Treatment of infectious diseases after organ transplantation using antigen-specific memory T cells in the peripheral blood

动物模型：SPF条件下饲养的BALB/c小鼠腹腔内感染0.2LD50的小鼠巨细胞病毒（MCMV），即使在感染后6 ~ 12个月，肺中CD69^+/CD44^+ MCMV特异性CD8 T细胞的频率也很高（分别为11.1±3.2%和9.8±0.9%）。相比之下，尽管mcmv感染的of小鼠肺中IL-2、IL-7、IL-15和IFN-γ等细胞因子mRNA的病毒载量和表达水平与感染SPF的小鼠相当，但感染GF小鼠肺中mcmv特异性CD8 T细胞的频率在感染后6至12个月保持在1%以下。此外，通过口服SPF小鼠制备的粪便悬浮液重建mcmv感染GF小鼠的微生物群，使CD8^+/多聚体^+和CD8^+/多聚体T细胞的频率恢复到与SPF小鼠相似的水平。这些结果表明，本地微生物群在病毒特异性CD8记忆T细胞的扩增和维持中发挥了至关重要的作用，可能是通过mcmv特异性记忆T细胞的抗原表位与来自微生物群成员的各种肽之间的交叉反应。因此，这种交叉反应性可能是这些细胞的主要特征。然后，我们研究了mcmv特异性CD8^+/多计时器^+记忆T细胞的过继转移治疗巨细胞病毒疾病。首先，我们试图在体外扩增mcmv特异性CD8^+/多计时器^+记忆T细胞，方法是将记忆T细胞与抗原脉冲树突状细胞和IL-2和/或IL-15等细胞因子共培养。然而，在这种培养条件下，我们无法在体外扩增记忆T细胞。人体材料实验：从20名志愿者身上获得cmv特异性记忆T细胞，将记忆T细胞与抗原脉冲树突状细胞和IL-2共培养，进行记忆T细胞体外扩增。来自志愿者的记忆T细胞，具有cmv特异性记忆T细胞的高频率（约占总CD8细胞的0.2%），可以充分扩增。然而，来自其他志愿者的cmv特异性记忆T细胞不能扩增。少

Animal model : When the BALB/c mice bred under SPF condition were intra-peritoneally infected with 0.2LD50 of murine cytomegalovirus (MCMV), high frequencies of CD69^+/CD44^+ MCMV-specific CD8 T cells were noted in the lungs even at 6 to 12 months after infection (11.1±3.2% and 9.8±0.9%, respectively). In contrast, even though the viral load and expression levels of mRNA of such cytokines as IL-2, IL-7, IL-15 and IFN-γ in the lungs of MCMV-infected OF mice were comparable to those of infected SPF mice, the frequencies of MCMV-specific CD8 T cells in the lungs of infected GF mice were kept lower than 1% at 6 to 12 months after infection. In addition, the reconstitution of microbiota of MCMV-infected GF mice by orally administering a fecal suspension prepared from SPF mice restored both the frequencies of CD8^+/multimer^+ and CD8^+/multimer T cells to levels similar to those found in SPF mice. These results suggested the indigenous microbiota to play a crucial role in the expansion and m … More aintenance of viral specific CD8 memory T cells, probably by cross-reactivity between the antigenic epitope of the MCMV-specific memory T cells and the variety of peptides derived from the members of the microbiota. Such cross-reactivity may thus be a major feature of those cells. Then, we examined to adoptive transfer of the MCMV-specific CD8^+/multimer^+ memory T cells for the treatment of CMV disease, At first, we tried to in vitro expand the MCMV-specific CD8^+/multimer^+ memory T cells, by co-culture with the memory T cells with the antigen-pulsed dentritic cells and such cytokines as IL-2 and /or IL-15. However, we could not in vitro expand the memory T cells under this culture condition.Experiments using human materials : CMV-specific memory T cells were obtained from 20 volunteers, and then in vitro expansion of the memory T cells was done by co-culture with the memory T cells with the antigen-pulsed dentritic cells and IL-2. Memory T cells from the volunteer, who possessed the high frequency of CMV-specific memory T cells (>0.2% of total CD8 cells), could be adequately expanded. However, CMV-specific memory T cells form the other volunteers could not be expanded. Less