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Biomedical subjects

H Choi

Publications and source records attributed to H Choi.

At least 109 records · Page 6Linked to original sources

Three novel type I collagen mutations in osteogenesis imperfecta type IV probands are associated with discrepancies between electrophoretic migration of osteoblast and fibroblast collagen.

In three cases of type IV osteogenesis imperfecta (OI), we identified unique point mutations in type I collagen alpha1(I) cDNA. In two cases, the appearance of dimers indicated the presence of cysteine substitutions in the alpha1(I) protein chain. Cyanogen bromide digestion localized these cross-links to CB8 and 3, respectively. In the third case, the overmodification pattern of the CNBr peptides was compatible with a substitution in the aa 123-402 region of either type I collagen chain. We identified a unique point mutation in each proband, which resulted in substitutions for glycine residues in a 300-aa region of the alpha1(I) helix, specifically, Gly to Ala at codon 220 (GGT-->GCT), Gly to Cys at codon 349 (GGT-->TGT) and Gly to Cys at codon 523 (GGT-->TGT). We compared each proband's fibroblast and osteoblast collagen directly, as well as with fibroblast and osteoblast controls. For all cases, the OI osteoblast collagen was more electrophoretically delayed than OI fibroblast collagen. In the patient with G349C, OI fibroblast and osteoblast collagen synthesized in the presence of alpha,alpha'-dipyridyl co-migrated on gels, demonstrating that the electrophoretic discrepancy resulted from differences in post-translational modification. Melting temperature curves for stability of the collagen helix yielded an identical Tm for control fibroblast and osteoblast collagen (41.2 degrees C). By contrast, for collagen with the gly349-->cys substitution, the Tm of the fibroblast collagen was 1 degree C lower than the Tm of the osteoblast collagen. These data indicate that the metabolism of mutant collagen might be cell-specific and has significant implications for understanding the phenotype/genotype correlations and the pathophysiology of OI.

Adolescent↗

Reactivity and suitability of t-Boc-protected thiophosphotyrosine intermediate analogs for the solid or solution phase peptide synthesis.

N-(tert-Butoxycarbonyl)-O-(dimethylthiophosphono)-L-tyrosine (6) and N-(tert-butoxycarbony)-O-(dicyanoethylthiophosphono)-L-tyros ine (15) were prepared as intermediates for the synthesis of thiophosphotyrosine-containing peptides. The reactivity and suitability of two compounds for the solid phase or solution phase peptide synthesis utilizing t-Boc chemistry were examined.

Indicators and Reagents↗

The effect of pyrimidine nucleosides on adenosine-induced apoptosis in HL-60 cells.

Among several nucleosides, adenosine is the only one to induce typical apoptotic cell death in human promyelocytic leukemia HL-60 cells. Intracellularly transported adenosine seemed to be required for the induction of apoptosis, since dipyridamole, which inhibits the transport of adenosine, strongly suppressed apoptosis, and 8-phenyltheophylline, a receptor antagonist, did not affect the adenosine-induced effect. The viability of adenosine-treated HL-60 cells was partially recovered by supplementation with a pyrimidine nucleoside, uridine or thymidine. Cytidine or deoxycytidine had no effect on the growth and survival of adenosine-treated cells, while uridine or thymidine inhibited adenosine-induced intracellular DNA fragmentation. These results suggest that the quantitative adjustment of purine and pyrimidine nucleosides might play an important role in the adenosine-induced apoptosis of HL-60 cells. The reduction of c-Myc expression in adenosine-treated cells was prevented by uridine or thymidine. These observations suggest that the expression of c-Myc might be related to an intracellular sensing system for the quantitative balance of nucleosides or nucleotides.

Adenosine↗

Telepathology.

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Humans↗

A mutation in QRDR in the ParC subunit of topoisomerase IV was responsible for fluoroquinolone resistance in clinical isolates of Streptococcus pneumoniae.

Forty-one strains of Streptococcus pneumoniae were isolated at Seoul National University Children's Hospital from 1991 to 1997. Isolates were divided into six groups based on MICs of three quinolones, ciprofloxacin, ofloxacin and norfloxacin. Sequencing showed that the isolates which were intermediately resistant to three quinolones or resistant to at least one kind of quinolone had one missense mutation, Lys137-->Asn(AAG-->AAT) substitution in the ParC subunit of topoisomerase IV without additional mutation in QRDR of the GyrA subunit of DNA gyrase. In conclusion, the ParC subunit of DNA topoisomerase IV is the primary target site for fluoroquinolone in S. pneumoniae and Lys137-->Asn substitution renders the quinolone resistance in S. pneumoniae.

