[Complications of implant-supported full-arch immediate prosthesis: a retrospective analysis of 114 cases]

Objective: To evaluate the feasibility of long-term function of implant-supported full-arch immediate prosthesis via assessing the complications and risk factors. Methods: This historical cohort study included patients treated with implant-supported full-arch restoration under immediate loading protocol between April, 2008 to June, 2016 and wearing the immediate prosthesis for more than 6 months. Medical charts were reviewed for patients' general information, implant information, prosthetic information and details of prosthetic complications. COX proportional hazards ratio model was adopted to analyze the potential risk factors for prosthesis fracture. Results: A total of 114 patients with a mean age of (56.7±10.2) years old and 144 prostheses were included. The median wearing time of immediate prosthesis was 17.6 months. Sixty-two (54%) patients experienced prosthetic complication, 30 of them suffered more than once. Artificial teeth fractures were more common in anterior region while resin base fractured more often in the posterior region. The possibility of immediate prosthesis fracture in the first year was high but declined over the following years. COX regression analysis showed that fibre-reinforcement (HR=0.486, P=0.017) and rigid opposing dentition (HR=2.272, P=0.016) were significantly related to the prosthesis fracture. Conclusions: Long-term function of implant-supported full-arch immediate prosthesis renders a high prosthetic complication prevalence, featuring the prosthesis fracture as the most common complication and the first year of highest fracture probability. Fibre-reinforced acrylic immediate prosthesis may function well in cases with a removable denture restored opposing jaw.

Molecular cloning and characterization of full-length cDNAs encoding a novel high-molecular-weight Dermatophagoides pteronyssinus mite allergen, Der p 11

BACKGROUND

Dermatophagoides pteronyssinus (Dp) and D. farinae (Df) mites are the most important source of indoor aeroallergens. Most Dp mite allergens identified to date have relatively low molecular weights (MWs). Identification of high-MW mite allergens is a crucial step in characterizing the complete spectrum of mite allergens and to provide appropriate tools for diagnostic and therapeutic application.

METHODS

The full-length Der p 11 cDNA clone was isolated using cDNA library immunoscreening, the 5'-3' rapid amplification of cDNA ends (RACE) system and polymerase chain reactions (PCR). The whole cDNA insert and its PCR-derived DNA fragments (p1 to p4) were generated and expressed in the Escherichia coli expression system. The allergenicity of the recombinant protein and its peptide fragments was examined by IgE immunodot assays. The IgE-binding reactivity of rDer p 11 was analyzed in the serum of 50 asthmatic children with positive reactivity to Dp mite extract. Its recombinant peptide fragments were also examined by immunodot assays in 30 mite-allergic children.

RESULTS

Der p 11 cDNA consists of a 2625-bp open reading frame encoding a 103-kDa protein with 875 amino acids. It exhibits significant homology with the paramyosin of other invertebrates. The protein sequence alignment of this newly identified Dp mite allergen (denominated as Der p 11) revealed over 89% identity with Der f 11 and Blo t 1. Among 50 Dp-sensitive asthmatic children, rDer p 11 showed positive IgE-binding reactivity to 39 patients (78%). Using immunodot assays, multiple human IgE-binding activities were demonstrated in all four fragments of Der p 11. Using immunoblot assays, the dominant IgG-binding epitope for monoclonal antibody (mAb642) was located in fragment p3 only. In immunoblot assays, cross-inhibition between rDer p 11 and rDer f 11 was up to 73-80% at concentrations of 100 microg/ml.

CONCLUSIONS

This study confirms that the newly identified recombinant Der p 11 is a novel and important high-MW Dp mite allergen for asthmatic children. Our data also indicates that human IgE-binding major epitopes are scattered over the entire molecule of Der p 11.

Deficient transforming growth factor beta and interleukin-10 responses contribute to the septic death of burned patients

In order to understand the roles of pro-inflammatory and anti-inflammatory cytokines in burn injury and sepsis post-burn, serial changes in serum levels of transforming growth factor beta-1 (TGF-beta-1) were determined and compared to those of IL-6 and IL-10 in 15 burned patients. Among these 15 patients, 8 recovered without sepsis. The other seven, who were septic, expired. Our results showed that an initial peak serum TGF-beta-1 response was detected within 1 day post-burn. Peak serum IL-6 and IL-10 responses were also detected within 4 days after the burn injury of these patients. Significant differences in peak serum IL-6, IL-10 and TGF-beta-1 levels were not found between patients with total body surface area (TBSA) of greater or less than 50% and between patients who survived or expired from burn injury. Afterwards, levels of circulating IL-6 and IL-10 remained low in the survivors. However, a second peak response in serum TGF-beta-1 levels was observed in all burned patients analyzed. The second peak serum TGF-beta-1 levels post-burn of the eight survivors and the seven non-survivors were from 28,542 to 76,554 pg/ml (a mean value of 51,256+/-14,264 pg/ml) and from 8616 to 40,851 pg/ml (a mean value of 24,079+/-10,399 pg/ml), respectively. A significant difference (P<0.01) in mean values of the second peak TGF-beta-1 responses between groups of survivors and non-survivors was detected. Levels of circulating IL-6 in the septic non-surviving patients showed a tendency to increase 1-2 weeks post-burn and reached high levels before the expiration of these patients. After an initial peak response, the serum IL-10 level remained low in one of the seven non-survivors, while it increased in the other six non-survivors. However, marked increases in circulating IL-10 levels were observed only just before the death of these non-survivors. In conclusion, an initial increase in serum levels of IL-6, IL-10 and TGF-beta-1 was detected post-burn. A marked increase in serum levels of IL-6 before death suggests its role in the pathophysiology of sepsis in burned patients. In addition, a low secondary TGF-beta-1 response and a lack and/or delay in the increase of circulating IL-10 in the non-survivors may all contribute to the pathophysiology of septic death in burned patients.

Identification of vacuolar serine proteinase as a major allergen of Aspergillus fumigatus by immunoblotting and N-terminal amino acid sequence analysis

Aspergillus species are common airborne fungi that have been identified as causative agents of extrinsic bronchial asthma. More than 10 allergens from A. fumigatus have been recently characterized by cDNA cloning. The objective of this study is to identify A. fumigatus allergens through immunoblot analysis using sera from asthmatic patients. IgE-binding components of A. fumigatus and IgE cross-reactivity among allergens of different prevalent airborne fungal species were analysed by immunoblot and immunoblot inhibition, respectively, using sera from asthmatic patients. The N-terminal amino acid sequences of major allergens identified were determined by Edman degradation. Among two batches (70 and 41 sera) of asthmatic sera tested, 19 (27%) and 14 (34%), respectively, have IgE immunoblot reactivity towards components of A. fumigatus. A 34-kDa protein that reacts with IgE antibodies in 15 (79%) and 11 (79%) of the 19 and 14 positive samples, respectively, may be considered a major allergen of A. fumigatus. The N-terminal amino acid sequences of the 34 kDa major allergen and the 30.5 and 30 kDa IgE-binding components of A. fumigatus showed sequence identity to that of the vacuolar serine proteinase from A. fumigatus. The results from immunoblot inhibition show IgE cross-reactivity among major allergens of A. fumigatus, P. notatum and P. oxalicum. Results obtained suggest that the 34 kDa major allergen of A. fumigatus may be a vacuolar serine proteinase. There is IgE cross-reactivity among serine proteinase allergens of A. fumigatus, P. notatum and P. oxalicum.

cDNA cloning and immunologic characterization of Pen o 18, the vacuolar serine protease major allergen of Penicillium oxalicum

