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Notes: Background Atopy is closely associated with the cellular T helper type-2 (Th2) phenotype, that is dominated by the pleiotrophic cytokine IL-4. The cellular source of IL-4 has yet to be determined, although basophils have been proposed. Eosinophils and mast cells are likely contenders investigated here, and the eosinophil-like leukaemia line AML14.3D10 is compared to eosinophils as an in vitro culturable model for eosinophils. Lectins can cross-link-specific surface glycoproteins and are found in the ingested (processed foods) and inhaled (airborne pollen grains) human environment. Therefore it is of interest to determine whether lectins can elicit the release of IL-4 from Th2-associated granulocytes other than basophils.Method This study investigated the ability of eosinophils, AML14.3D10 and mast cells to secrete preformed IL-4 in response to stimulation with lectins, and explored molecular mechanisms underlying the interaction.Results Purified eosinophils and basophils, and cultured mast cells and AML14.3D10 cells were incubated with 1 µm lectin. Agglutination was scored by microscopy. IL-4 secretion was measured by enayme-linked immunosorbent assay. Biotinylated lectins were used to determine binding to cells by flow cytometry and in lectin blots of sodium dodecyl sulphate (SDS) gels.Discussion Purified human eosinophils, AML14.3D10 cells and cultured mast cells secrete IL-4 with a pattern similar to that found in basophils when stimulated with a panel of reactive and unreactive lectins. The lectin SNA induces IL-4 secretion from mast cells and basophils, but not from eosinophils or AML14.3D10. Eosinophils appear to secrete only pre-formed IL-4, whereas mast cells may synthesize IL-4 on ligation with the lectin LCA. Lectins that agglutinate the granulocytes investigated do not necessarily induce secretion of IL-4. Lectins that elicit secretion of IL-4 bind more to eosinophils than unreactive lectins as determined by flow cytometry and lectin blotting of SDS gels.Conclusion As granulocytes with functions related to that of basophils, eosinophils, AML14.3D10 and cultured mast cells respond to stimulation with lectins similarly to basophils. This emphasizes the possibility that eosinophils and mast cells may be linked in their cellular heritage as the cellular partners, and lectins as ligands, may contribute to the maintenance of a Th2-favoured microenvironment that is thought to underlie the allergic march.

Notes: Combining inhaled long-acting β-2 agonist (LABA) and inhaled corticosteroid (ICS) seems to offer asthma control at a lower dose of ICS than achieved by ICS alone. Fine mapping of T-cell surface markers by flow cytometry offers a detailed status of the individual's inflammatory response. The frequency of MT2 (CD4+CD45RA–CD62L+CD11adim) and MT1 (CD4+CD45RA–CD62L–CD11abright) cells in peripheral blood, and their ratio, has been shown to differ predictably in atopics and patients with leprosy, where MT2 correlates with a Th2 phenotype and MT1 with a Th1 phenotype. Stable asthmatics, requiring fluticasone propionate (FP) 750–1000 µg daily or equivalent, were randomized to receive, double-blinded, either Seretide®[salmeterol and fluticasone propionate (SFC, n = 16)] 50 µg/500 µg bd or FP 500 µg bd (n = 17). If asthma was controlled based on lung function and symptoms at clinic visits every 6 weeks, ICS dose was tapered until asthma exacerbated or 0 µg was reached. The frequency and ratio of MT2 and MT1 T cells of the patients was monitored at 6 week intervals. As treatment tapered, the frequency of MT2 cells decreased (P = 0038 from first to final visit), whereas that of MT1 cells increased. The ratio of MT2/MT1 decreased (P = 0049 from first to final visit). In patients receiving LABA + ICS, the fall in MT2/MT1 ratio appeared to be more pronounced than in patients receiving ICS alone. Thus, the MT2 phenotype may be associated with stable asthma, whereas an imminent exacerbation may associate with an increase in the MT1 phenotype. LABA may allow for a greater effect of FP on the MT ratio.

