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.     

Construction of derivatives of the diphtheria toxin gene and their expression in Escherichia coli cells

A fragment of diphtheria toxin (tox) gene from beta 45 phage DNA was cloned on pUC19 plasmid in E. coli cells. The fragment is coding for toxA fragment of the toxin and contains the control region of the tox gene. The tox gene promoter is active in E. coli. The toxA protein is found mainly in periplasm of E. coli cells. The protein is enzymatically active in ADP-ribosilation of elongation factor 2 from eucaryotic cells. An in frame toxA-lacZ' fusion was constructed on pUC8 plasmid. The hybrid protein expresses both toxA and lacZ' activities. Two or seven base pairs were deleted from the central part of toxA gene by means of S1 nuclease digestion. Translation of hybrid toxA-lacZ' mRNA should be terminated downward the delections due to the frameshifts caused by them. Nevertheless, a functionally active alpha-peptide of beta-galactosidase is expressed by both the deletion fusions. The existence of another translational start site functioning in E. coli and located inside 3'-end region of toxA mRNA is suggested.     

Comparisons of brain weight and neocortical thickness in 21-day-old fetuses and 1-day-old rats with the histophysiological indices of the ovaries and adrenal glands of their mothers (a correlational and cluster analysis)]

The correlation and cluster analysis revealed that the brain weight of the rat 21-day-old foetus obviously depended on 3 beta-hydroxysteroiddehydrogenase activity in adrenal cortex. No such dependence was found in 1-day-old foetus. Thickness of the brain cortex in 21-day-old foetus and in 1-day-old rat correlated with parameters of the enzyme activity in the corpus luteum, corpus atretic, and theca folliculi of mother's ovaries.     

Experimental study of new polymer dressings in the treatment of burn wounds

Data on the experimental study of a new polymer coverage for treatment of burn wounds are presented in the article. Application of this coverage, which has a tanning and absorbing affect promotes formation of a dry eschar over a burn wound within the first two days after the accident. This allows to perform early chemical necrectomy on the 6-7th day after the accident. Microbiological investigations show that wound dissemination after application of the coverage remains low and is 3.5 +/- 0.1 per. 1.0 g of the tissue.     

Cloning in Escherichia coli of the mutant gene coding the diphtheria toxin

Bacteriophage beta 45 of Corynebacterium diphtheriae was harvested. The extracted DNA of the bacteriophage was digested by the restriction endonuclease BamHI and inserted into the BamHI cleavage site of pUC19 vector plasmid. Plasmid pNVY5 containing a mutant gene crm45 of diphtheriae toxin in a 3.9 bpn fragment was isolated from the hybrid plasmids obtained. Cell free extracts of E. coli strain TG1 (pVNY5) contain the nontoxic protein crm45 possessing the specific enzymatic activity of diphtheriae toxin (ADP ribosylation on wheat elongation factor two). According to orientation of BamHI fragment in pNVY5 plasmid it is concluded that the crm45 gene is expressed using its own promoter.