Basophils infiltrate into skin lesions more commonly than previously thought, and thus they may play important roles in a variety of inflammatory skin diseases.

The activation of oncogenic signaling pathways induces the reprogramming of glucose metabolism in tumor cells and increases lactic acid secretion into the tumor microenvironment. This is a well-known characteristic of tumor cells, termed the Warburg effect, and is a candidate target for antitumor therapy. Previous reports show that lactic acid secreted by tumor cells is a proinflammatory mediator that activates the IL-23/IL-17 pathway, thereby inducing inflammation, angiogenesis and tissue remodeling. Here, we show that lactic acid, or more specifically the acidification it causes, increases arginase I (ARG1) expression in macrophages to inhibit T-cell proliferation and activation. Accordingly, we hypothesized that counteraction of the immune effects by lactic acid might suppress tumor development. We show that dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinases, targets macrophages to suppress activation of the IL-23/IL-17 pathway and the expression of ARG1 by lactic acid. Furthermore, lactic acid-pretreated macrophages inhibited CD8 1 T-cell proliferation, but CD8 1 T-cell proliferation was restored when macrophages were pretreated with lactic acid and DCA. DCA treatment decreased ARG1 expression in tumor-infiltrating immune cells and increased the number of IFN-c-producing CD8 1 T cells and NK cells in tumor-bearing mouse spleen. Although DCA treatment alone did not suppress tumor growth, it increased antitumor immunotherapeutic activity of Poly(IC) in both CD8 1 T cell-and NK cell-sensitive tumor models. Therefore, DCA acts not only on tumor cells to suppress glycolysis but also on immune cells to improve the immune status modulated by lactic acid and to increase the effectiveness of antitumor immunotherapy.Many types of immune cells infiltrate tumors. Although these immune cells were classically thought to attack and eliminate tumors, recent studies indicate that they actually induce inflammation within tumors, thereby promoting tumor progression by inducing angiogenesis and tissue remodeling within the tumor microenvironment and tumor invasion and metastasis. 1,2 Furthermore, immune cells such as tumorassociated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), all of which have potent suppressive effects on anticancer immune responses, are also recruited to tumors. 3,4 We previously showed that lactic acid secreted by tumor cells enhances the production of IL-23 by monocytes/macrophages stimulated with Toll-like receptor (TLR) ligands. 5

Osteoclasts, multinucleated cells of myeloid-monocytic origin, are responsible for bone resorption, which is crucial for maintenance of bone homeostasis in concert with bone-forming osteoblasts of nonhematopoietic, mesenchymal origin. Receptor activator of NF-κB ligand (RANKL) and M-CSF, expressed on the surface of and secreted by osteoblasts, respectively, are essential factors that facilitate osteoclast formation. In contrast to the activation processes for osteoclast formation, inhibitory mechanisms for it are poorly understood. Herein we demonstrate that inhibitory Ig-like receptors recruiting Src homology 2 domain-containing tyrosine phosphatase 1 (SHP-1) are expressed on osteoclast precursor cells like other myeloid cells, and that they play a regulatory role in the development of osteoclasts. We detected cell-surface expression of paired Ig-like receptor (PIR)-B and four isoforms of leukocyte Ig-like receptor (LILR)B on cultured osteoclast precursor cells of mouse and human origin, respectively, and showed that all of these ITIM-harboring inhibitory receptors constitutively recruit SHP-1 in the presence of RANKL and M-CSF, and that some of them can suppress osteoclast development in vitro. Fluorescence energy transfer analyses have suggested that the constitutive binding of either murine PIR-B or its human ortholog LILRB1 to MHC class I molecules on the same cell surface comprises one of the mechanisms for developmental regulation. These results constitute the first evidence of the regulation of osteoclast formation by cell-surface, ITIM-harboring Ig-like receptors. Modulation of these regulatory receptors may be a novel way to control various skeletal system disorders and inflammatory arthritis.

This study concerns the significance of nuclear/cytoplasmic expression of beta-catenin and mutation of the beta-catenin gene in craniopharyngiomas. Fourteen adamantinomatous type and one squamous papillary type craniopharyngiomas were studied. Histologically, 13 of 14 adamantinomatous type craniopharyngiomas showed typical features, ie mixtures of 'palisading cells', 'stellate cells', and 'ghost cells'. In addition, 'whorl-like arrays' of epithelial cells were frequently observed in the areas of stellate cells. On immunohistochemistry, all typical adamantinomatous type craniopharyngiomas showed nuclear/cytoplasmic expression of beta-catenin predominantly in cohesive cells within the whorl-like arrays and in cells transitional towards ghost cells, where immunoreactivity for Ki-67 was almost absent. The cohesive cells in the whorl-like arrays also demonstrated loss of cytokeratin isoform expression. Using direct sequencing of amplified nucleic acids, nine of the 13 typical adamantinomatous type craniopharyngiomas with nuclear beta-catenin accumulation showed heterozygous one-base substitution mutation of the beta-catenin gene. The other unusual adamantinomatous type and squamous papillary type craniopharyngiomas showed no obvious nuclear/cytoplasmic beta-catenin immunoreactivity and no mutation of the beta-catenin gene, suggesting molecular heterogeneity. These findings suggest that the pathogenesis of typical adamantinomatous type craniopharyngioma is associated with abnormalities of Wnt signalling that act as a morphogenetic signal towards whorl-like arrays and ghost cells rather than as simple proliferation stimuli.