NF-kappaB involvement in the activation of primary adult T-cell leukemia cells and its clinical implications.

The HTLV-I provirus-encoded Tax protein induces NF-kappaB in Tax-transfected Jurkat T cells or HTLVL-I- infected T cells in vitro. Tax induction of NF-kappaB is presumed to be involved in proliferation and activation of primary leukemia cells in vivo. Recent studies have demonstrated that NF-kappaB activities in human T cells are mediated by at least four c-Rel-related DNA binding proteins - p50, p55, p75 and p85. We examined the significance of NF-kappaB induction in primary adult T cell leukemia cells and the induction kinetics of each of the four NF-kappaB species. Marked NF-kappaB activity was detected using an electrophoretic mobility shift assay (EMSA) in the primary cells of patients with acute disease, but little activity was noted in the cells of chronic patients. NF-kappaB activity was enhanced in a time-dependent manner in acute type cells cultured with mitogen-free medium; there was no induction of activity in chronic type cells. UV crosslinking demonstrated all four species of NFkappaB complex - high levels of p50 and lower levels of p55 and p75, in acute type cells; chronic type cells showed only the p50. As a control, normal resting T cells similarly showed only p50; control cells showed little change in activity when cultured without mitogenic stimulation, analogous to chronic type ATL. Northern blotting revealed enhancement of c-rel (encoding p85) and KBFI (encoding p50 and p55) expression in acute type cells during culture, while there was no significant enhancement of mRNAs in chronic type ATL cells or unstimulated normal T cells. Northern blotting also revealed that Tax is upregulated at the mRNA level in acute- but not chronic-type cells during culture. Expression of c-rel and KBF1 mRNAs in acute type cells appeared to be related to Tax mRNA expression. These results suggest that Tax is capable of inducing nuclear expression of all four NF-kappaB species in primary ATL cells of acute type patients, with marked effects on p55, p75, and p85. Tax induction of NF-kappaB species is regulated, at least in part, at a pretranslational level involving increases in c-rel and KBF1 mRNA.

Marked suppression of T cells by a benzothiophene derivative in patients with human T-lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis.

In a search for new anti-autoimmune agents that selectively suppress activation of autoreactive T cells, one such agent, 5-methyl-3-(1-methylethoxy)benzo[b]thiophene-2-carboxamide (CI-959-A), was found to be effective. This compound, which is known to suppress tumor necrosis factor alpha (TNF-alpha)-induced CD54 expression, inhibited the primary proliferative response of the T cell to antigen (Ag)-presenting cells (APCs) including allogenic dendritic cells (DCs), autologous Epstein-Barr virus-infected B cells, and human T lymphotropic virus type I (HTLV-I)-infected T cells. Autoreactive T cells from patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) spontaneously proliferate in vitro, and their activation is reported to be associated with CD54 expression. The spontaneous proliferation of T cells from patients with HAM/TSP was entirely blocked by CI-959-A. However, in this study, the T-cell proliferation in 15 patients with HAM/TSP was found to depend more extensively on major histocompatibility complex (MHC) class II and CD86 than on CD54 Ags. Since most important APCs for the development of HAM/TSP are DCs and HTLV-I-infected T cells, the effect of CI-959-A on DC generation and on the expression of surface molecules on activated T cells is examined. CI-959-A suppressed recombinant granulocyte-macrophage colony stimulating factor (GM-CSF)- and recombinant interleukin-4-dependent differentiation of DCs from monocytes and inhibited the expression of CD54 and, more extensively, MHC class II and CD86 Ags. CI-959-A showed little toxicity toward lymphoma or HTLV-I-infected T-cell lines or toward monocytes and cultured DCs. These results suggest that CI-959-A might be a potent anti-HAM/TSP agent.

Microleakage of composite resins in cavities of upper primary molars.

OBJECTIVE: To improve the quality of resin restorations, studies are necessary not only of the physical properties of materials but also of the cavity geometry. We have evaluated marginal microleakage for two types of photo-curing composite resin applied to cavities with different marginal structures. SAMPLE AND METHODS: The test materials were 91 extracted upper primary molars. The two composite resins used in this experiment were Liner Bond II (LBII) and Photo Clearfil A (PCA). A class I cavity was created in each tooth; the cavity configuration was a round bevel, a straight bevel and a butt joint. The tooth was then restored with each composite resin. Each tooth was exposed to thermal cycles, followed by immersion in 0.2% basic fuchsin solution. Three sections, through the mesial, central and distal areas of each tooth were taken. The penetration of the dye was examined with a stereoscopic microscope. The sites of observation for examination of microleakage were awarded scores of between 0 and 7. RESULTS: LBII-among the three marginal forms, absence of leakage was observed most frequently in the straight bevel group followed by the round bevel and the butt joint groups, in the mesial and distal sections. In the central section, the straight bevel did not show any scores of 0, 6 or 7. PCA-an absence of leakage in the mesial section occurred most frequently for the round bevel group. However, the absence of leakage in the central and distal sections was most frequent for the straight bevel group. Microleakage of the central section (with scores from 1 to 7) was frequently lower than that for the mesial and distal sections. Scores of 5 and above in the central section were observed only in the butt joint group. The frequency and mean score of leakage were clearly higher in LBII than in PCA, with one significant exception. For both composite resins, the butt joint group showed higher-mean scores of leakage than did either the round or straight bevel group, but for PCA, the mean score of the central section was lower than the other two sections in all groups. CONCLUSION: Our study shows that beveling does reduce marginal leakage. This leakage was more frequently observed with the use of LBII than with PCA. However, the amount of tooth ground away was greater for the bevel-treated cavity. In considering these features, special care is necessary in selecting the bur for treating a bevelled cavity.

