New Frontiers and Expanding Boundaries: The Diverse Roles of CD40-CD40L

Introduction

CD40, a transmembrane protein belonging to the tumor necrosis factor receptor superfamily, is predominantly expressed on antigen-presenting cells such as B cells, macrophages, and dendritic cells. Its ligand, CD40 Ligand (CD40L), is primarily found on activated T cells. The interaction between CD40 and CD40L plays a crucial role in immune responses, particularly in B cell activation, antibody production, and the proliferation of inflammatory cells like macrophages and lymphocytes. Additionally, the CD40-CD40L signaling pathway is implicated in various pathological processes, including autoimmune diseases, inflammatory disorders, and cancers. Recent advancements have further expanded its potential applications, particularly in neurological disorders and emerging immunotherapies.

Traditional Research and Applications of CD40/CD40L

Current drug development efforts targeting CD40/CD40L primarily focus on monoclonal antibodies. Most studies involving antibodies center around agonists and antagonists. Agonists are chiefly utilized in cancer treatment, while antagonists are being explored for autoimmune diseases. Development of CD40 agonists has been slow due to dose-limiting side effects, causing setbacks for major pharmaceutical companies such as Roche, AbbVie, and Novartis (e.g., Roche's selicrelumab was discontinued due to significant adverse reactions).

These setbacks in oncology have prompted these companies to redirect their focus toward autoimmune diseases. Dapirolizumab Pegol, developed by UCB and Biogen, demonstrated a significant reduction in Systemic Lupus Erythematosus (SLE) disease activity in Phase 3 data presented at the American College of Rheumatology. Sanofi and ImmuNext's Frexalimab has exhibited promising efficacy and tolerability in Phase II trials for multiple sclerosis (MS) and Type 1 diabetes, with Phase III trials underway in China. In addition, Innovent Biologics 's IBI355 has started Phase I clinical trials for primary Sj?gren's syndrome.

Moreover, novel therapeutic approaches such as small interfering RNA (siRNA), fusion proteins, and peptides are being developed to reduce CD40 expression or target different sites, offering potential advantages in reducing side effects and improving specificity.

Emerging Bispecific Agonists

In a groundbreaking development, Aman Mebrahtu et al. have introduced a novel CD40 agonistic antibody, BiA92_HF, has been developed within the Adaptive Drug Affinity Conjugate (ADAC) platform, enabling cancer-specific peptide delivery. This bispecific construct, with an IgG2 subclass, exhibits potent agonistic activity on monocyte-derived dendritic cells, independent of Fcγ receptor engagement. Humanization of the anti-pTag scFv resulted in improved protein quality and yield, favoring fusion to the heavy chain for enhanced production efficiency. In vivo studies demonstrate that ADAC induces significant antigen-specific CD8+ and CD4+ T cell expansion, with the pTag-peptide linked to BiA92_HF enhancing T cell proliferation. The platform shows efficacy in inhibiting tumor growth and improving survival in tumor models, surpassing traditional adjuvants like CpG. ADAC transforms previously ineffective neoantigens into potent anti-tumor agents, offering a promising avenue for personalized cancer immunotherapy. The platform's ability to induce robust immune responses, enhance anti-tumor immunity, and minimize systemic toxicity underscores its potential in precision oncology.

Potential in Neurological Disorders

Recent advancements have expanded the comprehension of CD40-CD40L beyond its conventional roles in autoimmunity and cancer, revealing its potential in addressing various neurological disorders. The CD40-CD40L axis has emerged as a key regulator in various neurological disorders, influencing neuroinflammation, neurodegeneration, and disease progression. Its diverse roles highlight its potential as a therapeutic target.

Zhou et al. have delved into the role of CD40-CD40L in neurological diseases and therapeutic advancements, shedding light on mechanisms and strategies:

In traumatic brain injury (TBI),elevated CD40 and CD40L levels in macrophages and microglia at the injury site drive neuroinflammation. Soluble CD40L (sCD40L) serves as a biomarker for poor prognosis, and inhibiting CD40 signaling may mitigate brain edema and improve outcomes.

