
The HCMV-encoded protein US10 selectively binds to and regulates the expression of different HLA-I allotypes in a multimodal manner, contributing to immune evasion.


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To control human cytomegalovirus (HCMV) infection, NK cells and CD8+ T-cells are crucial. HLA class I (HLA-I) molecules play a central role for both NK and T-cell responses and are targets of multifaceted HCMV-encoded immunoevasins. A so far insufficiently studied HLA-I immunoevasin is the glycoprotein US10. It was shown that US10 targets HLA-G, but it is unknown whether US10 contributes also to escape from classical HLA-I antigen presentation. Our biochemical analysis revealed that early during maturation, all investigated HLA-I (HLA-A/B/C/E/G) heavy chains are recognized and bound by US10. Remarkably, the consequences of this initial binding strongly depended on both the HLA-I geno- and allotypes: i) HLA-A molecules escaped down-regulation by US10, ii) tapasin-dependent HLA-B molecules exhibited impaired recruitment to the peptide loading complex and maturation, iii) HLA-C and HLA-G, but not HLA-A/B/E, strongly bound US10 also in their β2m-assembled form. Thus, US10 senses geno- and allotypic differences in a so far unparalleled and multimodal manner, suggestive of adaptation to HLA-I genotype differences. At a further level of complexity, in HCMV-infected fibroblasts inhibition of overlapping US10 and US11 transcription revealed an additional HLA-I specificity, suggesting targeting of HLA-I in a synergistically arranged manner. Our study unveils the exceptional HLA-I selectivity of HCMV-encoded US10 and underlines its contribution to immune escape.

### Competing Interest Statement

The authors have declared no competing interest.

Multimodal HLA-I genotype regulation by human cytomegalovirus US10 and resulting surface patterning

cytomegalovirus-protein-us10-selectively-regulates-expression-of-human-leukocyte-antigen-class-i-molecules


Cytomegalovirus Protein US10 Selectively Regulates Expression of Human Leukocyte Antigen Class I Molecules
