Background: Lupus nephritis (LN) is a chronic systemic B-cell-driven auto-immune disorder and associated with oxidative stress coupled with pro-inflammation. CD4 ⁺ T-cells are potent stimulator of B-cells and autoantibody production; making T-cells a potential therapeutic target. Studies have shown that in pro-oxidant milieu, activated CD4 ⁺ T-cells (CD4 ⁺ /CD69 ⁺ ) demonstrated altered status of metabolic bioenergetics which makes it crucial to study the unexplored role of activated T-cells upon oxidative stress and it’s association (if any) towards disease progression [1-3].

Objectives: Evaluating the possible role of T-cell mediated oxidative stress and associated pro-inflammatory milieu in CD4 ⁺ T-cells in LN cases.

Methods: Generation of reactive oxygen species (ROS) including mitochondrial superoxides, status of mitochondrial membrane polarization (JC-1) along with intracellular pro-inflammatory cytokine levels in activated CD4 ⁺ T-cells (CD4 ⁺ /CD69 ⁺ ) were assessed by flow cytometryin peripheral blood of LN (n=12) and age/sex matched healthy controls (n=10). Furthermore, PBMCs were assessed in terms of their generation of ROS and potential to release DNA (t/t±Plasma of LN). Clinical parameters (C3, C4, Anti-dsDNA) were also assessed by nephelometry/ELISA to corroborate and explore the potential of oxidative stress as a biomarker.

Results: In LN patients (n=12) activated CD4 ⁺ T-cells (CD4 ⁺ /CD69 ⁺ ) demonstrated enhanced generation of ROS (p<0.01), mitochondrial superoxides (p<0.001) and altered membrane polarization (p<0.001). Moreover, generation of ROS and superoxides correlated positively with Anti-dsDNA and disease activity score SLEDAI which was also substantiated by negative correlation with C3 and C4. In ex-vivo study, plasma (LN) caused significant increase in ROS generation possibly resulting into enhancement of DNA extrusion (Etosis). Furthermore, increased IFN-γ, IL-6 in activated CD4 ⁺ T-cells of LN cases and positive correlation with ROS generation was observed.

Conclusion: Altered redox status (generation of ROS, Mitochondrial superoxides) and their correlation with clinical parameters suggested their potential impact. Moreover, the crucial role of microenvironment was established when induction with plasma (LN) resulted redox imbalance and “Etosis” in lymphcoytes. Furthermore, association between redox and cytokine levels suggested the role of CD4 ⁺ T-cells in inflammation-induced disease progression in Lupus, cumulatively indicated the potential of oxidative stress towards disease progression.

REFERENCES: [1] Morel L, Immunometabolism in systemic lupus erythematosus, Nat Rev Rheumatol, 2017;13(5):280-290.

[2] Yin Y, Choi SC, Xu Z, Perry DJ, Seay H, Croker BP, Sobel ES, Brusko TM, Morel L. Normalization of CD4+ T Cell Metabolism Reverses Lupus. Science translational medicine. 2015 11;7(274):274.

[3] Costanza M, Poliani PL, Portararo P, Cappetti B, Musio S, Pagani F, Steinman L, Colombo MP, Pedotti R, Sangaletti S. DNA threads released by activated CD4+ T lymphocytes provide autocrine costimulation. Proceedings of the National Academy of Sciences. 2019 30;116(18):8985-94.

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Acknowledgements: I want to acknowledge my supervisors Dr. Pradyot Sinhamahapatra, Prof. Alakendu Ghosh along with Prof. Dr. Nitaipada Bhattacharyya for constantly guiding and supporting in my Ph.D and Prof. Parasar Ghosh (HOD) for allowing me to utilize departmental resources. Furthermore, I wish to express gratitude to Multidisciplinary research Unit in IPGME&R for providing instruments, Department of Science and technology & Biotechnology, Govt. of West Bengal for funding, and ICMR-Govt. of India for my Senior Research Fellowship (SRF).

Disclosure of Interests: None declared.