Spontaneous, heritable colitis in a new substrain of C3H/HeJ mice.

Background/aims: C3H/HeJ mice at the Jackson Laboratory have periodically been culled because of the occurrence of soft feces, perianal ulceration, and right-sided colitis. No pathogens have been isolated. The goal of the current study was to establish a substrain with a high incidence of this disease.

Dextran sulfate sodium-induced colitis occurs in severe combined immunodeficient mice.

Background/aims: Oral administration of dextran sulfate sodium (DSS) has been reported to induce colitis in mice. The purpose of this study was to determine whether the possible pathogenic mechanism involved the acquired immune system.

Methods: Normal BALB/c and related C.

The functional activity of human monocytes passively sensitized with monoclonal anti-D suggests a novel role for Fc gamma RI in the immune destruction of blood cells.

The role of Fc gamma RI in the immune destruction of blood cells is uncertain as serum IgG levels are sufficient to competitively inhibit interactions between this high-affinity receptor and sensitized red cells. In the current study, it is proposed that, rather than functioning as a receptor for opsonized red cells, Fc gamma RI might, under appropriate conditions, mediate the passive sensitization (or 'arming') of human macrophages with IgG antibodies resulting in the in vivo destruction of unsensitized cells expressing the corresponding antigen. To examine this hypothesis, Fc gamma RI-bearing human monocytes and U937 cells were first passively sensitized by incubation in vitro with human monoclonal anti-D, and then incubated with D-positive red cells.

Tumor necrosis factor-alpha receptor expression on chondrocytes isolated from human articular cartilage.

Objective: To determine whether the previously observed enhanced susceptibility of osteoarthritic (OA) cartilage to tumor necrosis factor-alpha (TNF-alpha) induced degradation could be due to differences in receptor expression.

Methods: Using specific monoclonal antibodies flow cytometry was used to identify and quantify 2 TNF-alpha receptors on the surface of chondrocytes isolated from human articular cartilage.

Results: The proportion of chondrocytes expressing p55 TNF-alpha receptor was significantly higher in populations from OA cartilage (p < 0.

Characterisation of an oxidative response inhibitor produced by Streptococcus pneumoniae.

Background: Pneumonia caused by infection with Streptococcus pneumoniae is still a major clinical problem. Reactive oxygen species contribute to the killing of these bacteria by polymorphonuclear leucocytes (PMNs). Defence mechanisms of Str pneumoniae which counter reactive oxygen species are characterised.

Multiple self epitopes on the Rhesus polypeptides stimulate immunologically ignorant human T cells in vitro.

The extent of autoreactive T cell repertoire in the normal individual has previously been unclear. Here we demonstrate that T cells from healthy humans can be stimulated by multiple epitopes on a self protein to give primary proliferative responses in vitro. Synthetic 15-mer peptides, corresponding to the sequence of a human red blood cell Rhesus polypeptide, were tested for the ability to stimulate normal T cells.

Chondro-osseous metaplasia, bone density and patellar cartilage proteoglycan content in the osteoarthritis of STR/ORT mice.

The evolution of osteoarthritis (OA) was compared in male and female STR/ORT mice and in male CBA mice with particular emphasis on the changes in para-articular structures which occur before the classical degenerative phenomena in the articular cartilage of the knee. In male STR but not female STR mice or male CBA mice, chondro-osseous metaplasia was found in the tendinous structures which surround the joint and in the major ligamentous entheses such as the patellar ligament. This change was detectable from the age of three months.

Radiological scoring of osteoarthritis progression in STR/ORT mice.

The progressive changes observed in the knee and ankle joints of male STR/ORT mice, which spontaneously develop osteoarthritis (OA), were quantified by a radiological scoring system. The knee scores for males increased with age whereas those for females plateaued from 5 months. Comparison of scores for the knee and ankle joints showed that the male knee scores increased directly with age but were not significantly different from female scores until 7 months whereas the male ankle scores increased dramatically at 5-6 months and plateaued thereafter.

Intraperitoneal immunization of human subjects with tetanus toxoid induces specific antibody-secreting cells in the peritoneal cavity and in the circulation, but fails to elicit a secretory IgA response.

Five patients on continuous ambulatory peritoneal dialysis (CAPD) were immunized intraperitoneally with tetanus toxoid (TT) through an indwelling catheter. Four control patients on CAPD received the same dose of TT intramuscularly. Before immunization, virtually no anti-TT antibody-secreting cells (AbSC) were detected by the enzyme-linked immunospot (ELISPOT) assay in peripheral blood or peritoneal fluid from patients of either group.

The chemoprevention of cancer by mevalonate-derived constituents of fruits and vegetables.

Anutritive isoprenoid constituents of fruits, vegetables, cereal grains and essential oils exhibit a spectrum of anticarcinogenic activities. The induction of hepatic Phase II detoxifying activities by dietary isoprenoids appears to underlie their blocking action. The second anticarcinogenic action of the dietary isoprenoids, suppression of the growth of chemically initiated and transplanted tumors is, we suggest, secondary to the inhibition of mevalonate pathway activities.

Oral tolerance in humans. T cell but not B cell tolerance after antigen feeding.

The purpose of this study was to investigate whether oral tolerance, defined as Ag-specific immunologic unresponsiveness after Ag feeding, could be induced in humans after prolonged Ag ingestion. Eight adult volunteers ingested a total dose of 0.5 g of keyhole limpet hemocyanin (KLH) followed by subcutaneous immunization with KLH.

Inhibitor regulation of tissue kallikrein activity in the synovial fluid of patients with rheumatoid arthritis.

