Blood Res (2024) 59:42
Published online December 18, 2024
https://doi.org/10.1007/s44313-024-00048-0
© The Korean Society of Hematology
Correspondence to : Behzad Poopak
bpoopak@gmail.com
© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Purpose This study aimed to determine the frequency of regulatory T cells (Tregs) (CD4+/FOXP3+) and indoleamine 2,3-dioxygenase (IDO) expression in patients with acute myeloid leukemia (AML).
Methods This cross-sectional case–control study was conducted between Jan 2022 and Dec 2023. Bone marrow samples were collected from 20 healthy individuals and 15 patients with AML. Flow cytometry, real-time polymerase chain reaction (PCR), and western blotting were used to evaluate the frequency of Treg and IDO expression levels.
Results The Treg percentage among total lymphocytes was lower in the AML group than that in the normal group. However, Treg percentage among T-helper (Th) lymphocytes was significantly higher in the AML group than that in the normal group (p < 0.05). The mean IDO expression in the AML group was significantly higher than that in the normal group (p = 0.004). A significant relationship was observed between IDO expression and Treg percentage among Th lymphocytes in the AML group (correlation = 0.637; p = 0.003). Moreover, western blot analysis showed a significant increase in IDO protein intensity in the AML group compared with that in the control group (p < 0.001). A significant difference was observed between the IDO concentrations in the AML group and that in the control group (p < 0.001). In addition, a significant difference between TGF-β levels in the AML group and those in the control group (p < 0.01) was observed.
Conclusion IDO inhibition using novel IDO inhibitors along with chemotherapy is a promising approach to overcome the immune escape mechanisms in patients with AML, who exhibit increased levels of IDO expression and Tregs.
Keywords Acute myeloid leukemia, Flow cytometry, Indoleamine 2,3-dioxygenase, Real-time polymerase chain reaction, T regulatory cells
Blood Res 2024; 59():
Published online December 18, 2024 https://doi.org/10.1007/s44313-024-00048-0
Copyright © The Korean Society of Hematology.
Raziyeh Hakak1, Behzad Poopak1,2* and Ahmad Majd1
1 Department of Cellular and Molecular Biology, Faculty of Biological Sciences, North Tehran Branch, Azad University, Tehran, Iran
2 Payvand Clinical and Specialty Laboratory, Tehran, Iran
Correspondence to:Behzad Poopak
bpoopak@gmail.com
© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Purpose This study aimed to determine the frequency of regulatory T cells (Tregs) (CD4+/FOXP3+) and indoleamine 2,3-dioxygenase (IDO) expression in patients with acute myeloid leukemia (AML).
Methods This cross-sectional case–control study was conducted between Jan 2022 and Dec 2023. Bone marrow samples were collected from 20 healthy individuals and 15 patients with AML. Flow cytometry, real-time polymerase chain reaction (PCR), and western blotting were used to evaluate the frequency of Treg and IDO expression levels.
Results The Treg percentage among total lymphocytes was lower in the AML group than that in the normal group. However, Treg percentage among T-helper (Th) lymphocytes was significantly higher in the AML group than that in the normal group (p < 0.05). The mean IDO expression in the AML group was significantly higher than that in the normal group (p = 0.004). A significant relationship was observed between IDO expression and Treg percentage among Th lymphocytes in the AML group (correlation = 0.637; p = 0.003). Moreover, western blot analysis showed a significant increase in IDO protein intensity in the AML group compared with that in the control group (p < 0.001). A significant difference was observed between the IDO concentrations in the AML group and that in the control group (p < 0.001). In addition, a significant difference between TGF-β levels in the AML group and those in the control group (p < 0.01) was observed.
Conclusion IDO inhibition using novel IDO inhibitors along with chemotherapy is a promising approach to overcome the immune escape mechanisms in patients with AML, who exhibit increased levels of IDO expression and Tregs.
Keywords: Acute myeloid leukemia, Flow cytometry, Indoleamine 2,3-dioxygenase, Real-time polymerase chain reaction, T regulatory cells
Table 1 . Primers and reaction conditions used in qRT-PCR.
