Gene modification strategies to induce tumor immunity.

The immune system provides an attractive option for use in cancer therapy. Our increasing understanding of the molecular events important in the generation of an effective immune response presents us with the opportunity to manipulate key genes to boost the immune response against cancer. Genetic modification is being employed to enhance a range of immune processes including antigen presentation, activation of specific T cells, and localization of immune effectors to tumors.

Carpal tunnel syndrome caused by an intraosseous ganglion of the capitate.

Intraosseous ganglions often arise in the foot and ankle but are less common within the carpal bones. We present a case of an intraosseous ganglion of the capitate bone associated with compression of the median nerve that was seen on plain radiographs and magnetic resonance images.

Cancer/testis antigen expression in human mesenchymal stem cells: down-regulation of SSX impairs cell migration and matrix metalloproteinase 2 expression.

Several families of genes by and large located on the X chromosome encode proteins of unspecified function. Commonly known as cancer/testis (CT) antigens, they are considered, under normal conditions, only to be expressed in cells of the germ line and placenta. CT genes are also often expressed in cancer cells, hence their classification.

Colon epithelial cell differentiation is inhibited by constitutive c-myb expression or mutant APC plus activated RAS.

Blocked differentiation is a hallmark of cancer cells and the restoration of differentiation programs in vivo is an actively pursued clinical aim. Understanding the key regulators of cyto-differentiation may focus therapies on molecules that reactivate this process. c-myb expression declines rapidly when human colon cancer epithelial cells are induced to differentiate with the physiologically relevant short-chain fatty acid, sodium butyrate.

Biochemical and growth regulatory activities of the HIN-200 family member and putative tumor suppressor protein, AIM2.

The human HIN-200 family member AIM2 was originally identified in a screen for suppressors of melanoma tumorigenicity following introduction of chromosome 6 into the UACC903 human melanoma cell line. Although the AIM2 protein contained many of the conserved structural motifs common to other HIN-200 proteins, the biochemical characteristics of AIM2 and the ability of overexpressed AIM2 to phenocopy the effect of introduction of chromosome 6 in the UACC903 cells had not been assessed. Herein we demonstrated that AIM2 was localised within the nucleus of transfected or interferon-treated human cells.

The functional basis for hemophagocytic lymphohistiocytosis in a patient with co-inherited missense mutations in the perforin (PFN1) gene.

About 30% of cases of the autosomal recessive immunodeficiency disorder hemophagocytic lymphohistiocytosis are believed to be caused by inactivating mutations of the perforin gene. We expressed perforin in rat basophil leukemia cells to define the basis of perforin dysfunction associated with two mutations, R225W and G429E, inherited by a compound heterozygote patient. Whereas RBL cells expressing wild-type perforin (67 kD) efficiently killed Jurkat target cells to which they were conjugated, the substitution to tryptophan at position 225 resulted in expression of a truncated ( approximately 45 kD) form of the protein, complete loss of cytotoxicity, and failure to traffic to rat basophil leukemia secretory granules.

Gene-engineered T cells as a superior adjuvant therapy for metastatic cancer.

The major limiting factor in the successful application of adjuvant therapy for metastatic disease is the lack of adjuvant specificity that leads to severe side effects. Reasoning that T cells of the immune system are highly specific, we generated tumor-specific T cells by genetic modification of mouse primary T cells with a chimeric receptor reactive with the human breast cancer-associated Ag erbB-2. These T cells killed breast cancer cells and secreted IFN-gamma in an Ag-specific manner in vitro.

Immunotherapy of cancer using systemically delivered gene-modified human T lymphocytes.

The use of gene-engineered T cells expressing chimeric single-chain (scFv) receptors capable of codelivering CD28 costimulation and T cell receptor zeta chain (TCR-zeta) activation signals has emerged as a promising treatment regimen for cancer. Using retroviral transduction, primary human T lymphocytes were gene-engineered to express the scFv-CD28-zeta chimeric receptor reactive with the ErbB2 tumor-associated antigen. We demonstrated the ability of these gene-engineered human T cells to produce high levels of cytokines, proliferate vigorously, and mediate lysis of ErbB2(+) tumors in an antigen-specific manner.

