Chronic cytomegalovirus (CMV) infection leads to long-term maintenance of extraordinarily large CMV-specific T cell populations. The magnitude of this so-called ‘memory inflation’ is thought to mainly depend on antigenic stimulation during the chronic phase of infection. However, by mapping the long-term development of CD8⁺ T cell families derived from single naive precursors, we find that fate decisions made during the acute phase of murine CMV infection can alter the level of memory inflation by more than 1,000-fold. Counterintuitively, a T cell family’s capacity for memory inflation is not determined by its initial expansion. Instead, those rare T cell families that dominate the chronic phase of infection show an early transcriptomic signature akin to that of established T central memory cells. Accordingly, a T cell family’s long-term dominance is best predicted by its early content of T central memory precursors, which later serve as a stem-cell-like source for memory inflation.

慢性巨细胞病毒 (CMV) 感染导致长期维持非常大的 CMV 特异性 T 细胞群。这种所谓的“记忆膨胀”的程度被认为主要取决于感染慢性期的抗原刺激。^{但是，通过映射CD8 +}的长期发展T 细胞家族来源于单个幼稚前体，我们发现在小鼠 CMV 感染急性期做出的命运决定可以将记忆膨胀水平改变 1000 倍以上。与直觉相反，T 细胞家族的记忆膨胀能力并非由其初始扩张决定。相反，那些主导感染慢性期的稀有 T 细胞家族显示出类似于已建立的 T 中央记忆细胞的早期转录组特征。因此，T 细胞家族的长期优势最好通过其早期 T 中央记忆前体的含量来预测，该前体后来用作记忆膨胀的干细胞样来源。