Targeting of Immune Cells by Dual TLR27 Ligands Suppresses Features of Allergic Th2 Immune Responses in Mice

Abstract EN

Background.

TLR ligands can promote Th1-biased immune responses, mimicking potent stimuli of viruses and bacteria.

Aim.

To investigate the adjuvant properties of dual TLR2/7 ligands compared to those of the mixture of both single ligands.

Methods.

Dual TLR2/7 ligands: CL401, CL413, and CL531, including CL264 (TLR7-ligand) and Pam2CysK4 (TLR2-ligand), were used.

Immune-modulatory capacity of the dual ligands with the individual ligands alone or as a mixture in mouse BMmDCs, BMmDC:TC cocultures, or BMCMCs was compared and assessed in naïve mice and in a mouse model of OVA-induced intestinal allergy.

Results.

CL413 and CL531 induced BMmDC-derived IL-10 secretion, suppressed rOVA-induced IL-5 secretion from OVA-specific DO11.10 CD4+ TCs, and induced proinflammatory cytokine secretion in vivo.

In contrast, CL401 induced considerably less IL-10 secretion and led to IL-17A production in BMmDC:TC cocultures, but not BMCMC IL-6 secretion, or IL-6 or TNF-α production in vivo.

No immune-modulating effects were observed with single ligands.

All dual TLR2/7 ligands suppressed DNP-induced IgE-and-Ag-specific mast cell degranulation.

Compared to vaccination with OVA, vaccination with the mixture CL531 and OVA, significantly suppressed OVA-specific IgE production in the intestinal allergy model.

Conclusions.

Based on beneficial immune-modulating properties, CL413 and CL531 may have utility as potential adjuvants for allergy treatment.