Penicillium species are prevalent indoor airborne fungi that have been identified as causative agents of human extrinsic bronchial asthma. In the preparation of standardized diagnostic reagents, it is imperative to define the allergens of these ubiquitous fungi. Results from our previous study on P. oxalicum suggest that the 34-kd major immunoglobulin E-reacting component of this prevalent Penicillium species is probably a vacuolar serine protease. The purpose of the present study was to define this major P. oxalicum allergen (Pen o 18) through cDNA cloning and immunologic characterization. The cDNA of Pen o 18 was isolated through a combination of reverse transcriptase-polymerase chain reaction and 5'- and 3'-rapid amplification cDNA ends reactions. The primers used in these reactions were constructed according to the internal amino acid sequences of Pen o 18 and the conserved amino acid sequences of fungal serine proteases. Our results showed that a 1897-bp cDNA with an open reading frame of 503 residues was isolated for the proenzyme of Pen o 18. The encoded protein has a 16-residue signal peptide and a 119-residue prosequence. On maturation, the protein has an N-terminal glutamate that is the 136th residue encoded by the cDNA. Apparently the precursor also undergoes C-terminal processing with the cleavage of about 47 amino acids. The cDNA for Pen c 18 (the vacuolar serine protease allergen from P. citrinum ) was also isolated for comparison. Contrary to a previous report, the C-terminal region of Pen c 18 is similar to that of Pen o 18. Recombinant proteins (rPen o 18 and rPen c 18) with the putative mature N-termini and a his-tag were obtained by expressing the corresponding cDNAs in Escherichia coli. Serum samples from 7 asthmatic patients with immunoglobulin E reactivity to the 34-kd component of P. oxalicum also react to his-tagged recombinant Pen o 18. The presence of immunoglobulin E cross-reactivity between rPen o 18 and rPen c 18 was detected by immunoblot inhibition. Two monoclonal antibodies (PCM39 and FUM20) against fungal serine proteases react with rPen o 18, rPen c 18, and the 35/34-kd components in the corresponding crude fungal extracts. These components also react with immunoglobulin E antibodies in serum samples from asthmatic patients. In conclusion, results obtained confirm that the 34-kd major allergen of P. oxalicum is a vacuolar serine protease. The cDNAs of Pen o 18 and Pen c 18 encode precursor molecules that appear to undergo both N-terminal and C-terminal processing. Constructs beginning with mature N-terminal can be expressed in E. coli to produce recombinant polypeptides that are reactive to monoclonal antibodies or immunoglobulin E antibodies in serum samples from asthmatic patients. Results obtained may provide useful information and materials for preparation of standardized diagnostic reagents in clinical mold allergy.

Production and characterization of monoclonal antibodies to serine proteinase allergens in Penicillium and Aspergillus species

BACKGROUND

Alkaline and/or vacuolar serine proteinases are major allergens in prevalent airborne Penicillium and Aspergillus species.

OBJECTIVE

The object of this study is to generate and characterize monoclonal antibodies against these serine proteinase allergens.

METHODS

BALB/c mice were immunized individually with the Penicillium citrinum culture medium or the crude extract and culture medium preparations of Aspergillus fumigatus. Hybridoma cells that secrete monoclonal antibodies against serine proteinase allergens were selected by immunoblotting. Antigens in three different Penicillium (P. citrinum, P. notatum and P. oxalicum) and two different Aspergillus species (A. fumigatus, and A. flavus) recognized by these monoclonal antibodies were analysed by sodium dodecyl sulphate and two-dimensional polyacrylamide gel electrophoresis immunoblotting and N-terminal amino acid sequence analysis.

RESULTS

Four (PCM8, PCM10, PCM16 and PCM39) and one (FUM20) monoclonal antibodies against serine proteinase allergens were generated after fusion of NS-1 cells with spleen cells obtained from BALB/c mice immunized with antigens from P. citrinum and A. fumigatus, respectively. Immunoblotting results showed that PCM8 reacted with an alkaline serine proteinase allergen in P. citrinum and P. notatum. PCM10 and PCM39 reacted with the alkaline serine proteinase in two Penicillium (P. citrinum, P. notatum) and two Aspergillus species (A. fumigatus, and A. flavus) tested. PCM16 reacted with the alkaline serine proteinase allergen in P. citrinum, A. fumigatus and A. flavus but not with that in P. notatum. MoAb FUM20 reacted with the alkaline serine proteinase allergen in two Aspergillus species (A. fumigatus and A. flavus) but not with that in two different Penicillium species (P. citrinum, P. notatum) tested. Among these five monoclonal antibodies generated, only PCM39 and FUM20 can react with the vacuolar serine proteinase allergen in P. notatum, P. oxalicum and in A. fumigatus. The 35 kDa P. citrinum component that reacted with FUM20 has an N-terminal amino acid sequence of DSPSVEKNAP.

CONCLUSION

Five monoclonal antibodies against different epitopes of the serine proteinase major allergens in prevalent Penicillium and Aspergillus species were generated in the present study. Antibodies obtained may be useful in the characterization and standardization of serine proteinase allergens in crude fungal extracts.

Changes in circulating levels of an anti-inflammatory cytokine interleukin 10 in burned patients

In order to understand the role of an anti-inflammatory cytokine interleukin 10 (IL-10) in the pathophysiology of burn injury, IL-10 levels in serial serum samples of 22 burned patients were analyzed. The total body surface areas (TBSA) of the burn injury ranged from 30 to 90%. Among these 22 patients, 14 recovered and the other eight, who were septic, expired. A significant difference in serum IL-10 values on admission (5-20 h postburn) was found (P<0.05) between patients who survived or died from burn injury as analyzed by the Student's t test. In addition, a significant difference in serum IL-10 on admission was also found (P<0.05) between patients with TBSA of greater or less than 50%. An initial peak serum IL-10 response was detected within 2.5 days postburn. Significant differences in the peak serum IL-10 levels were not found between patients with TBSA of greater or less than 50% and patients who survived or expired from burn injury. Afterwards, serum IL-10 remained low in the survivors, while an increase in serum IL-10 could be detected in the non-survivors with proven sepsis. Levels of circulating IL-6 in these non-surviving patients showed a tendency to increase starting from about 1-2 weeks postburn which coincided temporally with the detection of infections. However, marked increases in circulating IL-10 levels were observed just before death in four of the eight non-survivors. The serum samples of these four patients were collected at 31 h (404.8 pg/ml), 2 h (773.9 pg/ml), 5 days (150.7 pg/ml) and 12 h (177.1 pg/ml) before the expiration of these patients, respectively. IL-10 levels of 28.6, 27. 5 and 13.5 pg/ml were detected in sera of three of the remaining four non-survivors that were collected at 2.5 h, 36 h and 30 h before the expiration of these patients, respectively. There was one non-surviving patient who suffered an 80% burn (patient D4 in Table 1 and Fig. 4) and his IL-10 level at 20 days postburn was 13.4 pg/ml. The serum sample of this patient was collected 22 days before death and he was not suffering from sepsis at this stage. In conclusion, an initial increase in serum levels of IL-10 was detected postburn. A marked increase in serum levels of IL-10 was detected in four of the eight septic patients just before their death. It was considered that a lack and/or a delay in the increase of circulating IL-10 may play a significant role in the pathophysiology of sepsis in burned patients.

Respiratory fungal allergy

Fungal allergy including allergic rhinitis, conjunctivitis, bronchial asthma, and allergic bronchopulmonary mycoses results from exposure to spores. In this review we have dealt with the common allergenic fungi and allergens, immunopathogenesis, diagnostic assays, and the possible control of allergy in the future based on epitope-specific immunotherapy and vaccination.

Cross-reactivity of T-cell responses to Dermatophagoides pteronyssinus and D. farinae. Studies with group 1 and 7 allergens

BACKGROUND

Comparative information on T-cell responses to allergens from different Dermatophagoides species is limited even though differences in the epitypic recognition have been described.

OBJECTIVE

To compare the level of T-cell proliferation and cytokine production to allergens from the mite species, D. pteronyssinus and D. farinae.

METHODS

Freshly isolated peripheral blood mononuclear cells (PBMC) from house dust mite (HDM)-allergic and HDM-nonallergic donors were stimulated with the group 1 and group 7 allergens of D. pteronyssinus and D. farinae and the level of proliferation as well as IL-5 and IFNgamma production were measured.

RESULTS

The proliferative response and the level of IL-5 produced after in vitro challenge with group 1 and group 7 allergens were equivalent for the allergens from both mite species even though D. farinae is not detected in the environment where the study population live. As expected the level of IL-5 production to the individual allergens was higher for the allergic donor group than for the nonallergic donors, however, there was no difference in the level of T-cell proliferation between the different donor groups.

CONCLUSION

The proliferative and cytokine response to the group 1 and group 7 allergens for D. pteronyssinus and D. farinae indicates that there is a large degree of T-cell cross-reactivity between the whole purified allergens from each species. This is despite previous reports demonstrating different responses to synthetic peptides representing Der p 1 and Der f 1 in a similar study population.

Complementary DNA cloning and immunologic characterization of a new Penicillium citrinum allergen (Pen c 3)

BACKGROUND

Penicillium citrinum has been identified as the most prevalent airborne Penicillium species in the Taipei area. It is important to understand the allergenic composition of this ubiquitous fungal species.

OBJECTIVE

The complementary DNA (cDNA) clone of an allergen from P citrinum was isolated and expressed in Escherichia coli as a fusion protein. mAbs were prepared with the recombinant protein as antigen. The corresponding natural allergen in the fungal extracts was identified with the mAbs.

METHODS

A Uni-Zap XR P citrinum cDNA library was screened with sera from asthmatic patients. An IgE-binding cDNA clone was isolated and expressed as a glutathione-S-transferase fusion protein. The frequency of IgE binding to the expressed protein was analyzed by immunoblotting. Spleen cells from BALB/c mice immunized with the recombinant protein were fused with NS-1 cells for mAb generation.

