bypassing EGFR-blocking effect. Knockdown of integrin ß1 or inhibition of Src or Akt sensitized cetuximab-resistant (CtxR) PDAC cells to cetuximab. We found that neuropilin-1 (NRP1) physically interacts with active integrin ß1, but not inactive one, on the cell surface. To inhibit active integrin ß1-driven signaling by targeting NRP1, while suppressing EGFR signaling, we generated an EGFR and NRP1 dual targeting antibody, Ctx-TPP11, by genetic fusion of the NRP1-targeting peptide, TPP11, to the C terminus of the cetuximab heavy chain (Ctx-TPP11). We demonstrate that Ctx-TPP11 efficiently inhibited the growth of CtxR PDAC cells, in vitro and in vivo. The sensitization mechanism involved downregulating active integrin ß1 levels through NRP1-coupled internalization mediated by the TPP11 moiety, leading to the inhibition of active integrin ß1-driven bypass signaling. Our findings identify aberrant active integrin ß1-driven Src-Akt hyperactivation as a primary resistance mechanism to cetuximab in PDAC cells and offer an effective therapeutic strategy to overcome this resistance using an EGFR and NRP1 dual targeting antibody.

Enhancement of adenovirus-mediated gene delivery by use of an oligopeptide with dual binding specificity.

The efficiency of human adenovirus serotype 5 (Ad5) transgene delivery was tested on several human and animal cell lines in vitro, by using a bimodular 35-mer oligopeptide carrying two peptide domains with different ligand specificities. One domain mimicked the fiber knob-binding region of the alpha2 domain of human MHC-1 molecules (MH20), and the other corresponded to the gastrin-releasing peptide (GRP). Two synthetic peptides with different configurations were analyzed in Ad-mediated gene transfer assays using Ad5Luc3 vector carrying the luciferase reporter gene. One peptide (GRP-MH20) had the GRP domain on the N-terminal side of MH20, while the other (MH20-GRP), the C-terminally amidified GRP, was on the C-terminal side of MH20. The GRP-MH20 peptide, but not MH20-GRP, was capable of enhancing luciferase gene delivery to Ad-susceptible cells in a GRP receptor-dependent manner. More importantly, GRP-MH20 could also confer susceptibility to Ad infection to normal or cancer cells that lack fiber receptors for the virus. Our data suggested that GRP receptors could function efficiently as alternative attachment receptors for Ad5, but that Ad5 bound to GRP receptors still depended, at least partially, on the penton base-mediated endocytotic pathway for subsequent cell entry. Gene delivery by a human adenovirus serotype 5 (Ad5) vector was assayed with a bimodular oligopeptide carrying two peptide domains of different binding specificities. One domain was a high-affinity peptide ligand of the Ad5 fiber knob (MH20), and the other corresponded to the gastrin-releasing peptide (GRP). The synthetic peptide GRP-MH20 was found to be capable of enhancing Ad-mediated gene transfer to Ad-susceptible cells in a GRP receptor-dependent manner. More importantly, GRP-MH20 could also confer susceptibility to Ad infection to normal or cancer cells that lack fiber receptors. Our data suggested that GRP receptors could function efficiently as alternative attachment receptors for Ad5, but virus bound to GRP receptors still depended partially on the penton base-mediated pathway for cell entry.

Genetic modification of adenovirus 5 tropism by a novel class of ligands based on a three-helix bundle scaffold derived from staphylococcal protein A.

The use of adenovirus (Ad) as an efficient and versatile vector for in vivo tumor therapy requires the modulation of its cellular tropism. We previously developed a method to genetically alter the tropism of Ad5 fibers by replacing the fiber knob domain by an extrinsic trimerization motif and a new cellular ligand. However, fibers carrying complex ligands such as single-chain antibody fragments did not assemble into functional pentons in vitro in the presence of penton base, and failed to be rescued into infectious virions because of their inability to fold correctly within the cytoplasm of Ad-infected cells. Here we show that the coding sequence for a disulfide bond-independent three-helix bundle scaffold Z, derived from domain B of Staphylococcal protein A and capable of binding to the Fc portion of immunoglobulin (Ig) G1, could be incorporated into modified knobless Ad fiber gene constructs with seven shaft repeats. These fiber gene constructs could be rescued into viable virions that were demonstrated to enter 293 cells engineered for IgG Fc surface expression but not unmodified 293 cells, via a mechanism that could be specifically blocked with soluble Fc target protein. However, the tropism modified viruses showed a slightly impaired cellular entry and a lower infectivity than wildtype (WT) virus. In addition, we generated recombinant fibers containing an IgA binding Affibody ligand, derived from combinatorial specificity-engineering of the Z domain scaffold. Such fiber constructs also showed the expected target specific binding, indicating that the affibody protein class is ideally suited for genetic engineering of Ad tropism.