DNA Topoisomerase IV↗

N-alkylated derivatives of [D-Pro10]dynorphin A-(1-11) are high affinity partial agonists at the cloned rat kappa-opioid receptor.

As part of an effort to develop peptides with selective kappa-opioid antagonist activity, a series of N-alkylated [D-Pro10]dynorphin A-(1-11) derivatives were made through solid-phase peptide synthesis: R-Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-D-Pro-LysOH, where R = N-benzyl, N-cyclopropylmethyl, N,N-dicyclopropylmethyl, or N,N-diallyl. These derivatives and dynorphin A-(1-13)NH2 were evaluated for kappa-opioid receptor binding affinity and potency as inhibitors of adenylyl cyclase. Equilibrium competition binding experiments using [3H]diprenorphine (approximately 600 pM) were performed on membranes prepared from cultured Chinese hamster ovary (CHO) cells stably expressing the rat kappa-opioid receptor. Tissue prepared from this cell line was used to evaluate opioid peptide inhibition of forskolin-stimulated (50 microM) adenylyl cyclase activity. Displacement of [3H]diprenorphine specific binding by these peptides was observed with a rank order of affinity (Ki, nM) = [D-Pro10]dynorphin A-(1-11) (0.13) > dynorphin A-(1-13)NH2 (0.34) > N-cyclopropylmethyl- (1.4) > N,N-dicyclopropylmethyl- (12.6) approximately N-benzyl- (18.3) approximately N,N-diallyl-[D-Pro10]dynorphin A-(1-11) (26.0). A similar rank order was observed for potency of adenylyl cyclase inhibition (IC50, nM): [D-Pro10]dynorphin A-(1-11) (0.12) approximately dynorphin A-(1-13)NH2 (0.19) > N-cyclopropylmethyl- (2.7) > N,N-dicyclopropylmethyl- (13.2) approximately N,N-diallyl- (18.0) approximately N-benzyl-[D-Pro10]dynorphin A-(1-11) (36.4). The peptides differed in their percent maximal inhibition of adenylyl cyclase activity: dynorphin A-(1-13)NH2 (100%) approximately N-cyclopropylmethyl- (94.3%) approximately [D-Pro10]dynorphin A-(1-11) (87.9%) > N-benzyl- (71.4%) >> N,N-dicyclopropylmethyl- (23.6%) approximately N,N-diallyl-[D-Pro10]dynorphin A-(1-11)(18.9%). As the N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) derivatives were found to have only weak partial agonist activity with respect to adenylyl cyclase inhibition, they were evaluated for their ability to reverse dynorphin A-(1-13)NH2 (10 nM) inhibition of adenylyl cyclase activity. N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) reversed dynorphin A-(1-13)NH2 inhibition to levels equal to the maximal inhibition produced by N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) alone. This weak partial agonism combined with nanomolar potency render the N,N-dicyclopropylmethyl- and N,N-diallyl-[D-Pro10]dynorphin A-(1-11) compounds promising leads for further attempts to synthesize peptide kappa-opioid receptor antagonists.

Adenylyl Cyclase Inhibitors↗

Novel fluoroquinolone antibacterial agents containing oxime-substituted (aminomethyl)pyrrolidines: synthesis and antibacterial activity of 7-(4-(aminomethyl)-3-(methoxyimino)pyrrolidin-1-yl)-1-cyclopropyl-6- fluoro-4-oxo-1,4-dihydro[1,8]naphthyridine-3-carboxylic acid (LB20304).

