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W R Thomas

Publications and source records attributed to W R Thomas.

At least 19 recordsLinked to original sources
PubMed2006

Genetic polymorphisms of major house dust mite allergens.

BACKGROUND: Polymorphic sequence substitutions in the major mite allergens can markedly affect immunoglobulin E binding and T cell responses, but there are few studies on environmental isolates from Dermatophagoides pteronyssinus and none for D. farinae. OBJECTIVE: To determine the sequence variation of the group 1 and 2 allergens from environmental D. pteronyssinus and D. farinae. METHODS: RNA from each species was isolated from homes in Bangkok and the sequence of Der p 1, Der p 2, Der f 1, and Der f 2 determined from cDNA produced by high fidelity polymerase chain reactions. RESULTS: The enlarged data set revealed preferred amino acid substitutions in residues 19, 81, and 215 of Der p 1 as well as sporadic changes. Der p 2 showed frequent variations with clusters of amino acid substitutions, but the canonical Der p 2.0101 was not found in any of 17 sequences. Der f 2 showed variants with clusters of substitutions similar to Der p 2 but in different amino acid positions and without any structural concordance. Der f 1 in contrast to the other allergens had few amino acid sequence substitutions. CONCLUSIONS: The sequence information on variants provides data important for the optimal design of allergen formulations and useful for the genetic engineering and structure-function analyses of the major allergens.

Allergens↗
PubMed2006

The chitinase allergens Der p 15 and Der p 18 from Dermatophagoides pteronyssinus.

BACKGROUND: House dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae cause allergic disease in humans as well as in dogs. In geographical regions where the two mite species coexist, they both elicit specific immunoglobulin (Ig E) responses in humans whereas dogs preferentially react to D. farinae extracts. In dogs the main IgE binding is directed to the D. farinae chitinase allergens Der f 15 and Der f 18 and not to the groups 1 and 2 allergens as found for humans. Although the IgE response of humans to Der f 18 has been investigated there is no report on Der f 15-specific IgE in humans. OBJECTIVE: This study aimed to characterize the chitinase allergens Der p 15 and Der p 18 of D. pteronyssinus and to find out whether they are important allergens for humans. METHODS: cDNA was cloned by a polymerase chain reaction strategy from D. pteronyssinus libraries using primers based on conserved chitinase sequences. IgE binding to the recombinant polypeptides was measured by immunosorbent assay. Mice were immunized with the polypeptides and cross-reactivity examined. RESULTS: Two variants of Der p 15 were isolated, encoding mature proteins of 58.8 and 61.4 kDa. The amino acid sequences had 90% identity to Der f 15. The cDNA for Der p 18 encoded a mature protein of 49.2 kDa with 88% sequence identity to Der f 18. Der p 15-specific IgE was detected in 70% and Der p 18-specific IgE in 63% of a panel of 27 human allergic sera. CONCLUSIONS: The D. pteronyssinus chitinases Der p 15 and Der p 18 show a high frequency of binding to IgE in allergic human sera. They are therefore potentially important allergens for humans as well as dogs.

Amino Acid Sequence↗
PubMed2005

Sensitization to airborne environmental allergens: unresolved issues.

Despite considerable advances in identifying the environmental agents that trigger allergy and the immunological mechanisms involved, progress in developing effective treatments remains frustratingly slow. Is it time to rethink some of the paradigms guiding this research?

Air Pollutants↗
PubMed2005

Comparison of purified Dermatophagoides pteronyssinus allergens and extract by two-dimensional immunoblotting and quantitative immunoglobulin E inhibitions.

