Selective glucocorticoid receptor modulation inhibits cytokine responses in a canine model of mild endotoxemia

Automated blood sampling in canine telemetry model: Enhanced assessment of immune liabilities

INTRODUCTION

This manuscript presents a successful integration of multi-timepoint biomarker blood sampling (e.g., cytokines) in a conscious dog cardiovascular study using automated blood sampling via vascular access ports in telemetry instrumented dogs. In addition to determining plasma exposure of the test compound, the assessment of biomarkers of interest allows for more comprehensive preclinical evaluation on a traditional conscious dog cardiovascular (CV) telemetry study especially for immunology and immune-oncology molecules. This model system provides a rapid and efficient means to quickly gain understanding of potential effects on key cardiovascular parameters in large species that are commonly used for preclinical safety evaluations while collecting multiple blood samples for drug and cytokine analysis.

METHODS

Male beagle dogs were chronically implanted with telemetry devices (PhysioTel™ model D70-PCTP) and vascular access ports (SPMID-GRIDAC-5NC). BASi Culex-L automated blood sampling (ABS) (Bioanalytical Systems, Inc) system was used to collect blood samples at multiple time points for cytokine analysis. Four beagles received low-dose lipopolysaccharide solution (LPS) (0.1 and 0.5 μg/mL). The following cytokines were measured by Milliplex® map Canine Cytokine Magnetic Bead Panel: Interleukin (IL) 2, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, TNF-α, MCP-1, KC-like, GM-CSF, IFN gamma, and IP10.

RESULTS

Low dose LPS administration induced a pronounced dose-dependent, transient release of key inflammatory cytokines (IL-2, IL-6, IL-10, TNF-α, MCP-1, and KC-like). Cytokine responses were similar to other canine and human endotoxin models. LPS administration led to an increase in body temperature, heart rate, and mean arterial pressure, as well as a decrease in QTcV interval.

CONCLUSION

Successful incorporation of cytokine analysis in telemetry instrumented dogs with vascular access ports allows for translational PK/PD modeling of both efficacy and safety of compounds in the immunology as well as the immune-oncology therapeutic areas designed to modulate the immune system. Remote collection of blood samples simultaneously with CV endpoints is a significant enhancement for assessment of biomarkers that are sensitive to animal handling and excitement associated with room disturbances which are obligatory with manual blood collection. Furthermore, implementing this approach has also refined our animal welfare procedure by reducing the handling during a study and thereby reducing stress (positive refinement 3R impact).

Natural Endotoxemia in Dogs-A Hidden Condition That Can Be Treated with a Potential Probiotic Containing Bacillus subtilis, Bacillus licheniformis and Pediococcus acidilactici: A Study Model

Spore-based Bacillus spp. products are considered to have a higher probiotic potential compared to products containing only lactic acid bacteria because their viability in the gastrointestinal (GI) tract is higher, even when GI environmental conditions are unfavorable. The aim of this study was to assess the effect of a Bacillus subtilis, Bacillus licheniformis and Pediococcus acidilactici spore-based potential probiotic on the natural levels of postprandial endotoxemia. A total of 11 dogs completed the study: group 1-healthy dogs: n = 5; group 2-dogs with apparent dysbiosis: n = 6. For 30 days, the dogs were fed the probiotic product; clinical examinations and blood sampling were done before and after completion of the probiotic treatment. Endotoxin levels were assessed pre-meal, 6 h and 12 h post-meal, before initiation and after completion of the treatment. The results showed a decrease in endotoxin levels after treatment, especially 12 h post-meal (group 1: 20.60%; group 2: 44.93%). This study reports new information with regard to natural endotoxemia levels in dogs and suggests that a multi-strain formula (spore-based) consisting of B. subtilis, B. licheniformis and P. acidilactici is able to diminish endotoxin values.

Improved Glucocorticoid Receptor Ligands: Fantastic Beasts, but How to Find Them?

Exogenous glucocorticoids are widely used in the clinic for the treatment of inflammatory disorders and hematological cancers. Unfortunately, their use is associated with debilitating side effects, including hyperglycemia, osteoporosis, mood swings, and weight gain. Despite the continued efforts of pharma as well as academia, the search for so-called selective glucocorticoid receptor modulators (SEGRMs), compounds with strong anti-inflammatory or anti-cancer properties but a reduced number or level of side effects, has had limited success so far. Although monoclonal antibody therapies have been successfully introduced for the treatment of certain disorders (such as anti-TNF for rheumatoid arthritis), glucocorticoids remain the first-in-line option for many other chronic diseases including asthma, multiple sclerosis, and multiple myeloma. This perspective offers our opinion on why a continued search for SEGRMs remains highly relevant in an era where small molecules are sometimes unrightfully considered old-fashioned. Besides a discussion on which bottlenecks and pitfalls might have been overlooked in the past, we elaborate on potential solutions and recent developments that may push future research in the right direction.