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

动物模型：在SPF条件下饲养的BALB/c小鼠经腹腔感染小鼠巨细胞病毒(MCMV)0.2LD50后，即使在感染后6~12个月，肺内仍有较高的CD69~+/CD44~+MCMV特异性CD8 T细胞出现(分别为11.1±3.2%和9.8±0.9%)。尽管巨细胞病毒感染组小鼠肺组织中IL-2、IL-7、IL-15、干扰素-γ等细胞因子的病毒载量和基因表达水平与SPF小鼠相当，但在感染后6~12个月，小鼠肺组织中巨细胞病毒特异性CD8T细胞的频率仍低于1%。此外，通过口服SPF小鼠制备的粪便悬浮液，对感染MCMV的GF小鼠的微生物区系进行重建，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，本土微生物区系在扩张和m-…中起着关键作用。更多地维持病毒特异性CD8记忆T细胞，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组成员的各种多肽之间的交叉反应。因此，这种交叉反应可能是这些细胞的一个主要特征。然后，我们研究了MCMV特异性CD8^+/多聚体^+记忆T细胞过继转移治疗CMV病的方法。首先，我们尝试将MCMV特异性CD8^+/多聚体^+记忆T细胞与抗原致敏的树突状细胞以及IL-2和/或IL-15等细胞因子共培养，体外扩增MCMV特异性CD8^+/多聚体^+记忆T细胞。然而，在这种培养条件下，我们不能在体外扩增记忆T细胞。使用人类材料的实验：从20名志愿者获得CMV特异性的记忆T细胞，然后将其与抗原致敏的树突状细胞和IL-2共培养，进行体外扩增。来自志愿者的记忆T细胞具有高频率的CMV特异性记忆T细胞(占CD8细胞总数的0.2%)，可以充分扩增。然而，其他志愿者的CMV特异性记忆T细胞无法扩增。较少

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