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Trogocytosis is a cellular process whereby a cell acquires a membrane fragment from a donor cell in a contact-dependent manner allowing for the transfer of surface proteins with functional integrity. It is involved in various biological processes, including cell-cell communication, immune regulation, and response to pathogens and cancer cells, with poorly defined molecular mechanisms. With the exception of eosinophils, trogocytosis has been reported in most immune cells and plays diverse roles in the modulation of anti-tumor immune responses. Here, we report that eosinophils acquire membrane fragments from tumor cells early after contact through the CD11b/CD18 integrin complex. We discuss the impact of trogocytosis in innate immune cells on cancer progression in the context of the evidence that eosinophils can engage in trogocytosis with tumor cells. We also discuss shared and cell-specific mechanisms underlying this process based on

Objective To recapitulate the more recent epidemiologic studies on the association of air pollution with respiratory allergic diseases prevalence and to discuss the main limitations of current approaches used to establish a link between pollinosis and pollution. Data Sources Through the use of PubMed, we conducted a broad literature review in the following areas: epidemiology of respiratory allergic diseases, effect of pollution and climate changes on pollen grains, and immunomodulatory properties of pollen substances. Study Selections Studies on short- and long-term exposure to air pollutants, such as gaseous and particulate materials, on allergic sensitization, and on exacerbation of asthma symptoms were considered. Results Trend in respiratory allergic disease prevalence has increased worldwide during the last 3 decades. Although recent epidemiologic studies on a possible association of this phenomenon with increasing pollution are controversial, botanic studies suggest a clear effect of several pollutants combined to climatic changes on the increased expression of allergenic proteins in several pollen grains. The current literature suggests the need for considering both pollen allergen and pollutant contents for epidemiologic evaluation of environmental determinants in respiratory allergies. We propose that a measure of allergenic potential of pollens, indicative of the increase in allergenicity of a polluted pollen, may be considered as a new risk indicator for respiratory health in urban areas. Conclusion Because public greens are located in strict proximity to the anthropogenic sources of pollution, the identification of novel more reliable parameters for risk assessment in respiratory allergic diseases is an essential need for public health management and primary prevention area.

Background: Cupressaceae allergy is a worldwide pollinosis caused by several species. Some species in limited geographic areas pollinate in fall and winter. Juniperus oxycedrus matches these features. Objective: We sought to define the immunochemical, allergologic, and environmental aspects of J. oxycedrus pollen. Methods: Pollen extract from J. oxycedrus was prepared and characterized by biochemical analysis and human specific IgE binding by means of ELISA and immunoblotting. A 3-year phenological study was conducted to define the pollinating period of J. oxycedrus . Forty consecutive patients allergic to cypress were recruited in two areas and divided into two groups according to their exposure to J. oxycedrus pollen. Clinical evaluation, skin prick tests, and specific IgE determination with J. oxycedrus , J. ashei , and Cupressus arizonica extracts were carried out on both groups. Results: J. oxycedrus pollen extract was obtained, and it showed specific IgE binding and wide cross-reactivity with other Cupressaceae species. The extract caused a positive skin test response in all the patients tested, with about 80% of them having detectable specific IgE. Symptoms related to J. oxycedrus pollen exposure were recorded in 72% of the directly exposed patients and occasionally in 9% of the nonexposed patients. In the Mediterranean coastal area considered, J. oxycedrus was the first Cupressaceae species that started to pollinate at the beginning of November and ended in the first part of December. Conclusions: J. oxycedrus represents a newly characterized pollen species of the Cupressaceae family that cross-reacts with other members of the same family. Subjects with cypress allergy have in vivo and in vitro positive test responses for J. oxycedrus and can show symptoms when exposed to its pollen. Finally, the most important feature of J. oxycedrus is its early pollinating period in southern Europe (Italy), causing a further extension of the cypress pollen season in areas where other Cupressaceae species are present. (J Allergy Clin Immunol 1998;101:755-61.)

Background: Cupressus arizonica and C. sempervirens, two species belonging to the Cupressaceae family, are recognized as an important cause of respiratory allergies in countries with a Mediterranean climate. Objective: The relationship between pollen extracts from these two species was studied by evaluating the reactivity with polyclonal rabbit antisera and human IgE. Methods: The two extracts were analyzed by sodium dodecylsulfate–polyacrylamide gel electrophoresis. Cross-reactivity was evaluated by ELISA and immunoblotting inhibition experiments. Results: The electrophoretic patterns of the two extracts are quite different, although some components display identical molecular weights. The immunoblotting developed with human IgE from subjects allergic to members of the Cupressaceae family indicated that two major IgE-reactive components, displaying molecular weights of about 43,000 and 36,000 d, were similarly detected in both extracts. Inhibition experiments showed a high degree of cross-reactivity between the two extracts when tested with rabbit polyclonal antibodies against C. arizonica and C. sempervirens . When tested with human IgE inhibition methods, both extracts were able to reciprocally inhibit all of the IgE-reactive bands, although C. arizonica extract was always a better inhibitor. Conclusions: C. arizonica and C. sempervirens extracts are highly cross-reactive at the IgE level and share a number of common epitopes also identified by polyclonal rabbit antisera. (J ALLERGY CLIN IMMUNOL 1996;98:797-804.)

