Respiratory syncytial virus-approved mAb Palivizumab as ligand for anti-idiotype nanobody-based synthetic cytokine receptors

Synthetic cytokine receptors can modulate cellular functions based on an artificial ligand to avoid off-target and/or unspecific effects. However, ligands that can modulate receptor activity so far have not been used clinically because of unknown toxicity and immunity against the ligands. Here, we developed a fully synthetic cytokine/cytokine receptor pair based on the antigen-binding domain of the respiratory syncytial virus-approved mAb Palivizumab as a synthetic cytokine and a set of anti-idiotype nanobodies (AIPVHH) as synthetic receptors. Importantly, Palivizumab is neither cross-reactive with human proteins nor immunogenic. For the synthetic receptors, AIPVHH were fused to the activating interleukin-6 cytokine receptor gp130 and the apoptosis-inducing receptor Fas. We found that the synthetic cytokine receptor AIPVHHgp130 was efficiently activated by dimeric Palivizumab single-chain variable fragments. In summary, we created an in vitro nonimmunogenic full-synthetic cytokine/cytokine receptor pair as a proof of concept for future in vivo therapeutic strategies utilizing nonphysiological targets during immunotherapy.

Synthetic PPAR Agonist DTMB Alleviates Alzheimer's Disease Pathology by Inhibition of Chronic Microglial Inflammation in 5xFAD Mice

Abnormal productions of amyloid beta (Aβ) plaque and chronic neuroinflammation are commonly observed in the brain of patients with Alzheimer's disease, and both of which induce neuronal cell death, loss of memory, and cognitive dysfunction. However, many of the drugs targeting the production of Aβ peptides have been unsuccessful in treating Alzheimer's disease. In this study, we identified synthetic novel peroxisome proliferator-activating receptor (PPAR) agonist, DTMB, which can ameliorate the chronic inflammation and Aβ pathological progression of Alzheimer's disease. We discovered that DTMB attenuated the proinflammatory cytokine production of microglia by reducing the protein level of NF-κB. DTMB also improved the learning and memory defects and reduced the amount of Aβ plaque in the brain of 5xFAD mice. This reduction in Aβ pathology was attributed to the changes in gliosis and chronic inflammation level. Additionally, bulk RNA-sequencing showed that genes related to inflammation and cognitive function were changed in the hippocampus and cortex of DTMB-treated mice. Our findings demonstrate that DTMB has the potential to be a novel therapeutic agent for Alzheimer's disease.

Modulation of the CCR6-CCL20 Axis: A Potential Therapeutic Target in Inflammation and Cancer

Prototypical functions of the chemokine receptor CCR6 include immune regulation by maneuvering cell chemotaxis and selective delimiting of the pro-inflammatory T_H17 and regulatory T_reg subsets during chronic or acute systemic inflammation. Inhibition of CCR6 is proposed to attenuate disease symptoms and promote recuperation of multiple inflammatory and autoimmune disorders. Prescription medicines with pharmacodynamics involving the inhibition of the chemokine axis CCR6–CCL20 are very limited. The development of such therapeutics is still at an early experimental stage and has mostly involved the utilization of pre-clinical models and neutralizing mono or polyclonal antibodies against either partner (CCR6 or CCL20). Other methods include the constitutive use of small molecules as peptide inhibitors or small interfering ribonucleic acid (siRNA) to interfere with transcription at the nuclear level. In our review, we aim to introduce the wide array of potential CCR6–CCL20 inhibitors with an emphasis on attendant immune-modulator capacity that have been tested in the research field to date and are immensely promising compounds as forerunners of future curatives. Sixteen different tractable inhibitors of the CCR6–CCL20 duo have been identified as possessing high medicinal potential by drug developers worldwide to treat autoimmune and inflammatory diseases as shown in Figure 1. A multitude of antibody preparations are already available in the current pharmaceutical market as patented treatments for diseases in which the CCR6–CCL20 axis is operative, yet they must be used only as supplements with existing routinely prescribed medication as they collectively produce adverse side effects. Novel inhibitors are needed to evaluate this invaluable therapeutic target which holds much promise in the research and development of complaisant remedies for inflammatory diseases.