Increased effector memory CD8⁺ T cell differentiation in Prion protein-deficient mice after viral infection 

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Presentation Time: 08:00 AM - 08:15 AM
Abstract ID: 4289 - B

Presenting Author:
Karla M Viramontes , PhD Graduate Student at Univ. of California, Irvine

Abstract:

Cellular prion proteins (PrPc) are glycoproteins primarily located at the outer plasma membrane. While most abundantly expressed in neurons and microglia, they are also expressed on the surface of hematopoietic stem cells. Prions have been widely studied for their role in transmissible spongiform encephalopathies (TSEs), which result in fatal neurodegenerative diseases in humans. However, the precise role of prions in the immune response against viral infection remains to be fully investigated. Using WT or PrPc deficient (Prnp^-/-) mice infected with Lymphocytic choriomeningitis virus Armstrong (LCMV-Arm), an acute strain, we characterized the differentiation of effector and memory T cells during the response. We found increased accumulation of virus-specific CD4⁺ and CD8⁺ memory T cells in Prnp^-/-mice post Arm infection. We did not observe changes in PD-1 and CD127 expression throughout infection, indicating similar activation and survival expression levels between WT and Prnp^-/- mice respectively. However, we observed differentiation differences in Prnp^-/- T cells, with increased effector memory (Tem), decreased terminal effector memory (t-Tem), and no changes in central memory phenotype (Tcm). Consistent with these findings, we found increased cytokine production of memory T cells in Prnp^-/- mice. These studies underline a new role for prion proteins during acute viral infections and play an important role in regulating memory T cell immune responses.