Combined treatment of radiation and local injections of misonidazole.

The radiosensitizing effect of misonidazole is dose dependent, so theoretically it would be desirable to use as large a dose as possible. However, clinical studies have indicated a maximum tolerable dose restricting the effects of misonidazole in patients. We injected misonidazole directly into tumor tissues in combination with irradiation in an attempt to obtain a sufficiently high concentration in tumors while maintaining a low level in the blood. Concentration of the drug in tumor tissues was confirmed to be high by examination of the resected low-grade chondrosarcoma into which the drug had been locally injected prior to the operation. Blood levels were confirmed to be significantly low. Seventeen patients were treated with local injections of the drug, each with radiotherapy. All patients either had advanced tumors, or were in the terminal stage after repeated radiotherapy and chemotherapy. A relatively high radiation dose per fraction was used. Complete response was obtained in eight patients (47%) and partial response in four (24%). No change was observed in three patients (18%) while two (12%) exhibited progressive disease. In the seven patients with multiple metastatic lesions, the response of the tumors treated with this method were compared to that of the tumors treated by radiation alone in the same patient. The sensitizing effect of the drug was clearly observed in three out of seven patients. No toxicities in the nervous system or in the gastrointestinal system were observed, and no local skin damage by the injections was seen. Local injections of misonidazole were shown to have a significant radiosensitizing effect without any side effects. The combined treatment of radiation and local injections of misonidazole is considered to be a promising new treatment method.

Radiosensitization of two murine fibrosarcomas with 6-thioguanine.

In Vivo murine tumor experiments were carried out to determine whether 6-thioguanine (6-TG) could enhance the cytotoxic effects of radiation on tumors. The combined effects of single and fractionated x-irradiation were evaluated on the transplanted methylcholanthrene induced fibrosarcoma (Meth-A) in BALB/c mice, a moderately radioresponsive tumor and on the radiation induced fibrosarcoma (RIF) in C3H/He mice, a highly radioresistant tumor. The combined treatment of single administration of 6-TG (25 mg/kg) and of x-irradiation (20 Gy) on Meth-A tumors produced more than 90% tumor control, whereas the radiation alone resulted in less than 5% tumor control. The radiosensitizing effect by 6-TG was higher when the drug was administered either 1 to 8 hr prior to or 24 hr after x-irradiation. The dose modification factor of single dose 6-TG (10 mg/kg) is estimated to be 1.47 for Meth-A tumor and 1.25 for RIF tumor. The tumor control rates of fractionated irradiation alone and with concomitant 6-TG in Meth-A tumors were 14% and 59%, respectively. Based on the studies reported here and well documented pharmacokinetics in humans, it is suggested that combined radiation therapy and 6-TG may provide an enhanced therapeutic effect even in tumor varieties where the drug has no apparent anti-tumor activity on non-irradiated cells.

A structure-activity relationship study of benzylic modifications of 4-[1-(1-naphthyl)ethyl]-1H-imidazoles on alpha 1- and alpha 2-adrenergic receptors.