Gene | Sequence | Product size (bp) |
---|---|---|
IDO | F: 5′-TCC TGG ACA ATC AGT AAA GAG TAC C-3′ | 122 |
R: 5′-TCA GGC AGA TGT TTA GCA ATG AAC -3′ | ||
Albumin | F: 5′-GCT ATC CGT GGT CCT GAA CC-3′ | 200 |
R: 5′-CTT CTC AGA AAG TGT GCA TAT ATC TG-3′ |
Table 2 . Basic and clinical characteristics of patients in the two groups.
Characteristics | Normal group | AML group | p-value |
---|---|---|---|
Gender | |||
Male | 13 (65%) | 4 (7.26%) | 0.023 |
Female | 7 (35%) | 11 (3.73%) | |
Age, year | 33.27 ± 90.28 | 33.24 ± 00.37 | ≥ 0.001 |
Less than 5 years (toddler) | 4 (20%) | 2 (3.13%) | |
5–13 years (child) | 6 (30%) | 2 (3.13%) | |
14–19 years (adolescent) | 1 (5%) | 0 (0%) | ≥ 0.001 |
20–55 years (adult) | 3 (15%) | 7 (7.46%) | |
Over 55 years (older adult) | 6 (30%) | 4 (7.26%) | |
Subtype | |||
Common B | 0 (0%) | 0 (0%) | |
M0 | 0 (0%) | 1 (7.6%) | |
M1 | 0 (0%) | 4 (7.26%) | |
M1/M2 | 0 (0%) | 1 (7.6%) | |
M2 | 0 (0%) | 1 (7.6%) | |
M4/M2 | 0 (0%) | 1 (7.6%) | ≥ 0.001 |
M5 | 0 (0%) | 2 (3.13%) | |
Non-M3 | 0 (0%) | 5 (3.33%) | |
Pro B | 0 (0%) | 0 (0%) | |
Relapsed B | 0 (0%) | 0 (0%) | |
Relapsed T | 0 (0%) | 0 (0%) | |
T | 0 (0%) | 0 (0%) | |
Blast percentage | 53.0 ± 87.0 | 99.28 ± 13.5 | ≥ 0.001 |
Table 3 . Comparison of mean percentages of Tregs in patients in the two groups.
Treg percentage | Normal group | AML group | p-value |
---|---|---|---|
Percentage of total Tregs | 00.0 ± 69.0 | 0.00 ± 55.0 | 0.309 |
Percentage of Tregs in total lymphocytes | 1.00 ±72.1 | 00.0 ± 55.56 | 0.023 |
Percentage of Tregs in T lymphocytes | 3.1 ± 32.99 | 4.1 ± 28.3 | 0.134 |
Percentage of Tregs in Th lymphocytes | 7.2 ± 25.97 | 9.2 ± 01.53 | 0.030 |
Table 4 . Correlation coefficients of IDO expressions with the percentages of Tregs.
Percentage Treg | Normal group | AML group | ||
---|---|---|---|---|
Correlation coefficient | p-value | Correlation coefficient | p-value | |
Percentage of total Tregs | 083.0 | 0.729 | 246.0 | 0.377 |
Percentage of Tregs in total lymphocytes | 350.0 | 0.130 | 305.0 | 0.269 |
Percentage of Tregs in T lymphocytes | 251.0 | 0.286 | 191.0 | 0.494 |
Percentage of Tregs in Th lymphocytes | 637.0 | 0.003 | 164.0 | 0.559 |
Dario Campana, and Elaine Coustan-Smith
Korean J Hematol 2012; 47(4): 245-254Sahar Jalilivand, Maryam Nabigol, Mehdi Bakhtiyaridovvombaygi and Ahmad Gharehbaghian
Blood Res 2024; 59():Hyunwoo Kim, Ja Young Lee, Sinae Yu, Eunkyoung Yoo, Hye Ran Kim, Sang Min Lee and Won Sik Lee
Blood Res 2024; 59():