W.A. van Leeuwen

Profilin Is a Cross-Reactive Allergen in Pollen and Vegetable Foods

Sera with IgE antibodies against grass pollen often contain IgE against vegetable foods. We investigated the role of the ubiquitous protein profilin in this cross-reactivity. Profilin was purified from Lolium perenne grass pollen by means of affinity purification with Sepharose-coupled poly(L-proline). This solid phase was also used as capturing agent for profilin from pollen and food extracts for application in a radioallergosorbent test. It was shown that profilin is an allergen in grass pollen and in a wide range of vegetable foods, like potato and celery. Within a grass-pollen-sensitive population, patients with IgE to vegetable foods have a high incidence of antibodies against profilin. IgE antibodies against grass pollen profilin were shown to be cross-reactive with respect to vegetable foods.

Variability of crossreactivity of IgE antibodies to group I and V allergens in eight grass pollen species

Crossreactivity to Dactylis glomerata, Festuca rubra, Phleum pratense, Anthoxanthum odoratum, Secale cereale, Zen mays, and Phragmites communis of IgE antibodies against Lol p I or Lol p V was investigated by means of RAST‐inhibition. Within a group of sera the degree of crossreactivity was demonstrated to be highly variable. Individual sera were not always equally crossreactive to all pollen species. A high degree of crossreactivity for Group I allergens did not necessarily implicate the same for Group V. Group I and Group V representatives were found to be present in all eight species. It was demonstrated that within this group of grass species significant quantitative and qualitative differences exist, with respect to Group I and Group V allergens. Species with a low phylogenetic affinity to Lolium perenne, like Zea mays and Phragmites communis showed a very low degree of reactivity, even when measured with the most crossreactive sera. A higher taxonomic relationship however, did not always implicate a closer antigenic resemblance. Antigenically both allergens from Zea mays are more similar to Lol p I and Lol p V, than the analogues in Secale cereale.

On relativistic kinetic gas theory: IX. Transport coefficients for systems of particles with arbitrary interaction

Abstract A relativistic method to calculate transport coefficients for arbitrary particle interaction is developed. The heat conductivity, the shear viscosity and the volume viscosity are expressed in terms of relativistic omega integrals.

IgE and IgG cross-reactivity among Lol p I and Lol p II/III. Identification of the C-termini of Lol p I, II, and III as cross-reactive structures.

In this study, the homologous C‐termini of Lol p I Lol p II, and Lol p III were shown to contain cross‐reactive B‐cell epitopes. This was demonstrated by inhibition studies with purified Lol p I, II, and III and synthetic peptides of their C‐termini. It was ruled out that the observed cross‐reactivity was caused by cross‐contamination of the purified allergens. Both human IgE and IgG bound to the C‐terminus of Lol p I. These antibodies were cross‐reactive with Lol p II and, more specifically, with its C‐terminus. Within a small panel of allergic patients, no cross‐reactivity with Lol p III was found. A hyperimmune polyclonal rabbit antiserum against Lol p I also recognized the Lol p I C‐terminus. As for human antibodies, cross‐reactivity with Lol p II and its C‐terminus was demonstrated. Cross‐reactivity with Lol p III was demonstrated with C‐terminal peptides, but not with native Lol p III. A polyclonal rabbit antiserum against Lol p II bound to the C‐terminal peptides of both Lol p II and III. This binding was inhibited with Lol p I, confirming that cross‐reactive structures exist not only on the C‐termini of Lol p II and Lol p I, but also of Lol p III and Lol p I. The existence of cross‐reactivity between Lol p I and Lol p II and III possibly contributes to the frequently observed cosensitization for these allergens in grass‐pollen‐allergic patients.

On relativistic kinetic gas theory: II. Reciprocal relations between transport phenomena

Abstract Relativistic reciprocal relations between the cross effects of heat conduction and diffusion are derived from time reversal invariance for a gas mixture, which obeys the linearized relativistic transport equation.

Allergenicity Assessment of Apple Cultivars: Hurdles in Quantifying Labile Fruit Allergens

Background: Assessment of allergenicity of foods is important for allergic consumers and regulators. Immunoassays to measure major food allergens are widely applied, often giving variable results. Using the major apple allergen Mal d 1 as a model, we aimed to establish at the molecular level why different immunoassays for assessing allergenicity of apple cultivars produce conflicting outcomes. Methods: Mal d 1 was measured in 53 cultivars from Italy and 35 from The Netherlands, using four different immunoassays. Purified Mal d 1 standards were molecularly characterized by size-exclusion chromatography (SEC) and mass spectrometry (MS). Results: Three immunoassays using an identical standard gave similar results. Minor differences in sample preparation already resulted in significant loss of allergenicity. The fourth assay, using a different Mal d 1 standard, gave 10- to 100-fold lower outcomes. By SEC, this standard was shown to be almost fully aggregated. This aggregation was accompanied by a decrease of the mass of the Mal d 1 molecule by ∼1 kDa as analyzed by MS. The deviating immunoassay was shown to selectively recognize this aggregated form of Mal d 1, whereas the other three assays, including the one based on IgE antibody recognition, preferentially bound non-aggregated allergen. Conclusions: Variable and poorly controllable major allergen modification in both extracts and standards hamper accurate allergenicity assessments of fruits.

On relativistic kinetic gas theory: XIV. Transport coefficients of a binary mixture. General expressions

Abstract A relativistic method to calculate transport coefficients is developed for a binary mixture with arbitrary particle interaction. The heat conductivity, the diffusion coefficient, the thermal-diffusion coefficient, the shear viscosity and the volume viscosity are expressed in terms of relativistic omega integrals.

Relativistic Boltzmann theory for a plasma

Abstract The linear or phenomenological laws such as Ohms law, Fouriers law and Ficks law are derived for a relativistic plasma in an electromagnetic field. It is shown that the choice of a reference frame as proposed by Landau and Lifshitz entails-in contrast to, for instance, the choice of Eckart-the validity of Onsagers reciprocity relations.

Relativistic Boltzmann theory for a plasma: I. The entropy production

Abstract An expression for the entropy production has been derived on the basis of which it is argued that the choice of reference frame as proposed by Landau and Lifshitz is to be preferred rather than any other possibility.

Elements of relativistic kinetic theory

The following subjects are treated: scattering matrix, transition rate and cross section in relation to relativistic kinetic theory; unitarity, bilateral normalization and H theorem; covariant one-particle distribution function; relativistic transport equation.