New pyrrolidine derivatives, which bear an alkyloxime substituent in the 4-position and an aminomethyl substituent in the 3-position of the pyrrolidine ring, have been synthesized and coupled with various quinolinecarboxylic acids to produce a series of new fluoroquinolone antibacterials. These fluoroquinolones were found to possess potent antimicrobial activity against both Gram-negative and Gram-positive organisms, including methicillin resistant Staphylococcus aureus (MRSA). Variations at the C-8 position of the quinolone nucleus included fluorine, chlorine, nitrogen, methoxy, and hydrogen atom substitution. The activity imparted to the substituted quinolone nucleus by the C-8 substituent was in the order F (C5-NH2) > F (C5-H) > naphthyridine > Cl = OMe = H against Gram-positive organisms. In the case of Gram-negative strains, activity was in the order F (C5-NH2) > naphthyridine = F (C5-H) > H > Cl > OMe. The advantages provided by the newly introduced oxime group of the quinolones were clearly demonstrated by their comparison to a desoximino compound 30. In addition, the oxime moiety greatly improved the pharmacokinetic parameters of the novel quinolones. Among these compounds, compound 20 (LB20304) showed the best in vivo efficacy and pharmacokinetic profile in animals, as well as good physical properties. The MICs (microgram/mL) of LB20304, compound 30, and ciprofloxacin against several test organisms are as follows: S. aureus 6538p (0.008, 0.031, and 0.13), methicillin resistant S. aureus 241 (4, 16, and 128), Streptococcus epidermidis 887E (0.008, 0.016, and 0.13), methicillin resistant S. epidermidis 178 (4, 32, and 128), Enterococcus faecalis 29212 (0.063, 0.13, and 1), Pseudomonas aeruginosa 1912E (0.25, 0.5, and 0.13), Escherichia coli 3190Y (0.008, 0.016, and 0.008), Enterobacter cloacae P99 (0.008, 0.031, and 0.008), Actinobacter calcoaceticus 15473 (0.063, 0.13, and 0.25). On the basis of these promising results, LB20304 was selected as a candidate for further evaluation.

Animals↗

Synthesis and opioid activity of [D-Pro10]dynorphin A-(1-11) analogues with N-terminal alkyl substitution.

Several N-terminal di- and monoalkylated derivatives of [D-Pro10]dynorphin A-(1-11) were synthesized in order to explore the structure-activity relationships for antagonist vs agonist activity at kappa-opioid receptors. N,N-Dialkylated and N-monoalkylated (alkyl = allyl, benzyl, and cyclopropylmethyl (CPM) tyrosine derivatives were prepared from tyrosine tert-butyl ester and the corresponding alkyl halides. [D-Pro10]Dyn A-(2-11) was prepared by solid phase synthesis using Fmoc-protected amino acids, and the tyrosine derivatives were coupled to the peptide with BOP ((benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate). Both the degree of substitution and the identity of the alkyl group affected kappa-receptor affinity, selectivity, and efficacy. All of the N-monoalkylated derivatives exhibited much higher affinity (Ki < 0.05 nM) for kappa receptors in the guinea pig cerebellum and greatly enhanced kappa-receptor selectivity (Ki ratio (kappa/mu) > 200) compared to the N,N-dialkyl [D-Pro10]Dyn A-(1-11) analogues, although one disubstituted analogue, N,N-diCPM[D-Pro10]Dyn A-(1-11), retained high affinity (Ki = 0.19 nM) for kappa receptors. Thus the introduction of the second alkyl group at the N-terminus lowered kappa-receptor affinity and selectivity. The N-allyl and N-CPM analogues were moderately potent agonists in the guinea pig ileum (GPI) assay, while the N-benzyl derivative was a weak agonist in this assay. In vivo in the phenylquinone abdominal stretching assay the N-CPM analogue exhibited potent antinociceptive activity (ED50 = 1.1 micrograms/mouse), while N-allyl[D-Pro10]Dyn A-(1-11) exhibited weak antinociceptive activity (ED50 = 27 micrograms/mouse). For the N,N-dialkyl derivatives the identity of the N-terminal alkyl group affected the efficacy observed in the smooth muscle assays. The N,N-diCPM analogue exhibited negligible agonist activity, and N,N-diallyl[D-Pro10]Dyn A-(1-11) showed weak antagonist activity against Dyn A-(1-13)NH2 in the GPI. In contrast, the N,N-dibenzyl compound showed appreciable opioid agonist activity in this assay. In vivo the N,N-diallyl analogue exhibited weak antinociceptive activity (ED50 = 26 micrograms/mouse in the phenylquinone abdominal stretching assay). The N-monoalkylated peptides are among the most kappa-selective opioid peptides reported to date, showing comparable or greater selectivity and higher affinity than the kappa-selective non-peptide agonists U-50,488 and U-69,593. The N,N-diCPM and N,N-diallyl peptides are lead compounds in the development of peptide-based kappa-receptor antagonists.

Alkylation↗

Regulation of developing dopaminergic axonal arbor size in three-dimensional reaggregate tissue culture.

