CD8+ and CD8- NKT Cells Exhibit Phenotypic Changes During Pregnancy

ABSTRACT

Background

NKT cell population is a relatively well-characterized immune cell subset. Numerous publications have characterized the phenotypical features of its subpopulations even in human pregnancy. Nevertheless, there have not been studies investigating the distribution of the NKT cells based on the surface presence of the CD8 receptor.

Methods

Thirty-four pregnant women from the first trimester, 30 from the second, and 36 from the third trimester of pregnancy in addition to 35 healthy non-pregnant women have been involved in the study. PBMCs were isolated from peripheral blood, CD8+ and CD8- NKT cells were then studied by flow cytometry using monoclonal antibodies. Immune checkpoint molecules and intracellular markers were also measured.

Results

Substantial differences were revealed in the proportions of the NKT cell subpopulations in the healthy control cohort and the pregnant groups. By comparing the investigated groups, significant changes were detected in the expression levels of PD-L1, TIGIT, CD155, and NKG2D. Further associations were observed through examination of the relative expressions of TIGIT and CD226 in the CD8+ NKT subset.

Conclusion

Data suggest that the CD8+ NKT cells are under fine regulation during healthy human pregnancy.

KEYWORDS:

• CD8 receptor
• immune checkpoint
• NKT cells
• pregnancy

Acknowledgements

We would like to thank the University of Pecs, Medical School for the institutional and technical support and the Flow Cytometry Core Facility at the Szentágothai Research Centre, University of Pecs for their collaboration. We also would like to thank Etelka Nemeth Meszarosne for her help in the sample collection and all the women who participated in the study.

Disclosure statement

The authors report there are no competing interests to declare.

Author contributions

M.M. contributed to the planning and execution of the flow cytometric experiments, and to the writing of the paper. D.U.N. performed statistical analyses. B.P. performed the immunolabeling of the isolated leukocytes. I.S.A.D. performed the flow cytometric analyses. L.SZ. involved in the funding support of the project and in the writing and supervision of paper.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/08820139.2022.2119863

Additional information

Funding

This work was supported by the University of Pecs Medical School Research Grant [PTE-ÁOK KA 2021-20, KA 2021-38], and the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences to M. Meggyes.