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SCIENCE CHINA Life Sciences, Volume 63 , Issue 5 : 737-749(2020) https://doi.org/10.1007/s11427-019-9550-4

Dihydroartemisinin regulates the immune system by promotion of CD8+ T lymphocytes and suppression of B cell responses

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  • ReceivedFeb 11, 2019
  • AcceptedApr 18, 2019
  • PublishedJul 8, 2019

Abstract

Artemisia annua is an anti-fever herbal medicine first described in traditional Chinese medicine 1,000 years ago. Artemisinin, the extract of A. annua, and its derivatives (dihydroartemisinin (DHA), artemether, and artesunate) have been used for the treatment of malaria with substantial efficacy. Recently, DHA has also been tested for the treatment of lupus erythematosus, indicating that it may function to balance the immune response in immunocompromised individuals. In the present study, the regulatory effect of artemisinin on the murine immune system was systematically investigated in mice infected with two different protozoan parasites (Toxoplasma gondii and Plasmodium berghei). Our results revealed that the mouse spleen index significantly increased (spleen enlargement) in the healthy mice after DHA administration primarily due to the generation of an extra number of lymphocytes and CD8+ T lymphocytes in both the spleen and circulation. DHA could increase the proportion of T helper cells and CD8+ T cells, as well as decrease the number of splenic and circulatory B cells. Further, DHA could reduce the production of proinflammatory cytokines. Our study revealed that apart from their anti-parasitic activity, artemisinin and its derivatives can also actively modulate the immune system to directly benefit the host.


Funded by

the National Key Research and Development Program of China(2017YFD0500400)

the National Natural Science Foundation of China(81420108023,81772219)

distinguished scientist grant from Shenyang Agricultural University.


Acknowledgment

This work was supported by the National Key Research and Development Program of China (2017YFD0500400), the National Natural Science Foundation of China (81420108023, 81772219) and distinguished scientist grant from Shenyang Agricultural University.


Interest statement

The author(s) declare that they have no conflict of interest.


Supplement

SUPPORTING INFORMATION

Figure S1 Detection of cytokine production after treatment with DHA via flow cytometry.

Figure S2 Spleen indexes.

Figure S3 The number of splenic Th cells, CD8+ T, and B cells from the T. gondii ME49 strain-infected and the DHA treatment group.

Figure S4 Spleen indexes. The spleen was observed 14 days after treatment with DHA and the spleen indexes (spleen weight (mg)×10/body weight (g) × 100%) were calculated. The number of splenic Th cells and circulating CD8+ T cells in the P. berghei (ANKA strain) infected and the DHA-treated groups.

Figure S5 Splenic immune cells, circulating immune cells, and serum collection.

The supporting information is available online at http://life.scichina.com and https://link.springer.com. The supporting materials are published as submitted, without typesetting or editing. The responsibility for scientific accuracy and content remains entirely with the authors.


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  • Figure 1

    The number of splenic CD8+ T cells in the DHA group. The population distribution of splenic CD8+ T cells (A and B) was detected by flow cytometry on days 2, 4, 6, 8, 15, 20, and 25 following treatment with DHA. The spleen was observed after DHA treatment, and the spleen indexes (spleen weight (mg)×10/body weight (g) × 100%) were calculated. C, The spleen index of the control and DHA groups. The results are representative of three independent experiments with three to five mice per group per experiment. Data are presented as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 2

    DHA stimulated the proliferation of circulatory Th cells, but down-regulated circulatory B cells in healthy mice over a certain period of time. The number and distribution of circulatory Th (A and B) and circulatory B cells (C and D) were detected by flow cytometry on days 2, 4, 6, 8, 15, 20, and 25 after treatment with DHA. The results are representative of three independent experiments with three to five mice per group per experiment. Data are presented as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 3

    Detection of cytokine production during gavage by flow cytometry. A, Comparison of the Th1 cytokine levels (TNF-α) in the sera from the CMC-Na group and CMC-Na+DHA group. B, Comparison of the Th2 cytokine levels (IL-5) in the sera from the CMC-Na group and CMC-Na+DHA group. C, Heatmaps directly showing the difference in the detected cytokines. The results are representative of three independent experiments with seven to ten mice per group per experiment. Data are expressed as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 4