The role of target availability in determining axonal size of the developing dopaminergic neuron was examined in three-dimensional reaggregate culture in which these neurons undergo normal neurochemical and morphological development. The ratio of striatal target cells to dopaminergic neurons was systematically increased from 2:1 to 50:1 (striatal to mesencephalic cells). These ratios provide sufficient target for quantitative survival of dopaminergic neurons similar to that seen in vivo. After 3 weeks in culture, dopamine levels increased linearly and proportionally to dopaminergic cell number over a 25-fold relative increase in target cell availability. The amount of neurotransmitter per dopaminergic cell remained constant, suggesting that the axonal arbor did not increase as a function of target availability. This conclusion was directly tested by morphological analysis of the dopaminergic axonal arbor in single aggregates containing between 0 and 45 dopaminergic cells under conditions in which sufficient target was not a factor in dopaminergic cell survival. As was the case with respect to dopamine concentration, axonal arbor size per cell remained constant in the face of increasing target availability. Thus, availability of target cells under these conditions, is not, per se, the limiting factor on the rate of growth of the developing dopaminergic axonal arbor.

Animals↗

Improvement of the 3'-5' exonuclease activity of Taq DNA polymerase by protein engineering in the active site.

Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in the polymerase chain reaction method. Taq DNA polymerase has a domain at its amino terminus (residue 1 to 291) that has a 5'-3' exonuclease activity, a 3'-5' exonuclease domain in the middle (residue 292 to 423), and a domain at its C-terminus that catalyzes polymerase reactions. Taq DNA polymerase is classified into the polI family which is represented by E. coli DNA polymerase I. The three dimensional structural alignment of 3'-5' exonuclease domains from the polI family, DNA polymerases leads us to understand why Taq DNA polymerase does not carry out proof-reading in the polymerase chain reaction. Three sequence motifs, called ExoI, II, and III must be present in order to carry out proof-reading by the 3'-5' exonuclease reaction in DNA polymerization, but Taq DNA polymerase contains none of them. The key catalytic module in the 3'-5' exonuclease is two metal ions chelated by active-site carboxylic amino acids. In order to render the 3'-5' exonuclease activity in Taq DNA polymerase, a catalytic module was constructured in the active site by protein engineering. The mutant Taq DNA polymerase shows twice as much the 3'-5' exonuclease activity as that of wild-type DNA polymerase.

Amino Acid Sequence↗

A linkage study of bipolar illness.

BACKGROUND: Although genetic epidemiological studies of bipolar (BP) illness are consistent with a heritable component, inherited risk factors remain unknown. The goal of the present study is to describe the localization of BP susceptibility loci through linkage strategies, including a genome-wide search. METHODS: A linkage study of 22 BP families has been performed. These BP families include almost 400 persons, 173 of whom have been diagnosed as having BP I, schizoaffective, BP II with major depression, or recurrent unipolar illness. Using an autosomal dominant disease model with 85% or 50% age-dependent penetrance, and a recessive model with 85% penetrance, linkage analyses were performed assuming a narrow (BP and schizoaffective) or a broad (BP, schizoaffective, or unipolar) definition of the BP spectrum. Affected sibling pairs and affected pedigree member analyses were performed when positive lod scores were observed in multiple pedigrees. The present article describes linkage analysis of 310 DNA markers on chromosomes 1, 5p, 6, 8, 10q, 11q, and 12 to 18. RESULTS: None of the loci examined disclosed compelling evidence for linkage using lod score analyses. Model-independent analysis by multilocus affected pedigree member method in the pericentromeric chromosome 18 region disclosed statistically significant evidence (P < .0001) for a BP susceptibility gene in this region. Multilocus analysis by affected sibling pair method also disclosed evidence for linkage (P < .00008). CONCLUSIONS: Our results imply that a BP susceptibility gene exists near the centromere of chromosome 18. Confirmation of this finding (by independent investigators studying different pedigrees) has been published, suggesting that a valid BP disease linkage may have been discovered.

Bipolar Disorder↗

Mapping murine loci for seizure response to kainic acid.

