Systemic Immune Remodeling in Breast Cancer: Selective Enrichment of TNFR2+ Circulating Lymphocytes in Breast Cancer

Faezeh Absalan,1,* Reza Azizi,2,* Hosein Hakimi,1 Mahmood Shariat,3 Abdolrasoul Talei,4 Farnaz Sedghy,2 Fereshteh Mehdipour,1 Abbas Ghaderi1,5 1Shiraz Institute for Cancer Research, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; 2Department of Immunology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran; 3Department of Pathology, Shiraz Central Hospital, Shiraz, Iran; 4Breast Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; 5Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran*These authors contributed equally to this workCorrespondence: Fereshteh Mehdipour, Shiraz Institute for Cancer Research, School of Medicine, Shiraz University of Medical Sciences, P.O. Box: 71345- 3119, Shiraz, Iran, Tel +98 713 2303687, Fax +98 713 2304952, Email [email protected] Farnaz Sedghy, Department of Immunology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran, Email [email protected]: Tumor necrosis factor-alpha (TNF-α) exerts both tumor-promoting and tumor-suppressive effects in breast cancer through its two molecular forms, transmembrane (tmTNF-α) and soluble (sTNF-α), which signal via distinct receptors, TNFR1 and TNFR2. While TNFR1 is minimally expressed on lymphocytes within tumor-draining lymph nodes, TNFR2 predominates on B and T cells, highlighting its key role in immune regulation. Considering that cancer affects systemic immunity, this study assessed TNFR2 expression on circulating lymphocytes in breast cancer patients to elucidate immune alterations across disease stages.Patients and Methods: Peripheral blood was collected from 50 women with histologically confirmed breast cancer and 24 age-matched healthy volunteers. Lymphocytes were isolated using density gradient centrifugation, and TNFR2 expression on B and T cell subsets was evaluated by flow cytometry with specific monoclonal antibodies.Results: Patients exhibited marked lymphopenia, with significantly reduced frequencies of CD19+ B cells, CD3+ T cells, and CD4+ T cells (all p < 0.001), a pattern present even in patients without lymph node involvement. In contrast, CD3−CD8+ cells were increased, consistent with expansion of innate lymphocytes. Despite overall lymphocyte decline, the proportion of TNFR2+ cells was elevated in patients, including CD19+TNFR2+ B cells (p = 0.036) and CD3+TNFR2+ T cells (p = 0.009), with a borderline rise in CD4+TNFR2+ T cells (p = 0.061). These immune alterations were observed across multiple clinical subgroups, though with distinct patterns, such as enrichment of TNFR2+ T cells in LN+ patients and higher TNFR2+ B-cell frequencies in LN− patients.Conclusion: Elevated TNFR2 expression on peripheral lymphocytes, despite overall lymphocyte depletion, underscores its potential as a biomarker and immunomodulatory target in breast cancer progression.Keywords: TNFR2, peripheral blood lymphocytes, systemic immunity, breast cancer