BACKGROUND: The allergens of the house dust mite (Dermatophagoides pteronyssinus, Der p), one of the most important indoor allergen sources, occur as isoallergens that differ in their amino acid sequence. These variations may influence allergenic activity and thus may have impact on diagnostic tests and specific immunotherapy. OBJECTIVE: We investigated whether single purified recombinant mite allergens contain the IgE epitopes of the natural Der p isoallergens. METHODS: A panel of purified recombinant (rDer p 2, 5, 7, 8, 10 and 14) and two natural (nDer p 1 and 4) mite allergens were used to establish IgE reactivity profiles of Der p allergic patients and to inhibit IgE reactivity to two-dimensionally separated Der p isoallergens. In addition, we determined the percentage of Der p extract-specific IgE which could be preadsorbed with a mixture of purified mite allergens (nDer p 1, rDer p 2, 5, 7, 8 and 10) from sera of mite-allergic patients (n=18) in a non-denaturing RAST-based inhibition. RESULTS: We demonstrate that single recombinant mite allergens inhibit IgE reactivity to the corresponding natural isoallergens. A mixture of purified mite allergens (nDer p 1, rDer p 2, 5, 7, 8 and 10) bound on an average 76% of Der p-specific IgE antibodies. CONCLUSION: The studied recombinant and natural mite allergens contain a large portion of Der p-specific IgE and may be used for diagnostic tests and therapy of Der p allergy.

Adolescent↗
PubMed2004

Fel d 4, a cat lipocalin allergen.

BACKGROUND: Cat allergy is unique among allergy to mammals in that the major allergen Fel d 1 is a uteroglobin-like protein and not a lipocalin. The biochemical spectrum of the cat allergens is thus uncertain, particularly with regard to the role that a cat lipocalin protein may play in sensitization to cats in allergic individuals. OBJECTIVE: To analyse cDNA encoding a lipocalin allergen and the corresponding recombinant allergen at both the molecular and immunological levels. METHODS: A submandibular salivary gland cDNA expression library was constructed and screened for clones producing IgE-binding polypeptides. cDNA encoding a lipocalin allergen and its corresponding recombinant allergen were analysed. RESULTS: An IgE binding molecule with high sequence identity to the boar salivary lipocalin and the horse lipocalin Equ c 1 allergen was isolated and designated, Fel d 4. Serum from 62.96% of cat-allergic subjects examined had measurable IgE antibody to Fel d 4 but typically at low levels. Despite this in 47% of sera the anti-Fel d 4 IgE titres were higher than the anti-Fel d 1 titres. IgE binding to the lipocalin allergen could be blocked by an allergen extract from cow and to a lesser degree by extracts from horse and dog. CONCLUSION: Fel d 4 is a lipocalin allergen produced by the cat, which binds IgE at relatively high frequency in cat-sensitive individuals. The allergen provides not only a means for investigating differences in the immune response to lipocalin allergens from that found for other mammalian species but also an important reagent for the diagnosis of cat allergy.

Allergens↗
PubMed2004

Component-resolved diagnosis of house-dust mite allergy with purified natural and recombinant mite allergens.

BACKGROUND: Mites belong to the most frequent and potent allergen sources. Immunotherapy with mite allergen extracts is frequently performed if allergen avoidance is not possible or successful. However, highly controversial results have been reported for mite-specific immunotherapy. OBJECTIVE: The aim of this study was to develop diagnostic concepts that may contribute to an improved selection of patients for immunotherapy with Der p allergen extracts and that may be used for immunological monitoring of patients undergoing this treatment. METHODS: The IgE reactivity profiles to Der p extract were determined in a Middle European mite-allergic population by IgE immunoblotting and by using a panel of seven purified natural or recombinant Der p allergens (nDer p 1, nDer p 4, rDer p 2, rDer p 5, rDer p 7, rDer p 8, rDer p 10). Furthermore, we investigated the sensitization and cross-reactivity to house-dust- and storage-mite allergen extracts by CAP FEIA measurements and by IgE competition studies. RESULTS: More than 95% of the patients could be diagnosed with a combination of nDer p 1 and rDer p 2. With the methods used, we could discriminate mite-allergic patients who were mainly sensitized to the major Der p allergens (Der p 1, Der p 2) from patients with a broad sensitization profile, including highly cross-reactive allergens (e.g. Der p 10: tropomyosin) as well as reactivity to storage mites. CONCLUSIONS: Diagnostic tests containing the major mite allergens (i.e. Der p 1, Der p 2) and highly cross-reactive mite allergens (e.g. Der p 10) may improve the diagnostic selection of patients for immunotherapy with Der p extracts. These tests may also be used for the immunological monitoring of patients undergoing immunotherapy.

Adolescent↗
PubMed2002

Non-allergenic antigen in allergic sensitization: responses to the mite ferritin heavy chain antigen by allergic and non-allergic subjects.