Mutational analysis of P-glycoprotein: suppression of caspase activation in the absence of ATP-dependent drug efflux.

P-glycoprotein (P-gp) can induce multidrug resistance (MDR) through the ATP-dependent efflux of chemotherapeutic agents. We have previously shown that P-gp can inhibit nondrug apoptotic stimuli by suppressing the activation of caspases. To determine if this additional activity is functionally linked to ATP hydrolysis, we expressed wild-type and ATPase-mutant P-gp and showed that cells expressing mutant P-gp could not efflux chemotherapeutic drugs but remained relatively resistant to apoptosis.

A functional role for CD28 costimulation in tumor recognition by single-chain receptor-modified T cells.

T cells engineered to express single-chain antibody receptors that incorporate TCR-zeta and cluster designation (CD)28 signaling domains (scFv-alpha-erbB2-CD28-zeta) can be redirected in vivo to cancer cells that lack triggering costimulatory molecules. To assess the contribution of CD28 signaling to the function of the scFv-CD28-zeta receptor, we expressed a series of mutated scFv-CD28-zeta receptors directed against erbB2. Residues known to be critical for CD28 signaling were mutated from tyrosine to phenylalanine at position 170 or proline to alanine at positions 187 and 190.

Blastocyst MHC, a putative murine homologue of HLA-G, protects TAP-deficient tumor cells from natural killer cell-mediated rejection in vivo.

Blastocyst MHC is a recently identified mouse MHC class Ib gene, which is selectively expressed in blastocyst and placenta, and may be the mouse homolog of HLA-G gene the products of which have been implicated in protection of fetal trophoblasts from maternal NK cells and evasion of some tumor cells from NK cell attack. In this study, we identified two blastocyst MHC gene transcripts encoding a full-length alpha-chain (bc1) and an alternatively spliced form lacking the alpha2 domain (bc2), which may be homologous to HLA-G1 and HLA-G2, respectively. Both placenta and a teratocarcinoma cell line predominantly expressed the bc2 transcript.

Rejection of syngeneic colon carcinoma by CTLs expressing single-chain antibody receptors codelivering CD28 costimulation.

A new strategy to improve the therapeutic utility of redirected T cells for cancer involves the development of novel Ag-specific chimeric receptors capable of stimulating optimal and sustained T cell antitumor activity in vivo. Given that T cells require both primary and costimulatory signals for optimal activation and that many tumors do not express critical costimulatory ligands, modified single-chain Ab receptors have been engineered to codeliver CD28 costimulation. In this study, we have compared the antitumor potency of primary T lymphocytes expressing carcinoembryonic Ag (CEA)-reactive chimeric receptors that incorporate either TCR-zeta or CD28/TCR-zeta signaling.

Cutting edge: tumor rejection mediated by NKG2D receptor-ligand interaction is dependent upon perforin.

We have investigated the primary immunity generated in vivo by MHC class I-deficient and -competent tumor cell lines that expressed the NKG2D ligand retinoic acid early inducible-1 (Rae-1) beta. Rae-1beta expression on class I-deficient RMA-S lymphoma cells enhanced primary NK cell-mediated tumor rejection in vivo, whereas RMA-Rae-1beta tumor cells were rejected by a combination of NK cells and CD8(+) T cells. Rae-1beta expression stimulated NK cell cytotoxicity and IFN-gamma secretion in vitro, but not proliferation.

P-glycoprotein inhibits caspase-8 activation but not formation of the death inducing signal complex (disc) following Fas ligation.

Previous studies by our laboratory have shown that the drug transporter protein P-glycoprotein, P-gp, can specifically inhibit Fas-induced caspase-3 activation and apoptosis. Importantly, inhibition of both caspase-3 activation and cell death could be reversed by pharmacological and antibody inhibitors of P-gp function. However, the molecular mechanisms underpinning P-gp-mediated resistance to Fas-induced cell death and caspase activation remained unknown.

Single-chain antigen recognition receptors that costimulate potent rejection of established experimental tumors.