The naphthalene analog of medetomidine (1), 4-[1-(1-naphthyl)ethyl]-1H- imidazole (2), is a highly potent, selective alpha 2-adrenoceptor agonist. We have initiated a structure-activity relationship study of the replacement of the methyl group on the carbon bridge between the naphthalene and imidazole rings of 2 with a hydrogen, hydroxy, methoxy, carbonyl, or trifluoromethyl group and compared their biological activities with medetomidine 1 and the optical isomers of 2. Analogs of 2 were antagonists of alpha 2A-adrenoceptor-mediated human platelet aggregation and agonists on alpha 1- and alpha 2-adrenoceptors in guinea pig ileum. The rank order and potencies of these analogs on platelets (alpha 2A-subtype) and guinea pig ileum (alpha 1-subtype) were nearly the same, whereas racemic and S-(+)-2, desmethyl, and hydroxy analogs were potent agonists on alpha 2-adrenoceptors in guinea pig ileum. With the exception of the desmethyl analog 5, none of the other analogs were as potent as the parent drug 2 on alpha 2A- (human platelets), alpha 1- (guinea pig ileum), or alpha 2- (guinea pig ileum) adrenergic receptor systems. As with analog 2, the desmethyl- and methoxy-substituted analogs retained a greater alpha 2/alpha 1-selectivity in both functional (agonist activity) and biochemical (receptor displacement) studies. Receptor binding studies indicate that S-(+)-2 possessed greater affinity than the R-(-)-isomer on both alpha 1- and alpha 2-adrenoceptors in rat brain. In addition, R-(-)-2 did not show agonist activity in alpha 2-adrenoceptors of guinea pig ileum and was 10-fold more potent than S-(+)-2 as an antagonist of alpha 2A-adrenoceptors in human platelets. Thus, the nature of the substituent and the chirality at the carbon bridge between the naphthalene and imidazole rings play an important role in maintaining potent alpha 2-adrenoceptor activity and high alpha 2/alpha 1-selectivity within the 4-substituted imidazole class.

Synthesis and alpha-adrenergic activities of 2- and 4-substituted imidazoline and imidazole analogues.

Seven analogues of medetomidine and naphazoline were synthesized and evaluated for their alpha 1 (aorta) and alpha 2 (platelet) activities. The analogues were composed of 2- and 4-substituted imidazoles and imidazolines attached through a methylene bridge to either the 1- or 2-naphthalene ring system. In general the 1-naphthalene analogues were the most potent inhibitors of epinephrine-induced platelet aggregation. Of considerable interest was the fact that the 1-naphthalene analogues (2, 5-7) were partial agonists while the 2-naphthalene analogues (3, 8, 9) were antagonists in an alpha 1-adrenergic system (aorta). Thus, appropriately substituted naphthalene analogues of medetomidine and naphthazoline provide a spectrum of alpha 1-agonist, alpha 1-antagonist, and alpha 2-antagonist activity.

Binding of O-alkyl derivatives of serotonin at human 5-HT1D beta receptors.

In humans, 5-HT1D serotonin receptors represent terminal autoreceptors, and there is some evidence that 5-HT1D ligands may be useful in the treatment of migraine. The most widely used 5-HT1D agonist is sumatriptan; however, this agent reportedly displays little selectivity for 5-HT1D versus 5-HT1A receptors. To identify novel serotonergic agents with enhanced 5-HT1D versus 5-HT1A selectivity, we attempted to take advantage of possible differences in the regions of bulk tolerance associated with the 5-position of the 5-HT binding sites for these two populations of receptors. Examination of a series of 5-(alkyloxy)tryptamine derivatives demonstrated that compounds with unbranched alkyl groups of up to eight carbon atoms bind with high affinity at human 5-HT1D beta receptors (Ki < 5 nM) but demonstrate less than 50-fold selectivity relative to 5-HT1A receptors. Alkyl groups longer than eight carbon atoms impart reduced affinity for 5-HT1A receptors whereas groups longer than nine carbon atoms lead to compounds with reduced affinity at 5-HT1D beta receptors. 5-(Nonyloxy)tryptamine (10) represents a compound with optimal 5-HT1D beta affinity (Ki = 1 nM) and selectivity (> 300-fold). Branching of the alkyl chain, to 5-[(7,7-dimethylheptyl)oxy]tryptamine (15), results in an agent with somewhat lower affinity (5-HT1D beta Ki = 2.3 nM) but with greater (i.e, 400-fold) 5-HT1D versus 5-HT1A selectivity. Replacement of the oxygen atom of 10 with a methylene group (i.e., 20), replacement of the O-proximate methylene with a carbonyl group (i.e., ester 26), or cyclization of the aminoethyl moiety to a carbazole (e.g., 34, 36) or beta-carboline (i.e., 37), result in reduced affinity and/or selectivity. None of the compounds examined displayed significant selectivity for 5-HT1D beta versus 5-HT1D alpha sites; nevertheless, compounds 10 (recently shown to have as a 5-HT1D agonist) and 15 represent the most 5-HT1D versus 5-HT1A selective agents reported to date.

Immunoelectron microscopy of carbonic anhydrase isozyme VI in rat submandibular gland: comparison with isozymes I and II.

