LCMV-mediated hepatitis in rhesus macaques: WE but not ARM strain activates hepatocytes and induces liver regeneration.

Lymphocytic chorimeningitis virus (LCMV), the prototype arenavirus, and Lassa virus (LASV), causative agent of Lassa hemorrhagic fever (LHF), belong to the Old World group of the family Arenaviridae. Both viruses have extensive strain diversity and significant variations in lethality and pathogenicity for man and experimental animals. We have shown that the LHF-like infection of rhesus macaques with the WE strain of LCMV affects liver functions, induces hepatocyte proliferation, and causes a rise in IL-6 and soluble TNF receptors (sTNFR) concomitant with a rise in viremia. The levels of IL-6 and sTNFR can serve as an additional diagnostic tool for liver involvement in pathogenesis of arenavirus infection. Mucosal inoculation of rhesus macaques with LCMV-WE can result in attenuated infection with a transient viremia and liver enzyme abnormalities. The ARM strain of LCMV shares 88% amino acid homology with WE. In contrast to LCMV-WE, ARM strain does not induce manifested disease in monkeys, does not affect liver functions, and does not induce hepatocyte proliferation. Previously we demonstrated that LCMV-ARM infection protected rhesus macaques challenged with LCMV-WE. Here we have shown that the protected animals have no signs of hepatitis and hepatocyte proliferation.

Neutrophil alpha-defensin human neutrophil peptide modulates cytokine production in human monocytes and adhesion molecule expression in endothelial cells.

Defensins, a family of small, cationic, antimicrobial peptides, are found in mammals, insects and plants. alpha-defensins are stored in granules of neutrophils and released upon activation by exocytosis. It was shown here that human neutrophil peptide (HNP), at concentrations of 10(-8) -10(-9) M, up-regulated the expression of TNF-alpha and IL-1 beta in monocytes activated with Staphylococcus aureus or PMA, while expression of IL-10 mRNA was down-regulated and production of IL-8 was not affected. HNP alone was unable to induce TNF-alpha or IL-1 beta expression in resting monocytes. At concentrations of 10(-4) -10(-5)M, HNP was cytotoxic for monocytes in serum-free medium. The cytotoxicity was abrogated in the presence of serum, while a cytokine-modulating effect of HNP was observed in the presence of serum and in whole blood, suggesting that this mechanism may function in vivo. Similarly, serum did not abrogate bactericidal activity of HNP. It was also demonstrated herein that HNP at 10 (-8) -10(-9) M, attenuated the inhibitory action of dexamethasone on TNF-alpha production. In parallel to monocyte studies, we have showed that HNP at concentrations ranging from 10(-9)M to 10(-6)M caused about 5-fold suppression of VCAM-1 expression in TNF-alpha-activated human umbilical vein endothelial cells, while the ICAM-1 expression was not affected. Our findings suggest that neutrophil defensins have the potential to modulate the inflammatory responses through regulation of cytokine production and adhesion molecule expression.

[Role of IL-8 and defensins in pathogenesis of chronic glomerulonephritis and pyelonephritis]. / Znachenie interleikina-8 i defenzinov v patogeneze khronicheskogo glomerulonefrita i pielonefrita.

AIM: The study of interleukine-8 (IL-8) and defensines contribution to pathogenesis of chronic glomerulonephritis (CGN) and pyelonephritis (PN). MATERIALS AND METHODS: 122 patients were assigned to three groups: 42 CGN patients with isolated urinary syndrome (group 1); 60 patients with chronic pyelonephritis (CP) with normal nitrogen-excretory function (group 2); 20 patients with CGN and chronic renal failure (CRF) (group 3). 24 healthy volunteers served control. IL-8 and defensines were measured in urine and plasm of all the patients and controls using enzyme immunoassay. RESULTS: IL-8 in urine and plasm of controls was not found, in plasm of patients was found in 45%, the differences between the groups being insignificant. The highest IL-8 urine concentration was found in group 2. It was significantly higher than in group 1 and 3 (p < 0.001). Mean IL-8 urine concentration in patients with secondary pyelonephritis was significantly higher than in those with primary pyelonephritis (p < 0.05). In primary pyelonephritis, urinary IL-8 was higher than in patients of groups 1 and 3 (p < 0.001). Mean urinary IL-8 was significantly higher in patients of group 3 than 1 (p < 0.005). IL-8 urinary concentrations of group 3 patients tended to an increase with growing severity of renal failure. Plasm defensines were present in 46.5% of patients without marked differences between the groups. Urine defensines were the highest in group 2 being significantly higher than in group 1, 3 and controls (p < 0.001). Urine defensines in group 1 were slightly higher than in controls and significantly reduced vs group 3 (p < 0.005). Urine defensines concentrations rose with CGN stage. A strong positive correlation was established between IL-8 and defensines in urine (r = 0.62), leukocyturia and IL-8 in urine (r = 0.52). A weak positive correlation (r = 0.38) existed between proteinuria and urine IL-8 only in group 3 patients. A week later concentrations of IL-8 and defensines were low in group 2. In group 1 they rose, fell or remained unchanged. CONCLUSION: IL-8 and defensines may be of the same pathogenetic importance both in infectious and non-infectious inflammation in the kidneys. Cytotoxic action of defensines can be related to location of the inflammation in the kidney. IL-8 urine tests can be used in monitoring of inflammation activity and diagnosis of latent glomerulonephritis and pyelonephritis.

[Transfer of dominant selective genes using retroviral vectors--a simple and quick method for obtaining hybridoma hybrids]. / Perenos dominantnykh selektivnykh genov pri pomoshchi retrovirusnykh vektorov--prostoi i bystryi metod polucheniia gibridov gibridom.

Two different techniques were used for labeling cells for subsequent generation of hybrid hybridomata. One of them was described earlier by De Lau and included isolation of an HATSNeoR double mutants of hybridomata cells. We proposed the second one consisting of introduction of dominant selectable genes conferring resistance to genecetin (G418) and hygromycin B into distinct hybridomata by retroviral vectors. Hybrid hybridomata secreting the bispecific antibodies have been obtained by both methods. However, comparison of the methods has revealed that highly efficient retroviral gene transfer of the selectable genes is a simpler and more convenient method for generation of cellular hybrids.