Tumor cells are usually weakly immunogenic as they largely express self-antigens and can down-regulate major histocompatability complex/peptide molecules and critical costimulatory ligands. The challenge for immunotherapies has been to provide vigorous immune effector cells that circumvent these tumor escape mechanisms and eradicate established tumors. One promising approach is to engineer T cells with single-chain antibody receptors, and since T cells require 2 distinct signals for optimal activation, we have compared the therapeutic efficacy of erbB2-reactive chimeric receptors that contain either T-cell receptor zeta (TCR-zeta) or CD28/TCR-zeta signaling domains.

A role for IFN-gamma in primary and secondary immunity generated by NK cell-sensitive tumor-expressing CD80 in vivo.

We have investigated the primary and secondary immunity generated in vivo by a MHC class I-deficient tumor cell line that expressed CD80 (B7-1). CD80 expression enhanced primary NK cell-mediated tumor rejection in vivo and T cell immunity against secondary tumor challenge. CD80 expression enhanced primary NK cell-mediated tumor rejection, and both NK cell perforin and IFN-gamma activity were critical for the rejection of MHC class I-deficient RMA-S-CD80 tumor cells.

The effect of lofepramine and other related agents on the motility of Tetrahymena pyriformis.

Tricyclic antidepressants (TCAs) were introduced almost 50 years ago. Whilst there is no doubt that TCAs are effective in treating depression, they are also more cardiotoxic when taken in overdose than other antidepressant groups. Lofepramine is a more recently introduced modified TCA, which in animals and man has low toxicity when compared to older TCAs.

Identification and characterization of a novel family of mammalian ependymin-related proteins (MERPs) in hematopoietic, nonhematopoietic, and malignant tissues.

Evidence is presented for a family of mammalian homologs of ependymin, which we have termed the mammalian ependymin-related proteins (MERPs). Ependymins are secreted glycoproteins that form the major component of the cerebrospinal fluid in many teleost fish. We have cloned the entire coding region of human MERP-1 and mapped the gene to chromosome 7p14.

Induction of tumor-specific T cell memory by NK cell-mediated tumor rejection.

Natural killer (NK) cells may modulate the development of adaptive immune responses, but until now there has been little evidence to support this hypothesis. We investigated the primary and secondary immunity elicited by various tumor cell lines that express CD70 and interact with CD70 ligand (CD27), which is constitutively expressed on NK cells. CD70 expression enhanced primary tumor rejection in vivo as well as T cell immunity against secondary tumor challenge.

Redirecting mouse CTL against colon carcinoma: superior signaling efficacy of single-chain variable domain chimeras containing TCR-zeta vs Fc epsilon RI-gamma.

The structurally related TCR-zeta and Fc receptor for IgE (Fc epsilon RI)-gamma are critical signaling components of the TCR and Fc epsilon RI, respectively. Although chimeric Ab receptors containing zeta and gamma signaling chains have been used to redirect CTL to tumors, a direct comparison of their relative efficacy has not previously been undertaken. Here, in naive T lymphocytes, we compare the signaling capacities of the zeta and gamma subunits within single-chain variable domain (scFv) chimeric receptors recognizing the carcinoembryonic Ag (CEA).

Redirected perforin-dependent lysis of colon carcinoma by ex vivo genetically engineered CTL.

The redirection of autologous lymphocytes to predefined tumor target Ags has considerable potential for the immunotherapeutic treatment of cancer; however, robust experimental systems for comparing various approaches have not been developed. Herein, we have generated a single chain variable domain anti-carcinoembryonic Ag (CEA) Fcepsilon receptor I gamma-chain fusion (scFv anti-CEA) receptor and demonstrated high-level expression of this chimeric receptor in naive mouse T lymphocytes by retroviral gene transduction. These gene-modified CTL were able to lyse CEA+ targets and secrete high levels of IFN-gamma following Ag stimulation.

Acute toxicity profile of maprotiline in the rat.

The aim of the present study was to examine the toxic effects of single oral administrations of the antidepressant maprotiline at 150 mg/kg or 300 mg/kg using female Sprague-Dawley rats. Body-weight gain was significantly reduced in the group receiving 300 mg/kg on days 1-5 of the study (P<0.01).