Immunogene therapy of murine fibrosarcoma using IL-15 gene with high translation efficiency.

We have recently found that translational efficiency is up-regulated by an alternative exon in IL-15 mRNA in mice. In a malignancy model using BALB/c mice and syngeneic Meth A fibrosarcoma (Meth A), we successfully applied immunological gene therapy with IL-15 protein using alternative IL-15 cDNA with high translational efficiency. Two expression vectors carrying the murine IL-15 gene were constructed for use in tumor immunotherapy, one utilizing IL-15 cDNA with alternative exon 5 and the second utilizing IL-15 cDNA with normal exon 5.

The roles of intrahepatic Valpha14(+) NK1.1(+) T cells for liver injury induced by Salmonella infection in mice.

To investigate the roles of intrahepatic T cells in liver injury after Salmonella infection, we examined serum alanine transaminase (ALT), histopathology, and bacterial numbers in liver after infection with Salmonella choleraesuis strain 31N-1 in mice genetically lacking TCRalpha beta+, CD4(+), CD8(+), or NK1.1(+)T cells with C57BL/6 background. In control (+/+) mice, serum ALT reached a peak level by day 7 after an intraperitoneal inoculation of 2 x 10(6) CFU Salmonella choleraesuis 31N-1.

Immunopotentiating activity of nigerooligosaccharides for the T helper 1-like immune response in mice.

The immunopotentiating activity of nigerooligosaccharides (NOS), a mixture of nigerose, nigerosyl glucose and nigerosyl maltose, was studied in vitro and in vivo in mice. Mitogen-induced proliferation of splenocytes from normal mice was augmented in a dose-dependent manner by nigerose of NOS. NOS enhanced interleukin 12 (IL-12) and interferon-gamma (IFN-gamma) production by normal splenocytes in the presence of the potent IL-12 inducer, heat-killed Lactobacillus plantarum L-137, in vitro.

Characterization of CD4+ CD8alphaalpha+ and CD4-CD8alphaalpha+ intestinal intraepithelial lymphocytes in rats.

Intestinal intraepithelial lymphocytes (i-IEL) of aged rats comprise CD4+CD8alphaalpha+ and CD4-CD8alphaalpha+ T cells expressing TCR alphabeta. In the present study, we compared characteristics between CD4+CD8alphaalpha+ and CD4-CD8alphaalpha+ i-IEL, which were purified by a cell sorter from the i-IEL of 6-month-old Lewis rats. Most of the CD4+CD8alphaalpha+ i-IEL were of the CD44(hlgh) phenotype, while CD4-CD8alphabeta+ i-IEL were CD44(low).

MHC class II-dependent NK1.1+ gammadelta T cells are induced in mice by Salmonella infection.

We observed the emergence of a novel population of gammadelta T cells expressing NK1.1 Ag in the peritoneal cavity of mice infected with Salmonella choleraesuis. The NK1.

Interleukin-15 may be responsible for early activation of intestinal intraepithelial lymphocytes after oral infection with Listeria monocytogenes in rats.

Exogenous interleukin-15 (IL-15) stimulates intestinal intraepithelial lymphocytes (i-IEL) from mice to proliferate and produce gamma interferon (IFN-gamma) in vitro. To determine whether endogenous IL-15 is involved in activation of i-IEL during intestinal infection, we examined IL-15 synthesis by intestinal epithelial cells (i-EC) after infection with Listeria monocytogenes in rats. In in vitro experiments, invasion of L.

Prostaglandin E2 protects against liver injury after Escherichia coli infection but hampers the resolution of the infection in mice.

cAMP-increasing agents such as prostaglandin E2 (PGE2) are known to protect against LPS-induced liver injury by downregulating the production of inflammatory cytokines such as TNF-alpha. However, the effects of such reagents on host defense against bacterial infection remain unknown. We show here that in vivo administration of PGE2 significantly protected mice against liver injury after Escherichia coli infection but hampered the resolution of the infection.

[The roles of heat shock proteins in host defense against bacterial infection].

Heat shock proteins (HSP) are widely distributed in nature, and are highly conserved proteins among prokaryotes and eukaryotes. These proteins are known to be involved in cytoprotection against various stress conditions including bacterial infection, and immune responses to various pathogens such as bacteria. In this study, we showed that HSP70 protected macrophages infected with Salmonella choleraesuis against TNF-alpha-induced cell death.

