Immune Abnormalities Induced by Human Endogenous Retroviral Peptides: With Reference to the Pathogenesis of Systemic Lupus Erythematosus

P15E is a specific sequence among the envelope gene (env)-encoded transmembrane proteins of exogenous and endogenous retroviruses. A synthetic peptide (CKS-17) that shows homology to this p15E region in several species of retrovirus is known to induce immune abnormalities. In this study, we examined the effect of a synthetic peptide derived from a region of human endogenous retrovirus (HERV) clone 4-1 ( 4-1) similar to sequences of CKS-17 on the induction of systemic lupus erythematosus (SLE)-related immune abnormalities. Our results indicated that this peptide could induce T-cell activation and anergy in normal peripheral blood mononuclear cells, and the peptide could also promote the production of interleukins IL-6 and IL-16. These phenomena are representative immune abnormalities observed in SLE patients. Thus, our findings support the possibility that HERV acts as a pathogen in human SLE.     

The effect of jogging on P300 event related potentials

Physical exercise has beneficial effects not only on cardiovascular system and fat metabolism, may also directly effect the cognitive process. We studied the effect of physical exercise on cognitive processes by measuring the P300 event related-potential (ERP) after jogging. Seven well-trained joggers were enrolled in this study and the P300 potentials using auditory oddball paradigm. ERPs were measured before and after 30 minutes of jogging. The amplitude of the P300 significantly increased after jogging compared to values recorded before jogging. These findings suggest that jogging has the effect of facilitating cognitive processes involved in generation of the P300.     

Anti-allergic activities of a new benzopyranopyridine derivative Y-12,141 in rats.

Passive cutaneous anaphylaxis (PCA) mediated in rats by IgE-like antibodies against egg albumin or the benzylpenicilloyl determinant was inhibited in a dose-dependent manner by intravenous treatment with Y-12,141; the ED50 was 0.09--0.2 mg/kg. The inhibitory effect of Y-12,141 ON PCA was about 5 times as potent as that of disodium cromoglycate (DSCG). Oral treatment with Y-12,141 resulted in the inhibition of PCA, showing an ED50 of 2.5 mg/kg. This action of Y-12,141 on PCA was considered to be due to the inhibition of the release of allergic mediatros from mast cells in a manner similar to DSCG. The results suggest that Y-12,141 may have an anti-allergic activity.     

Appearance of prolactin-releasing peptide-producing neurons in the area postrema of adrenalectomized rats

Prolactin-releasing peptide (PrRP) was found to be a novel hypothalamic peptide that stimulates prolactin release in vitro and in vivo. In the normal adult rat brain, PrRP neurons are known to be located in only three areas, i.e. the dorsomedial hypothalamic nucleus, ventrolateral reticular formation; and nucleus of the tractus solitarius in the medulla oblongata. These PrRP neurons project neurites into various brain areas, including regions such as the paraventricular nucleus, supraoptic nucleus, and bed nucleus of the stria terminalis. Both PrRP nerve fibers and a high level of PrRP receptor, UHR-1, mRNA are observed in the area postrema (AP),but no PrRP neurons are detected in the AP of normal rats. In this study, we clearly demonstrated that PrRP-producing cells newly appeared in the AP of adrenalectomized rats by in situ hybridization and immunocytochemistry. Our results suggest that PrRP may have some important roles in the AP of adrenalectomized rats. This is the first report demonstrating the appearance of PrRP-positive cells in the AP.     

Granulocyte-macrophage colony-stimulating factor enhances the production of eosinophil chemotactic lymphokine by egg-associated granulomas of Schistosoma japonicum-infected mice.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) produced by splenic lymphocytes obtained from Schistosoma japonicum-infected mice was partially purified by a combination of DEAE anion-exchange chromatography, concanavalin A-Sepharose affinity chromatography, and high-pressure liquid chromatography. When this partially purified GM-CSF was added to the culture of isolated intact granulomas, eosinophil chemotactic factor (ECF) lymphokine production by granulomas was significantly enhanced. The partially purified GM-CSF also enhanced ECF lymphokine production by granuloma T cells cocultured with syngeneic macrophages and specific antigen. The partially purified GM-CSF itself had neither ECF activity nor a synergistic effect with ECF lymphokine. When normal splenic macrophages were preincubated with the partially purified GM-CSF, they potentiated the ECF production by granuloma T cells under the presence of specific antigen. Augmentation of ECF lymphokine production by partially purified GM-CSF was further confirmed by using T-cell clones that were established from granuloma T cells. These results suggest that T-cell-derived GM-CSF primarily activate macrophages so that these activated macrophages can cooperate more effectively with T lymphocytes to produce ECF. Such potentiation of macrophage-T-cell interaction by GM-CSF may be important in the mechanisms of granuloma formation during an acute stage of schistosomiasis.     

The role of saliva of Anopheles stephensi in inflammatory response: identification of a high molecular weight neutrophil chemotactic factor

Mosquito bites can elicit dermal hypersensitivity reactions, but little is known about the chemotactic factors for host leukocytes in mosquito saliva. In this study, we determined that saliva from a malarial vector mosquito, Anopheles stephensi, possesses intense neutrophil chemotactic activity. In contrast, the midgut extract had only marginal neutrophil chemotactic activity. Eosinophil chemotactic activity was detected in the midgut but not in the saliva. According to the results of size-exclusion HPLC on a G3000SW column and Western blot analysis, the apparent molecular weight (MW) of the main neutrophil chemotactic factor (NCF) was estimated to be 200 kDa. NCF could bind with IgG from the pooled serum of Solomon islanders, whereas not with that of healthy Japanese. NCF activity was increased upon heating to 56 degrees C for 30 min or protease digestion, whereas it was affected by periodate treatment. Protease-digested NCF and naive NCF bound to lentil lectin-Sepharose, and both were eluted with a competitive sugar, methyl-alpha-D-glucoside. These results indicate that A. stephensi saliva-derived NCF is a high MW glycoprotein, and its protein moiety is important for neutrophil chemotactic activity. This NCF is thought to contribute to the inflammatory reactions through the accumulation of neutrophils at the site of the mosquito bite.     

Ca2+-induced excess capacitance fluctuation studied by phase-sensitive detection method in exocrine pancreatic acinar cells

A phase-sensitive detection method in combination with whole-cell voltage-clamp was applied to exocrine pancreatic acinar cells from rat. The results have shown that cell-aialysis with a solution containing 5×10^–7 M Ca²⁺ induces stp-wise changes in cell capacitance. The size distribution of increasing and decreasing capacitance steps is compatible with the idea that these capacitance steps are the results of individual granular fusion and retrieval events. This method may enable experiments studying the exo-and endo-cytotic mechanisms in morphologically polarized secretory cells.     

Functionality of chimeric Rev proteins of HIV/SIV

Studies on functional compatibility of various Rev proteins derived from all known human and simian immunodeficiency virus subgroups have shown that this essential gene product is not always exchangeable among the viruses. In an attempt to map the region of Rev proteins responsible for the observed nonreciprocal complementation, hybrid genomic Rev expression vectors were constructed by exchanging the first and second exons ofrev genes, and were examined for their abilities to activate reporter clones by transfection. With one exception, the second coding exon ofrev gene determined the functional specificity of Rev proteins.