Prevention of murine AIDS development by (R)-9-(2-phosphonylmethoxypropyl)adenine.

LP-BM5 murine leukemia virus (MuLV) infection causes severe immunodeficiency termed murine AIDS (MAIDS). The acyclic nucleoside phosphonates, (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA) and 9-(2-phosphonylmethoxyethyl)adenine (PMEA) were examined, in comparison with zidovudine (AZT), for their inhibitory effect on the development of MAIDS. Although no significant difference in inhibition of LP-BM5 MuLV replication was identified between PMPA and PMEA in cell cultures, PMPA was obviously less cytotoxic to the host lymphocytes. None of the mice treated in vivo with 5 or 25 mg/kg of PMPA or 25 mg/kg of PMEA developed MAIDS at 5 weeks after viral infection. However at 9 weeks, none of the 25 mg/kg PMPA-treated mice progressed to MAIDS, except for one that developed mild MAIDS, whereas PMEA, even at 100 mg/kg, could not prevent disease progression. MAIDS-associated activation of lymphocytes and viral replication were drastically inhibited by PMPA treatment. These results indicate that PMPA is a highly effective antiretroviral agent in vivo.

IL-2-induced growth of CD8+ T cell prolymphocytic leukemia cells mediated by NF-kappaB induction and IL-2 receptor alpha expression.

The binding of interleukin-2 (IL-2) to its receptor on normal T cells induces nuclear expression of nuclear factor kappaB (NF-kappaB), activation of the IL-2 receptor (IL-2R) alpha chain gene, and cell proliferation. In the present study, the role of IL-2R signaling in the growth of CD8+ T cell prolymphocytic leukemia (T-PLL) cells has been investigated. Flow cytometry revealed that primary leukemia cells from a patient with CD8+ T-PLL expressed IL-2Ralpha and beta chains, and the cells showed a proliferative response and an increase in IL-2Ralpha expression on culture with exogeneous IL-2. Northern blot analysis failed to detect IL-2 mRNA, suggesting that IL-2 may act in a paracrine manner in vivo. Electrophoretic mobility-shift assays revealed that recombinant IL-2 increased NF-kappaB binding activity in nuclear extracts of the leukemia cells, and Northern blot analysis showed that IL-2 increased the abundance of mRNAs encoding the NF-kappaB components c-Rel and KBF1 in these cells. IL-2 binding analysis demonstrated that IL-2 markedly increased the number of low affinity IL-2Rs on the leukemia cells, without an effect on the number of high-affinity IL-2Rs. These results show that IL-2 is capable of inducing the nuclear expression of NF-kappaB in primary CD8+ T-PLL cells, and that this effect is mediated, at least in part, at a pretranslational level.

Granulocyte-colony stimulating factor-induced proliferation of primary adult T-cell leukaemia cells.

Granulocyte-colony stimulating factor (G-CSF) is known to induce proliferation and differentiation of granulocyte progenitors, and is widely used to treat neutropenia induced by intensive chemotherapy for malignant lymphoma or adult T-cell leukaemia/lymphoma (ATL). G-CSF is thought not to stimulate malignant lymphoid cells. In the present study we examined the ability of G-CSF to induce in vitro growth of primary ATL cells from 14 patients (nine acute-type, two chronic-type and three lymphoma-type), and we analysed the in vivo counts of ATL cells in patients who received G-CSF for neutropenia. FACS analysis using phycoerythrin-labelled recombinant G-CSF demonstrated that ATL cells from 11/14 patients express some G-CSF receptor (G-CSFR), with a range between 5.4% and 87.3%. Cells expressing G-CSFR also expressed CD4. Reverse polymerase chain reaction (PCR) analysis demonstrated expression of G-CSFR messenger RNA in G-CSFR expressing cells. Leukaemic cells derived from seven (four acute-type, one chronic-type and two lymphoma-type) of the 14 patients proliferated in vitro in response to G-CSF, as measured by [3H]thymidine incorporation; maximum responses were at G-CSF concentrations of 10-100 ng/ml. Nine of 14 patients receiving rG-CSF for neutropenia were analysed retrospectively for ATL cell numbers. Four patients whose primary tumour cells proliferated in response to rG-CSF in vitro showed a significant increase in ATL cell count after administration of rG-CSF (P = 0.038), whereas five patients whose leukaemic cells did not proliferate in vitro showed no significant increase in ATL cell count. G-CSF can stimulate proliferation of ATL cells which may complicate therapy for this disease.

[The etiology of acute lower respiratory tract infections in infants].

The etiology of acute lower respiratory tract infections (ALRI) was studied in pediatric inpatients under 2 years of age admitted to Chiba Municipal Hospital between June 1994 and March 1995. Eighty-seven patients, 99 episodes were investigated for bacterial infection with the use of blood culture and washed sputum culture, for viral infection with the use of virus isolation, antigen detection and antibody assays, for Mycoplasma pneumoniae infection with the use of antibody assay and for Chlamydia infection with the use of antigen detection. Pathogens were identified in 71 (71%) of the 99 episodes. Evidence of bacterial infection was detected in 43 episodes (43%), viral infection in 37 episodes (37%), Mycoplasma pneumoniae infection in 4 episodes (4%) and Chlamydia infection 3 episodes (3%). The major bacterial pathogens were H. influenzae, M. (B) catarrhalis and S. pneumoniae. RS virus and influenza virus epidemics occurred during the winter. A mixed bacterial and viral infection was documented in 13 episodes (13%). RS virus infection was common in infants up to 6 months old. Mixed bacterial and influenza virus infections were common in 1 or more year old children. Virus isolation was useful for the grasp of the viral epidemic. Bacterial associated infections were common in children under 2 years of age with ALRI. Washed sputum culture and sputum gram stains' were useful for the treatment of infant ALRI.