Notes: Background:  Mast cells have long been recognized as the principal cell type that initiates the inflammatory response characteristic of acute allergic type 1 reactions. Our goal has been to further characterize maturation of progenitors to mast cells.Methods:  Mast cells were cultured from human cord blood derived CD133+ progenitors. Mast cell function was tested using histamine release. During differentiation mast cells surface marker expression was monitored by flow cytometry.Results:  CD133+ progenitors expressed the early haematopoietic and myeloid lineage markers CD34, CD117, CD13 and CD33. Mature mast cells expressed CD117, CD13 and CD33, and expression of the high affinity immunoglobulin E recpetor FcɛRI increased during culture. Cytokine receptors interleukin (IL)-5R, IL-3R, granulocyte-macrophage-colony stimulating factor (GM-CSF)R and IL-18R were expressed at high levels during maturation. Chemokine receptors CXCR4 and CXCR2 were highly expressed on both newly purified CD133+ cells and mature cells.Conclusion:  Human mast cells can be cultured from a CD34+/CD117+/CD13+/CD33+ progenitor cell population in cord blood that is tryptase and chymase negative. Developing and mature mast cells express a wide range of chemokine and cytokine receptors. We found high levels of expression of CD123, IL-5R and GM-CSF receptors, also found on eosinophils and basophils, and high levels of expression of the receptor for the inflammatory cytokine IL-18.

Notes: T lymphocytes play a major role in many immune responses. In the last decade, special focus has been on the function of Th1 and Th2 effector cells. Now the importance of regulatory CD4+CD25+ T cells in maintenance of the immunological homeostasis emerges. Sarcoidosis is a multisystem granulomatous disorder often affecting the lungs. The typical sarcoid granulomas consists of epitheloid cells, macrophages and lymphocytes, mainly CD4+ T cells of Th1 phenotype. We have cultured T cells from bronchial biopsies of patients with sarcoidosis as well as from controls in high levels of interleukin 2 (IL-2) and IL-4 and demonstrate spontaneously arising CD4+ CD25+ populations and high concentrations of IL-10 in these cultures. The main difference between cultures of sarcoid origin compared to controls is a very much higher concentration of the inflammatory cytokines IL-6 and TNF-α in cultures of sarcoid origin.

Notes: Abstract. According to many textbooks on optics, the deviation angle of a prism with the apex angle (or prism angle), γ, and the refractive index, n, with respect to the surrounding medium can be approximated by δappr=(n-1)γ, if γ≪π/2 and the angle of incidence α1≪π/2. The validity of this approximation is investigated considering the relative error of the deviation. It is shown that this approximation can be extended to angles of incidence α1=nγ with very fair accuracy and even to larger prism angles γ〈π/4 in the range of angles of incidence near the minimum of deviation depending on the acceptable relative error.

Notes: Abstract. The spectral transmittance of Christiansen filters made of glass beads immersed in an index-matching fluid is described theoretically based on geometrical optics. The glass beads and the immersion fluid are considered to be homogeneous and free of absorption. The diameter is assumed to be the same for all of the beads. Fresnel reflection and prismatic deviation of the incident light are considered to be the dominant losses in transmission experiments. The parameters for these losses can be estimated a priori by a simple model. Losses by Rayleigh scattering and diffraction can be included by additional parameters to fit the experimental spectral extinction curves. For the range of wavelengths sufficiently far from the transmittance maximum the theoretical results of the model predict that the spectral extinction increases sublinearly with the thickness of the filters, the inverse of the diameter of the glass spheres, and the difference of the refractive indices between the glass and the immersion fluid. Due to the total reflection of the glass spheres, if their refractive index is smaller than that of the immersion fluid, an asymmetry of the spectral transmittance curves is observed. Furthermore, the halfwidth of the spectral transmission passband decreases with increasing thickness of the filters and with decreasing average diameter of the beads for given dispersion curves of the refractive indices. The simple theory to describe the spectral transmittance curves of Christiansen filters made of glass beads quantitatively seems to solve a 100-year-old problem in physics.