It is unknown whether formoterol and salmeterol, two long-acting beta(2)-adrenoreceptor agonists, have regulatory functions in the production of T-helper cell (Th) type 2- and Th1-related chemokines by monocytes and bronchial epithelial cells. In the present study, the effects of formoterol and salmeterol on lipopolysaccharide (LPS)-induced expression of the Th2-related chemokine macrophage-derived chemokine (MDC; CCL22) and the Th1-related chemokine interferon-gamma-inducible protein (IP)-10 (CXCL10) were investigated in a monocytic cell line, THP-1, and in human primary monocytes. In addition, their effects on the expression of the Th2-related chemokine thymus- and activation-regulated chemokine (TARC; CCL17) were evaluated in an epithelial cell line, BEAS-2B. Formoterol enhanced MDC but suppressed IP-10 production in monocytes induced by LPS. Higher doses of salmeterol were required to enhance LPS-induced MDC expression in THP-1 cells. Formoterol and salmeterol could significantly suppress TARC expression in BEAS-2B cells. These effects could be reversed by a selective beta(2)-adrenoreceptor antagonist, ICI-118551. Formoterol- and LPS-induced MDC expression was inhibited by budesonide. Both long-acting beta(2)-adrenoreceptor agonists suppressed thymus- and activation-regulated chemokine expression in bronchial epithelial cells mediated via beta(2)-adrenoreceptors. Formoterol at physiological concentrations could suppress lipopolysaccharide-induced T-helper cell type 1-related chemokine (interferon-gamma-inducible protein-10) but enhance T-helper cell type 2-related chemokine (macrophage-derived chemokine) expression in human monocytes. Long-acting beta(2)-adrenoreceptor agonists may increase T-helper cell type 2-related chemokine expression in monocytes and T-helper cell type 2 recruitment and, therefore, long-acting beta(2)-adrenoreceptor agonist monotherapy may not be an appropriate therapeutic option for asthma.

Epidemiological studies suggest that an environmental factor (possibly a virus) acquired early in life may trigger multiple sclerosis (MS). The virus may remain dormant in the central nervous system but then becomes activated in adulthood. All existing models of MS are characterized by inflammation or demyelination that follows days after virus infection or antigen inoculation. While investigating the role of CD4+ T cell responses following Theiler's virus infection in mice deficient in STAT4 or STAT6, we discovered a model in which virus infection was followed by demyelination after a very prolonged incubation period. STAT4-/- mice were resistant to demyelination for 180 days after infection, but developed severe demyelination after this time point. Inflammatory cells and up-regulation of Class I and Class II MHC antigens characterized these lesions. Virus antigen was partially controlled during the early chronic phase of the infection even though viral RNA levels remained high throughout infection. Demyelination correlated with the appearance of virus antigen expression. Bone marrow reconstitution experiments indicated that the mechanism of the late onset demyelination was the result of the STAT4-/- immune system. Thus, virus infection of STAT4-/- mice results in a model that may allow for dissection of the immune events predisposing to late-onset demyelination in MS.