Differences in immune response of C57BL/6, В10.D2 (R101) and BALB/c mice to EL-4; [Особенности иммунного ответа на опухолевые штаммы EL-4 у мышей линий C57BL/6, В10.D2 (R101) и BALB/c]

Introduction. The immune system provides antitumor immunity, or immune surveillance. Syngeneic adoptive immunotherapy is often used for cancer therapy, but it is ineffective due to the weak immunogenicity of tumor antigens for the own immune system. In theory, allogeneic adoptive immunotherapy should be significantly more effective. Aim – to study the immune response to EL-4 in C57BL/6, B10.D2 (R101) and BALB/c mice and evaluate the possibility of syngeneic and allogeneic adoptive immunotherapy. Material and methods. In the study, we used C57BL/6, BALB/c and B10.D2 (R101) mice. Allogeneic mice BALB/c and B10.D2 (R101) were immunized with EL-4 cells intraperitoneally, syngeneic C57BL/6 mice – intradermally with tight ligation of the tumor in the future and reimmunization in 2 months. To assess the immune response to a tumor in the spleen, the cellularity and subpopulations of T-lymphocytes and NK cells were determined on days 3, 12, 15 by flow cytometry. Results. The primary immune response to EL-4 in syngeneic C57BL/6 mice consisted of an increase in the amount of T-cell subpopulations (central memory T helpers and central memory CTLs), and NK cells in the spleen on day 7. During the secondary immune response, there was a decrease in the amount of T-lymphocytes, T-helpers, and effector memory cells (CD4+-TEM and CD8+-TEM) in the spleen in the early periods after reimmunization, with a further increase in all CTLs, including subpopulations of central and effector memory CTLs after a week. Moreover, the amount of effector memory CTLs in the spleen by day 7 exceeded 2.5 times compared with the control. The amount of natural killers increased by the end of the 1st week and was raised up to 12 days. None of the reimmunized mice showed tumor growth during the observation period (400 days). After administration of EL-4 to allogeneic B10.D2 (R101) mice we detected a decrease in almost all the studied cell subpopulations in the early periods in the spleen. An increase in the amount of CTL was detected on the 12th day, and the level of NK cells was raised by the 13th day. In allogeneic BALB/c mice, a decrease in the amount of all studied cell subpopulations was also observed in the early periods after immunization. We; noted an increase in the number of T-lymphocytes from the end of the 1st week and persisting up to 13 days, and an increase in the amount of T-helpers and CTL from 7 to 11 days in BALB/ c mice. Conclusion. We showed that the maximum expansion of effector cytotoxic T-lymphocytes in syngeneic C57BL/6 mice was on day 7 and it was later in allogeneic mice: on day 11 in BALB/c mice and on day 12 in B10.D2 (R101) mice. Therefore, the greatest therapeutic effect can be expected from the transfer of CTL effector subpopulations for adoptive immunotherapy during these periods. © 2022 Meditsina Publishers. All rights reserved.