View Point: Semaphorin-3E: An Emerging Modulator of Natural Killer Cell Functions?

Semaphorin-3E (Sema-3E) is a member of a large family of proteins originally identified as axon guidance cues in neural development. It is expressed in different cell types, such as immune cells, cancer cells, neural cells, and epithelial cells. Subsequently, dys-regulation of Sema-3E expression has been reported in various biological processes that range from cancers to autoimmune and allergic diseases.

Expression of IL-9 receptor alpha chain on human germinal center B cells modulates IgE secretion.

Background: IL-9 has been shown to affect the differentiation pathway of different cell types. However, its potential role in the maturation pathway of antigen-driven B-cell differentiation and its functional effects remain unknown.

Objective: To characterize IL-9 receptor alpha chain (IL-9R alpha) expression on human tonsillar B cells at different maturational stages, and to assess its effect on IgE production.

Increased expression of Th2-associated chemokines in bullous pemphigoid disease. Role of eosinophils in the production and release of these chemokines.

Bullous pemphigoid is an inflammatory disease of the skin associated with eosinophil infiltration and the presence of high levels of Th2 cytokines in the associated blister fluid. Little is known about the contribution of chemokines in this disease. We found that eotaxin and MCP-4 mRNA and immunoreactivity were expressed in all biopsies of BP patients and were mainly localized to the epidermis and eosinophils.

Modulation of allergic response in nasal mucosa by antisense oligodeoxynucleotides for IL-4.

Background: The cytokine IL-4 is highly involved in T(H)2 inflammation, such as that seen in allergic rhinitis. IL-4 can induce IgE synthesis and eotaxin. Recent studies have shown that stimulation of allergic nasal tissue with ragweed allergen can induce local IL-4 mRNA production.

The CCR3 receptor is involved in eosinophil differentiation and is up-regulated by Th2 cytokines in CD34+ progenitor cells.

The involvement of chemokines in eosinophil recruitment during inflammation and allergic reactions is well established. However, a functional role for chemokines in eosinophil differentiation has not been investigated. Using in situ RT-PCR, immunostaining, and flow cytometric analysis, we report that human CD34+ cord blood progenitor cells contain CCR3 mRNA and protein.