CD40 - CD40L Pathway

The CD40-CD40L (CD154) signaling pathway is a pivotal regulator of adaptive immunity, bridging innate and adaptive responses. CD40, a member of the TNF receptor superfamily, is expressed on antigen-presenting cells (APCs) such as dendritic cells, macrophages, and B cells, while its ligand CD40L is transiently expressed on activated CD4⁺ T cells. Engagement of CD40 by CD40L drives a cascade of immune-activating events. In dendritic cells and macrophages, CD40 signaling enhances antigen presentation, cytokine secretion, and upregulation of co-stimulatory molecules. In B cells, CD40-CD40L interactions promote germinal center formation, isotype switching, and the generation of long-lived plasma cells and memory B cells. Interaction between CD40-CD40L stimulates cytokines secretion of B cells with subsequent T cell activation and antitumor immunity.

LIT: CD40 stimulation as a molecular adjuvant for cancer vaccines and other immunotherapies: T.N.J. Bullock; Cell. Mol. Immunol. 19, 14 (2022) • Co-stimulators CD40-CD40L, a potential immune-therapy target for atherosclerosis: A review: S. Tian, et al.; Medicine 103, e37718 (2024) • Soluble CD40 Ligand as a Promising Biomarker in Cancer Diagnosis: A. Pazoki, et al.; Cells 13, 1267 (2024) • Facts and Hopes of CD40 Agonists in Cancer Immunotherapy: J.C. McVey & G.L. Beatty; Clin. Cancer Res. 31, 2079 (2025) • The role of soluble CD40L in autoimmune diseases: M. Mabrouk, et al.; J. Transl. Autoimmun. 10, 100288 (2025)

NEW: CD40L (human) ELISA Kit  - Biomarker for Autoimmune Diseases & Cancers

The CD40L (human) ELISA Kit (Prod. No. AG-45B-0018) is a sandwich ELISA for specific quantitative determination of human soluble CD40L in serum, plasma and cell culture supernatants. This ELISA Kit shows a very high specificity and sensitivity (20pg/ml).

Download the ELISA Kit Manual

B Cell Expansion:  Highly Potent B Cell Activators and T Cell Priming Reagents

CD40 activation tools can be used to expand B cells, which, as antigen-presenting cells (APCs), are as effective as dendritic cells and promises to streamline the generation of antitumor CD8+ T cells. Several studies show that usage of the agonistic anti-CD40 antibody (FGK45) (Prod. No. AG-20B-0036PF) and MultimericCD40L (Prod. No. AG-40B-0010) are strong stimulators of antitumor immunity.

LIT: R.S. Kornbluth, et al.; Int. Rev. Immunol. 31, 279 (2012) • K.T. Byrne & R.H. Vonderheide; Cell Rep. 15, 2719 (2016)

POTENT  CD40L (human) (multimeric) (rec.)  (Prod. No. AG-40B-0010)

NEW  CD40L (human) (multimeric) (rec.) (Certified Serum Grade)  (Prod. No. AG-40B-0010CSG)

NEW  B-Xpander™ CD40L (human) (multimeric) (rec.) (Animal Free)  (Prod. No. AG-40B-0010AF)

Figure: CD40L (human) (multimeric) (rec.) (Prod. No. AG-40B-0010), CD40L (human) (multimeric) (rec.) (Certified Serum Grade) (Prod. No. AG-40B-0010CSG) or CD40L (human) (multimeric) (rec.) (Animal Free) (Prod. No. AG-40B-0010AF) do not need an enhancer to induce B cell activation.

POTENT  anti-CD40 (mouse), mAb (FGK45) (Prod. No. AG-20B-0036) 

Figure: Systemic immune activation by CD40 ligation. Mice were sacrificed on day 8 after daily treatment on day 4-7 with FGK45 or control. FGK45 treatment elevated splenocyte numbers. *P < 0.005. Data represent mean ± SD for three to four mice per group.

Biologically Active CD40 and CD40L Proteins  

VALIDATED Antibodies for CD40 and CD40L Research

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