Heat-killed Lactobacillus plantarum L-137 suppresses naturally fed antigen-specific IgE production by stimulation of IL-12 production in mice.

Background: Food allergy is caused by production of IgE against dietary antigen induced by T(H2) response. IL-12 inhibits T(H2) responses and strongly suppresses IgE production. We have recently established a murine model for IgE production with a predominant T(H2) response induced by feeding antigen.

Dibutyryl cyclic adenosine monophosphate protects mice against tumor necrosis factor-alpha-induced hepatocyte apoptosis accompanied by increased heat shock protein 70 expression.

Liver injury accompanied by apoptosis of hepatocytes was provoked in mice by an intravenous injection of recombinant tumor necrosis factor-alpha (rTNF-alpha) (1.0 microg/kg) together with an intraperitoneal injection of D-galactosamine (D-gal) (500 mg/kg). Injection of various doses of dibutyryl cAMP (DBcAMP) protected mice from TNF-alpha/D-gal-induced liver injury as assessed by serum alanine aminotransferase (ALT) levels, histological examination and DNA fragmentation.

Interleukin 15 activity in the rectal mucosa of inflammatory bowel disease.

Background & Aims: Interleukin (IL)-15 has been found to share many immunoregulatory activities in lymphocytes with IL-2. The aim of this study was to investigate IL-15 activity in organ cultures, localization of IL-15 messenger RNA (mRNA), and proliferation of lamina propria mononuclear cells (LPMCs) in response to recombinant IL-15 using the mucosal tissues obtained from patients with inflammatory bowel disease (IBD).

Methods: The contents of IL-15, tumor necrosis factor alpha, and IL-2 in the culture supernatant of the rectal mucosal tissues were determined by an enzyme-linked immunosorbent assay.

The NF-kappaB binding site is essential for transcriptional activation of the IL-15 gene.

We cloned the 5' upstream region of IL-15 genomic DNA and examined promoter activity in macrophages stimulated with lipopolysaccharide(LPS). The 1.2 kilobase (kb) fragment of the 5' upstream region contained binding elements for LPS-inducible transcription factors such as NFIL-6 or NF-kappaB.

Translational efficiency is up-regulated by alternative exon in murine IL-15 mRNA.

IL-15 promotes the growth of T cells and shares properties of IL-2. IL-2 is produced exclusively by T cells, while IL-15 message is expressed by a variety of tissues. However, it has been difficult to demonstrate IL-15 in the supernatants of many cells that express message for this cytokine.

The regulatory role of heat shock protein 70-reactive CD4+ T cells during rat listeriosis.

Protection against infection with Listeria monocytogenes depends primarily on Listeria-specific T cells. We show here that CD4+ TCR alphabeta+ T cells are capable of recognizing the mycobacterial heat shock protein (HSP) 70, that appears in the peritoneal cavity of F344 rats infected i.p.

A sustained increase of cytosolic Ca2+ in gammadelta T cells triggered by co-stimulation via TCR/CD3 and LFA-1.

We previously reported that co-stimulation with LFA-1 triggered apoptosis in gammadelta T cells but not in alphabeta T cells after TCR engagement. We extended our earlier study on TCR/LFA-1 triggered apoptosis to two autoreactive TCR gammadelta and TCR alphabeta T cell clones, which were derived from syngeneic mixed lymphocyte culture of BALB/c mice. A gammadelta T cell clone, KM1, expressed the Vgamma4 and Vdelta5 genes and CD4-CD8-CD45RB+ phenotype; and an alphabeta T cell clone, BASL1.

Murine model of IgE production with a predominant Th2-response by feeding protein antigen without adjuvants.

Stimulation of systemic antigen-specific IgE production plays an important role in the mediation of food allergy; however, the mechanism of IgE production against food antigens is not fully understood. The development of relevant animal models may help to elucidate the pathogenesis of food allergy. We here show that DBA/2 mice receiving a casein diet without any adjuvant produced high levels of IgE specific for casein, accompanied by predominant Th2-like responses in liver lymphocytes, mesenteric lymph node cells and spleen cells.

Interleukin-15 preferentially promotes the growth of intestinal intraepithelial lymphocytes bearing gamma delta T cell receptor in mice.

