House-dust mite allergy: mapping of Dermatophagoides pteronyssinus allergens for dogs by two-dimensional immunoblotting

Abstract

IntroductionSpecific immunotherapy has shown to be very useful for allergy control in dogs, with a common success rate ranging from 65% to 70%. However, this efficacy could probably be improved and the identification of individual allergomes, with the choice of more adequate molecular allergen pools for specific immunotherapy, being the strategy.AimTo map Dermatophagoides pteronyssinus (Der p) allergens for mite-sensitized atopic dogs, for better understanding how individual allergograms may influence the response to house-dust mite immunotherapy.Material and methodsTo identify the Der p mite allergome for dogs, 20 individuals allergic to dust-mites and sensitized to Der p, were selected. The extract from Der p was submitted to isoelectric focusing (IEF), one-dimensional (1-D) and two-dimensional (2-D) sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Separated proteins were blotted onto polyvinylidene difluoride (PVDF) membranes and immunoblottings were performed with patient sera. Allergen-bound specific IgE was detected.ResultsEleven allergens were identified from isoelectric focusing (IEF), as well as from 1-D SDS PAGE. From 2-D SDS-PAGE, 24 spots were identified.ConclusionsSeveral similarities were found between dog and human allergograms and no absolute correlation between sensitization and allergy was observed either. As in humans, different individual allergograms do not seem to implicate different clinical patterns, but may influence the response to specific immunotherapy. The molecular epidemiology approach in veterinary allergy management, by the characterization of individual patients’ allergoms and by choosing the best molecular allergen pool for each patient could also improve the efficacy of allergy immunotherapy.

The novel high molecular weight Dermatophagoides farinae protein Zen‐1 is a major allergen in North American and European mite allergic dogs with atopic dermatitis

“…That the Dermatophagoides HDM allergome for dogs is very complex was further confirmed by a study testing sera from 20 Portuguese atopic dogs with hypersensitivity to Df and D. pteronyssinus (Dp) . In that study, which used isoelectric focusing and two‐dimensional immunoblotting with Dp (but not Df) proteins, 11 allergens for dogs were identified by the first method and 20 different spots by the second .…”

“…In that study, which used isoelectric focusing and two‐dimensional immunoblotting with Dp (but not Df) proteins, 11 allergens for dogs were identified by the first method and 20 different spots by the second . Interestingly, IgE reactivity to putative group 1 and 2 Dp allergens was found in 16 of 20 (80%) and 10 of 20 dogs (50%), respectively, potentially making these two proteins major allergens for dogs in Portugal …”

Allergy to grass pollen: mapping of Dactylis glomerata and Phleum pratense allergens for dogs by two-dimensional immunoblotting

“…6 showed a remarkable clinical improvement, with a change in D. glomerata and P. pratense spectrotype complexity, which could be associated with several Th2-like immunological mechanisms, occurred in the initial phase of immunotherapy [ 27 – 29 ], and suggesting a lack of absolute correlation between sensitization and allergy. Such observations were also made by Martins et al [ 24 ], with an allergic patient, regarding Dermatophagoides pteronyssinus mite spectrotypes, but so far it has not been possible to detect any correlation between that and the efficacy of immunotherapy. More patients should be studied to confirm any possible early/late evolution in sensitization during the course of specific immunotherapy.…”

“…Hence, no specific IgE level, IDT score or pattern of spectrotype was possible to relate to a specific clinical pattern. Similarly to house-dust mite allergy [ 24 ], IDT scoring seemed to be a reliable parameter in terms of correspondence to the level of specific IgE to D. glomerata and P. pratense . However, such high correlation may not occur between specific IgE levels or IDT scores and the number of recognized allergens from PAGE.…”

Consideration of methods for identifying mite allergens

“…For antigen discovery, the authors excised two high molecular weight species and microsequenced them with Edman degradation to identify a protein resembling Der f 14 [ 25 ] and a protein resembling the chitinase allergen from prawns. A similar study used IEF, ID, and 2D electrophoresis to catalogue multiple IgE-binding D. pteronyssinus proteins using sera from allergic dogs [ 26 ].…”