10.3389/fimmu.2019.00054.s002 Paul David Paul David Dominik A. Megger Dominik A. Megger Tamara Kaiser Tamara Kaiser Tanja Werner Tanja Werner Jia Liu Jia Liu Lieping Chen Lieping Chen Barbara Sitek Barbara Sitek Ulf Dittmer Ulf Dittmer Gennadiy Zelinskyy Gennadiy Zelinskyy Table_2_The PD-1/PD-L1 Pathway Affects the Expansion and Function of Cytotoxic CD8+ T Cells During an Acute Retroviral Infection.xlsx Frontiers 2019 CD8 T cells PD-1 PD-L1 retrovirus caspase 3 apoptosis immunoregulation 2019-02-05 04:10:22 Dataset https://frontiersin.figshare.com/articles/dataset/Table_2_The_PD-1_PD-L1_Pathway_Affects_the_Expansion_and_Function_of_Cytotoxic_CD8_T_Cells_During_an_Acute_Retroviral_Infection_xlsx/7671248 <p>Cytotoxic CD8<sup>+</sup> T lymphocytes (CTL) efficiently control acute virus infections but can become exhausted when a chronic infection develops. The checkpoint receptor PD-1 suppresses the functionality of virus-specific CD8<sup>+</sup> T cells during chronic infection. However, the role of the PD-L1/PD-1 pathway during the acute phase of infections has not been well characterized. In the current study the effects of PD-1 or PD-L1 deficiency on the CD8<sup>+</sup> T cell response against Friend retroviral (FV) infection of knockout mice was analyzed during acute infection. We observed an enhanced proliferation, functional maturation, and reduced apoptosis of effector CD8<sup>+</sup> T cells in the absence of PD-1 or PD-L1. The knockout of PD-L1 had a stronger effect on the functionality of CD8<sup>+</sup> T cells than that of PD-1. Augmented CTL responses were associated with an improved control of FV replication. The strong phenotype of FV-infected PD-L1 knockout mice was independent of the interaction with CD80 as an additional receptor for PD-L1. Furthermore, we performed a detailed analysis of the production of different granzymes in virus-specific CD8<sup>+</sup> T cells and observed that especially the simultaneous production of multiple granzymes in individual T cells (multifunctionality) was under the control of the PD-1/PD-L1 pathway. The findings from this study allow for a better understanding of the development of antiviral cytotoxic immunity during acute viral infections.</p>