BACKGROUND: The majority of house dust mite proteins are non-allergenic. There is, however, no information on the type of immune responses produced to these proteins and if the responses are affected by allergic sensitization. OBJECTIVE: To identify and produce a non-allergenic antigen of the house dust mite and compare antibody and T cell responses with the responses to allergens in sensitized and non-sensitized individuals. RESULTS: Ferritin heavy chain was cloned from a cDNA library as a candidate non-allergen of the house dust mite. It bound IgG but not IgE in the sera of allergic and non-allergic subjects and induced high T cell proliferative responses that correlated highly with the responses to the major allergen Der p 2. The cytokine response to the non-allergen was characterized by the release of high levels of both Th1 and Th2 cytokines from the PBMC of both allergic and non-allergic subjects. In contrast, the response to Der p 2 showed the expected high level of Th2 cytokine release from the PBMC of allergic subjects, while the Th2 cytokine production from PBMC of non-allergic subjects was low and even lower than that induced by ferritin heavy chain. The levels of IFN-gamma release were similar for all groups. Der p 2 induced significantly more IL-10 than ferritin in the non-allergic group. CONCLUSION: The T cell responses to a non-allergenic protein of the house dust mite were high and strongly correlated with the response to the major allergen. The non-allergenic protein induced high levels of Th1 and Th2 cytokine in both allergic and non-allergic subjects, while the allergen induced high levels of Th2 cytokine in allergic subjects and low levels in non-allergic subjects. The responses to the allergen were thus independently up- and down-regulated with no evidence of bystander regulation.

Adult↗
PubMed2002

T cell cytokine responses to outer membrane proteins of Haemophilus influenzae and the house dust mite allergens Der p 1 in allergic and non-allergic subjects.

BACKGROUND: Haemophilus influenzae are ubiquitous colonizers of the nasopharynx, Little is known about the T cell cytokine responses to the antigens of these bacteria and whether or not the responses may interact with responses to aeroallergen. OBJECTIVE: To measure the T cell cytokine responses to conserved outer membrane protein antigens of Haemophilus influenzae and to house dust mite allergen of subjects allergic to the house dust mite and of subjects without allergic sensitization. METHODS: T cell responses were measured by in vitro proliferation and cytokine release from peripheral blood monocytes (PBMC). The allergen used was Der p 1 and outer membrane proteins were recombinant polypeptides representing the OMP6 and D15 antigens. RESULTS: The PBMC of most subjects had proliferative responses to OMP6 and D15, which were highly correlated. The pattern of cytokine release was Th1 biased with high levels of IFN-gamma and usually little IL-5 or IL-13 although PBMC from a few subjects did release IL-5 independent of allergic status. IL-10 release was readily detected. There was no difference in the anti-OMP cytokine response of PBMC from subjects without any known allergy and the responses of PBMC from subjects who were highly allergic to house dust mite. The responses to the Der p 1 allergen showed the expected Th2 cytokine release. CONCLUSION: The outer membrane protein antigens of the ubiquitous colonizing bacteria Haemophilus influenzae induce Th1 cytokine responses which are similar for PBMC from non-allergic individuals and subjects with a high degree of allergy to the perennial house dust mite allergen and strong Th2 responses to Der p 1.

Adult↗
PubMed2002

Stimulatory and inhibitory epitopes in the T cell responses of mice to Der p 1.