Carbonic anhydrase (CA) was purified from the saliva of pilocarpine-treated rats by inhibitor-affinity chromatography, and its localization in the rat submandibular gland was studied by the indirect immunoperoxidase technique using a monoclonal antibody (MAb) raised against the enzyme. SDS-polyacrylamide gel electrophoresis of the CA VI gave three bands of 33, 39, and 42 KD. Enzyme digestion experiment showed that the 42 KD molecule was degraded into the 39 KD molecule and the 39 KD molecule into the 33 KD molecule. The cleavage of the 42 KD molecule was independent and that of the 39 KD molecule was dependent on endo-beta-N-acetylglucosaminidase F. The 42 KD molecule was detected in the CA purified from the pilocarpine-treated but not the untreated salivary gland. The MAb recognized all the three components of the enzyme. Immunostaining for CA VI was seen in the cytosol and secretory granules of serous acinar cells and in the duct luminal contents. Staining specific for erythrocyte CA (CA I and CA II) was observed in the cytosol of the epithelial cells of granular, striated, and excretory ducts. Among these duct cells, the agranular varieties in the granular and excretory ducts were essentially devoid of the immunoreactivity.

Immunoelectron microscopy of carbonic anhydrase isozyme VI in human submandibular gland: comparison with isozymes I and II.

Carbonic anhydrase VI (CA VI) was purified from human saliva by inhibitor-affinity chromatography, and its distribution was studied in human submandibular gland by the indirect immunoperoxidase technique with a rabbit polyclonal antibody raised against the isozyme. Polyclonal antibodies to human CA I and CA II purified from erythrocytes were also raised and used for immunostaining. SDS-polyacrylamide gel electrophoresis of the purified isozymes revealed a single protein band (CA VI, 42 KD; CA I and CA II, 30 KD). Antibody raised against CA VI did not crossreact with CA I or CA II either by Western or by dot-blotting. However, antibodies against CA I and CA II showed slight crossreaction with each other's antigen by dot-blotting. In a Western blot of purified submandibular gland CA, antibody to CA VI stained the 42 and 30 KD bands, and antibodies to CA I and CA II stained the 30 KD band. The 42 KD but not the 30 KD molecule was cleaved by endo-beta-N-acetylglucosaminidase F, indicating that the former contains N-linked oligosaccharides. Immunostaining for CA VI was seen in the secretory granules and cytosol of serous acinar cells and in the duct luminal contents. Staining specific for CA II was observed in the cytosol of serous acinar and duct epithelial cells. Antibody to CA I reacted only with the walls of small blood vessels. These results suggest that (a) serous acinar cells secrete 42 KD CA VI which functions in the oral cavity and that (b) serous acinar and duct epithelial cells possess cytosolic CA (30 KD CA VI and CA II) which functions in situ.

Immunoreactive domains and integrin-binding motifs in adenovirus penton base capsomer.

A panel of nine independent mouse monoclonal antibodies (MAbs) against penton base capsomers of subgenus C adenovirus serotypes 2 (Ad2) and 5 (Ad5) were isolated and characterized. Two of them (1D2 and 5A5), raised against Ad5 virion as the immunogen, bound to sodium dodecyl sulfate (SDS)-resistant and subgenus C-specific epitopes that were not present in subgenus B Ad3 penton base. The 1D2 and 5A5 epitopes were mapped to two distinct regions that did not belong to the main variable region carrying the integrin-binding RGD motif at position 340. For the other seven MAbs, raised against recombinant Ad2 penton base protein (9S-pentamers), the epitopes were sensitive to SDS-denaturation, but reacted with native Ad2, Ad5, and Ad3 penton base. The epitopes recognized by the nine MAbs and by polyclonal antipenton base antibodies defined three major immunoreactive regions. One (I) mapped to the N-terminal domain (residues 116-165); the other two regions were almost symmetrically disposed on both sides of the integrin-binding RGD motif at position 340, within residues 248-270 (II), and within residues 368-427 (III) in the C-terminal domain. Region II overlapped the fiber-binding site in penton base (residues 254-260). None of the MAbs showed any detectable virus neutralization effect, but they all slightly augmented the efficiency of Ad-mediated gene transfer. Although none of their epitopes included the RGD-340 tripeptide, substitutions of the arginine residue in the RGD motif abolished the reactivity of six individual and distant epitopes, suggesting a major conformational role for the RGD-containing domain.