γδ T cells are considered to be innate lymphocytes that play an important role in host defense against tumors and infections. We recently reported that IL-18 markedly amplified γδ T cell responses to zoledronate (ZOL)/IL-2. In an extension of this finding, we analyzed the mechanism underlying the IL-18–mediated expansion of γδ T cells. After incubation of PBMCs with ZOL/IL-2/IL-18, the majority of the cells expressed γδ TCR, and the rest mostly exhibited CD56brightCD11c+ under the conditions used in this study. CD56brightCD11c+ cells were derived from a culture of CD56intCD11c+ cells and CD14+ cells in the presence of IL-2 and IL-18 without the addition of ZOL. They expressed IL-18Rs, HLA-DR, CD25, CD80, CD83, CD86, and CD11a/CD18. In addition, they produced IFN-γ, TNF-α, but not IL-12, when treated with IL-2/IL-18, and they exerted cytotoxicity against K562 cells, thus exhibiting characteristics of both NK cells and dendritic cells. Incubation of purified γδ T cells with CD56brightCD11c+ cells in the presence of ZOL/IL-2/IL-18 resulted in the formation of massive cell clusters and led to the marked expansion of γδ T cells. However, both conventional CD56−/intCD11chigh dendritic cells induced by GM-CSF/IL-4 and CD56+CD11c− NK cells failed to support the expansion of γδ T cells. These results strongly suggest that CD56brightCD11c+ cells play a key role in the IL-18–mediated proliferation of γδ T cells.

Zoledronate (Zol) has recently been shown to expand gammadelta T cells that play important roles in host defenses against infection and tumors. In this study, we examined effects of interleukin-18 (IL-18) on expansion of gammadelta T cells in human peripheral blood mononuclear cells (PBMCs) stimulated by Zol and IL-2. The expansion of gammadelta T cells stimulated by Zol and IL-2 was strongly promoted by exogenous IL-18, and to the contrary, inhibited by neutralizing anti-IL-18 receptor antibody. The gammadelta T cells that expanded in the presence of Zol, IL-2, and IL-18 exhibited the phenotype of effector memory cells characterized by CD44 (+), CD27 (-), and CD45RA (-). In addition, they expressed NKG2D, perforin, CD94, CD25, and CD122, and 15% to 40% of them were positive for CD56. Incubation of gammadelta T cells in the presence with IL-18 produced GM-CSF, IFN-gamma, and TNF-alpha at much higher levels than those incubated without IL-18. They showed strong cytotoxicity against tumor cells including mesothelioma cells and inhibited growth of xenograft of mesothelioma in mice. These observations indicate that IL-18 can efficiently promote expansion of gammadelta T cells with potent antitumor activity.

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ATP, UTP, ADP and UDP induced intracellular Ca(2+) responses and oscillations in HeLa cells that sometimes lasted over 1 h. The response is due to the activation of P2Ys, G-protein coupled ATP receptors, because the oscillations persisted for several minutes even in Ca(2+)-free solution, and suramin and PPADS, antagonists of ATP receptors, partially inhibited the response. The potency of these nucleotides varied with the culture or cell conditions, i.e. UTP was generally most potent but in some cases UDP was more potent; responses to UDP were variable while those to ATP were constant. In addition, Ca(2+) responses to ATP and UDP were additive. These findings suggested the existence of two or more subtypes of P2Ys in HeLa cells. RT-PCR experiments revealed the existence of P2Y(2), P2Y(4) and P2Y(6). Recovery from starvation (culture in FBS-free medium overnight and re-addition of FBS) increased the responses to UTP and UDP but not to ATP, suggesting that the number or activity of P2Y(6) and/or P2Y(4) receptors may increase with cell proliferation in HeLa cells.

Human γδ T cells augment host defense against tumors and infections, and might have a therapeutic potential in immunotherapy. However, mechanism of γδ T cell proliferation is unclear, and therefore it is difficult to prepare sufficient numbers of γδ T cells for clinical immunotherapy. Recently, natural killer (NK)-like CD56brightCD11c+ cells were shown to promote the proliferation of γδ T cells in an IL-18-dependent manner. In this study, we demonstrated that the NK-like CD56brightCD11c+ cells could directly interact with γδ T cells to promote their sustained expansion, while conventional dendritic cells (DCs), IFN-α-induced DCs, plasmacytoid DCs or monocytes did not. We also examined the cellular mechanism underlying the regulation of CD56brightCD11c+ cells. CD14+ monocytes pre-incubated with IL-2/IL-18 formed intensive interactions with CD56intCD11c+ cells to promote their differentiation to CD56brightCD11c+ cells with helper function. The development of CD56brightCD11c+ cells was suppressed in an IFN-α dependent manner. These results indicate that CD14+ monocytes pretreated with IL-2/IL-18, but neither DCs nor monocytes, play a determining role on the development and proliferation of CD56brightCD11c+ cells, which in turn modulate the expansion of γδ T cells. CD56brightCD11c+ NK-like cells may be a novel target for immunotherapy utilizing γδ T cells, by overcoming the limitation of γδ T cells proliferation.

Inferior vena cava (IVC) thrombosis or obstruction is a complication rarely associated with blunt trauma. We present a case of IVC thrombo-occlusive lesion with both hepatic and renal failure which developed after a thoracoabdominal blunt trauma. Direct thrombectomy and patch cavoplasty were successfully carried out under deep hypothermia using cardiopulmonary bypass.

Calcium ion is an intracellular second messenger important for cellular functions in a variety of cells. In many cell types, transient and repetitive increases in the intracellularHere we found that the application of RB induced Ca 2ϩ oscillations in HeLa cells. We also found that RB-induced Ca 2ϩ oscillations had unique characteristics different from the other receptor-activated Ca 2ϩ oscillations reported in HeLa cells [6][7][8]. Materials and MethodsHeLa cells were grown in DME/F12 (SIGMA, MO, USA) supplemented with 10% fetal bovine serum, 50 units/ml penicillin, and 50 g/ml streptomycin. Cells were cultured on glass coverslips (25-mm diameter, MATSUNAMI #1) in a humidified atmosphere (5% CO 2 , 95% air) at 37°C.To introduce fura-2 into the cells, they were incubated with 2 M fura-2 AM (acetoxymethyl ester; Dojindo, Kumamoto, Japan) and 0.2% cremophor EL (SIGMA) for 50 min at 37°C. Coverslips bearing the

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