PTPRC and infection: To evaluate whether CHIKV-infected cells display poor MHC-I antigen presentation in vivo, WT C57BL/6 mice were inoculated in the left-rear footpad with 103 PFU of either CHIKV-VENKL or CHIKVQMS-VENKL and ankle-associated cells were evaluated by flow cytometry for VENUS, as an indicator of infection (Figs 4A and S4), and cell surface CD45, CD29, CD44, H2-Kb and H2-Kb-SIINFEKL expression on day 1, 2, and 5 post inoculation.