BACKGROUND: The responses of mice to the mite allergen Der p 1 have been used to study the mechanisms of allergic sensitization and the development of new types of immunotherapy. Many of the studies require a knowledge of the T cell epitopes, and because Der p 1 is polymorphic, the effect of natural amino acid substitution in the allergen. The intranasal administration of peptides containing T cell epitopes can induce a mucosal tolerance but it is not known if the major activity is limited to stimulatory peptides and if, as found for autoimmunity, some epitopes are not inhibitory. OBJECTIVE: To determine and compare the sequences of Der p 1 which contain stimulatory epitopes for the high responding H-2(b) and H-2(q) mice and the sequences which induce tolerance by intranasal administration of peptides. METHODS: T cell responses of mice immunized with Der p 1 were measured by in vitro T cell stimulation assays so an extensive study of epitope recognition and intranasal tolerance could be made. Synthetic peptides were used to examine the stimulatory and inhibitory ability of all Der p 1 sequences and to map the major H-2(b) epitope in detail. This included the effect of the common polymorphic amino acid 124 substitution found within this epitope. RESULTS: Three and two regions, respectively, were found to contain stimulatory T cell epitopes for H-2(b) and H-2(q) mice. The peptides in these regions were also the most active at inducing intranasal tolerance for the responding haplotype. The correspondence between inhibitory and stimulatory peptides was maintained for the fine mapping of the major H-2(b) epitope. This was found about a core region of 118-126 which was overlapping but separate to a consensus sequence for the binding of endogeneous peptides. Peptides with alanine at the naturally polymorphic residue 124 stimulated and inhibited responses to Der p 1 more effectively, while peptides with the valine 124 variant were immunogenic but poorly cross-reactive. CONCLUSIONS: The intranasal administration of peptides representing each of five epitopes recognized by two strains of mice were able to induce mucosal tolerance and the major tolerizing activity was limited to these epitopes. The position of the core major epitope for C57 mice, which differs from a previously predicted epitope, and its specificity for the natural alanine 124 variant is described.

Administration, Intranasal↗
PubMed2002

Genetic variation of Der p 2 allergens: effects on T cell responses and immunoglobulin E binding.

BACKGROUND: Der p 2 is a highly polymorphic allergen that shows a distinct pattern of sequence divergence. The effect of the variations on T cell and antibody responses has not been compared. OBJECTIVES: To compare IgE antibody binding and T cell proliferation and cytokine release induced by variants of Der p 2. METHODS: Peripheral blood mononuclear cells (PBMC) from 19 allergic and 15 non-allergic people were stimulated with recombinant variants of Der p 2. IL-5, IL-10, IL-13 and IFN-gamma were measured by a time resolved fluorescence (TRF) assay. Serum IgE antibody was measured using a solid-phase TRF assay. RESULTS: Overall the most prevalent variant of Der p 2 (Der p 2. 0101) was the highest or approximately equal highest inducer of T cell proliferation and IL-5, IL-10, IL-13 and IFN-gamma release. The most divergent variant 0104 induced the next highest responses. The variants 0107 and 0108 showed interesting changes especially when the allergic status was considered. Responses to 0107 showed poor Th1/Th2 polarization and, except for IL-10 release, cytokine responses to 0108 were low for non-allergic subjects. The variant 0101 showed similar monoclonal antibody binding but moderately less IgE binding than the other variants. CONCLUSIONS: The most prevalent variant, Der p 2. 0101, was the most active for T cell stimulation and although its IgE binding was slightly less than other variants that was highly correlated. The variant Der p 2. 0104 which contains the known common polymorphic changes had a response which was similar to Der p 2. 0101 and thus these two variants were the most stimulatory representations of Der p 2. The T cell responses to the less common variants 0107 and 0108 however, showed consistent differences demonstrating that changes in the sequence could change the cytokine response.

Adult↗
PubMed2001

Allergens of wild house dust mites: environmental Der p 1 and Der p 2 sequence polymorphisms.

BACKGROUND: Sequence diversity is a common feature of mite allergens. Previous studies, using predominantly commercial mite clones, have described several polymorphic residues for Der p 1 and Der p 2. OBJECTIVE: This study aimed at determining the occurrence of sequence diversity in environmental mite isolates. METHODS: Mites were isolated from houses in Perth and Sydney, Australia. Total RNA was extracted from 1 to 30 Perth mites, and cDNA was synthesized by reverse transcriptase PCR. Der p 1 and Der p 2 cDNAs were PCR amplified and sequenced. Genomic Der p 1 DNA was amplified from whole Sydney mites directly by PCR and then sequenced. RESULTS: Twelve Der p 1 and 9 Der p 2 cDNA clones and 3 Der p 1 genomic DNA were analyzed and showed a high frequency of amino acid polymorphisms. Der p 2 displayed a clear pattern of divergence toward 2 alleles that differed by 4 amino acids and had characteristic silent nucleotide changes. The pattern for Der p 1 was different and unusual, with almost no silent nucleotide substitutions but frequent sporadic missense changes. Proliferative responses of peripheral blood mononuclear cells to peptides containing polymorphic residues of Der p 1 were detected in 8 of 19 subjects, with stimulation being found only for either one of the variant forms of the peptides. However, the responses to variants of whole recombinant allergens were similar, as shown for 4 variants of Der p 2. CONCLUSION: Two clones for each of the allergens were identified as containing sequences that were largely representative of environmental isolates. A small-scale reverse transcriptase PCR used to produce cDNA from individual mites isolated from house dust will have wide application for studies on mite genetics and the production of recombinant mite allergens. Differences in T-cell responses to peptides representing variant epitopes were found, but responses to variants of whole recombinant allergens were similar. The GenBank and Swiss Prot database entries for Der p 1 (U11695) and Der p 2 (P49278) have been updated with the inclusion of the sequence polymorphisms described in this study.

