Validation of an anti-PA-ELISA for the potency testing of anthrax vaccine in mice.

The potency test for the anthrax vaccine currently licensed for human use in the United States (Anthrax Vaccine Adsorbed) involves the protection of actively immunized guinea pigs from a lethal challenge with a virulent strain of Bacillus anthracis. Lethal challenge tests entail the use of specialized containment facilities for the safe and secure handling of the challenge strain. This potential difficulty, plus humane considerations, have prompted us to investigate non-lethal, alternative immunogenicity assays that could be considered as potency tests not only for the current vaccine, but also for vaccines under development.

Antitumor therapy with bacterial DNA and toxin: complete regression of established tumor induced by liposomal CpG oligodeoxynucleotides plus interleukin-13 cytotoxin.

Despite urgent need, no single strategy has been widely effective at controlling the growth of rapidly progressive solid tumors. We demonstrate here a potent antitumor therapy using modified bacterial DNA and toxin. Treatment of human head and neck cancer established as xenografts in athymic mice with immunostimulatory CpG oligodeoxynucleotides encapsulated in sterically stabilized cationic liposome [(CpG ODN)(SSCL)] and recombinant interleukin-13 Pseudomonas exotoxin (IL13-PE) significantly reduced the tumor growth followed by complete regression in most animals.

Radicicol suppresses transformation and restores tropomyosin-2 expression in both ras- and MEK-transformed cells without inhibiting the Raf/MEK/ERK signaling cascade.

The antibiotic radicicol suppresses transformation in a variety of transformed cells. The antineoplastic effects of the drug have been attributed to the degradation of Raf and the inactivation of the Ras/Raf/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling cascade. Here we demonstrate that radicicol induces cell spreading, suppresses anchorage-independent cell growth, and increases the expression of the high-molecular weight tropomyosin isoform TM-2 in cells stably expressing a constitutively active form of MEK-1 as well as in ras-transformed cells.

Membrane raft-dependent regulation of phospholipase Cgamma-1 activation in T lymphocytes.

Numerous signaling molecules associate with lipid rafts, either constitutively or after engagement of surface receptors. One such molecule, phospholipase Cgamma-1 (PLCgamma1), translocates from the cytosol to lipid rafts during T-cell receptor (TCR) signaling. To investigate the role played by lipid rafts in the activation of this molecule in T cells, an influenza virus hemagglutinin A (HA)-tagged PLCgamma1 was ectopically expressed in Jurkat T cells and targeted to these microdomains by the addition of a dual-acylation signal.

Familial autoimmunity and the idiopathic inflammatory myopathies.

Many lines of evidence suggest that autoimmune diseases result from chronic immune activation following environmental exposures in genetically susceptible individuals. A genetic basis for autoimmunity is supported by twin and family studies, candidate gene investigations, animal models, and whole genome microsatellite scans. These findings predict, and clinical observations support, familial clustering of a number of individual autoimmune diseases, notably lupus, multiple sclerosis, type-1 diabetes mellitus, rheumatoid arthritis, and recently the idiopathic inflammatory myopathies.

Loss of annexin 1 correlates with early onset of tumorigenesis in esophageal and prostate carcinoma.

Annexin I protein expression was evaluated in patient-matched longitudinal study sets of laser capture microdissected normal, premalignant, and invasive epithelium from human esophageal squamous cell cancer and prostatic adenocarcinoma. In 25 esophageal cases (20 by Western blot and 5 by immunohistochemistry) and 17 prostate cases (3 by Western blot and 14 by immunohistochemistry), both tumor types showed either complete loss or a dramatic reduction in the level of annexin I protein expression compared with patient-matched normal epithelium (P < or = 0.05).

Target cell-induced apoptosis in IL-2-activated human natural killer cells.

