No abstract

Single subject and group analyses (n ϭ 12) showed that the eyes-open and eyes-closed states in complete darkness considerably and consistently differ in the patterns of associated brain activation in fMRI. During nonchanging external stimulation, ocular motor and attentional systems were activated when the eyes were open; the visual, somatosensory, vestibular, and auditory systems were activated when the eyes were closed. These data suggest that there are two different states of mental activity: with the eyes closed, an "interoceptive" state characterized by imagination and multisensory activity and with the eyes open, an "exteroceptive" state characterized by attention and ocular motor activity. Our study also shows that the chosen baseline condition may have a considerable impact on activation patterns and on the interpretation of brain activation studies.

Tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2 are proteins with proteinase-inhibiting and cytokine properties. TIMP-1 is active primarily in B cells and B-cell lymphomas, whereas TIMP-2 expression is restricted to T cells. The expression of TIMP-1 and TIMP-2 in lymph nodes from patients with Hodgkin disease (HD) and in Hodgkin-derived cell lines was investigated. In situ hybridization showed TIMP-1 RNA expression in 3% to 80% of Hodgkin/Reed-Sternberg (H/R-S) cells from 14 of 15 patients, with results in one patient being at the lowest detection limit; no expression of TIMP-2 in H/R-S cells; and only weak expression of TIMP-2 in reactive lymphoid tissue. Production of TIMP-1 protein by H/R-S cells was accordingly found on immunohistochemical analysis of lymph nodes from patients with HD. There was only low expression of matrix metalloproteinase (MMP)-2, which is mainly inhibited by TIMP-2; no expression of MMP-1 and MMP-3 in reactive lymphoid tissue; and no expression of these MMPs in H/R-S cells. Thus, TIMP-1 expression in lymph nodes was not correlated with metalloproteinase expression. Five of 7 Hodgkin-derived cell lines expressed TIMP-1 at the protein level. Only one of these cell lines expressed TIMP-2, at the lowest detection limit. TIMP-1 levels in plasma from patients with HD were within the same range as those in plasma from healthy controls. Recombinant human TIMP-1 inhibited induced cell death in Hodgkin-derived cell lines in vitro. TIMP-1 and TIMP-2 inhibited T-cell cytotoxicity against autologous cells presenting tumor-associated antigens and in allogeneic mixed lymphocyte cultures. Thus, TIMP-1, aside from its role in proteinase equilibrium, is an autocrine and paracrine survival factor for H/R-S cells and an immunosuppressive protein expressed in Hodgkin lymphomas.

Although spontaneous remissions may rarely occur in B-cell chronic lymphocytic leukemia (B-CLL), T cells do generally not develop a clinically significant response against B-CLL cells. Because this T-cell anergy against B-CLL cells may be caused by the inability of B-CLL cells to present tumor-antigens efficiently, we examined the possibility of upregulating critical costimulatory (B7-1 and B7-2) and adhesion molecules (ICAM-1 and LFA-3) on B-CLL cells to improve antigen presentation. The stimulation of B-CLL cells via CD40 by culture on CD40L expressing feeder cells induced a strong upregulation of costimulatory and adhesion molecules and turned the B-CLL cells into efficient antigen-presenting cells (APCs). CD40-activated B-CLL (CD40-CLL) cells stimulated the proliferation of both CD4+ and CD8+ T cells. Interestingly, stimulation of allogeneic versus autologous T cells resulted in the expansion of different effector populations. Allogeneic CD40-CLL cells allowed for the expansion of specific CD8+cytolytic T cells (CTL). In marked contrast, autologous CD40-CLL cells did not induce a relevant CTL response, but rather stimulated a CD4+, Th1-like T-cell population that expressed high levels of CD40L and released interferon-γ in response to stimulation by CD40-CLL cells. Together, these results support the view that CD40 activation of B-CLL cells might reverse T-cell anergy against the neoplastic cell clone, although the character of the immune response depends on the major histocompatibility complex (MHC) background on which the CLL or tumor antigens are presented. These findings may have important implications for the design of cellular immunotherapies for B-CLL.

Gene transfer of the costimulatory molecules of B7-1 and of immunostimulatory cytokine transcripts and by ELISA B7-2 induces a potent antitumor immune response in a quantification of cytokines in the supernatant. Stimulation variety of tumor models. B cell neoplasms including mulof T cells with rAAV/B7-1 or rAAV/B7-2 transduced LP-1 tiple myeloma (MM) often show little or no expression of cells resulted in an up to 10-fold increase of T cell prolifer-B7 antigens; they are therefore a potential target for this ation when compared with LP-1 cells transduced with approach. To increase the expression of human B7 genes rAAV/Neo. Similar results were obtained with RPMI 8226 in MM cells, both genes and the neomycin phosphocells. Both rAAV/B7-1 and rAAV/B7-2 transduced LP-1 transferase gene were packaged into recombinant adenocells stimulated the T cell secretion of IL-2 and IFN-␥. Furassociated virus vectors (rAAV). The resulting recombinant thermore, [ 51 Cr] release assays showed that rAAV/B7-1 or viruses rAAV/B7-1, rAAV/B7-2 and rAAV/Neo were used rAAV/B7-2 transduced LP-1 cells induced a cytolytic T cell to transduce the MM cell lines LP-1 and RPMI 8226. This (CTL) response, in contrast to LP-1 cells transduced with allowed the transduction of up to 80% of LP-1 cells 4 days rAAV/Neo. In all assays, the effects of rAAV/B7-1 and after infection with purified rAAV particles. The response rAAV/B7-2 were similar. Taken together, the results show of human allogeneic T cells to rAAV/B7-1 and rAAV/B7-2 that rAAV-mediated transfer of B7 genes into MM cell lines transduced, ␥-irradiated LP-1 cells was assessed by is able to enhance the antitumor T cell response and to [ 3 H]thymidine incorporation, by RT-PCR-based detection elicit a cytolytic T cell response.Keywords: B7; adeno-associated virus (AAV); lymphoma; multiple myeloma; immunotherapy; gene therapy rejected in vivo and could protect against subsequent Introduction challenge with wild-type, B7-negative tumors. [8][9][10][11][12][13][14] There Cytolytic T cells (CTLs) play a major role in the rejection are several variables influencing the efficiency of tumor of immunogenic tumors.1 Therefore, many different strarejection, eg the immunogenicity of the tumor and the tegies have been used to enhance the specific antitumor amount of B7 molecule expressed by the tumor cell. 9,15 CTL response in order to eradicate residual tumor cells. While there is overwhelming evidence that transfer of For full activation of T cells at least two signals are B7-1 and B7-2 genes into tumor cells induces a CTL required, ie an antigen-specific signal delivered through response at least against immunogenic tumors, 16 less is the T cell receptor (TCR) and a costimulatory signal known about the effects of B7 gene combinations used through the CD28 molecule on the T cell surface. CD28 for this purpose. Moreover, the combined gene transfer is stimulated by counter-receptors designated B7-1 of both B7-1 and B7-2 has not been studied for B cell (CD80) and B7-2 (CD86) on antigen presenting cells lym...