The immunohistology of CD40 in human oral epithelium in health and disease

DuoBody-CD40x4-1BB induces dendritic-cell maturation and enhances T-cell activation through conditional CD40 and 4-1BB agonist activity

Background

Despite the preclinical promise of CD40 and 4-1BB as immuno-oncology targets, clinical efforts evaluating CD40 and 4-1BB agonists as monotherapy have found limited success. DuoBody-CD40×4-1BB (GEN1042/BNT312) is a novel investigational Fc-inert bispecific antibody for dual targeting and conditional stimulation of CD40 and 4-1BB to enhance priming and reactivation of tumor-specific immunity in patients with cancer.

Methods

Characterization of DuoBody-CD40×4-1BB in vitro was performed in a broad range of functional immune cell assays, including cell-based reporter assays, T-cell proliferation assays, mixed-lymphocyte reactions and tumor-infiltrating lymphocyte assays, as well as live-cell imaging. The in vivo activity of DuoBody-CD40×4-1BB was assessed in blood samples from patients with advanced solid tumors that were treated with DuoBody-CD40×4-1BB in the dose-escalation phase of the first-in-human clinical trial (NCT04083599).

Results

DuoBody-CD40×4-1BB exhibited conditional CD40 and 4-1BB agonist activity that was strictly dependent on crosslinking of both targets. Thereby, DuoBody-CD40×4-1BB strengthened the dendritic cell (DC)/T-cell immunological synapse, induced DC maturation, enhanced T-cell proliferation and effector functions in vitro and enhanced expansion of patient-derived tumor-infiltrating lymphocytes ex vivo. The addition of PD-1 blocking antibodies resulted in potentiation of T-cell activation and effector functions in vitro compared with either monotherapy, providing combination rationale. Furthermore, in a first-in-human clinical trial, DuoBody-CD40×4-1BB mediated clear immune modulation of peripheral antigen presenting cells and T cells in patients with advanced solid tumors.

Conclusion

DuoBody-CD40×4-1BB is capable of enhancing antitumor immunity by modulating DC and T-cell functions and shows biological activity in patients with advanced solid tumors. These findings demonstrate that targeting of these two pathways with an Fc-inert bispecific antibody may be an efficacious approach to (re)activate tumor-specific immunity and support the clinical investigation of DuoBody-CD40×4-1BB for the treatment of cancer.

Investigation of CD40 gene rs4810485 and rs1883832 mutations in patients with recurrent aphthous stomatitis

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is a common painful disorder affecting oral health, mucosa and overall quality of life. The etiopathogenesis of RAS remains unclear. RAS shows a large genetic diversity among the patients. In present study, we investigated whether CD40 gene rs4810485 and rs1883832 are associated with RAS and its clinical findings in Turkish patients.

MATERIALS AND METHODS

Genomic DNA obtained from 387 individuals (160 patients with RAS and 227 healthy controls) were used in the study. CD40 gene rs4810485 and rs1883832 mutations were determined by using polymerase chain reaction with the specific primers.

RESULTS

There was no statistically significant difference between the groups with respect to genotype and allele distribution (p>0.05, OR 0.94, 95% CI 0.70-1.28, OR 1.01 95% CI 0.75-1.37, respectively). Additionally, there was no statistically significant difference in the combined genotype analysis of CD40 gene rs4810485 and rs1883832 mutations (p>0.05).

CONCLUSIONS

According to our results, we found that CD40 gene mutations are not associated with RAS. We are convinced that CD40 gene mutations do not predispose to develop RAS in Turkish population. To our knowledge, this is the first study regarding CD40 gene rs4810485 and rs1883832 mutations investigated in RAS patients.

CD40 in human oral epithelia

CD40 is a transmembrane glycoprotein belonging to the tumour necrosis factor receptor superfamily, which has a role in a number of biological functions, including the regulation of cell growth and division, and cell mediated immunity. Although originally described on leucocytes, principally B lymphocytes, there is now abundant evidence for the cellular diversity of CD40. The aim of this article is to review the available data on CD40 in oral epithelium, principally that lining the oral mucosa, but also that of the salivary glands.

Altered CD40 and E-cadherin expression--putative role in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is characterized among other features by apoptosis of basal keratinocytes. To identify potential regulatory mechanisms associated with basal cell apoptosis in OLP, we investigated the expression of CD40, CD40 ligand (CD40L), CD44 and epithelial (E)-cadherin.

METHODS

Biopsies from 22 patients with OLP were investigated by immunohistochemistry for detection of CD40, CD40L, E-cadherin, CD44, Laminin-5 and Collagen IV, double-labelling for CD40 and CD3, and in situ mRNA hybridization for CD40 and CD40L.

RESULTS

In actively diseased areas of OLP lesions, basal keratinocytes did not express CD40 and were focally E-cadherin-negative, in contrast to non-diseased areas and normal oral mucosa. Demonstration of intraepithelial T cells expressing CD40 and CD40L, indicates a potential role in inflammatory cell responses involved in the disease process of OLP.

CONCLUSION

T cells may orchestrate inflammatory cell responses in OLP via CD40-CD40L interactions. As basal keratinocytes downregulate CD40, they may escape CD40-CD40L-induced apoptosis in OLP. On the other hand, loss of E-cadherin expression may contribute to epithelial basal cell destruction and T-cell migration into the epithelial compartment in OLP.