We demonstrated that tumor cells induce cell death in lymphokine-activated NK (LAK) cells, but not in non-activated NK cells. Cell death in LAK cells involves nuclear condensation and DNA cleavage, all of which are characteristic features of apoptosis. The mechanism involves signaling through integrins and requires src family tyrosine kinases and protease activities.

Multiple mechanisms of peripheral T cell tolerance to the fetal "allograft".

The fetus represents a foreign entity to the maternal immune system, yet this "natural" allograft is not normally rejected. This unique situation provides a physiologic system to evaluate peripheral tolerance in which the maternal immune system is challenged with relatively rare Ags not previously encountered in the thymus. Using H-Y-specific TCR transgenic mice, we demonstrate that T cells specific for fetal Ags decrease in an Ag-specific manner during pregnancy and remain low postpartum, the result of an encounter with fetal cells expressing the appropriate MHC/peptide complexes.

IL-6 induction of protein-DNA complexes via a novel regulatory region of the inducible nitric oxide synthase gene promoter: role of octamer binding proteins.

Macrophage inducible nitric oxide synthase (iNOS) catalyzes the synthesis of NO. IL-6-stimulated macrophage differentiation of murine myeloid M1 cells is accompanied by iNOS gene induction and steady-state mRNA expression. Two regions within the iNOS promoter mediate transcriptional responsiveness to LPS and IFN-gamma.

Target cell-induced apoptosis of interleukin-2-activated human natural killer cells: roles of cell surface molecules and intracellular events.

We previously reported that natural killer (NK)-sensitive target cells, K562, kill interleukin-2-stimulated (lymphokine-activated killer [LAK]) but not unstimulated NK cells. We have now investigated the molecular basis of this phenomenon. Soluble monoclonal antibody (MoAb) to CD18 inhibited 75% of K562-induced DNA fragmentation and membrane disruption, whereas blocking MoAb to Fas partially inhibited only the DNA fragmentation.

IL-12 administered in vivo to young and aged mice. Discrepancy between the effects on tumor growth in vivo and cytotoxic T lymphocyte generation ex vivo: dependence on IFN-gamma.

Because IL-12 restores allogeneic cytotoxic T lymphocyte (CTL) activity by T cells of aged mice in vitro, we initially assessed whether IL-12 could overcome age-related deficits when given to aged mice in vivo. Growth of P815(H-2(d)) was enhanced in aged compared with young BALB/c (H-2(d)) mice and tumor growth was curtailed by IL-12 in both age groups. Unexpectedly, secondary CTL stimulated ex vivo with P815 were reduced in IL-12-treated mice compared with controls.

Effects of two viral inactivation methods on platelets: laser-UV radiation and merocyanine 540-mediated photoinactivation.

Two viral inactivation methods suggested for use with cellular blood products have been evaluated as to their effects on platelets. In the first study, it was proposed that pulsed laser-ultraviolet radiation (UVB) at 308 nm could favor photodamage to UVB-sensitive viral nucleic acid with minimal effects on blood platelets. A "window of efficacy" was observed with UVB doses of 10.

Quantitation of poliovirus antigens in inactivated viral vaccines by enzyme-linked immunosorbent assay using animal sera and monoclonal antibodies.

Recent advances in methods for the manufacture of inactivated poliovirus vaccines have resulted in increased vaccine immunogenicity. In conjunction with this capability it is important to have available highly sensitive and quantitative potency assays. The potential suitability of enzyme-linked immunoassay (ELISA) was evaluated using animal sera with neutralizing antibodies or neutralizing monoclonal antibodies for antigen detection in potency tests.

Modulation of class I and class II histocompatibility antigens on human T cell lines by IFN-gamma.

IFN-gamma is an immunomodulatory agent which is known to induce or enhance the expression of class II histocompatibility Ag (Ia Ag) on many lymphoid cells and cell lines of diverse origin. However, we have observed that IFN-gamma did not induce the expression of Ia Ag on Ia- human T cell lines. Neither did IFN-gamma enhance the expression of Ia Ag on Ia+ T cells.