RESULTS

A P citrinum cDNA library was screened with a mixture of serum samples from 4 asthmatic patients. An IgE-binding cDNA clone was obtained and designated as PCE2. PCE2 has a 694-bp insert that contains a 167 amino acids open reading frame. The deduced amino acid sequence of the encoded protein has 82.6% (138 amino acids) identity with an Aspergillus fumigatus peroxisomal membrane protein allergen (Asp f 3). PCE2 was expressed in E coli as a fusion protein and designated as Pen c 3. Sera from 13 (46%) of the 28 Penicillium-sensitized asthmatic patients demonstrated IgE binding to Pen c 3. In addition, 11 of the 13 Pen c 3-positive serum samples have IgE immunoblot reactivity to recombinant Asp f 3. The presence of IgE cross-reactivity between Pen c 3 and Asp f 3 was also detected by immunoblot inhibition. Four of the 6 mAbs generated against Pen c 3 cross-react with Asp f 3. The presence of the corresponding 18-k natural allergens in the crude extracts of P citrinum and A fumigatus were detected by immunoblot with use of the mAbs and sera from asthmatic patients.

CONCLUSION

Results obtained suggest that the peroxisomal membrane protein (Pen c 3) is an important allergen of P citrinum. PCE2 is a full-length cDNA clone encoding this allergen. In addition, the mAbs generated may be useful in standardizing the diagnostic allergenic extracts.

Purification of group 2 Dermatophagoides pteronyssinus allergen and prevalence of its specific IgE in asthmatics

Group 2 allergens are a major cause of sensitization in patients allergic to house dust mites. This study was performed to determine the prevalence of hypersensitivity to group 2 allergens (Der p 2) of Dermatophagoides pteronyssinus (Dp) in asthmatic patients in Taiwan. To facilitate the analysis of Der p 2-specific IgE, we raised a panel of monoclonal antibodies (MoAbs) to Der p 2 antigens. Purified Der p 2 was obtained after MoAb affinity column purification. There were 82 asthmatic patients (41 adults and 41 children) with hypersensitivity to Dp who were analyzed for hypersensitivity to Der p 2. All of them were both skin test- and serology test-reactive to Dp. Using purified Der p 2, 87.8% (72/82) of patients had a skin-test-positive reaction. Six adults (6/41) and 4 children (4/41) had negative skin tests for Der p 2. Ten families (both parents and children were asthmatics) of the 82 patients were selected for Der p 2 skin testing and Der p 2-specific IgE determination using immunoblot analysis. Results showed that 90% (18/20) of patients' skin reactions to Der p 2 and serum contained specific IgE to Der p 2. Because 87.8% (85.4% of adults and 90.2% of children) of the asthmatic patients with Dp hypersensitivity were allergic to Der p 2, its role in the pathogenesis of asthma in Taiwan appears to be important. Purified Der p 2 allergens can be further used for allergen skin testing and immunotherapy.

Alkaline serine proteinase is a major allergen of Aspergillus flavus, a prevalent airborne Aspergillus species in the Taipei area

BACKGROUND

Aspergillus species are prevalent indoor airborne fungi and have been identified to be a causative agent of human allergic disorders. In the present study, we identified, purified and characterized the allergen(s) from Aspergillus flavus, a predominant airborne Aspergillus species in the Taipei area.

METHODS

The IgE-binding components of A. flavus were identified by SDS-PAGE immunoblotting with sera from asthmatic patients. The N-terminal amino acid sequences of the major allergens were determined by Edman degradation. The allergenic cross-reactivity among allergens from different fungi was analyzed by immunoblot inhibition using sera from asthmatic patients. The detected major allergen was purified from the culture medium. It was further characterized in terms of its N-terminal amino acid sequence, its IgE-binding activity and its enzymatic activity.

RESULTS

The results of the immunoblot analysis indicate that a 34-kD component that has high IgE-binding (63%) frequency is a major allergen of A. flavus. The N-terminus of this 34-kD major allergen (GLTTQKSAP) has high sequence identity with that of the 34-kD alkaline serine proteinase major allergen of A. oryzae. Results from immunoblot inhibition studies indicate that IgE cross-reactivity occurs among the 34-kD major allergens of A. flavus, A. fumigatus and Penicillium citrinum. The 34-kD major allergen of A. flavus was purified from the culture medium by ammonium sulfate precipitation and DEAE ion exchange chromatography. The N-terminal amino acid sequence of the purified allergen (Asp fl 13) is identical to that determined previously for the 34-kD major allergen in the crude extract of A. flavus. The IgE immunoblot reactivity to the 34-kD major allergen in the crude extract can be dose-dependently inhibited by the purified Asp fl 13. The degree of IgE binding to the 34-kD major allergen in the crude extract correlates with that of the purified Asp fl 13 in sera of 8 asthmatic patients. The purified Asp fl 13 has proteolytic activity with casein as substrate at pH 8.0. This enzymatic activity can be inhibited by either phenylmethylsulfonyl fluoride or diethylpyrocarbonate.

CONCLUSION

Our results suggest that the 34-kD alkaline serine proteinase is a major allergen of A. flavus. There was IgE cross-reactivity among allergens of A. flavus, A. fumigatus and P. citrinum.

The importance of serine proteinases as aeroallergens associated with asthma

Penicillium and Aspergillus species have been identified as prevalent indoor airborne fungi that are associated with extrinsic bronchial asthma. We have recently analyzed the IgE-binding components in 8 prevalent Penicillium and Aspergillus species (P. citrinum, P. notatum, P. oxalicum, P. brevicompactum, A. fumigatus, A. flavus, A. oryzae and A. niger) by immunoblotting and N-terminal amino acid sequence analysis. Our results show that the alkaline and/or vacuolar serine proteinases are the major allergens in these prevalent fungal species. IgE cross-reactivity among these major allergens was also detected. Results obtained provide an important basis for clinical allergy. In addition, monoclonal antibodies against alkaline and/or vacuolar serine proteinase allergens have been generated. These antibodies can be applied for the standardization of allergenic extracts.

Identification and expression of Pen c 2, a novel allergen from Penicillium citrinum

The mould genus, Penicillium, is known to be a significant source of environmental aero-allergens. One important allergen from Penicillium citrinum, Pen c 2, has been identified by means of two-dimensional immunoblotting using IgE-containing patients' sera. This novel allergen was cloned, sequenced and expressed in Escherichia coli. The cloned cDNA encodes a large 457-amino acid protein precursor containing a 16-amino acid signal peptide, a 120-amino acid propeptide and the 321-amino acid mature protein. Comparison of the Pen c 2 sequence with known protein sequences revealed shared high sequence similarities with two vacuolar serine proteases from Aspergillus niger and Saccharomyces cerevisiae. Asp-46, His-78 and Ser-244 were found to constitute the catalytic triad of the 39-kDa Pen c 2. The DNA coding for Pen c 2 was cloned into vector PQE-30 and expressed in E. coli as a His-tag fusion protein that bound serum IgE from Penicillium-allergic patients on immunoblots. Recombinant Pen c 2 could therefore be used effectively for diagnosis and also potentially for the treatment of mould-derived allergic disorders.

Characterization of allergens from Penicillium oxalicum and P. notatum by immunoblotting and N-terminal amino acid sequence analysis

BACKGROUND

Penicillium species are important causative agents of extrinsic bronchial asthma. However, little is known about the allergens of these ubiquitous fungal species. Objective The object was to analyse the composition, the allergenic cross-reactivity and the N-terminal sequences of allergens from two prevalent airborne Penicillium species, P. oxalicum and P. notatum.

METHODS

The allergenic composition and the immunoglobulin (Ig)E cross-reactivity were analysed by immunoblot and immunoblot inhibition, respectively, using sera from asthmatic patients. The N-terminal amino acid sequences of major allergens were determined by Edman degradation. Allergens identified were also characterized by immunoblotting using monoclonal antibody (MoAb) PCM39 against the alkaline serine proteinase major allergen of P. citrinum.

RESULTS

Among the 70 asthmatic sera tested, 18 (26%) and 17 (24%) had IgE immunoblot reactivity towards components of P. oxalicum and P. notatum, respectively. Major allergens (> 80% frequency of IgE-binding) from both species are the 34 and 30 kDa proteins of P. oxalicum and the 34 and 32 kDa proteins of P. notatum. IgE cross-reactivity among these major allergens and the 33 kDa major allergen of P. citrinum can be detected by immunoblot inhibition studies. The N-terminal amino acid sequences of the 34 kDa allergen of P. oxalicum and of the 32 and the 28 kDa allergens of P. notatum share homology with sequences of the vacuolar serine proteinase from Aspergillus fumigatus. The N-terminal amino acid sequence of the 34 kDa allergen of P. notatum shows sequence homology with that of alkaline serine proteinase from P. citrinum. Results obtained from immunoblotting showed that MoAb PCM39 reacted with the 34, 30 and 16 kDa IgE-binding components of P. oxalicum, and with the 34, 32 and 28 kDa IgE-binding components of P. notatum.