Background: There is increasing evidence for the relevance of Cupressaceae pollinosis among persons living in geographic areas where these species are native or imported. Objective: Previously reported problems in obtaining valid allergenic extracts to be used in the diagnosis of this winter pollinosis prompted us to assess the value of available Cupressaceae pollen extracts for in vivo and in vitro diagnosis. Methods: Commercial and in-house allergenic extracts from Cupressaceae and Taxodiaceae families were used for skin prick testing and specific IgE detection in six groups of subjects exposed to a high concentration of Cupressaceae pollen. Results: Four commercial and two in-house Cupressus sempervirens pollen extracts showed low cutaneous reactivity. Positive test results were recorded in 26% of the 713 subjects tested. C. arizonica in-house pollen extracts gave rise to larger cutaneous reactions. Furthermore, the skin prick test response was positive in a greater number of subjects (38%) of the same group. Six commercial immunoassays were able to detect specific IgE to C. sempervirens in rates ranging from 8.1% to 81.1%. Specific IgE to C. arizonica was detected by means of an in-house immunoenzymatic method in 70.3% of 54 patients with suspected "cypress" allergy, and specific IgE to C. sempervirens was detected in 75.9% of these patients by using a commercial system. High rates of cross-reactivity within the Cupressaceae family and with species of the Taxodiaceae family were recorded with both in vivo and in vitro tests. Conclusions: The use of C. sempervirens in vivo diagnostics should be carefully evaluated until better characterized extracts are developed. In-house–characterized extracts of C. arizonica seem to be more reliable in the diagnosis of Cupressaceae allergy by means of skin prick testing. The sensitivity of commercially available in vitro methods to detect specific IgE to C. sempervirens should be carefully evaluated; nevertheless, valid results can be obtained with some already available immunoassays. (J ALLERGY CLIN IMMUNOL 1996;98:21-31.)

Two monoclonal antibodies (MoAb) specific for Parietaria judaica allergenic components were selected on the basis of their capability to recognize either the Parietaria judaica major allergen (MoAb 1A6/1D1) or several other allergenic components (MoAb 1A4/2F8) except the major allergen. These two antibodies, either individually or combined, were used to develop an ELISA-inhibition system using a reference Parietaria judaica extract (in-house Reference preparation, IHR). The assays performed with these reagents were firstly standardized by testing the IHR several times. A good reproducibility, evaluated both at the level of 50% inhibition values, and in terms of analysis of the variance of the slopes of the regression curves, was obtained. Subsequently, the potency of several Parietaria judaica extracts, either obtained by manufacturing companies or produced in other laboratories, was evaluated by these tests. Data obtained by interpolation with the IHR values and expressed in terms of arbitrary units (AU) were compared with those obtained by classical human IgE inhibition, performed with sera from allergic patients. Results indicate that the monoclonal antibodies produced in our laboratory can be successfully employed, either individually or combined, in the standardization of allergenic preparations in addition to, and possibly replacing, the classical IgE-based standardization procedures which require human specimens often available in limited amounts only.

Background Cypress pollen causes respiratory syndromes with different grades of severity, including asthma. IL-33, its receptor ST2, and dendritic cells (DCs) have been implicated in human respiratory allergy. Objective We sought to define a new mouse model of allergy to cypress pollen that recapitulates clinical parameters in allergic patients and to evaluate the implications of DCs and the IL-33/ST2 pathway in this pathology. Methods BALB/c mice, either wild-type or ST2 deficient (ST2 −/− ), were sensitized and challenged with the Cupressus arizonica major allergen nCup a 1. Local and systemic allergic responses were evaluated. Pulmonary cells were characterized by means of flow cytometry. DCs were stimulated with nCup a 1 and tested for their biological response to IL-33 in coculture assays. Results nCup a 1 causes a respiratory syndrome closely resembling human pollinosis in BALB/c mice. nCup a 1–treated mice exhibit the hallmarks of allergic pathology associated with pulmonary infiltration of eosinophils, T cells, and DCs and a dominant T H 2-type immune response. IL-33 levels were increased in lungs and sera of nCup a 1–treated mice and in subjects with cypress allergy. The allergen-specific reaction was markedly reduced in ST2 −/− mice, which showed fewer infiltrating eosinophils, T cells, and DCs in the lungs. Finally, stimulation of DCs with nCup a 1 resulted in ST2 upregulation that endowed DCs with increased ability to respond to IL-33–mediated differentiation of IL-5– and IL-13–producing CD4 T cells. Conclusions Our findings define a novel preclinical model of allergy to cypress pollen and provide the first evidence of a functionally relevant linkage between pollen allergens and T H 2-polarizing activity by DCs through IL-33/ST2.