Animals↗
PubMed2001

The molecular basis of antigenic cross-reactivity between the group 2 mite allergens.

BACKGROUND: Mite group 2 allergens Der p 2, Der f 2, and Eur m 2 are 14-kDa proteins of unknown function that share 83% to 85% amino acid sequence identity. Isoforms of the allergens within each genus have been identified which differ by 3 or 4 amino acids, but little is known of the influence of group 2 polymorphisms on human IgE antibody binding. OBJECTIVE: The purpose of this study was to investigate the importance of interspecies and isoform substitutions on murine mAb and IgE antibody binding and on the molecular structure of the group 2 allergens. METHODS: Site-directed mutagenesis was used to incorporate the isoform amino acid substitutions onto the Der p 2.0101 sequence. Recombinant allergens were expressed and purified from Escherichia coli and used to evaluate antibody binding by enzyme-linked immunosorbent assay (ELISA). Molecular modeling of the tertiary structure was used to analyze structural differences between the various group 2 allergens. RESULTS: The substitution of asparagine for aspartic acid at position 114 restored mAb binding of rDer p 2.0101; the other Der p 2 isoforms and the 3 rDer f 2 isoforms also reacted in the 2-site ELISA. The correlation of IgE binding to the Der p 2 isoforms was excellent and tended to be higher in the isoforms with the asparagine 114 substitution (r (2) = 0.87 vs r (2) = 0.95). rEur m 2.0101 bound to all mAb except 7A1; when compared with rDer p 2 for IgE binding, rEur m 2.0101 gave a correlation coefficient of r (2) = 0.68. Molecular modeling revealed that Eur m 2 and the storage mite homologs Lep d 2 and Tyr p 2 retain the tertiary fold of Der p 2. Eur m 2 has a conserved surface, whereas Lep d 2 and Tyr p 2 present most of the amino acid substitutions on this surface. Lep d 2 and Tyr p 2 did not react with mAb or with sera from patients with IgE to Dermatophagoides species. CONCLUSION: The isoform substitutions of rDer p 2 can be distinguished by mAb. The allergenic cross-reactivity between Der p 2, Der f 2, and Eur m 2 is a direct result of the conserved antigenic surface, whereas the lack of cross-reactivity with Lep d 2 and Tyr p 2 is a result of the multiple substitutions across this surface.

Amino Acid Sequence↗
PubMed2001

Inhibition of mucosal and systemic T(h)2-type immune responses by intranasal peptides containing a dominant T cell epitope of the allergen Der p 1.

Although the intranasal administration of peptides containing T cell epitopes has been shown to be a potent method of inhibiting responses to the allergen Der p 1, the experiments to date have concentrated on their ability to regulate immune responses to the injection of antigen in a T(h)1-type adjuvant. Their ability to regulate responses to a T(h)2-type immunization and to sensitization via the respiratory mucosa has not been examined. Here it is shown that peptide used in doses required to block delayed-type hypersensitivity can also readily inhibit IgE responses to Der p 1 injected in alum. To examine responses induced in the respiratory mucosa, mice pretreated with intranasal peptide were sensitized with an intranasal dose of Der p 1 in conjunction with a mutated enterotoxin adjuvant. Intranasal peptide even in very high doses did not reduce IgE titers, but the ability of cells from the draining lymph nodes to release IL-4 and IL-13 but not IL-2, IL-5, IL-10 or IFN-gamma was reduced. These are the first reports on the effect of intranasal peptides containing T cell epitopes on IgE in T(h)2 immunization and on responses to respiratory immunization. Thus the effect of the peptide-induced mucosal tolerance differs depending on the type of immunization used for sensitization, but the potential to inhibit T(h)2 responses and responses to respiratory sensitization as well as T(h)1 responses has been demonstrated.