CONCLUSIONS

Results obtained suggest that the 34 kDa major allergen of P. oxalicum may be a vacuolar serine proteinase. The 34 and the 32 kDa major allergens of P. notatum may be the alkaline and the vacuolar serine proteinases of P. notatum, respectively. The 30 and 16 kDa IgE-binding components of P. oxalicum and the 28 kDa IgE-binding component of P. notatum may be breakdown products of the 34 and the 32 kDa major vacuolar serine proteinase allergens of P. oxalicum and P. notatum, respectively.

Pen c 1, a novel enzymic allergen protein from Penicillium citrinum. Purification, characterization, cloning and expression

A 33-kDa alkaline serine protease secreted by Penicillium citrinum strain 52-5 is shown to be an allergenic agent in this fungus. The protein, designated Pen c 1, was purified by sequential DEAE-Sepharose and carboxymethyl (CM)-Sepharose chromatographies. Pen c 1 has a molecular mass of 33 kDa and a pI of 7.1. The caseinolytic enzyme activity of this protein was studied. The protein binds to serum IgE from patients allergic to Penicillium citrinum. The cDNA encoding Pen c 1 is 1420 bp in length and contains an open reading frame for a 397-amino-acid polypeptide. Pen c 1 codes for a larger precursor containing a signal peptide, a propeptide and the 33-kDa mature protein. Sequence comparison revealed that Pen c 1 possesses several features in common with the alkaline serine proteases of the subtilisin family. The essential Asp, His, and Ser residues that make up the catalytic triad of serine proteases are well conserved. Northern blots demonstrated that mRNAs transcribed from this gene are present at early stages of culture. The allergen encoded by Pen c 1 gene was expressed in Escherichia coli as a fusion protein bearing an N-terminal histidine-affinity tag. The protein, purified by affinity chromatography with a yield of 130 mg of pure protein per liter of culture, was able to bind to both a monoclonal anti-Pen c 1 antibody and IgE from the serum of patients allergic to Penicillium. Recombinant Pen c 1 can therefore be expressed in E. coli in large quantities and should prove useful as a standardized specific allergen for immuno-diagnosis of atopic disorders. In addition, full caseinolytic enzyme activity could be generated in the purified recombinant protein by sulfonation and renaturation, followed by removal of the affinity tag, indicating that the refolded protein can assume the same conformation as the native protein.

Changes in circulating levels of interleukin 6 in burned patients

Interleukin 6 (IL-6) levels in serial serum samples of 10 burned patients were analyzed. The total body surface areas (TBSA) of the burn injury varied from 30 to 85%. Among these 10 patients, five recovered and the other five, who were septic, expired. A significant difference in serum IL-6 values on admission (5-13 h postburn) was found (p < 0.05) between patients who survived or died from burn injury as analyzed by the Wilcoxon's rank sum test. In addition, a significant difference in serum IL-6 on admission was also found (p < 0.05) between patients with TBSA of greater or less than 50%. Afterwards, an initial peak serum IL-6 response was detected within 4 days postburn. Significant differences in the peak serum IL-6 levels were not found between patients with TBSA of greater or less than 50% and patients who survived or expired from burn injury. In the survivors, serum IL-6 remained low, while IL-6 increased markedly starting at about one to two weeks postburn in four of the five nonsurvivors with proven sepsis. Except for the patient who expired 42 days postburn, the maximum serum IL-6 values of the other four nonsurvivors were all greater than those of the five survivors from burn injury. Significant correlation (p < 0.05) relating the change in serum IL-6 and body temperature was observed in only two (one survivor and one nonsurvivor) of the ten patients. Changes in serum IL-6 were also compared with changes in circulating TNF-alpha and IL-8 determined previously. A similar pattern in the dynamic changes of circulating TNF-alpha, IL-8 and IL-6 was observed in the individual burned patient. An increase in serum levels of all three cytokines was detected postburn. Serum levels of three cytokines were significantly higher in the septic patients, who all died. It was considered that all three cytokines analyzed may play a significant role in the pathophysiology of sepsis in burned patients.

Denaturation of ovalbumin abrogates oral induction of airway hyperreactivity and IgG1, IgG2 antibody responses in guinea pigs

BACKGROUND

The effects of denaturation of ovalbumin (OVA) on the induction of oral sensitization in guinea pigs were examined.

METHODS

Guinea pig antibody and airway responses were assessed after 10 feedings of chemically or heat-denatured OVA or egg white (EW).

RESULTS

Their specific IgG, IgG1 and IgG2 antibody responses were orally sensitized by OVA or EW, but not by chemically or heat-denatured OVA or EW. When further exposed to 0.1% OVA or conalbumin aerosol, those fed OVA or EW, but not denatured OVA or EW, had increased pulmonary resistance and decreased tidal volume. On the other hand, in those fed denatured OVA, boiled EW or saline only, a second sensitization with 1% OVA aerosol generated antibody responses and airway hyperreactivity. Using a sandwich ELISA, guinea pig serum OVA was detected after feeding EW, but not chemically denatured or boiled EW.

CONCLUSIONS

It is likely that guinea pig gut absorption of OVA may result in oral sensitization. Chemical or heat denaturation of proteins may minimize their intestinal uptake and thus abrogates the induction of oral sensitization in guinea pigs.

Heat denaturation of egg-white proteins abrogates the induction of oral tolerance of specific Th2 immune responses in mice

Human foods are usually prepared by cooking. Boiling of chicken egg-white (EW) led to decreased allergenicity, and abrogated intestinal uptake of immunoreactive ovalbumin (OVA) when fed to mice. Therefore, the effects of oral administration of boiled EW were examined further in BALB/c mice. Specific IgE, IgG1 and IgG antibody responses were suppressed by raw EW, but not by EW boiled for 5 or 60 min, fed prior to sensitization with 10 microg OVA or 1 microg DNP-OVA in alum. Similar results were obtained when mice were sensitized with 10 microg conalbumin, ovomucoid or lysozyme in alum. BALB/c spleen cell proliferation and secretion of Th2 cytokines IL-4 and IL-5 during in vitro stimulation with OVA were also suppressed by feeding raw EW, but not by boiled EW. Although heat denaturation of proteins can minimize allergenicity, the present results suggest that over-cooking of proteins may affect their intestinal antigen processing and thus prevent the induction of oral tolerance.

Characterization of allergens of Penicillium and Aspergillus species

Penicillium and Aspergillus species are common indoor airborne fungi and have been identified to be important causative agents of extrinsic bronchial asthma. However, little was known about allergens of these ubiquitous fungal species. Results from a survey conducted by us showed that P. citrinum was the most prevalent Penicillium species in the Taipei area. Characterization of allergens by SDS-PAGE-immunoblotting using sera from asthmatic patients showed that there was an IgE cross-reactivity among the 33 KDa group major allergens of P. citrinum, P. notatum and P. brevicompactum. Results obtained from N-terminal amino acid sequence analysis suggest that the 33 KDa major allergens of P. citrinum and P. brevicompactum may be the alkaline serine proteinase of individual Penicillium species. In addition, our results suggest that the 34 KDa major allergen of A. oryzae is also an alkaline serine proteinase. IgE cross-reactivity between the major serine proteinase allergens of A. oryzae and P. citrinum has also been detected. Furthermore, results from cDNA cloning suggest that the 68 KDa allergen of P. notatum is a beta-N-acetyl-glucosaminidase. Lastly, a heat shock protein in the hsp70 family has also been identified as an allergen of P. citrinum. Results obtained in these studies will provide important basis for clinical diagnosis and treatment of mould allergy.

Isolation and characterization of a novel 98-kd Dermatophagoides farinae mite allergen

BACKGROUND

Exposure to allergens from house dust mites is a significant cause of immediate hypersensitivity. Thus far, the active mite allergens defined are low molecular weight (MW) proteins or glycoproteins. However, other important mite allergens remain to be investigated. In this study a high MW mite antigen with a high IgE-binding activity was characterized.

METHODS

An anti-Dermatophagoides farinae (Df) monoclonal antibody, mAb642, which recognized a 98-kd allergenic mite protein, was used for affinity chromatography. The purified Df642 was characterized biochemically and immunologically.

RESULTS

Competitive ELISA demonstrated that mAb642 was inhibited by the interaction between serum IgE from allergic patients and Df642 antigen in a dose-dependent fashion. The IgE reactivity to both 98-kd and 92-kd components was removed or diminished by preincubation of asthmatic sera with Df642-coated CNBr-activated cellulose-4B gel. Two-dimensional immunoblot analysis revealed that there are at least 4 isoforms of Df642 that represent a minor component in the crude mite extract. The allergenicity of Df642 was assayed by IgE immunoassay with a large panel of 67 sera from asthmatic patients with positive skin reactions, and Df 642 showed positive IgE reactivity with more than 80% of the sera tested. Thus it should be classified as an important allergen. In addition, amino acid sequence analysis revealed that Df642 shares more than 50% homology with paramyosin from invertebrates.

