Eosinophil cationic protein (ECP), a secretory protein of the eosinophil granulocyte, is a basic and highly heterogeneous protein. This heterogeneity is dependent on polymorphisms in the ECP gene and post-translational modifications, and it affects the functional properties of the protein in terms of cytotoxicity. The aim of this study was to further investigate the molecular heterogeneity, hence, an affinity capture assay based on an antigen-antibody interaction with the surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS) technique was developed. Of three monoclonal antibodies tested, that is, EG2, 614, and 652, the 614 mab was chosen for the experiments. ECP heterogeneity of single individuals was studied in extracts of purified blood eosinophils, and the presence of approximately 5 major molecular species was demonstrated in each subject. ECP from subjects with different ECP 434(G>C) genotypes (arg97thr) showed mass differences corresponding to the amino acid shift from arginine to threonine. ECP purified from pooled leukocytes of large numbers of healthy blood donors demonstrated an extensive mass heterogeneity with approximately 10 major molecular species. By the use of a variety of glucosidases it was shown that this heterogeneity was mainly due to N-linked oligosaccharides on which sialic acid, galactose, and acetylglucosamine was positioned. We conclude that the SELDI-TOF MS technique using specific monoclonal antibodies is a convenient and versatile tool; by means of this technique, we could detect both genetic and post-translational causes of the molecular heterogeneity of the eosinophil cationic protein.

Monocytes from hemodialysis patients have the capacity to mobilize CD11b to the same extent as cells from healthy individuals at the inflammatory spot, but more intense stimuli are required for such actions, probably because of a transient refractoriness.

We have analyzed the antibody repertoire from normo- and hypercholesterolemic subjects to investigate how it can be related to macrophage-dependent modification of low-density lipoproteins, in comparison to the commonly used copper-oxidized LDL. Preexisting natural antibodies in plasma from normo- and hypercholesterolemic individuals were tested for their reactivity against copper ion oxidized LDL and LDL modified by macrophages. A crosswise comparison between these two antigen preparations demonstrated a different antibody repertoire in normo- and hypercholesterolemic patients. This study suggest that the search for antibodies that can influence the progression or regression of an atherosclerotic process has to take into account the process by which LDL is modified, and the repertoire of antibodies that is generated in the normal population, in comparison to that with, or at risk for, coronary artery diseases.

Expression of CD9 is a feature of both eosinophils and platelets. We have investigated the CD9 expression on resting and activated eosinophils with regard to possibly interacting platelets. Mixed leukocytes were obtained from the platelet‐containing (PC) and platelet‐depleted (PD) peripheral blood of healthy donors. A cell membrane permeabilization technique, the FOG method, enabled us to detect the eosinophils as a separate population and permitted flow cytometric analysis of both surface and intracellular antigens. Monoclonal antibodies against CD61 were used to identify platelets. The CD9/CD61 ratio indicated that CD9 on resting eosinophils originates mainly from eosinophils and not from adhered platelets. No difference in CD9 expression was obtained between resting eosinophils in PC and PD blood. However, the expression of CD9 was decreased (p<0.05) on eosinophils in PMA‐activated PD blood but increased (p=0.001) in PC blood, probably due to interacting platelets since CD61 increased simultaneously. In addition, we were able to detect an intracellularly stored pool of CD9 in eosinophils which decreased after activation with PMA. Together these results indicate a translocation of intracellularly stored CD9 to the cell membrane upon activation, probably followed by a subsequent shedding.

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This study highlights the importance of the exposure to a combination of particulate matters and pollen allergens, in the induction of allergic disease in the airways, and we have demonstrated that polluted tunnel dust has an effect on both the inflammatory and immunological components of experimental allergy. Immunization and challenge with carbon core particles together with birch pollen increased neither the BHR nor the specific IgE production significantly. Our results therefore strongly suggest that it is most likely to be the organic phase bound to the carbon core of the diesel exhaust particles that might have an important adjuvant effect in the induction of experimental allergy.

The present study shows that RBC can interact with mesenchymal cells in vitro. The ability of RBC to modulate fibroblast-mediated contraction in vitro, might therefore be an important mechanism regulating repair processes after injury.