Phenotype of bone marrow adaptive immune cells in lactating mice and newborn mice

Purpose: To identify subpopulations of T- lymphocytes in the bone marrow of lactating mice and newborn mice.

Materials and methods. The studies were carried out in lactating mice and newborn mice. 2 groups of 5 animals each were formed. For the experiment, bone marrow was collected from the animals from the proximal femur. The head of the femur was cut off and the bone marrow was removed using a syringe, which was used to wash the bone marrow cavity with saline solution. The phenotype of adaptive immune cells was determined using a set of fluorochrome-conjugated antibodies: CD4-PerCP-Cy5.5, CD8-PE/Cy7, CD62L-APC/Cy7, CD44-BV510. Data collection was carried out on a CytoFlex flow cytometer (Beckman Coulter, USA). The results were analyzed in the Kaluza Analysis 2.1 program.

Results. The study found that CD8⁺ T -cells of effector (T_EM; CD44⁺CD62L^-) and central memory (T_CM; CD44⁺CD62L⁺) are greater in adults, while the proportion of CD4⁺ T -cells of naïve memory (T_NV; CD44^-CD62L⁺ , predominates in pups. The content of the subpopulation of naive memory CD8⁺ T -cells (T_NV; CD44^-CD62L⁺) is 1,31 times higher in newborn pups and amounted to 81,97±2,38 % and 62,57±1,48 %, respectively. A significantly low content of populations of CD4⁺T - effector memory cells (T_EM; CD44⁺CD62L^-) in mice was established: 5,62±2,15 % compared to adults 13,26±1,93 % (p<0,05). ). Effector and central memory CD8⁺ T -cells (T_EM; T_CM;) enter the bone marrow in large numbers. This indicates that lymphocytes take an active part in the cellular mechanisms of the immune response. In the bone marrow, during immune reactions, numerous subpopulations of T -lymphocytes are formed and accumulate, in particular, cytotoxic cells and memory T -cells, which are directly responsible for adaptive immunity.

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16. Patent No. 2743345 C1 Russian Federation, IPC G01N 33/49. Method for assessing cellular immunity during colostrum feeding of animals: No. 2019143557: declared. 20.12.2019: published. 17.02.2021 / N. A. Panova, V. G. Skopichev; applicant FSBEI HE St. Petersburg State Academy of Veterinary Medicine FSBEI HE SPbGAVM.