CONCLUSION

We have identified and characterized a 98-kd house dust mite allergen that showed greater than 80% IgE reactivity with sera from patients allergic to mites. This is the first high MW allergen characterized to date, and it shares high sequence homology with paramyosins in invertebrates.

Immunoblot analysis of components of barley recognized by IgE antibodies in sera from pig farm workers

Components of the crude extract of barley, recognized by IgE antibodies in sera from 132 pig farm-workers in southern Taiwan, were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Among the sera tested, 43 (32.6%) showed IgE reactivity to 15 components of barley with molecular mass ranging from 148000 to 14000 daltons (Da). Heterogeneity in the IgE-binding patterns of the samples tested was observed. However, the major antigen appears to be the component with about 37 kDa, in 32 (74.4%) of the 43 immunoblot-positive serum samples. Furthermore, components with about 55 and 67 kDa which reacted with 26 (60.5%) and 18 (41.9%) of the positive samples, respectively. These might also be considered as important allergens of the flour made from entire seeds of barley. The results suggest that barley may be considered to play a role in the IgE-mediated occupational respiratory disorders and the 37 kDa component has also been shown to be the major allergen.

Alkaline serine proteinase: a major allergen of Aspergillus oryzae and its cross-reactivity with Penicillium citrinum

BACKGROUND

Aspergillus species are common indoor airborne fungi and have been considered as causative agents of human allergic disorders. However, allergens of different Aspergillus species have not been effectively characterized. The object of this study was to identify and characterize IgE-binding components of Aspergillus oryzae.

METHODS

Allergens of A. oryzae were identified by immunoblot analysis using sera from asthmatic patients. The N-terminal amino acid sequences of allergens thus identified were determined by Edman degradation. The antigenic and the allergenic cross-reactivities between allergens of different fungi were analyzed by immunoblotting and immunoblot inhibition analysis, respectively, using a monoclonal antibody (MoAb) 55A against the 33-kD major allergen of Penicillium citrinum and a mixture of IgE-containing asthmatic serum samples.

RESULTS

Thirteen components of A. oryzae ranging in apparent molecular weight from 16 to 42 kD react with IgE antibodies. A 34-kD component that showed intense IgE-binding reactivity and was detectable in the highest frequency in our asthmatic serum samples tested was considered a major allergen of A. oryzae. The 34-kD component also reacted with MoAb 55A. Results from immunoblot inhibition studies also demonstrated the IgE cross-reactivity between the 34-kD major allergens of A. oryzae and P. citrinum. In addition, the sequence of the N-terminal 18 amino acid residues of the 34-kD major allergen of A. oryzae was found to be identical to that of the alkaline serine proteinase from the same Aspergillus species.

CONCLUSION

The 34-kD major allergen of A. oryzae is an alkaline serine proteinase. There is IgE cross-reactivity between the major serine proteinase allergens of A. oryzae and P. citrinum.

Sensitization to Blomia tropicalis among asthmatic patients in Taiwan

House dust mites have been reported as one of the most important allergens in Taiwan especially in asthmatic patients. This study was conducted to determine the allergenicity of Blomia tropicalis and sensitization of asthmatic patients in Taiwan. Serial dust samples were collected every month between July 1993 and June 1994 from 13 houses of mite-allergic patients. About 1 m2 surface area of a quilt was vacuumed. The floating method was used to collect mites, then identification and counting were performed. Results showed that Dermatophagoides pteronyssinus and B. tropicalis were the two most common species of mites found in allergenic patients' houses in Taipei. D. pteronyssinus accounted for 52.1% of the total number of mites and was found in every house. B. tropicalis, although not present in every sample, accounted for 44.3% of the total number of mites. The skin test positive reaction to B. tropicalis, D. pteronyssinus and Dermatophagoides farinae were 73.3, 88.3 and 85.0% as determined from 60 allergic patients who attended our allergy clinics. The extract prepared from B. tropicalis was used to determine the allergenicity and contained at least 30 protein components when silver stained. The most frequently detected allergens were proteins with molecular weights of 14.3, 106.5, 94.0, 72.0, 91.9, 63.7, 100.3, 43.6, 27.3, 62.0, 34.7, 18.3, 41.1 and 21.9 kD. The frequency of IgE binding of patient sera to those proteins were 87.0, 65.2, 56.5, 43.4, 39.1, 39.1, 34.8, 30.4, 30.4, 17.4, 17.4, 17.4, 13.0 and 8.7%. The results from immunoblot inhibition showed that there was IgE cross-reactivity among the B. tropicalis and D. pteronyssinus. However, there were two major allergenic components of B. tropicalis not inhibited by D. pteronyssinus with molecular weights of about 14.3 and 27.3 kD. The use of B. tropicalis extract for diagnostic purposes to identify patients with specific sensitivity should be considered in Taiwan.

Changes in levels of serum IL-8 in burned patients

Interleukin (i.l.)-8 levels in serial serum samples of 10 burned patients were analysed. The total body surface areas (TBSAs) of the burn injury ranged 30 to 85 per cent. Of these ten patients, five recovered and the other five, who were septic, died. On admission at about 5-13 h postburn, one of the five survivors and two of the non-survivors had serum IL-8 levels higher than 18.1 pg/ml, which is the detection limit of the IL-8 assay kit. The serum IL-8 values of six healthy laboratory personnel included in the present study were all less than 18.1 pg/ml. Afterwards, an initial peak serum IL-8 response was detected within 2-4.5 days postburn. Significant differences in the peak serum IL-8 levels were not found between patients with TBSAs of greater or less than 50 per cent and patients who survived or expired from burn injury. In the survivors, serum IL-8 remained low, whereas IL-8 increased markedly, starting at about one week postburn in four of the five non-survivors with confirmed sepsis. Significant differences in the maximum serum IL-8 levels were detected between patients who recovered vs. those who died from the thermal injury. In conclusion, the results showed that there was an increase in serum IL-8 postburn. Serum IL-8 was significantly higher in the septic patients, who all died. This cytokine may play a significant role in the pathophysiology of sepsis in burned patients.

Biological activity of recombinant Der p 2, Der p 5 and Der p 7 allergens of the house-dust mite Dermatophagoides pteronyssinus

Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positivities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Derp 2 and either Derp 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites.

Characterization of the allergen Der f 7 from house dust mite extracts by species-specific and crossreactive monoclonal antibodies

BACKGROUND

The group 7 mite allergens react with IgE in 50% of sera from allergic patients.

OBJECTIVE

To determine the molecular and antigenic characteristics and heterogeneity of Der f 7 in mite extracts.

METHODS

Monoclonal antibodies (MoAbs) produced from mice immunized with recombinant Der f 7 were examined for crossreactivity to Der p 7 and then used for immunoblotting of 1 and 2-D gel electrophoresis. Deglycosylation was studied with N-glycosidase-F and N-terminal sequencing by Edman degradation. The epitopes of the monoclonal antibodies were compared by cross-inhibitory immunoassays.

RESULTS

Immunoblotting of D. farinae extracts with all the anti Der f 7 MoAbs showed major reactivities at 31, 30 and 25 kDa. The strongest immunostaining was at 25 kDa which contrasted with Der p 7 where the 31 and 30 kDa bands were strongest. The relative strength of staining however varied between extracts. The 31 and 30 kDa components were glycosylation products of the 25 kDa form which had the N-terminal sequence predicted from cDNA analysis. Two MoAbs stained an 18 kDa band consistent with a degradation product. The 2-D gels showed that different components with pIs from 5.6-6.4. Both species-specific and Der p 7 crossreactive MoAbs were produced and a two-site ELISA assay for detecting group 7 allergen was developed with MoAbs recognizing different epitopes.

CONCLUSIONS

Der f 7 has been defined by its natural N-terminal sequence and MoAbs. It apparently exists as different glycosylation and degradation products in mite extracts, the relative abundance of which differs with different preparations. A two-site ELISA to measure the allergen was developed.

Molecular cloning and expression of a Penicillium citrinum allergen with sequence homology and antigenic crossreactivity to a hsp 70 human heat shock protein

BACKGROUND

Penicillium citrinum has been identified as the most prevalent airborne Penicillium species in the Taipei area. However, detailed studies on allergens of this ubiquitous Penicillium species are still lacking.

OBJECTIVE

For the characterization of allergens of this prevalent Penicillium species, molecular cloning and expression of the allergen genes of P. citrinum were performed in the present study.

