A B-cell or a key player?

: The role of the humoral immune response in melanoma, highlighting the importance of method development

Abstract

Investigations of the humoral immune response to melanoma have revealed that B-cells and antibodies can play both pro and anti-tumourigenic functions. B-cells can infiltrate melanomas and become organised into a tertiary lymphoid structure; their presence have been associated with better survival.
Longitudinally collected serum samples from stage IV melanoma patients (n=10) enrolled in a phase I/II trial of autologous dendritic cell vaccines and healthy controls (n=40) were screened on a human protein microarray to detect IgG reactivities. Associations between these data and gene expression, tumour mutation burden, MHC types and protein subcellular location were explored in relation to potential drivers of autoantibody production. The reactivity profiles of patients with metastasised melanoma prior to receiving treatment were then compared to healthy controls to determine baseline autoantibody characteristics. The effect of treatment on autoantibody profiles and association with clinical response were then investigated. Pre-treatment and post-treatment targets statistically significantly enriched in melanoma patients were identified and warrant further investigation for their use as either biomarkers or as functional anti-tumour responses.
The development of an ELISA to confirm autoantibody reactivities of interest identified by protein microarray was explored. The ELISA was not suitable for this intended purpose because a specific signal with minimal non-specific signal was not achieved.
Finally, ovine uveal melanocytes were successfully isolated and cultured using a protocol designed for the isolation of human uveal melanocytes. This renewable source of primary cells was ideal for the successful development of a method for the 3D culture of cells of uveal origin, with the view to use in future studies of the tumour immune microenvironment.
In conclusion, we identified aspects of the humoral response to melanoma that could provide vital information about the B-cell response to disease and investigated the development of techniques to further study these findings. This is a field open for extensive discovery, for which the work presented here forms the basis of substantial future investigation.

Date of Award	20 Jun 2022
Original language	English
Awarding Institution	University of the Highlands and Islands
Sponsors	ESF PRA & Tenovus Scotland
Supervisor	Antonia Pritchard (Supervisor) & Jun Wei (Supervisor)