Friday, May 12, 2023 1:45 PM – 2:30 PM ET Exhibit Hall D, Room 2
Exhibitor Workshop: BioLegend
Modulating Levels of Cell Surface CD6 Regulates Effector T Cell Activity and Treg Development
- Jeanette Ampudia, Associate Director, Immunology and Research Operations
CD6 is a co-stimulatory receptor that is highly expressed on the surface of proinflammatory Teff cells, whereas it is expressed at low levels on anti-inflammatory Treg cells despite similar levels of CD6 mRNA. Not only does this make CD6 an interesting target for suppression of autoreactive Teff cells, it also suggests a role in controlling Treg cell function. Recent data suggest that modulation of this receptor may be important to regulating autoimmunity. Equillium is developing itolizumab, a clinical stage humanized anti-CD6 monoclonal antibody that modulates cell surface levels of CD6 by instigating cleavage of the receptor via a membrane bound serine protease, for the treatment of autoimmune conditions. Previously, it was thought that itolizumab only inhibited Teff activity, while leaving the Treg population unaffected. However, we have recently shown that treatment of naïve T cells with itolizumab to remove CD6 results in Tregs with better stability and function as indicated by a higher frequency of FoxP3+Helios+ double positive cells and increased suppression of Teff cells. These data suggest that reduced levels of cell surface CD6 associated with itolizumab treatment improve Treg function and Treg:Teff ratios in patients with autoimmune and inflammatory diseases.