Increased cAMP-PKA signaling pathway activation is involved in up-regulation of CTLA-4 expression in CD4+ T cells in acute SIVmac239-infected Chinese rhesus macaques.

"Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product service and/or company that could be construed as influencing the position presented in or the review of the manuscript entitle."

"Funding statement This work was supported in part by grants from the National Key R & D Program of China (2023YFC2306700), the National Natural Science Foundation of China (32070181, 82071847, U23A20473, U1604287), Yunnan Applicative and Basic Research Program (202101AT070282) and the Key Scientific and Technological Program of China (2013ZX10001002–001)."