Mature DBA/2J (D2) mice are very sensitive to seizures induced by various chemical and physical stimuli, whereas C57BL/6J (B6) mice are relatively seizure resistant. We have conducted a genome-wide search for quantitative trait loci (QTLs) influencing the differential sensitivity of these strains to kainic acid (KA)-induced seizures by studying an F2 intercross population. Parental, F1, and F2 mice (8-10 weeks of age) were injected subcutaneously with 25 mg/kg of KA and observed for 3 h. Latencies to focal and generalized seizures and status epilepticus were recorded and used to calculate an overall seizure score. Results of seizure testing indicated that the difference in susceptibility to KA-induced seizures between D2 and B6 mice is a polygenic phenomenon with at least 65% of the variance due to genetic factors. First-pass genome screening (10-cM marker intervals) in F2 progeny (n = 257) documented a QTL of moderate effect on Chromosome (Chr) 1 with a peak LOD score of 5.5 (17% of genetic variance explained) localized between D1Mit30 and D1Mit16. Provisional QTLs of small effect were detected on Chr 11 (D11Mit224-D11Mit14), 15 (D15Mit6-D15Mit46) and 18 (D18Mit9-D18Mit144). Multiple locus models generally confirmed the Mapmaker/QTL results and also provided evidence for another QTL on Chr 4 (D4Mit9). Multilocus analysis of seizure severity suggested that additional loci on Chrs 5 (D5Mit11), 7 (D7Mit66), and 15 (D15Nds2) might also contribute to KA-induced seizure response. Overall, our results document a complex genetic determinism for KA-induced seizures in these mouse strains with contributions from as many as eight QTLs.

Animals↗

Immunopathologic responses to Aspergillus antigen in interleukin-4 knockout mice.

Two strains of interleukin-4 (IL-4) gene knockout mice were studied and compared with wild strains to determine the role of IL-4 in the immunopathogenesis of murine allergic aspergillosis. Animals immunized intraperitoneally were subsequently challenged with Aspergillus antigen intranasally. The animals were evaluated for total serum immunoglobulin E (IgE) levels, Aspergillus-specific IgG antibody isotypes, peripheral blood eosinophils, cytokine and chemokine mRNA transcripts in spleen cells, and pulmonary histology. No serum IgE was detected in animals deficient in the IL-4 gene. Aspergillus-specific IgG1 was detected in all animals, while enhanced levels of IgG2a were detected in IL-4 knockout animals challenged with A. fumigatus antigen. There were no differences in the peripheral blood or lung eosinophils in the two groups of mice exposed to A. fumigatus. These results indicate that lung injury in Aspergillus-antigen challenged animals may be the result of the eosinophil mediators and that IgE-mediated injury may not be significant in this model, which may be a significant variation between the model and human allergic aspergillosis.

Animals↗

Dynamic-robotic telepathology: Department of Veterans Affairs feasibility study.

In this retrospective study, we assess the accuracy, confidence levels, and viewing times of two generalist pathologists using both dynamic-robotic telepathology and conventional light microscopy (LM) to render diagnoses on a test set of 100 consecutive routine surgical pathology cases. The objective is to determine whether telepathology will allow a pathology group practice at a diagnostic hub to provide routine diagnostic services to a remote hospital without an on-site pathologist. For TP, glass slides were placed on the motorized stage of the robotic microscope of a telepathology system by a senior laboratory technologist in Iron Mountain, MI. Real-time control of the motorized microscope was then transferred to a pathologist in Milwaukee, WI, who viewed images of the glass slides on a video monitor. The telepathologists deferred rendering a diagnosis in 1.5% of cases. Clinically important concordance between the individual diagnoses rendered by telepathology and the "truth" diagnoses established by rereview of glass slides was 98.5%. In the telepathology mode, there were five incorrect diagnoses out of a total of 197 diagnoses. In four cases in which the telepathology diagnosis was incorrect, the pathologist's diagnosis by LM was identical to that rendered by telepathology. These represent errors of interpretation and cannot be ascribed to telepathology. The certainty of the pathologists with respect to their diagnoses was evaluated over time. Results for the first 50 cases served as baseline data. For the second 50 cases, confidence in rendering a diagnosis in the telepathology mode was essentially identical to that of making a diagnosis in the LM viewing mode. Viewing times in the telepathology mode also improved with more experience using the telepathology system. These results support the concept that an off-site pathologist using dynamic-robotic telepathology can substitute for an on-site pathologist as a service provider.

Feasibility Studies↗

Use of telepathology for routine surgical pathology review in a test bed in the Department of Veterans Affairs.

