Tag Archives: granulocytes
ROS production and phagocytic activity in human blood phagocytes treated with bacteriophage preparation Pyofag
I. Semchuk1, A. Kharina1, N. Korniienko2, M. Rudyk1, R. Dovhyi1,
K. Ostrovska1, K. Liashenko1, Yu. Kortous1, L. Skivka1
1NSC “Institute of Biology and Medicine”,
Taras Shevchenko National University of Kyiv, Ukraine;
2NPBC-UKRAINE LLC;
*e-mail: 03semiramida02@knu.ua
Received: 19 November 2025; Revised: 22 January 2026;
Accepted: 30 January 2026; Available on-line: February 2026
The growing use of bacteriophages in the treatment of antibiotic-resistant infections highlights the need to clarify their direct effects on innate immune cells. This study investigated the effect of polyvalent phage preparation Pyofag on oxidative metabolism and phagocytic function of nonsensitized peripheral blood monocytes and granulocytes under physiological whole-blood conditions. Blood samples from healthy donors were collected using lithium heparin, incubated with Pyofag at phage-to-cell ratios of 1:2, 1:5, and 1:10, centrifuged and the cell pellet was used. ROS production was assessed with the use of DCFDA, phagocytic activity was estimated by fluorescent polystyrene latex beads-uptake intensity. The percentage of phagocytic cells and their mean fluorescence index (MFI) were measured by flow cytometry. It was shown that Pyofag induced statistically significant moderate ROS generation in both phagocyte populations only at the highest dose, remaining markedly lower than that induced by phorbol 12-myristate 13-acetate. Upon Pyofag treatment, only minor reduction in the proportion of phagocytosing monocytes and minor increased in the percentage of phagocytosing granulocytes was observed with no effect on MFI. The mild oxidative activation and stable phagocytic performance observed in Pyofag-treated blood phagocytes point to a noninflammatory, balanced immunomodulatory profile, supporting the safety of this phage preparation for potential systemic administration.
Role of peripheral dopaminergic system in the pathogenesis of experimental colitis in rats
A. I. Prysiazhniuk, M. P. Rudyk, T. M. Chervinska, T. V. Dovbynchuk,
I. V. Opeida, L. M. Skivka, G. M. Tolstanova
Taras Shevchenko National University of Kyiv, Ukraine;
e-mail: gtolstanova@gmail.com
Dopamine (DA) is produced and released by immune cells. Recent data pointed to DA as a key mediator between the nervous and immune systems. In the present study we tested the hypothesis that peripheral dopaminergic system plays a negative role in ulcerative colitis pathogenesis via the effect on activity of peripheral blood phagocytes. The study was conducted on male Wistar rats (170-200 g). The peripheral dopaminergic system was destroyed by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) injection (20 mg/kg, s.c., 4 times every 2 h). Colitis was induced by 0.1 ml 6% iodoacetamide enema. Rats were subjected to autopsy on the 18th day. We found that MPTP-treated rats had decreased levels of tyrosine hydroxylase, rate-limiting enzyme of DA synthesis, in colon but not in brain. The number and activity of colonic and peripheral blood granulocytes did not significantly differ in saline- and MPTP-treated rats with colitis. The decreased ROS production by monocytes; increased 1.8-fold the number of CD69 (an early activation marker) positive monocytes and 6-fold intensity of CD69 surface expression were observed in MPTP-treated rats vs. saline-treated rats during colitis. The CD14 (the endotoxin coreceptor of phagocytes) surface expression was 2-fold increased in MPTP-treated rats without colitis, but significantly decreased in both saline- and MPTP-treated rats with colitis. We showed for the first time that the destruction of peripheral dopaminergic neurons leads to the improvement of morphological signs of experimental colitis, which might be through the regulatory effect of dopaminergic system on monocytes phenotype and their respiratory burst activity.