To investigate the mechanisms underlying the expression of allergic contact dermatitis, we compared the characteristics of nickel (Ni)-specific T cell responses in 10 patients with allergic contact dermatitis to Ni and in 10 healthy, nonallergic individuals. CD4+ T cells purified from peripheral blood of both allergic and nonallergic subjects proliferated similarly to NiSO4 in vitro, with the responses mostly restricted to CD4+ CD45RO+ memory T cells. In contrast, Ni-specific CD8+ T cell responses were detected only in allergic patients. Limiting dilution assay confirmed a high frequency of Ni-specific CD4+ T cells in both individual categories, and of Ni-specific CD8+ T cells in allergic patients, but not in nonallergic persons. Ni-specific CD4+ T cell clones prepared from nonallergic subjects displayed lower interferon-gamma and higher interleukin-10 production compared with T cell clones from allergic patients. The T cell skin-homing receptor, cutaneous lymphocyte-associated antigen, was expressed on the large majority of specific CD4+ clones from both the groups. Finally, Ni-specific CD8+ clones prepared from patients also expressed the cutaneous lymphocyte-associated antigen receptor, and released high interferon-gamma and no interleukin-4. In aggregate, the results suggest that the presence of specific CD8+ T cells and a distinct pattern of cytokine release (e.g., an augmented production of interleukin-10) by CD4+ T cells can be important elements in determining whether a hapten induces allergy or a silent immune response.

Testing IgE reactivity to a panel of nsLTP allergens unveils important associations between nsLTP sensitization profiles and clinical presentation and allows the identification of novel cluster patterns indicating likely cross-reactivities and highlighting potential allergens for nsLTP immunotherapy.

Poor or no biological activity and lack of clinical relevance of IgE-binding plant glycans (five out of five) was demonstrated using human lactoferrin expressed in rice as a model.

No abstract

Background: The order Fagales represents an important cause of tree-pollen allergy in northern countries. We investigated the IgE recognition profiles, mutual relationships, and association with clinical symptoms of a panel of allergens belonging to the PR-10 family, the main proteins responsible for Fagales allergy (Act d 8, Aln g 1, Api g 1, Ara h 8, Bet v 1, Cor a 1.0101, Cor a 1.0401, Gly m 4, Mal d 1, and Pru p 1). Methods: A total of 526 PR-10-reactive subjects living in central and southern Italy were studied by ImmunoCAP-ISAC-112 microarray analysis. Results: Overall, Bet v 1 reactivity was the most commonly (74%) observed among PR-10 proteins, but Cor a 1.0101 was the most prevalent in participants aged <6 years, and between 15 and 65 years. Overall, 26% of the PR-10-reactive persons were Bet v 1 negative, whilst 93.6% of the PR-10 polyreactive individuals were Bet v 1 positive. Among the 10 PR-10s evaluated, 100 combinations were recorded. The strongest association was observed between molecules with the highest sequence identities (Bet v 1 and Cor a 1.0101, Cor a 1.0401 or Aln g 1; Mal d 1 and Pru p 1). Bet v 1-, Cor a 1.0101-, and Aln g 1-specific IgE recognition was associated with respiratory symptoms, whilst Ara h 8, Cor a 1.0401, Gly m 4, Mal d 1, and Pru p 1 were selectively linked to an oral allergic syndrome. Conclusions: Testing IgE reactivity to a panel of PR-10s in a birch-free area discloses peculiar relationships between clinical phenotypes and sensitization profiles, allowing the identification of novel cluster patterns.