METHODS

Molecular cloning of the allergen genes was performed by using a lambda Uni-Zap XR cDNA library of P. citrinum and serum from an asthmatic patient. The cloned cDNA was excised from the phage vector as a recombinant pBluescript phagemid and sequenced. The cDNA of the IgE-binding clone was expressed as fusion protein with the glutathione-S-transferase. The corresponding natural allergen was analysed by absorption immunoblotting using monoclonal antibody and serum from asthmatic patient. The frequency of IgE-binding to the allergen cloned was analysed by dot immunoassay using recombinant allergen and by immunoblotting using the whole extract of P. citrinum.

RESULTS

In the screening of cDNA library of P. citrinum using serum from an asthmatic patient, IgE-binding cDNA clones designated SC4 and XL were obtained. The 5'-truncated, 0.7-kb and 1.7-kb cDNA inserts of clones SC4 and XL contained open reading frames of 163 and 503 amino acids, respectively. On alignment, the deduced amino acid sequences showed that 97 (60%) of the 163 amino acids and 376 (75%) of the 503 amino acids were identical to the corresponding amino acid sequence of the human heat shock protein in the hsp70 family. Both recombinant SC4 and XL showed positive SDS-PAGE-immunoblot reactivity to a monoclonal antibody MA3-006 against the human hsp 70 protein. For characterization of the corresponding natural allergen, immunoblotting reactivities of MA3-006 and IgE antibodies to the 70 kDa component of P. citrinum have been shown to be disappeared after absorption of these antibodies with the recombinant SC4 protein. Sera from 14 (41%) of 34 Penicillium-allergic patients showed IgE-binding to the recombinant XL protein and the 70 kDa component in the extract of P. citrinum.

CONCLUSION

Results obtained suggest that hsp 70 is an allergen of P. citrinum and that clones SC4 and XL contain partial cDNAs of this allergen gene.

Changes in serum tumour necrosis factor-alpha in burned patients

Dynamic tumour necrosis factor-alpha (TNF-alpha) changes in serial serum samples of 10 burned patients were analysed in this study. The total body surface areas (TBSA) of the burn injury were from 30 to 85 per cent. Among these 10 patients, five recovered and another five died with proved sepsis. On admission which was about 5-13 h postburn, eight of the 10 patients showed their serum TNF-alpha levels to be higher than the mean serum TNF-alpha value of five healthy laboratory personnel. Furthermore, an initial peak serum TNF-alpha response which could be detected within 2.5 days after burn injury has also been observed. However, significant differences in both the serum TNF-alpha values on admission, as well as the first peak serum TNF-alpha levels, were not found (P > 0.05) between patients with TBSA of greater or less than 50 per cent and patients who survived or died from burn injury. In the survivors, serum TNF-alpha stayed at low levels, while it increased markedly in four of the five non-survivors with proven sepsis starting at about 1 week postburn. A significant difference in the maximum serum TNF-alpha levels (P < 0.05) was detected between patients who recovered and died from the thermal injury. In conclusion, great increases in serum TNF-alpha levels have been detected in burned patients with the occurrence of bacterial infection postburn. It is suggested that strategies for the inhibition of TNF-alpha production or in the neutralization of TNF-alpha activity should also be considered in the better treatment of burned patients.

Characterization of the 33-kilodalton major allergen of Penicillium citrinum by using MoAbs and N-terminal amino acid sequencing

BACKGROUND

The 33 kD component has been identified as a major allergen of Penicillium citrinum, the most prevalent Penicillium species in the Taipei area of Taiwan.

OBJECTIVE

This study analyses the isoforms, antigenic cross-reactivity and the N-terminal amino acid sequence of the 33 kD allergen of P. citrinum.

METHODS

The composition of isoforms and antigenic cross-reactivity was analysed by SDS-PAGE and 2D-immunoblotting using MoAbs generated. The N-terminal sequence was analysed by using an automatic gas/liquid phase sequencer.

RESULTS

Two MoAbs (55A and 34H) against the 33 kD allergen were generated in the present study. In addition to the 33 kD component, MoAb 34H also showed immunoblot reactivity to other components in the crude extract of P. citrinum. Analysed by 2D-immunoblotting, at least six different isoforms of the 33 kD component with pI values ranging from 6.75 to greater than 7.0 were shown to be reactive to both MoAbs and IgE antibodies in serum of an asthmatic patient. Different immunoblot patterns were observed when both MoAbs were reacted with four different strains of P. citrinum used in the present study. Among another six different Penicillium and four different Aspergillus species tested, only an immunoblot reactivity of MoAb 55A to the 33 kD component of P. brevicompactum was observed. In 2D-immunoblotting, components of P. brevicompactum with an MW of about 33 kD and pI values similar to those of the 33 kD component of P. citrinum reacted with MoAb 55A and IgE antibodies in serum of the asthmatic patient. The N-terminal amino acid sequence of the 33 kD component of P. citrinum was determined to be ANVVQSNVP which was identical to the first 9 N-terminal amino acids of a heat-labile alkaline serine proteinase from P. citrinum.

CONCLUSION

Results obtained in the present study suggest that the 33 kD major allergen of P. citrinum may be an alkaline serine proteinase.

Secretory production of bioactive recombinant human granulocyte-macrophage colony-stimulating factor by a baculovirus expression system

The proliferation and differentiation of hematopoietic cells are stimulated by a group of glycoproteins called colony stimulating factors (CSFs). Previously, we found that the human hepatoma cell line HA22T/VGH secreted a high level of human granulocyte-macrophage colony-stimulating factor (hGM-CSF). The cDNA of hGM-CSF, including the signal peptide sequence, was amplified from the total RNA of HA22T/VGH by a reverse-transcription polymerase chain reaction and was cloned into the pUC18 vector. After confirming the nucleotide sequence, the cDNA was inserted into a pVL1393 baculovirus transfer vector. The recombinant baculovirus carrying hGM-CSF cDNA was generated by co-transfecting the hGM-CSF recombinant transfer vector and BaculoGold baculovirus DNA into the Sf9 insect cells. The expected hGM-CSF transcript was detected in the recombinant virus-infected Sf9 cells. The conditioned media of the infected cells were analyzed by a slot-blot immunoassay. The results indicate that the infected insect cells produced and secreted hGM-CSF. According to colony forming assay, a maximum titer of 2.1 x 10(6). U ml-1 of hGM-CSF in the medium was obtained on the third day after infection.

Analysis of sequence polymorphism of a major mite allergen, Der p 2

BACKGROUND

The major house dust mite allergen Der p 2 has been regarded as an important allergen involved in the immunopathogenesis of allergic asthma and eczema.

OBJECTIVES

To determine the degree of sequence polymorphism exists in Der p 2 at both the genomic DNA and cDNA levels.

METHODS

Isolation of cDNA clones was performed by screening the cDNA libraries with Der p 2 cDNA probe and the genomic sequences for Der p 2 were obtained by PCR amplification from environmental dust mites with Der p 2-specific primers. DNA sequencing was carried out by the dideoxynucleotide chain termination method. The study of Der p 2 isoforms was performed by 2-D gel immunoblot analysis using mouse anti-Der p 2 serum.

RESULTS

In this study, we have characterized the sequences of three different gene alleles coding for the major house dust mite allergen Der p 2 at the cDNA level. The translated polypeptides from these clones differed from each other by 3-4 amino-acid residues. These polymorphic residues determined were also found in Der f 2 and they were located in regions containing T-epitopes. In addition, the genomic DNA sequences of Der p 2 which were obtained by PCR amplification using the environmental mites isolated from Taiwan and Australia have helped to confirm the authenticity of the polymorphisms detected in the cDNA clones generated from CSL cultured mites. Furthermore, 2D- immunoblot analysis indicated that there were at least 10 different isoforms (p 1 values range from greater than 7.0-5.9) of Der p 2 proteins produced by CSL cultured mites.

CONCLUSION

The results showed that there was a small but significant degree of sequence polymorphisms exists in Der p 2 gene alleles. Interestingly, the polymorphic residues were found in regions containing previously determined T-epitopes. The polymorphism data reported here will be important for the understanding of the immune responses of mite allergens as well as for the development of the peptide-based immunotherapeutic reagents for mite allergy.

Allergenic components in three different species of Penicillium: crossreactivity among major allergens

BACKGROUND

Penicillium species have been considered as important causative agents of extrinsic bronchial asthma. However, little is known about the allergens of these ubiquitous airborne fungal species.

OBJECTIVE

This study compares the allergenic profiles and allergenic crossreactivity among allergens of three prevalent airborne Penicillium species.

METHODS

IgE-binding Penicillium components were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)-immunoblotting using sera from 67 asthmatic patients. The presence of allergenic crossreactivity was analysed by immunoblot inhibition.

