PSXVI-13 - Study of migration of antigen-presenting cells in the tissue of the lactating mammary gland under the influence of staphylococcal vaccine

Dairy cow mastitis is widespread in various countries. Data from researchers around the world show that Staphylococcus aureus is one of the most common causative agents of mastitis. One of the methods of preventing staphylococcal infection is the introduction of a staphylococcal vaccine containing a complex of thermostable antigens extracted from microbial cells of S. aureus. In connection with the great urgency of this problem, we set the task to study the effect of staphylococcal vaccine on the migration of macrophage cells in the tissue of the lactating mammary gland. For the experiment, two groups of pregnant mice were formed, 15 individuals in each. Animals from the experimental group were injected subcutaneously with staphylococcal vaccine at a dosage of 0.2 ml, once 5 days before delivery. The selection of pathological material was carried out in three stages at the beginning of the first second and third weeks of lactation. Each time, 5 mice were selected from each group in accordance with the bioethics standards. From the material obtained, histosections were made with hematoxylin-eosin staining.

In histosections, cells of the macrophage range were identified and counted in one hundred fields of view. We took into account cells that were defined by morphology as tissue macrophages, as well as dendritic cells. In the experimental group on the first, second and third weeks of lactation, the average number of macrophages was 69.6±2.07; 78.2±2.38 and 50.8±2.38 cells, in the control group at the same time - 38.3±2.51; 47.3±1.52 and 23.3±1.52 cells, respectively. The results obtained show an effective migration of antigen-presenting cells in the breast tissue, which is confirmed by higher rates in the experimental group by 1.7–2.2 times at all periods of the study (P < 0.05). The highest concentration of macrophages was found in vaccinated mice in the second week of lactation.