Murine models of graft versus host disease (GVHD): Focus on ocular GVHD

Exploratory study on the efficacy of topical pan-JAK inhibitor in ocular and skin GVHD in a sclerodermatous GVHD mouse model

Systemic administration of Janus kinase (JAK) inhibitors is effective in treating chronic graft-versus-host disease (cGVHD) but is associated with side effects. Topical drug administration effectively minimizes side effects. We aimed to investigate potential trends of the efficacy of topical delgocitinib administration in a mouse model. Allogenic bone-marrow transplantation (BMT) was performed from B10.D2. to BALB/c mice, leading to sclerodermatous GVHD. GVHD mice were treated with delgocitinib eye drops or ointment with samples analyzed at 4 weeks post-BMT. Topical delgocitinib ointment and eye-drop administration significantly increased the meibomian gland (MG) area and attenuated corneal epithelial damage. Pathological and immunohistochemical analyses revealed a substantial reduction in inflammation and pathological fibrosis of the skin and eyelids in delgocitinib-treated GVHD mice. Signal transducer and activator of transcription (STAT)1, STAT3, and STAT5A phosphorylation was significantly increased in the back skin and eyelids of vehicle-treated GVHD mice; topical delgocitinib administration significantly reduced the expression of these phosphorylated STAT molecules. Delgocitinib eye drops significantly attenuated corneal epithelial damage, MG acinar depletion, and inflammatory cells infiltration in GVHD mouse corneas. The JAK/STAT signaling pathway was significantly upregulated in GVHD mice. In summary, our data suggested that topical delgocitinib administration had the potential to attenuate cGVHD phenotype severity in the skin and eyes of sclerodermatous GVHD mice.

Inflammation in Dry Eye Disease-Pathogenesis, Preclinical Animal Models, and Treatments

Dry eye disease (DED) is a rapidly growing ocular surface disease with a significant socioeconomic impact that affects the patients' visual function and, thus, their quality of life. It is distinguished by a loss of tear film homeostasis, leading to tear film instability, hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities, with all of these playing etiological roles in the propagation of the vicious DED circle. While current treatments primarily focus on reducing tear film instability and hyperosmolarity, increasingly more attention is being placed on tackling the underlying inflammation that propagates and potentiates these factors. As such, preclinical models are crucial to further elucidate the DED pathophysiology and develop novel therapeutic strategies. This review outlines the role of inflammation in DED, highlighting related signs and diagnostic tools before focusing on relevant preclinical animal models and potential therapeutic strategies to tackle DED-associated inflammation.

Understanding Ocular Graft-versus-Host Disease to Facilitate an Integrated Multidisciplinary Approach

Ocular graft-versus-host disease (oGVHD) remains a challenging and potentially devastating complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although oGVHD significantly impacts the quality of life of affected survivors, it often goes unrecognized, particularly in the early stages. Targeting all providers in the HSCT community who see patients regularly and frequently for their post-allo-HSCT care, this review and opinion piece introduces the basic concepts of ocular surface pathophysiology, dissects the different stages of clinical presentation of oGVHD, explains why the current diagnostic criteria tend to capture the late disease stages, and highlights the warning signs of early disease development to facilitate prompt referral of oGVHD suspects for ocular specialist care. Along with introducing a comprehensive list of treatment options, this review emphasizes basic therapeutic strategy and options that can be safely and effectively initiated by any care provider. We believe in empowering patients as well as care providers beyond disciplinary boundaries to provide the most cohesive and integrated care in a multidisciplinary approach.

Deciphering Regulatory T-Cell Dynamics in Cancer Immunotherapy: Mechanisms, Implications, and Therapeutic Innovations

This Review explores how tumor-associated regulatory cells (Tregs) affect cancer immunotherapy. It shows how Tregs play a role in keeping the immune system in check, how cancers grow, and how well immunotherapy work. Tregs use many ways to suppress the immune system, and these ways are affected by the tumor microenvironment (TME). New approaches to cancer therapy are showing promise, such as targeting Treg checkpoint receptors precisely and using Fc-engineered antibodies. It is important to tailor treatments to each patient's TME in order to provide personalized care. Understanding Treg biology is essential for creating effective cancer treatments and improving the long-term outcomes of immunotherapy.

Lessons Learned From Ocular Graft versus Host Disease: An Ocular Surface Inflammatory Disease of Known Time of Onset

ABSTRACT

The ocular surface inflammatory disorders (OSIDs) comprise a group of conditions characterized by persistent inflammation of the ocular surface and adnexal tissues. Systemic autoimmune diseases and hypersensitivity reactions cause them, and, if left untreated, can result in severe inflammatory dry eye, corneal damage, and vision loss. Ocular graft-versus-host disease (oGVHD) forms part of the ocular surface inflammatory disease umbrella. It is a condition occurring after allogeneic hematopoietic stem cell or bone marrow transplantation, usually in chronic graft-versus-host disease. oGVHD can virtually affect any ocular adnexal tissue, especially the meibomian glands, and cause persistent inflammation, tissue fibrosis, and subsequent chronic, severe dry eye disease. Among the OSIDs, oGVHD has the particularity that it has a "time zero," meaning we know when the disease started. As such, preclinical models have leveraged this to investigate the molecular mechanisms involved in the damage oGVHD causes to the ocular surface. In oGVHD, establishing a "time zero" allows for predicting the clinical course and establishing adequate treatment. This is also possible because the inflammatory infiltration occurs in ocular surface tissues, which are readily accessible. Using oGVHD, we might be able to understand the immune response mechanisms in other OSIDs better (i.e., Sjögren syndrome, Stevens-Johnson syndrome, among others). This review presents an up-to-date overview of the pathogenesis, clinical presentation, and treatment of oGVHD. In addition, we will discuss the value of the "time zero" concept in the study of oGVHD.