Marmosets as models of infectious diseases.

Animal models of infectious disease often serve a crucial purpose in obtaining licensure of therapeutics and medical countermeasures, particularly in situations where human trials are not feasible, i.e., for those diseases that occur infrequently in the human population. The common marmoset (Callithrix jacchus), a Neotropical new-world (platyrrhines) non-human primate, has gained increasing attention as an animal model for a number of diseases given its small size, availability and evolutionary proximity to humans. This review aims to (i) discuss the pros and cons of the common marmoset as an animal model by providing a brief snapshot of how marmosets are currently utilized in biomedical research, (ii) summarize and evaluate relevant aspects of the marmoset immune system to the study of infectious diseases, (iii) provide a historical backdrop, outlining the significance of infectious diseases and the importance of developing reliable animal models to test novel therapeutics, and (iv) provide a summary of infectious diseases for which a marmoset model exists, followed by an in-depth discussion of the marmoset models of two studied bacterial infectious diseases (tularemia and melioidosis) and one viral infectious disease (viral hepatitis C).

Pim Kinases as Therapeutic Targets in Early Rheumatoid Arthritis.

OBJECTIVE: As well as being an established oncoprotein and therapeutic target in cancer, proviral integration site for Moloney murine leukemia virus 1 (Pim-1) is implicated in human autoimmunity. This study was undertaken to investigate Pim-1 and its family members as potential therapeutic targets in early rheumatoid arthritis (RA). METHODS: A flow cytometry assay for PIM1 transcript measurement in peripheral blood mononuclear cells from patients with early arthritis was validated and applied as a biomarker of Pim-1 activity at the cellular level. Synovial protein expression was similarly determined by multiplex immunofluorescence in tissue samples from untreated RA patients and non-RA disease controls. Functional consequences of Pim kinase family manipulation in freshly isolated CD4+ T cells from these individuals were ascertained, along with the impact of Pim inhibition on mice with collagen-induced arthritis (CIA). RESULTS: The percentage of circulating CD4+ T cells positive for PIM1 transcript by flow cytometry proved a faithful surrogate for gene expression and was significantly higher in patients with early RA than in those with other diseases. Pim-1 protein levels were similarly up-regulated in synovial CD4+ T cells from patients with early RA. Ex vivo, exposure of T cell receptor-stimulated early RA CD4+ T cells to Pim kinase inhibitors restrained their activation and proliferative capacity. Diminished production of proinflammatory cytokines (interferon-γ and interleukin-17) and an expanded CD25high FoxP3+ Treg cell fraction were also observed in exposed versus unexposed cells. Finally, administration of Pim inhibitors robustly limited arthritis progression and cartilage destruction in CIA. CONCLUSION: Our findings indicate that Pim kinases are plausible therapeutic targets in a readily identifiable subgroup of patients with early RA. Repurposing of Pim inhibitors for this disease should be considered.