IgD/FcδR is involved in T-cell acute lymphoblastic leukemia and regulated by IgD-Fc-Ig fusion protein

A novel IgD-FcδR blocker, IgD-Fc-Ig fusion protein, effectively alleviates abnormal activation of T cells the disease progression in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic, multi-organ autoimmune disease with complex pathogenesis and unclear causes. Elevated levels of IgD have been observed in the peripheral blood of SLE patients, suggesting a potential role for IgD through its interaction with the IgD Fc receptor (FcδR). This study aimed to explore the impact of IgD on T cell function in SLE and evaluate the therapeutic potential of targeting the IgD-FcδR pathway using an IgD-Fc-Ig fusion protein. In SLE patients, biomarkers such as BAFF, ESR, anti-dsDNA and SLEDAI-2k, which are used to assess disease activity and clinical presentations, were significantly correlated with sIgD levels. As an IgD-FcδR blocker, IgD-Fc-Ig effectively suppressed the activation and proliferation of CD4+ T cells stimulated by IgD, restored the balance between Th17 and Treg cell subsets, and reduced the expression and interaction of phosphorylated Lck (p-Lck) and JAK2 (p-JAK2). Moreover, in vivo study demonstrated that IgD-Fc-Ig may also ameliorates disease manifestations in MRL/lpr mice with lupus nephritis. IgD-Fc-Ig could reduce serum IgD levels, proteinuria level and the kidney deposition of immune complex C3, ameliorate histopathological changes in kidney and spleen tissue. Additionally, it reversed the state of excessive activation and imbalance of Th17/Treg cell subsets, reduced cytokine levels, and downregulated p-JAK2 and p-STAT3 expression. In conclusion, our study revealed a correlation between abnormally increased sIgD and SLE pathogenesis, IgD-FcδR-Lck-JAK2-STAT3 may act as an important mechanism contributing to T cell activation in SLE. IgD-Fc-Ig fusion protein may represent a promising targeted therapy for SLE.

Application of Immune Repertoire Analysis in Differentiating Thyroid Cancer and Large Benign Thyroid Nodules

This study compares the peripheral T-cell receptor (TCR) and B-cell receptor (BCR) immune repertoires among early-stage papillary thyroid carcinoma (PTC) patients, patients with benign thyroid nodules larger than 4 cm, and healthy controls. Adaptive immune repertoire sequencing is used to analyze peripheral immune profile differences among these groups. Results indicates that early PTC and large benign nodules show significantly higher proportions of expanded clones than healthy controls, reflecting antigen-driven clonal expansion. By introducing the concept of "publicness," disease-specific high-publicness clonotypes is identified. These clonotypes exhibits distinct V-J rearrangement characteristics and strong immune heterogeneity. This study further reveals that this immune heterogeneity may be associated with patients' thyroid hormone levels and autoimmune antibody levels. These findings provides new insights into the immunopathological mechanisms of thyroid disorders.

CD7-targeting pro-apoptotic extracellular vesicles: A novel approach for T-cell haematological malignancy therapy

T-cell haematological malignancies progress rapidly and have a high mortality rate and effective treatments are still lacking. Here, we developed a drug delivery system utilizing 293T cell-derived extracellular vesicles (EVs) modified with an anti-CD7 single-chain variable fragment (αCD7/EVs). Given the challenges of chemotherapy resistance in patients with T-cell malignancy, we selected cytochrome C (CytC) and Bcl2 siRNA (siBcl2) as therapeutic agents and loaded them into αCD7/EVs (αCD7/EVs/CytC/siBcl2). We found that αCD7/EVs efficiently targeted and were internalized by human T-ALL Molt-4 cells. In addition, the interaction between αCD7 and CD7 switched the EV entry pathway in Molt-4 cells from macropinocytosis-dependent endocytosis to clathrin-mediated endocytosis, thereby reducing EV-lysosome colocalization, ultimately improving CytC delivery efficiency and increasing the cytotoxicity of nascent EVs from EV-treated Molt-4 cells. Notably, αCD7/EVs/CytC/siBcl2 demonstrated similar efficacy against both Molt-4 and chemotherapy-resistant Molt-4 cells (CR-Molt-4). Furthermore, αCD7/EVs/CytC/siBcl2 exhibited high safety, low immunogenicity and minimal impact on human T cells. Therefore, αCD7/EVs/CytC/siBcl2 are promising therapeutic approaches for treating CD7+ T-cell malignancies.