Identification of immune subsets with distinct lectin binding signatures using multi-parameter flow cytometry: correlations with disease activity in systemic lupus erythematosus

Front Immunol. 2024 May 7:15:1380481. doi: 10.3389/fimmu.2024.1380481. eCollection 2024.


Objectives: Cell surface glycosylation can influence protein-protein interactions with particular relevance to changes in core fucosylation and terminal sialylation. Glycans are ligands for immune regulatory lectin families like galectins (Gals) or sialic acid immunoglobulin-like lectins (Siglecs). This study delves into the glycan alterations within immune subsets of systemic lupus erythematosus (SLE).

Methods: Evaluation of binding affinities of Galectin-1, Galectin-3, Siglec-1, Aleuria aurantia lectin (AAL, recognizing core fucosylation), and Sambucus nigra agglutinin (SNA, specific for α-2,6-sialylation) was conducted on various immune subsets in peripheral blood mononuclear cells (PBMCs) from control and SLE subjects. Lectin binding was measured by multi-parameter flow cytometry in 18 manually gated subsets of T-cells, NK-cells, NKT-cells, B-cells, and monocytes in unstimulated resting state and also after 3-day activation. Stimulated pre-gated populations were subsequently clustered by FlowSOM algorithm based on lectin binding and activation markers, CD25 or HLA-DR.

Results: Elevated AAL, SNA and CD25+/CD25- SNA binding ratio in certain stimulated SLE T-cell subsets correlated with SLE Disease Activity Index 2000 (SLEDAI-2K) scores. The significantly increased frequencies of activated AALlow Siglec-1low NK metaclusters in SLE also correlated with SLEDAI-2K indices. In SLE, activated double negative NKTs displayed significantly lower core fucosylation and CD25+/CD25- Siglec-1 binding ratio, negatively correlating with disease activity. The significantly enhanced AAL binding in resting SLE plasmablasts positively correlated with SLEDAI-2K scores.

Conclusion: Alterations in the glycosylation of immune cells in SLE correlate with disease severity, which might represent potential implications in the pathogenesis of SLE.

Keywords: flow cytometry; glycobiology of SLE; immunophenotyping; lectin binding; systemic lupus erythematosus.

MeSH terms

  • Adult
  • Female
  • Flow Cytometry* / methods
  • Galectins / immunology
  • Galectins / metabolism
  • Glycosylation
  • Humans
  • Lectins* / immunology
  • Lectins* / metabolism
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / metabolism
  • Lupus Erythematosus, Systemic* / immunology
  • Lupus Erythematosus, Systemic* / metabolism
  • Male
  • Middle Aged
  • Protein Binding
  • Severity of Illness Index
  • Young Adult

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was funded by the GINOP-2.3.2-15-2016-00030, 2020-1.1.6-JÖVŐ-2021-00003, 2019-1.1.1-PIACI-KFI-2019-00444, 2022-1.2.6-TÉT-IPARI-TR-2022-00023 and 142877 FK22 grants from the National Research, Development, and Innovation Office (NKFI), Hungary. This work was supported by the SZAOK-BRC collaboration grant and SZTE ÁOK-KKA Hetényi grant (LK). This work was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences BO/00582/22/8 (GS) and by the by the ÚNKP-23-5-SZTE-694 New National Excellence Program of the Ministry for Innovation and Technology (GS).