Rituximab efficiently depletes increased CD20 expressing T cells in multiple sclerosis patients1

• Published in: The Journal of immunology (1950) 2014-06, Vol.193 (2), p.580-586
• Main Authors: Palanichamy, Arumugam, Jahn, Sarah, Nickles, Dorothee, Derstine, Mia, Abounasr, Aya, Hauser, Stephen L., Baranzini, Sergio E., Leppert, David, von Büdingen, H.-Christian
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1400118

In multiple sclerosis (MS 4 ) B cell depleting therapy using monoclonal anti-CD20 antibodies, including rituximab (RTX) and ocrelizumab (OCR), effectively reduces disease activity. Based on indirect evidence, it is generally believed that elimination of the antigen presenting capabilities and antigen non-specific immune functions of B cells underlie the therapeutic efficacy. However, a small subset of T lymphocytes (T cells) was shown to also express CD20, but controversy prevails surrounding the true existence of this T cell subpopulation. Using single-cell imaging flow cytometry and expression profiling of sorted lymphocyte subsets, we unequivocally demonstrate the existence of CD3 + CD20 dim T cells. We show that in MS patients increased levels of CD3 + CD20dim T cells are effectively depleted by RTX. The pathological relevance of this T cell subset in MS remains to be determined. However, given their potential pro-inflammatory functionality, depletion of CD20-expressing T cells may also contribute to the therapeutic effect of RTX and other monoclonal antibodies targeting CD20.