A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

Nerve elements of the heart of the rat after right-sided vagotomy

A quantitative electron microscopical investigation of the sinus node of the atrioventricular His' bundle and of the perinodal working myocardium in intact rats and 7, 15 and 30 days after right-sided vagotomy has revealed variable character of changes in the neural elements of the zones mentioned. Certain ultrastructural rearrangements in the neural apparatus are described; they reflect a combination of destructive and regenerative processes in the heart under vagotomy. Thirty days after the operation, regeneration of the neural elements in the sinoauricular area is of restorative and in the atrioventricular area--of excess character. The data are presented on dynamics of changes in the diameter of the amyelinated neural fibers in the cardiac areas investigated. Participation of both nervi vagi in innervation of the main and additional pacemakers of the organ is discussed.     

Characteristics of the differentiation of hematopoietic stem cells of the bone marrow in experimental lesions of the liver

The liver lesion in the CBA mice has been induced by administration of one of three agents five times every day; gamma-globulin fraction of antihepatocytotoxic serum in doses of 4.8 and 7.7 mg of protein per 100 g of body mass; gamma-globulin fraction of normal rabbit serum and bovine serum albumin in a dose of 4.8 mg of protein; three- four- or five-fold introduction of carbon tetrachloride in a dose of 0.5 ml per 100 g of body mass with oil (1:1) each three days; calibrated stenosis of the portal vein was produced. The total number of hemopoietic stem cells in the bone marrow was estimated by the colony-forming unit/spleen assay. Histological analysis of the colony-forming units was applied. The liver lesion was accompanied by a decrease in the ratio of the erythroid/granulocytic colonies.     

The isolation and characteristics of variant plague microbes not producing the capsular antigen

Fifteen stable variants of Yersinia pestis strains exhibiting different degrees of virulence for white mice and guinea pigs were obtained. Multiple passages of the organisms at 37 degrees C in a fluid nutrient medium containing antiplague agglutinating serum were found to be the most efficient method for obtaining noncapsular forms of the plague agent. Acquisition of the Fra(-) phenotype both by wild and laboratory strains was not associated with a loss of the high-molecular plasmid by cells but was probably a result of mutational alterations in the plasmid genes.     

Effect of subinhibitory concentrations of antibiotics on catalase activity of plague microbes]

It was shown that the presence of subinhibitory concentrations of ampicillin, cefotaxime or gentamicin in the cultivation medium had a marked inhibitory effect on the catalase activity of plague microbe. The effect depended on the characteristic features of plague microbe strains and the incubation temperature. When the cells of a virulent strain of the plague microbe Y. pestis 1300 were cultivated at a temperature of 37 degrees C on a medium containing the subinhibitory concentrations of ampicillin or cefotaxime, the pathogen virulence for albino mice significantly decreased.