Clinical and Ultrastructural Studies of Gelatinous Drop-Like Corneal Dystrophy (GDLD) of a Patient with TACSTD2 Gene Mutation

A TROP2/Claudin Program Mediates Immune Exclusion to Impede Checkpoint Blockade in Breast Cancer

Immune exclusion inhibits anti-tumor immunity and response to immunotherapy, but its mechanisms remain poorly defined. Here, we demonstrate that Trophoblast Cell-Surface Antigen 2 (TROP2), a key target of emerging anti-cancer Antibody Drug Conjugates (ADCs), controls barrier-mediated immune exclusion in Triple-Negative Breast Cancer (TNBC) through Claudin 7 association and tight junction regulation. TROP2 expression is inversely correlated with T cell infiltration and strongly associated with outcomes in TNBC. Loss-of-function and reconstitution experiments demonstrate TROP2 is sufficient to drive tumor progression in vivo in a CD8 T cell-dependent manner, while its loss deregulates expression and localization of multiple tight junction proteins, enabling T cell infiltration. Employing a humanized TROP2 syngeneic TNBC model, we show that TROP2 targeting via hRS7, the antibody component of Sacituzumab govitecan (SG), enhances the anti-PD1 response associated with improved T cell accessibility and effector function. Correspondingly, TROP2 expression is highly associated with lack of response to anti-PD1 therapy in human breast cancer. Thus, TROP2 controls an immune exclusion program that can be targeted to enhance immunotherapy response.

Staged limbal stem cell transplantation and keratoplasty surgeries as a treatment for gelatinous drop-like corneal dystrophy

Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive corneal dystrophy that has been associated with mutations in the TACSTD2 (M1S1) gene, which is normally expressed in corneal epithelial cells. GDLD is characterized by progressive deposition of amyloid in the corneal stroma with rapid recurrence in grafts after penetrating keratoplasty. We report of case of a patient with GDLD treated bilaterally with staged limbal stem cell transplantation and penetrating keratoplasty that resulted in long-term control of his disease. This case demonstrates that staged allogenic limbal stem cell transplantation, before or after penetrating keratoplasty, can be used to restore vision long-term in GDLD patients.

Raman Spectroscopic Study of Amyloid Deposits in Gelatinous Drop-like Corneal Dystrophy

The genetic and histopathological features of the cornea of a Polish patient with Gelatinous Drop-like Corneal Dystrophy (GDCD) and the molecular composition with Raman spectroscopy of corneal deposits were examined. A 62 year-old Polish woman was diagnosed with GDCD and underwent penetrating corneal transplant. A blood sample was collected, and genetic analysis was performed. The cornea was processed for light microscopy and Raman analysis. The genetic exam revealed a previously undescribed homozygous 1-base pair deletion in exon 1 of TACSTD2 gene (c.185delT), resulting in a frame shift causing a premature stop codon. When compared with a control cornea, in GDCD cornea stained with PAS evident deposits were present over the anterior stroma, with apple green birefringence under polarized light. Raman spectroscopy showed peculiar differences between normal and GDCD cornea, consisting in peaks either of different height or undetectable in the normal cornea and related to amyloid. The possible causative role of the novel mutation was discussed and Raman spectroscopy as a further morphological tool in the evaluation of corneal dystrophies, characterized by the deposition of abnormal materials, was suggested.