2023-05-23 カロリンスカ研究所(KI)
◆105人の健康な献血者のT細胞免疫応答を分析することで、研究者は1976年以前に生まれた人々が両方のウイルスに対して明らかに強力な免疫応答を示していることを示しました。
◆昨年のmpoxの流行では男性同性愛者が最も感染しており、天然痘ワクチンはmpoxに対して約80%の保護効果があるという。この研究は、Cell Host & Microbe誌に掲載された。
<関連情報>
- https://news.ki.se/previous-smallpox-vaccine-provides-immunity-to-mpox
- https://www.sciencedirect.com/science/article/pii/S193131282300166X?via%3Dihub
記憶プロファイルは、天然痘に対する交差反応性T細胞免疫とウイルス特異的T細胞免疫を区別する。 Memory profiles distinguish cross-reactive and virus-specific T cell immunity to mpox
Sarah Adamo, Yu Gao, Takuya Sekine, Akhirunnesa Mily, Jinghua Wu, Elisabet Storgärd, Victor Westergren, Finn Filén, Carl-Johan Treutiger, Johan K. Sandberg, Matti Sällberg, Peter Bergman, Sian Llewellyn-Lacey, Hans-Gustaf Ljunggren, David A. Price, Anna-Mia Ekström, Alessandro Sette, Alba Grifoni, Marcus Buggert
Cell Host & Microbe Published: May 10, 2023
DOI:https://doi.org/10.1016/j.chom.2023.04.015
Highlights
•Cross-reactive T cells against MPXV are found in many unexposed adults
•TCF-1+ VACV-specific CD8+ T cells persist >4 decades after smallpox vaccination
•MPXV-specific CD4+ and CD8+ T cells acquire functional effector phenotypes upon mpox.
•MPXV-specific CD8+ T cells from patients with mild mpox show high effector potential.
Summary
Mpox represents a persistent health concern with varying disease severity. Reinfections with mpox virus (MPXV) are rare, possibly indicating effective memory responses to MPXV or related poxviruses, notably vaccinia virus (VACV) from smallpox vaccination. We assessed cross-reactive and virus-specific CD4+ and CD8+ T cells in healthy individuals and mpox convalescent donors. Cross-reactive T cells were most frequently observed in healthy donors over 45 years. Notably, long-lived memory CD8+ T cells targeting conserved VACV/MPXV epitopes were identified in older individuals more than four decades after VACV exposure and exhibited stem-like characteristics, defined by T cell factor-1 (TCF-1) expression. In mpox convalescent donors, MPXV-reactive CD4+ and CD8+ T cells were more prevalent compared to controls, demonstrating enhanced functionality and skewing towards effector phenotypes, which correlated with milder disease. Collectively, we report robust effector memory MPXV-specific T cell responses in mild mpox and long-lived TCF-1+ VACV/MPXV-specific CD8+ T cells decades after smallpox vaccination.
