T lymphocyte dynamics in methylisothiazolinone‐allergic patients

Abstract

MI-HSA is able to induce secondary responses in lymphocytes drawn from sensitized subjects, and provides a more effective source of antigen than free MI. Furthermore, individual donors show differential activity profiles with respect to T lymphocyte subsets.

T lymphocyte phenotype of contact‐allergic patients: experience with nickel and p‐phenylenediamine

“…An SI of ≥2.5 was regarded as being indicative of a biologically meaningful level of proliferation. 7 For nickel-sensitive donors, the range of SI values recorded and the proportions of positive donors were similar for weakly (5/7) and strongly (7/12) allergic individuals ( Figure 1A). However, only 5 of 12 extremely allergic (+++) donors achieved a positive SI.…”

“…We showed recently that the composition of the T cell compartment in the peripheral blood of patients with allergy to MI was significantly altered as compared with healthy (buffy coat) controls, with increases in the proportions of naïve CD4 + and CD8 + T cells, and corresponding decreases in the proportions of central memory, effector memory and EMRA cells. 7 For comparison, we have now characterized the T cell populations in nickel-allergic and PPD-allergic patients by flow cytometric analysis of the proportions of CD4 + and CD8 + T cells in each of four T cell subsets, that is, naïve, central memory, EMRA, and effector memory, defined on the basis of expression of CD27 and CD45RA. 19 The CD4 + or the CD8 hi population was gated (Supporting Information Figure 1), and the proportion of cells in each of four subpopulations was determined in comparison with healthy (buffy coat) control samples.…”

“…[2][3][4][5][6][7] One important tool for the characterization of human T cell responses to contact allergens is the lymphocyte transformation test, in which the proliferation of cultured T lymphocytes induced by contact allergens, or by contact allergens conjugated with proteins, is measured. [8][9][10][11][12][13][14][15] Experience with the lymphocyte transformation test has been predominantly with metals, and in particular nickel, although somewhat variable results have also been reported with certain organic contact allergens, including: 2,4-dinitrochlorobenzene, 9 methylisothiazolinone (MI), 7 and p-phenylenediamine (PPD). 11,12 In the present investigations, the lymphocyte transformation test was used to explore further the characteristics of T lymphocyte responses to nickel (as nickel sulfate), and to PPD, which is a proven contact allergen in hair dyes and henna tattoos 1,16 (delivered in culture as a hapten-protein conjugate).…”

“…In previous investigations of subjects with allergic contact dermatitis caused by MI, it was found that there was an association between skin sensitization and the relative frequencies of CD4 + and CD8 + naïve, memory and effector T lymphocytes. 7 Comparable studies were conducted here with PPD and nickel to determine whether similar patterns are found in subjects sensitized to these contact allergens, and previously published analyses of MI have been extended. Finally, experiments were performed to determine whether sensitization to PPD or nickel (and also to MI) is associated with changes in the relative frequency in peripheral blood of regulatory T cells (Tregs) 17 or skin-homing (cutaneous lymphocyte antigen [CLA] + ) T lymphocytes.…”

Current knowledge on biomarkers for contact sensitization and allergic contact dermatitis

“…Many important skin sensitizers have been shown to interact specifically with HSA, such as nickel, DNCB, PPD, and methylisothiazolinone (MI), whereas fragrances such as cinnamal, citronellol and eugenol have been shown to interfere with the related xenogeneic bovine serum albumin . Furthermore, some of these sensitizer–carrier‐albumin molecules may become immunologically active and affect sensitizer‐specific human T cell clone activation by, for example, by transferring nickel to the T cell receptor–MHC interface or by generating still unknown MI‐specific T cell epitopes . It is remarkable that similar results were obtained with nickel bound to human transferrin, usually known as iron carrier, indicating several distinct parallel mechanisms in nickel‐specific polyclonal T cell activation .…”