Inducible costimulator ligand (ICOSL) on CD19+ B cells is involved in immunopathological damage of rheumatoid arthritis (RA)

B cells and tertiary lymphoid structures in cancer therapy response

Recent advances in immuno-oncology research have revolutionised our understanding of the interplay between immune cells and the tumour microenvironment (TME), profoundly impacting patient responses to therapy. The TME, comprising tumour cells, immune cells, extracellular matrix, stromal cells, and co-existing microbes, orchestrates the immune phenotype of cancers, shaping disease progression and treatment outcomes. Immune-cell infiltration serves as a significant prognostic marker in various cancers, with higher rates correlating with improved prognosis. Recent discoveries have paved the way for immune checkpoint blockade therapies, which exhibit remarkable efficacy across multiple cancer types. However, understanding the nuanced contributions of different immune-cell populations to therapeutic responses remains a challenge. The majority of research has focussed on the role of T cells in the immune response to cancer therapies, with the potential importance of B cells only recently being recognised. Here, we review the diverse phenotypes of B cells within the TME, their structural organisation within tertiary lymphoid structures (TLS), and the role of both B cells and TLS in cancer prognosis and response to different therapies for cancer treatment.

Role of the Crosstalk B:Neoplastic T Follicular Helper Cells in the Pathobiology of Nodal T Follicular Helper Cell Lymphomas

Angioimmunoblastic T-cell lymphoma (AITL), the most common form of peripheral T-cell lymphoma, originates from follicular helper T (Tfh) cells and is notably resistant to current treatments. The disease progression and maintenance, at least in early stages, are driven by a complex interplay between neoplastic Tfh and clusters of B-cells within the tumor microenvironment, mirroring the functional crosstalk observed inside germinal centers. This interaction is further complicated by recurrent mutations, such as TET2 and DNMT3A, which are present in both Tfh cells and B-cells. These findings suggest that the symbiotic relationship between these 2 cell types could represent a therapeutic vulnerability. This review examines the key components and signaling mechanisms involved in the synapses between B-cells and Tfh cells, emphasizing their significant role in the pathobiology of AITL and potential as therapeutic targets.

Therapeutic and immunomodulatory potentials of mesenchymal stromal/stem cells and immune checkpoints related molecules

Mesenchymal stromal/stem cells (MSCs) are used in many studies due to their therapeutic potential, including their differentiative ability and immunomodulatory properties. These cells perform their therapeutic functions by using various mechanisms, such as the production of anti-inflammatory cytokines, growth factors, direct cell-to-cell contact, extracellular vesicles (EVs) production, and mitochondrial transfer. However, mechanisms related to immune checkpoints (ICPs) and their effect on the immunomodulatory ability of MSCs are less discussed. The main function of ICPs is to prevent the initiation of unwanted responses and to regulate the immune system responses to maintain the homeostasis of these responses. ICPs are produced by various types of immune system regulatory cells, and defects in their expression and function may be associated with excessive responses that can ultimately lead to autoimmunity. Also, by expressing different types of ICPs and their ligands (ICPLs), tumor cells prevent the formation and durability of immune responses, which leads to tumors' immune escape. ICPs and ICPLs can be produced by MSCs and affect immune cell responses both through their secretion into the microenvironment or direct cell-to-cell interaction. Pre-treatment of MSCs in inflammatory conditions leads to an increase in their therapeutic potential. In addition to the effect that inflammatory environments have on the production of anti-inflammatory cytokines by MSCs, they can increase the expression of various types of ICPLs. In this review, we discuss different types of ICPLs and ICPs expressed by MSCs and their effect on their immunomodulatory and therapeutic potential.

[Mechanism of Qingluo Tongbi Formula for regulating immune-bone erosion in rheumatoid arthritis]

OBJECTIVE

To explore the mechanism of Qingluo Tongbi formula for regulating "immune-bone erosion" in rheumatoid arthritis (RA).

METHODS

Sixty-four RA patients were randomized into two groups to receive treatment with oral methotrexate or Qingluo Tongbi Formula for 12 weeks. Flow cytometry was used to analyze the changes in the percentages of CD3-CD19+, CD19+CD27 and CD19+BAFFR+B cell subpopulations in peripheral blood of the patients, and serum levels of B cell activating factor (BAFF), RANKL, RANK and osteoprotegerin (OPG) levels were detected using ELISA. Before and after the treatment, serum levels of β-CTX, TRACP-5b, BGP, BALP, and PINP were measured with ELISA, and bone mineral density was determined with DXEA dual-energy X-ray absorptiometry. In the cell experiment, RAW264.7 cells were induced to differentiated into osteoclasts and treated with Qingluo Tongbi Formula at low-, moderate and high doses (125, 250 and 500 μg/mL, respectively) or with methotrexate (2 μg/mL) for 48 h, and the changes in the expression levels of RANKL, RANK, OPG and c-Fos were detected using Western blotting.

RESULTS

The B cell subgroups in RA patients were correlated with the RANKL/RANK/OPG system. Treatment with Qingluo Tongbi Formula obviously down-regulated the percentages of the B cell subgroups, lowered serum levels of BAFF, β-CTX and TRACP-5b, increased the levels of BGP, BALP and PINP, and improved lumbar bone density of RA patients (P<0.05); All these changes were significantly correlated with the regulation of B cell expressions (P<0.05). In RAW264.7 cells-derived osteoclasts, Qingluo Tongbi Formula significantly decreased the expressions of RANKL, RANK and c-Fos and increased the expression of OPG (P<0.05).

CONCLUSION

Qingluo Tongbi Formula inhibits bone erosion in RA possibly by regulating B cell subset percentages and BAFF expression and inhibiting osteoclast differentiation via the RANKL/RANK/OPG pathway.