    The ratio of circulating Th, CD8+ T, and B cells in the T. gondii (ME49 strain) and the treatment groups. B cells (A and B), Th cells (C and D), and CD8+ T cells (E and F) were detected by flow cytometry on days 0, 3, 5, 7, 9, and 11 after DHA treatment. A, Representative dot plots of CD3CD19+ B cells among the circulating lymphocytes. B, Comparison of the number of B cells in the circulation between the ME49 and treatment groups. C, Representative dot plots of CD3+CD4+ Th cells among the circulating lymphocytes. D, Comparison of the number of Th cells in the circulation between the ME49 and treatment groups. E, Representative dot plots of CD8+ T cells among the circulating lymphocytes. F, Comparison of the number of CD8+ T cells in the circulation between the ME49 and treatment groups. The results are representative of three independent experiments with three to five mice per group per experiment. Data are expressed as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 5

    Detection of cytokine production during infection with T. gondii and after DHA treatment via flow cytometry. A and C, Comparison of type 17 cytokine levels (IL-17A and IL-22) in the sera collected from the ME49 group and the treatment group. B, Comparison of Th1 cytokine levels (TNF-α) in the sera collected from the ME49 group, and the treatment group. D, Comparisons of Th2 cytokine levels (IL-5) in the sera collected from the ME49 group and the treatment group. E, Heatmaps directly showing the difference in the level of detected cytokine. The results are representative of three independent experiments with three to five mice per group per experiment. Data are expressed as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 6

    The number of splenic CD8+ T cells in the P. berghei (ANKA strain)-infected and the DHA-treated group. CD8+ T cells (A and B) were detected by flow cytometry on days 0, 4, 7, 8, 10, 12, and 14 post-infection. A, Representative histograms of CD8+ T cells among the circulating lymphocytes. B, Comparison of the number of CD8+ T cells in the circulation between the ANKA and DHA-treatment groups. The results are representative of three independent experiments with five to seven mice per group per experiment. Data are expressed as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 7

    The number of splenic NK and NKT cells of the P. berghei (ANKA strain)-infected and DHA-treated group. Splenic NK cells (A and B) and NKT cells (A and C) were detected by flow cytometry on days 0, 4, 7, 8, 10, 12, and 14 post-infection. A, Representative dot plots of CD3CD49b+ NK cells and CD3+CD49b+ NKT cells among the splenic lymphocytes. B, Comparison of the number of NK cells among the splenic lymphocytes between the ANKA and DHA-treated groups. C, Comparison of the number of NKT cells among the splenic lymphocytes between the ANKA and DHA-treated groups. The results are representative of three independent experiments with five to seven mice per group per experiment. Data are expressed as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 8

    The number of circulating Th cells in the P. berghei (ANKA strain)-infected and DHA-treated group. Th cells (A and B) were detected by flow cytometry on days 0, 4, 7, 8, 10, 12, and 14 post-infection. A, Representative histogram of CD3+CD4+ Th cells among the circulating lymphocytes. B, Comparison of the number of Th cells among the circulating lymphocytes between the ANKA and DHA-treated groups. The results are representative of three independent experiments with five to seven mice per group per experiment. Data representative of the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 9

    The number of circulating NK and NKT cells in the P. berghei (ANKA strain)-infected and DHA-treated groups. Circulating NK cells (A and B) and NKT cells (A and C) were detected by flow cytometry on days 0, 4, 7, 8, 10, 12, and 14 post-infection. A, Representative dot plots of CD3CD49b+ NK cells and CD3+CD49b+ NKT cells among the circulating lymphocytes. B, Comparison of the number of NK cells among the circulating lymphocytes between the ANKA and DHA-treated groups. C, Comparison of the number of NKT cells among the circulating lymphocytes between the ANKA and DHA-treated groups. The results are representative of three independent experiments with five to seven mice per group per experiment. Data are expressed as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

  • Figure 10

    Detection of cytokine production during infection with P. berghei (ANKA strain) and after DHA treatment by flow cytometry. A-C, Comparison of Th1 cytokine levels (IL-2, IFN-γ, and TNF-α) in the sera from the ANKA group and DHA-treated group. D-G, Comparison of Th2 cytokine levels (IL-4, IL-5, IL-6, and IL-10) in the sera collected from the ANKA group and DHA-treated group. H, Comparison of the Th9 cytokine levels (IL-9) in the sera from the ANKA group and DHA-treated group. I and J, Comparison of the type 17 cytokine levels (IL-22 and IL-17A) in the sera from the ANKA group and DHA-treated group. K, Heatmaps directly showing the difference in the cytokines detected. The results are representative of three independent experiments with five to seven mice per group per experiment. Data are expressed as the mean±SD. *, P<0.05; **, P<0.01; ***, P<0.001.

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