RESULTS

Among the 67 serum samples tested, 15, 14 and 11 samples showed IgE reactivity to components of P. citrinum, P. notatum and P. brevicompactum, respectively. All 15 P. citrinum-positive serum samples showed IgE-binding to a 33 kDa extract component of this species. Thirteen (93%) of the 14 P. notatum-positive serum samples and 10 (91%) of the 11 P. brevicompactum-positive sera also showed IgE reactivity to components with a molecular weight of about 33 kDa in individual Penicillium species. All of the 10 P. brevicompactum 33 kDa component-positive serum samples showed IgE reactivity to the 33 kDa components of the other two Penicillium species tested. Dose-dependent inhibition of IgE-binding to these major allergens was observed when the positive serum sample was absorbed with different amounts of individual allergenic extract as well as with different amounts of extracts prepared from the other two Penicillium species.

CONCLUSION

Although different allergenic profiles were observed in the three different Penicillium species tested, results showed that there was an IgE crossreactivity among the 33 kDa group major allergens of P. citrinum, P. notatum and P. brevicompactum.

IgE and monoclonal antibody binding by the mite allergen Der p 7

BACKGROUND

The recently characterized group 7 house dust mite allergens give positive skin-test reactions in 53% of allergic patients.

OBJECTIVE

This study was performed to compare the IgE binding activity of natural and recombinant Der p 7, to measure the binding in allergic sera in comparison to major allergen Der p 2 and characterize the response by competitive inhibition with monoclonal antibodies.

METHODS

IgE anti Der p 2 and Der p 7 antibodies against the recombinant allergens and monoclonal binding activities were measured by a solid phase radioimmune assay.

RESULTS

A competitive binding assay showed that rDer p 7 inhibited 91% of IgE-binding to natural Der p 7 in 2 sera and 73% in a further two. The IgE binding of rDer p 2 and Der p 7 from 41 sera was then compared. Of the sera 88% and 46% respectively showed positive binding. All of the 19 sera which bound Der p 7 also bound Der p 2 but 11 (58%) had bound IgE to Der p 7 as high or higher than the binding to Der p 2. These sera were mostly high responders to both allergens. A panel of six monoclonal antibodies produced against either rDer p 7 or rDer f7 was used for epitope analysis. All of these reacted with each allergen by enzyme linked immunosorbent assay (ELISA) and immunoblotting. Two patterns of cross inhibition of monoclonal antibody binding were observed and of five monoclonal antibodies tested, four could inhibit the binding of IgE (WH9, WH22, WP8 and HD19) while one (WH14) could not.

CONCLUSIONS

Although Der p 7 only reacts with 50% of allergic sera it often has a high IgE binding activity and may be more important than the major Der p 2 allergen in a high percentage of subjects. The combined competitive inhibition experiments show the IgE response is directed at several specificities.

Molecular cloning and immunological characterization of the house dust mite allergen Der f 7

BACKGROUND

The allergen Der p 7 from Dermatophagoides pteronyssinus has been defined by molecular cloning and shown to be an important specificity in 50% of mite-allergic patients.

OBJECTIVE

This study compares the cDNA sequence and serological reactivity of Der f 7 from D. farinae with Der p 7.

METHOD

cDNA encoding Der f 7 was amplified by polymerase chain reaction, sequenced and expressed as a fusion with glutathione-S-transferase for IgE and monoclonal antibody binding studies.

RESULTS

Der f 7 cDNA encoded a 213 polypeptide containing a predicted 17 amino acid leader sequence, no cysteines and a single N-glycosylation site similar to Der p 7. The predicted 196 residue mature polypeptide had 86% identity to Der p 7 and a calculated molecular weight of 22,348Da. No homologues were found in searches of the data banks. The Der f 7 fusion protein showed a single band of 46 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and reacted with IgE antibodies in 19/41 (46%) of sera from asthmatic children. The degree of binding was usually 30% of that to Der p 7 consistent with the exposure of the patients to D. pteronyssinus. Monoclonal antibodies (WH9 and WH22) against Der p 7 reacted with Der f 7 but inhibition studies showed a 10-fold difference in reactivity.

CONCLUSION

Der f 7 has a predicted 213 residue polypeptide with 86% homology and serological crossreactivity to Der p 7.

Characterization of the house dust mite allergen Der p 7 by monoclonal antibodies

The house dust mite allergen Der p 7, which was defined by cDNA cloning, has been shown to react with about 50% of allergic sera and corresponds to or is antigenically related to at least three different sized components in mite extracts. To characterize these entities, monoclonal antibodies (MoAbs) were generated by immunizing BALB/c mice affinity-purified Der p 7-GST (glutathione S-transferase) fusion protein. MoAbs WH9 and WH22 showed positive reactivity to recombinant Der p 7 negative reactivity to GST and the Der p 5-GST fusion protein in ELISA and immunoblotting. The specificity of both MoAbs was confirmed by inhibition of the ELISA activity by recombinant Der p 7 but not by the recombinant Der p 5. Immunoblot analysis demonstrated that both MoAbs showed reactivities to components with molecular weights (mol. wt.) of 31, 30 and 26 kDa reactive to both MoAbs. At least six major forms with different pI or size were indicated by 2-D gel analysis. In addition to characterization of Der p 7, both MoAbs may also be considered for use in the standardization of Der p 7 in mite extracts.

Molecular cloning of cDNA coding for the 68 kDa allergen of Penicillium notatum using MoAbs

To characterize the 68 kDa allergen of Penicillium notatum (also known as P. chrysogenum), a molecular antibody (MoAb) (P40) was previously generated. For cDNA cloning, three more MoAbs (3F, 5A3, 5G2) were generated in the present study. A mixture of all the four MoAbs was used in cloning of the gene coding for the 68 kDa allergen from a lambda gt11 cDNA library of P. chrysogenum. A cDNA clone (A6) with DNA insert of about 0.5 kb which encodes for the 3'-terminal nucleotide sequence of the 68 kDa allergen was obtained. The cloned sequence contained two putative N-glycosylation sites. The reduction in molecular weight from 68 to 62 kDa in immunoblotting after treatment of the crude extract of P. notatum with N-glycosidase F indicates that the 68 kDa allergen is a glycoprotein. Nucleotide sequence determination showed that 188 (54%) of the 348 nucleotides of the cDNA sequence obtained were identical to the same region of the nucleotide sequence of the beta-N-acetylglucosaminidase gene of Candida albicans. Although the cDNA clone obtained did not encode the full-length gene of the 68 kDa allergen, polypeptide expressed from the A6 cDNA showed positive immunological reactivities to all four MoAbs used in the cloning experiment and to IgE antibodies in sera of asthmatic patients. There was a loss of immunoblotting activity to the 68 kDa component after absorption of MoAb P40-containing culture supernatant with filters blotted on plaque lawns of cDNA clone A6. Moreover, the immunoblotting activity remained when the MoAbs affinity-purified with filters containing polypeptides encoded by the cDNA insert of clone A6 were used.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoblot analysis of components of Penicillium citrinum recognized by human IgE and IgG antibodies

Penicillium species are well-known indoor fungi and have been considered as one of the causative agents of extrinsic bronchial asthma. We have identified that Penicillium citrinum is the most prevalent Penicillium species in the Taipei area. In the present study, components of this airborne fungus recognized by human IgE and IgG antibodies were analyzed by immunoblotting. Eight components ranging in MWs from 112 to 17.5 kD reacted with IgE antibodies in 11 serum samples. The component with an MW of about 33 kD showed the highest frequency (81.8%) of IgE-binding. However, 11 components of P. citrinum showed IgG-immunoblotting activity, and the component with an MW of about 66 kD revealed the highest frequency (58.3%) of IgG-binding. Only 3 of the 9 serum samples which reflected IgE antibody activity to the 33 kD component of P. citrinum showed IgG-immunoblotting activity to the same 33 kD component. Furthermore, 4 of the 5 serum samples obtained from healthy laboratory personnel demonstrated IgG responses, but none had IgE antibody activity to components of p. citrinum. The discrepancy observed between IgE and IgG responses to the same allergenic extract requires further investigation.

Identification and characterization of a 30 kd major allergen from Parapenaeus fissurus

The allergenic components of the shrimp (Parapenaeus fissurus) were identified by immunoblotting with sera from 10 allergic patients. Six components, ranging in molecular weight from about 86 to 39 kd, showed IgE-binding activity and were identified as allergens of the shrimp. The component with a molecular weight of about 39 kd showed the highest frequency of IgE binding (70%) and was considered to be one of its major allergens. Two monoclonal antibodies against this 39 kd component were generated, and their antigenic cross-reactivity with five different kinds of seafood, shrimp, crab, cuttlefish, oyster, and pomfret was analyzed. Monoclonal antibody 1-6-10B reacted with the 39 kd component from shrimp only, but monoclonal antibody 2-7-1E also reacted with the 39 kd component from crab. By extraction with 0.5% sodium dodecylsulfate and ethanol precipitation, a highly purified shrimp 39 kd component was obtained. In two-dimensional gel electrophoresis six isoforms of this purified 39 kd component, with isoelectric point values from 5.1 to 5.6, were identified. No marked difference was observed when the amino acid composition of this purified 39 kd allergen was compared with those of serum albumin from different animals. They all contain a high proportion of acidic amino acids. There was also a 62% to 83% sequence homology among three different pairs of peptide fragments of purified 39 kd components of shrimp and crab. In conclusion, a 39 kd major allergen from the shrimp has been identified and characterized in the present study. According to the suggestions of the International Union of Immunological Societies, this allergen is designated as Par f I.

