Rational design of a hydrolysis-resistant mycobacterial phosphoglycolipid antigen presented by CD1c to T cells

Josephine F. Reijneveld, Laura Marino, Thinh-Phat Cao, Tan-Yun Cheng, Dennis Dam, Adam Shahine, Martin D. Witte, Dmitri V. Filippov, Sara Suliman, Gijsbert A. van der Marel, D. Branch Moody, Adriaan J. Minnaard, Jamie Rossjohn, Jeroen Codee*, Ildiko Van Rhijn*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Whereas proteolytic cleavage is crucial for peptide presentation by classical major histocompatibility complex (MHC) proteins to T cells, glycolipids presented by CD1 molecules are typically presented in an unmodified form. However, the mycobacterial lipid antigen mannosyl-β1-phosphomycoketide (MPM) may be processed through hydrolysis in antigen presenting cells, forming mannose and phosphomycoketide (PM). To further test the hypothesis that some lipid antigens are processed, and to generate antigens that lead to defined epitopes for future tuberculosis vaccines or diagnostic tests, we aimed to create hydrolysis-resistant MPM variants that retain their antigenicity. Here, we designed and tested three different, versatile synthetic strategies to chemically stabilize MPM analogs. Crystallographic studies of CD1c complexes with these three new MPM analogs showed anchoring of the lipid tail and phosphate group that is highly comparable to nature-identical MPM, with considerable conformational flexibility for the mannose head group. MPM-3, a difluoromethylene-modified version of MPM that is resistant to hydrolysis showed altered recognition by cells, but not by CD1c proteins, supporting the cellular antigen processing hypothesis. Furthermore, the synthetic analogs elicited T cell responses that were cross-reactive with nature-identical MPM, fulfilling important requirements for future clinical use.

Original languageEnglish
Article number101197
JournalThe Journal of Biological Chemistry
Volume297
Issue number4
Early online date15-Sep-2021
DOIs
Publication statusPublished - Oct-2021

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