Administration, Intranasal↗
PubMed2000

Allergen-specific production of interferon-gamma by peripheral blood mononuclear cells and CD8 T cells in allergic disease and following immunotherapy.

BACKGROUND: CD8 T cells are important immunoregulatory cells in animal models of allergic disease, but their role in human allergic immune responses has not been defined. With the development of novel immunotherapeutic reagents, it is clearly important to ascertain whether CD8 T-cell responses are altered following conventional allergen-specific immunotherapy (SIT) and hence targets for future developments/strategies. OBJECTIVE: To study the allergen-specific cytokine release of freshly isolated CD8 T cells from the blood of separate groups of house dust mite- (HDM) allergic patients, patients post-SIT and control nonatopic donors. METHODS: CD8 T cells were isolated by positive selection with immunomagnetic beads and cultured with the affinity purified major mite allergen Der p 1 or with different mitogens, using irradiated autologous peripheral blood mononuclear cells as antigen-presenting cells (APCs). Supernatants were collected at a number of time points and assayed by ELISA for the cytokines interleukin (IL) -4, IL-5 and interferon-gamma (IFNgamma). RESULTS: CD8 T cells stimulated with Der p 1 produced significant quantities of IFNgamma with cells from HDM-allergic subjects releasing considerably more IFNgamma than cells from nonatopic subjects, an average of 804 +/- 283 pg/mL of supernatant compared with 30.2 +/- 18.8 pg/mL (P = 0.006). The cytokine was detected in cultures of 16/17 of the allergic subjects and 4/7 of the nonatopic. CD8 T cells from 6/10 patients who had received HDM-SIT released IFNgamma at an average of 363 +/- 202 pg/mL, which was less than the allergic group but still higher than the nonatopic (P = 0.05). Equivalent levels of IFNgamma were detected when the cells were stimulated with the mitogen PHA and this was the same in all groups. Reliable allergen-specific release of significant quantities of IL-4 or IL-5 was not detected from CD8 T cells. CONCLUSION: Allergen-specific IFNgamma is produced at far greater levels from CD8 T cells of HDM-sensitive allergic patients than from nonatopic control individuals and this level is reduced following SIT.

Allergens↗
PubMed2000

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.

Adult↗
PubMed2000

Cytokine responses to Der p 1 and Der p 7: house dust mite allergens with different IgE-binding activities.

BACKGROUND: There is very limited information comparing T-cell responses to different house dust mite (HDM) allergens even though T cells are essential in the initiation and regulation of immunoglobulin (Ig) E synthesis and eosinophilia. OBJECTIVE: To compare the level of T-cell proliferation and cytokine production to the group 1 and group 7 HDM allergens which are known to have different IgE-binding capabilities. METHODS: Freshly isolated peripheral blood mononuclear cells (PBMC) from HDM-allergic and HDM-nonallergic donors were stimulated with the group 1 and group 7 allergens of Dermatophagoides pteronyssinus and the level of proliferation as well as IL-5 and IFNgamma production were measured. RESULTS: The proliferative and IL-5 production to the group 1 and group 7 allergens were equivalent despite the group 7 allergen's lower frequency of IgE-binding. However more IFNgamma was produced to Der p 7 than to Der p 1, particularly for the nonallergic donors. As expected IL-5 production was much higher for PBMC from the allergic donors than for cells from nonallergics; however, there was no difference in the level of T-cell proliferation between the donor groups. CONCLUSION: The relative importance of the individual HDM allergens is normally determined by measuring the frequency of IgE-binding to the allergen in sera from an allergic population. The equivalent increased IL-5 response of PBMC from allergic people to the group 1 and group 7 allergens despite the different IgE-inducing activity indicates that these allergens may be equally capable of contributing to an asthmatic response by inducing eosinophilia.

Adult↗