BACKGROUND: Routine surgical pathology review by telepathology could be an important service component of multi-institutional pathology laboratory systems. Such service networks would increase access for rural hospitals without on-site pathologists to a broader range of pathology services on a daily basis. METHODS: In this clinical trial, we analyzed the diagnostic accuracy, deferral rates, and viewing times of two generalist pathologists using a hybrid dynamic/store-and-forward (HDSF) telepathology (TP) system to render diagnoses in real time on 200 consecutive surgical cases. The objective was to assess the efficacy of TP in providing diagnostic surgical pathology services to a remote hospital without an onsite pathologist. Surgical pathology specimens underwent gross preparation by specially trained personnel. When appropriate, this was done under the video supervision of a telepathologist. For TP, glass slides were placed on the stage of a robotic microscope at the Iron Mountain (MI) Department of Veterans Affairs Medical Center (VAMC) (remote site); control of the motorized microscope was then transferred to a pathologist located 220 miles away at the Milwaukee VAMC (host site). For each case, the telepathologist had the option of rendering a diagnosis or deferring the case for later analysis by conventional light microscopy (LM). After the slides were read by TP and a surgical pathology report had been generated, the slides were transported to Milwaukee, where they were reexamined by the telepathologist using LM and then by the pathology group practice or, when there was no consensus, by an outside consultant to establish a "truth" diagnosis. RESULTS: Compared with the consensus ("truth") diagnosis, clinically important and overall concordance were 99.0% and 97.4%, respectively, by TP, and clinically important and overall concordance were 100.0% and 98.5%, respectively, by LM. The deferral rate was 2.5%. Examining glass slides by HDSF telepathology took an average of 4.43 minutes per slide and 12.09 minutes per case. CONCLUSION: The high diagnostic accuracy and low rate of case deferral support the proposal that an offsite pathologist using HDSF telepathology can substitute effectively for an onsite pathologist as a service provider.

Biopsy↗

Transverse carpal ligament: its effect on flexor tendon excursion, morphologic changes of the carpal canal, and on pinch and grip strengths after open carpal tunnel release.

A three-part study is described that examines postoperative weakness after open carpal tunnel release and investigates the role of the transverse carpal ligament in the digital flexor pulley system. The effect of this ligament on flexor tendon excursion is evaluated in a cadaver study. Magnetic resonance imaging analysis is used to determine whether division of the transverse carpal ligament promotes volar migration of the median nerve and flexor tendons. Finally, the effects of ligament division and various methods of transverse carpal ligament reconstruction on the return of grip and pinch strengths after open carpal tunnel release are evaluated. The authors were able to determine that transverse carpal ligament reconstruction, particularly the transposition flap repair technique, after open carpal tunnel release confers a mechanical advantage and that the transverse carpal ligament is an important pulley for flexor tendon excursion. Based on the magnetic resonance imaging studies, volar displacement of carpal contents is reduced in patients undergoing transverse carpal ligament reconstruction by means of a transposition flap compared with those undergoing no ligament reconstruction and those undergoing reconstruction using the palmar aponeurosis. Postoperative grip and pinch strength values for the transposition flap repair group surpassed those of the other two groups at 12 weeks.

Carpal Tunnel Syndrome↗

Anti-interleukin (IL)-4 and -IL-5 antibodies downregulate IgE and eosinophilia in mice exposed to Aspergillus antigens.

The effect of multiple divided doses compared with single-dose injections of antibodies to murine interleukin (IL)-4 and IL-5 in their respective downregulation of IgE and eosinophilia developing in a model of allergic aspergillosis is investigated. BALB/c mice were exposed to Aspergillus fumigatus antigens (Af) before and along with anticytokine antibodies. The kinetics of blood eosinophils, eosinophil peroxidase (EPO) in bone-marrow cells, serum levels of IgE and Af-specific antibodies, Af-induced cytokine production and mRNA, and lung histology were studied. The results indicate that only multiple anti-IL-5 antibodies were effective in maintaining baseline levels of blood eosinophils. Multiple anti-IL-4 antibodies also downregulated eosinophils in the bone marrow, lung, and peripheral blood, although to a lesser extent than in anti-IL-5 antibody-injected mice. Significant correlation between the EPO activity and the eosinophil numbers in anticytokine antibody-treated mice was observed. The different anti-IL-4 antibody treatments downregulated IgE to the same extent. We conclude that multiple divided doses of anti-IL-5 antibodies are required to sustain normal eosinophil levels in murine allergic aspergillosis. This information may be significant in the therapy of pulmonary allergic diseases.

Animals↗