Alzheimer’s disease (AD)is characterized by CD40-CD40L interactions that promote neuroinflammation by influencing amyloid precursor protein (APP) processing and tau phosphorylation. This contributes to the formation of neurofibrillary tangles and β-amyloid plaques, suggesting that targeting this pathway could slow disease progression.

Parkinson’s disease (PD) sees CD40 signaling in microglia and astrocytes upregulating pro-inflammatory molecules, leading to the selective loss of dopaminergic neurons. Inhibition of CD40-CD40L may protect neurons and reduce neurodegeneration.

Ischemic stroke involves CD40L expression in atherosclerotic lesions, destabilizing plaques and exacerbating neuroinflammation. Inhibiting CD40 signaling reduces infarct volume and improves outcomes in animal models, indicating therapeutic potential.

Epilepsyis marked by elevated plasma sCD40L and leukocyte CD40 expression, which correlate with increased seizure susceptibility and severity. Downregulating CD40-CD40L signaling attenuates neuroinflammation and may provide therapeutic benefits.

Multiple sclerosis (MS) is driven by CD40L+ T-cells activating microglial CD40 receptors, releasing inflammatory molecules that worsen demyelination. Elevated sCD40L in cerebrospinal fluid highlights the axis’s role in disease progression, with CD40-CD40L inhibition potentially reducing neuroinflammation.

Amyotrophic lateral sclerosis (ALS) features upregulated CD40 signaling in antigen-presenting cells and T-cells, contributing to disease progression. Anti-CD40L antibodies delay paralysis onset and extend survival in mouse models, indicating therapeutic potential.

Myasthenia gravis (MG)relies on CD40 signaling for B-cell activation and antibody production. CD40L knockout mice show resistance to MG induction, suggesting that targeting CD40-CD40L may reduce autoantibody production.

Brain tumors illustrate a dual role of the CD40-CD40L axis: it can enhance anti-tumor immunity but may also promote tumor progression. Elevated CD40 expression in some gliomas correlates with poor prognosis, highlighting the need for combination therapies to modulate its effects.

Overall, the CD40-CD40L axis plays a multifaceted role in neurological disorders, offering potential therapeutic targets for modulating neuroinflammation and disease progression. Future research should focus on elucidating its mechanisms and developing targeted interventions.

Summary

Enhancing our comprehension of the CD40/CD40L pathway unlocks novel avenues for disease treatment. Through ongoing research, we unearth its role in immune regulation and explore its clinical potential. Global pharmaceutical entities are dedicated to formulating CD40/CD40L-targeted drugs, with the objective of delivering more efficacious and safer treatments for patients.

To meet market demands for CD40/CD40L-related drug development, we have optimized a series of products, including high-quality target proteins and CD40L overexpression cell lines. These products support the entire drug development process from immunization, antibody screening and characterization, cell function validation, signaling pathway research to production quality control, accelerating the development of drugs for various diseases.

Target Proteins:High-purity CD40/CD40L proteins with CD40L trimer structure verified by SEC-MALS and high bioactivity confirmed by ELISA/BLI.

CD40 Overexpression Cell Line: Expression activity validated by FACS, Stable passage over 20 generations, ensuring reliability and effectiveness in research and drug development.

Assay Data

??CD40 Ligand Trimer structure of CD40L and high purity(＞95%) verified by SEC-MALS

??The binding activity of CD40 and CD40 Ligand was verified by ELISA

??The binding activity of CD40 and CD40 Ligand was verified by BLI

??The binding activity of CD40 and CD40 Ligand was verified by FACS

??FACS verified that CD40 Ligand stimulate secretion of IL-6 by human B cells.

Reference

1 Mebrahtu, A., Laurén, I., Veerman, R. et al. A bispecific CD40 agonistic antibody allowing for antibody-peptide conjugate formation to enable cancer-specific peptide delivery, resulting in improved T Cell proliferation and anti-tumor immunity in mice. Nat Commun 15, 9542 (2024). https://doi.org/10.1038/s41467-024-53839-5

2. Ots HD, Tracz JA, Vinokuroff KE, Musto AE. CD40-CD40L in Neurological Disease. Int J Mol Sci. 2022 Apr 8;23(8):4115. doi: 10.3390/ijms23084115. PMID: 35456932; PMCID: PMC9031401.