Tissue kallikrein (TK) and alpha 1-antitrypsin (AT)/TK complexes can be detected in SF from patients with RA if components of the fluids which interfere with the detection of TK are removed. alpha 2-Macroglobulin (alpha 2-M) in SF was demonstrated to contain trapped proteases which were still active in amidase assays. Removal of alpha 2-M from RA SF reduced their amidase activity.

Human metabolism of the experimental cancer therapeutic agent d-limonene.

d-Limonene has efficacy in preclinical models of breast cancer, causing > 80% of carcinomas to regress with little host toxicity. We performed a pilot study on healthy human volunteers to identify plasma metabolites of limonene and to assess the toxicity of supradietary quantities of d-limonene. Seven subjects ingested 100 mg/kg limonene in a custard.

Red cell-reactive non-specific immunoglobulins and autoantibodies in the sera of normal and anaemic dogs.

The levels of red blood cell (RBC) membrane-reactive IgG were measured in sera from normal and anaemic dogs using an enzyme-linked immunosorbent assay with erythrocyte ghosts as the target antigen (g-ELISA). The anaemic dogs were classified as cases of primary autoimmune haemolytic anaemia (AIHA), other anaemias with elevated levels of RBC-bound immunoglobulin detected by a direct enzyme-linked antiglobulin test (DELAT), or DELAT-negative anaemias. The g-ELISA detected IgG capable of binding RBC membranes in all the serum samples tested, and the levels were significantly higher (P < 0.

Enhancing effect of cholera toxin on interleukin-6 secretion by IEC-6 intestinal epithelial cells: mode of action and augmenting effect of inflammatory cytokines.

Oral administration of cholera toxin (CT) induces a strong mucosal immune response to CT as well as having a potent adjuvant effect. Since one of the first cell types to encounter CT during cholera infection or after oral administration is the epithelial cell, we studied the effect of CT on interleukin-6 (IL-6) secretion by the rat intestinal epithelial cell line IEC-6. CT was found to rapidly enhance IL-6 secretion and IL-6 gene expression by these cells.

Comparison between the protective effects of mycobacterial 65-kD heat shock protein and ovomucoid in pristane-induced arthritis: relationship with agalactosyl IgG.

The IgG of patients with rheumatoid arthritis and mice with pristane induced arthritis (PIA) tends to lack the terminal galactose normally on the conserved N-acetylglucosamine linked beta 1-2 to mannose in IgG. The terminal N-acetylglucosamine (GlcNAc) residues of oligosaccharides on agalactosyl IgG may be an important component of the action of these glycoforms. Here, administration of ovomucoid, a glycoprotein rich in terminal GlcNAc, before pristane injection was found to reduce the incidence of PIA.

Optimizing oral vaccines: induction of systemic and mucosal B-cell and antibody responses to tetanus toxoid by use of cholera toxin as an adjuvant.

Cholera toxin (CT) is an effective mucosal antigen and acts as an adjuvant when given orally with various antigens; however, few studies have compared the levels of antibody responses to CT and coadministered protein in systemic and mucosal tissues. In this study, we used tetanus toxoid (TT) for assessment of immune responses. Time course and dose-response studies established that 250 micrograms of TT given orally with 10 micrograms of CT three times at weekly intervals induced high serum and gastrointestinal tract anti-TT and anti-CT antibody responses.

Low-dose oral methotrexate in refractory inflammatory bowel disease.

The purpose of this study was to evaluate the efficacy and safety of low-dose weekly, oral methotrexate in patients with steroid-dependent or steroid-refractory inflammatory bowel disease (IBD). Oral methotrexate was given weekly at 15 mg/week. The primary criterion of response was based on steroid withdrawal.

Helper T cell subsets for immunoglobulin A responses: oral immunization with tetanus toxoid and cholera toxin as adjuvant selectively induces Th2 cells in mucosa associated tissues.

Antigen-specific B cell responses to mucosally delivered proteins are dependent upon CD4-positive T helper (Th) cells, and the frequency of Th1 and Th2 cell responses after oral immunization may determine the level and isotype of mucosal antibody responses. We have used a protein-based vaccine, tetanus toxoid (TT), together with the mucosal adjuvant cholera toxin (CT), for oral immunization of mice to study the nature of antigen-specific Th cell subsets induced in Peyer's patches (PP) of the gastrointestinal (GI) tract and in the spleen (SP) during peak antibody responses. Mice orally immunized with TT and CT responded with antigen-specific secretory immunoglobulin A (S-IgA) antibodies in the GI tract, and with both IgG and IgA antibody responses in serum.

New perspectives in mucosal immunity with emphasis on vaccine development.

In this review, we have purposely focused on five areas that are currently receiving extensive research attention and will be of major importance for development of mucosal and systemic immunity to oral vaccines. These five areas include the following: (1) helper T-cell (Th) subsets and cytokines for mucosal IgA responses; (2) Th1- and Th2-type subsets in regulation of mucosal IgA responses; (3) antigen uptake and presentation in the mucosal immune system; (4) the importance of memory in mucosal immunity to vaccines; and (5) the determination of whether oral immunization alone induces immunity in all mucosal effector tissues. It is now established that the mucosal immune system can be divided into discrete mucosal inductive sites where vaccines/antigens are encountered and taken up, processed, and presented to B and T cells, and separate areas where immune cells actually function (mucosal effector tissues).

Pathogenic autoantibodies in the NZB mouse are specific for erythrocyte band 3 protein.

NZB mice spontaneously develop autoimmune hemolytic anemia (AIHA). The red blood cell (RBC) autoantigen bound by pathogenic IgG autoantibodies, previously designated "X", was identified by immunoprecipitation. Autoantibody eluted from the RBC of AIHA-positive NZB mice precipitated a 105-kDa antigen that was identical in apparent molecular mass to Band 3, the RBC anion channel protein.