Several cytokines including stem cell factor (SCF) and interleukin (IL)-7 are known to be required for development of gamma delta T cell receptor (TCR) intestinal intraepithelial lymphocytes (i-IEL) in mice. We show here the effects of IL-15 on the proliferation and maintenance of murine gamma delta i-IEL in vitro. gamma delta i-IEL constitutively expressed a high level of IL-15 receptor alpha mRNA and proliferated in response to IL-15 more vigorously than alpha beta i-IEL.

Potential for involvement of Fas antigen/Fas ligand interaction in apoptosis of epithelial cells by intraepithelial lymphocytes in murine small intestine.

Intestinal epithelial cells (i-EC), which move to the villus tips from the crypts, rapidly die by apoptosis at the villus tips and are perpetually renewed at the crypts. To determine whether the Fas antigen (Fas)/Fas ligand (FasL) system is involved in the mechanism leading to apoptosis of i-EC, we examined the expression of Fas and FasL on the i-EC and intestinal intraepithelial lymphocytes (i-IEL) in normal mice. A high level of Fas was expressed on both the i-EC and i-IEL, whereas FasL was expressed in the i-IEL, especially in high-density fraction upon separation (high-density i-IEL), but not in the i-EC.

Protective effects of granulocyte colony-stimulating factor on endotoxin shock in mice with retrovirus-induced immunodeficiency syndrome.

Mice with retrovirus-induced murine acquired immunodeficiency syndrome (MAIDS) were hypersensitive to lipopolysaccharide (LPS)-induced lethal shock accompanied by marked elevations of systematic interleukin 1beta (IL-beta) and interferon gamma (IFN-gamma) after LPS challenge. Pretreatment with 10 microg of recombinant human granulocyte colony-stimulating factor (rhG-CSF) protected MAIDS mice from hypersensitivity to LPS-induced lethal shock and this protection was concomitant with suppression of IFN-gamma production.

T cells bearing Vbeta8 are preferentially infected with exogenous mouse mammary tumor virus.

We previously reported that a mouse mammary tumor virus (MMTV(II-TES14)), encoding a superantigen specific for TCR Vbeta14, can infect lymph node (LN) cells of mice in an I-E-independent manner. Here we examined the kinetics of cell types infected with exogenous MMTV in the draining LN after s.c.

Fas-mediated cytotoxicity by intestinal intraepithelial lymphocytes during acute graft-versus-host disease in mice.

Background & Aims: Host-derived intestinal intraepithelial lymphocytes (IELs) increase in number during acute graft-versus-host disease (GVHD) in mice. In the present study, we examined Fas-mediated cytotoxicity by host-derived IELs against Fas-expressing target cells to see whether Fas/Fas ligand (Fas-L) interaction is involved in the pathogenesis of enteropathy during acute GVHD.

Methods: Acute GVHD was induced by injection of parental spleen cells into nonirradiated F1 mice.

CD95 (Fas) may control the expansion of activated T cells after elimination of bacteria in murine listeriosis.

CD95 (Fas) is known to mediate activation-induced T-cell death by apoptosis. To understand the role of CD95 during the course of bacterial infection, we examined the kinetics of alphabeta and gammadelta T cells in the peritoneal cavities and livers of 5-week-old CD95-defective MRL/lpr mice after an intraperitoneal infection with Listeria monocytogenes. The number of bacteria in the spleen decreased to an undetectable level by day 10 after infection with 7 x 10(3) Listeria cells similar to the number in MRL/+/+ mice.

Hsp70 protects macrophages infected with Salmonella choleraesuis against TNF-alpha-induced cell death.

Hsp70 plays an important role in cytoprotection against tumor necrosis factor (TNF) alpha-mediated cytotoxicity. To investigate the role of Hsp70 in cytoprotection during Salmonella infection, we examined endogenous Hsp70 induction and TNF-alpha production in a monocyte/macrophage line, J774A.1, after infection with a virulent strain of Salm.

Aggravation of murine experimental allergic encephalomyelitis by administration of T-cell receptor gammadelta-specific antibody.

Experimental allergic encephalomyelitis (EAE) is thought to be dominantly mediated by Ag-specific CD4+ MHC class II-restricted T-cells. Recent reports demonstrated accumulation of gammadelta T-cells in active multiple sclerosis (MS) plaque and infiltration into brains with EAE. However, the role of gammadelta T-cells in pathogenesis of EAE remains unknown.