Molecular cloning of a house dust mite allergen with common antibody binding specificities with multiple components in mite extracts

Plaque radio-immuno assay has been used to isolate an IgE-binding clone from a lambda gt11 library of Dermatophagoides pteronyssinus cDNA. The clone HD6 contained DNA encoding a 215 residue protein which contained a predicted 17 amino acid residue leader sequence, no cysteines and a single N-glycosylation site. The 198 residue mature protein would have a predicted MW of 22,177 D. No homologues were found in searches of the data banks. Sera from 14/38 allergic children reacted strongly with the polypeptide produced by the clone (37%). Skin tests showed reactivity in 16/30 (53%) allergic patients and 0/10 of controls. Affinity purification of rabbit antibodies with the clone showed that antibodies to the polypeptide had specificities to multiple products in mite extracts corresponding to components of Mr 29, 27 and 24 K by Western blotting. Absorption studies of IgE in allergic serum indicated further entities at 13 and 11.5 kD. It is proposed to name this allergen Der p VII.

Analysis of ragweed allergens recognized by monoclonal antibody 8-5 using two-dimensional gel electrophoresis and immunoblotting

A series of MoAbs against major allergens (Amb a I and Amb a II) of the short ragweed pollen is reported by this laboratory. One of these MoAbs, 8-5, showed strong reactivity to Amb a II, weak reactivity to Amb a I-B and I-C, and no reactivity to Amb a I-B2 of the short ragweed pollen by SDS-PAGE and immunoblotting. In the present study, ragweed allergens recognized by MoAb 8-5 were further analyzed by two-dimensional gel electrophoresis and immunoblotting. The results showed that MoAb 36-6, which has been identified to be reactive with Amb a I only, reacted mainly with components with MW of about 39 kD, which corresponded to creatine kinase charge standards from -14 to -20 in both the Amb a I-B and I-C preparation and the crude extract of the short ragweed pollen. However, MoAb 8-5 showed strong reactivity to components with about the same MW but charge standards from -8 to -13 in Amb a II and the crude extract of the short ragweed pollen. Furthermore, a weak positive reactivity of MoAb 8-5 to components with MW of about 39 kD and charge standards from -8 to -14 in Amb a I-B and I-C was also observed. It was thus concluded that MoAb 8-5 reacted with Amb a II only.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of a monoclonal antibody (P40) against the 68 kD major allergen of Penicillium notatum

A monoclonal antibody (MoAb P40) against the 68 kD major allergen of Penicillium notatum (P. notatum) was obtained by immunizing the mouse with a crude extract of P. notatum. Analysed by two-dimensional gel electrophoresis and immunoblotting, P40 reacted with two different isoforms of the 68 kD component of P. notatum with pIs of 5.4 and 5.5. In addition to P. notatum, P40 showed positive ELISA activity to Aspergillus fumigatus (A. fumigatus) but not to components of six other fungi including Alternaria porri, Cladosporium cladosporoides, Aureobasidium pullulans, Fusarium solani, Rhizopus arrhizus and Candida albicans. Analysed by ELISA, MoAb P40 also showed positive activity to two (P. frequentans and P. roseopurpureum) of the 10 other Penicillium species and two (A. terreus and A. flavus) of the four other Aspergillus species tested. SDS-PAGE and immunoblotting studies demonstrated P40 positive reactivity to components with MW of about 67 kD in all these Penicillium and Aspergillus species with positive ELISA activity to P40. Furthermore, immunoblotting activity of MoAb P40 to the 67 kD component of A. niger was also observed. The epitope of the 68 kD allergen of P. notatum recognized by MoAb P40 was resistant to treatment of periodate oxidation with concentration of NaIO4 up to 20 mM. This MoAb may thus be useful in the characterization and purification of the 68 kD allergen from crude extracts, and in the molecular cloning of allergen genes.

The 40-kilodalton allergen of Candida albicans is an alcohol dehydrogenase: molecular cloning and immunological analysis using monoclonal antibodies

To characterize the 40-kilodalton (kD) major allergen of Candida albicans (C. albicans), six monoclonal antibodies (MoAbs) against this allergen were generated. In SDS-polyacrylamide gel electrophoresis and immunoblot analysis, these MoAbs showed four different reaction patterns to antigens of six different Candida species. With the exception of one MoAb, other MoAbs were resistant to periodate treatment indicating non-carbohydrate epitopes were probably being recognized by these MoAbs. These MoAbs were used in the molecular cloning and immunological analysis of the gene coding for the 40-kD allergen. Nucleotide sequence determination of the two lambda gt11 cDNA clones obtained showed that the 40-kD allergen is an alcohol dehydrogenase (ADH) which shares a 70% amino acid sequence homology with the ADH isozyme I of Saccharomyces cerevisiae. This finding was confirmed by positive immunological response of the lysates of the clones obtained and a preparation of ADH of Saccharomyces cerevisiae to various MoAbs and to IgE antibodies in sera of allergic patients.

Immunoblot analysis of components of Penicillium notatum recognized by human IgE antibodies

Components of the crude extract of Penicillium notatum recognized by human IgE antibodies (Abs) were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The allergenic components were identified with sera from 19 allergic patients and 20 blood donors. The allergen-Ab complexes were visualized by 125I-labeled monoclonal antihuman IgE and autoradiography. A total of 11 allergenic components, ranging in molecular weights (MWs) from 94,000 to 20,000 daltons, were identified. Heterogeneity in the IgE-binding patterns of the serum samples tested was also observed. However, the major allergen appears to be the component with an MW of about 68,000 daltons that was recognized by IgE Abs in 56% of the 39 sera analyzed. Furthermore, the component with an MW of about 64,000 daltons that was recognized by IgE Abs in 46% of the sera analyzed was also considered as an important allergen. Results obtained from this study will be useful in additional characterization of allergens of P. notatum and related fungal species.

Analysis of allergenic components of Bermuda grass pollen by monoclonal antibodies

A panel of 16 monoclonal antibodies (MoAbs) directed against Bermuda grass (Cynodon dactylon) pollen (BGP) were generated for identification and purification of the major allergenic components of the eliciting antigen (Ag). Radioimmunoprecipitation (RIP) analysis revealed that there were at least eight antigenic components with molecular weights (MW) ranging from 12 kilodalton (12 kDa) to 200 kDa. Each of these components has distinct biochemical characteristics based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF). Among them, Cyn d Bd67K and Cyn d Bd58K were basic proteins, Cyn d Bd35K consisted of at least four isomeric components with isoelectric points ranging from 6.2 to 7.2. The other antigens (Cyn d Bd68K, 48K, 38K, Cyn d Bd200K, Cyn d Bd46K, Cyn d Bd25K and Cyn d Bd12K) were all acidic proteins. The IgE binding capacity of all these antigens was determined with sera from 11 BGP-allergics by using a modified radioallergosorbent test. All but one of the antigens (Cyn d Bd200K) were found to react with human IgE from sera of BGP-allergic patients. Among those human IgE-binding molecules, Cyn d Bd35K reacted with allergic sera most frequently (10 of 11), followed by Cyn d Bd58K (8 of 11) and Cyn d Bd46K (7 of 11) respectively. Our results suggest that Cyn d Bd35K, Cyn d Bd58K, and Cyn d Bd46K are major allergens of BGP, and the MoAbs we obtained should be valuable tools for further purification of these allergens.

Isolation and partial characterization of Bermuda grass pollen allergen, BG-60a

In an earlier study we showed that Bermuda grass (Cynodon dactylon) pollen contains at least 12 IgE-binding proteins that can be analysed by immunoblot technique. One of the active components (BG-60) proved to be a basic protein of glycoprotein nature. It contained about 28% carbohydrate as determined from the dry weight and consisted of four molecules. One of the components was purified from the pollen extract by a combination of ammonium sulphate precipitation, ion-exchange chromatography on carboxymethyl-TSK, gel filtration on Ultrogel AcA 44 and chromatofocusing. Its molecular weight was approximately 60 kD by SDS-PAGE and 34 kD by gel filtration chromatography. The isoelectric point of the antigen was about 9.7. The homogeneity of the antigen BG-60a was assessed by one single arc of immunoprecipitation both in immunodiffusion and crossed immunoelectrophoresis and by one single band after SDS-PAGE. Its allergenicity was demonstrated by direct intradermal skin test on allergic patients and by examining IgE-binding reactivity with allergic patients' serum.