Donor-CD4 + T-cells: A Trojan horse for Human herpes virus 6 after Allogeneic Hematopoietic Cell Transplantation?

Author(s):  
Yeon Joo Lee ◽  
Yiqi Su ◽  
Christina Cho ◽  
Genovefa A Papanicolaou
Author(s):  
Derek J Hanson ◽  
Hu Xie ◽  
Danielle M Zerr ◽  
Wendy M Leisenring ◽  
Keith R Jerome ◽  
...  

Abstract We sought to determine whether donor-derived human herpesvirus (HHV) 6B–specific CD4+ T-cell abundance is correlated with HHV-6B detection after allogeneic hematopoietic cell transplantation. We identified 33 patients who received HLA-matched, non–T-cell–depleted, myeloablative allogeneic hematopoietic cell transplantation and underwent weekly plasma polymerase chain reaction testing for HHV-6B for 100 days thereafter. We tested donor peripheral blood mononuclear cells for HHV-6B–specific CD4+ T cells. Patients with HHV-6B detection above the median peak viral load (200 copies/mL) received approximately 10-fold fewer donor-derived total or HHV-6B–specific CD4+ T cells than those with peak HHV-6B detection at ≤200 copies/mL or with no HHV-6B detection. These data suggest the importance of donor-derived immunity for controlling HHV-6B reactivation.


2011 ◽  
Vol 208 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Daigo Hashimoto ◽  
Andrew Chow ◽  
Melanie Greter ◽  
Yvonne Saenger ◽  
Wing-Hong Kwan ◽  
...  

Acute graft-versus-host disease (GVHD) results from the attack of host tissues by donor allogeneic T cells and is the most serious limitation of allogeneic hematopoietic cell transplantation (allo-HCT). Host antigen-presenting cells are thought to control the priming of alloreactive T cells and the induction of acute GVHD after allo-HCT. However, whereas the role of host DC in GVHD has been established, the contribution of host macrophages to GVHD has not been clearly addressed. We show that, in contrast to DC, reducing of the host macrophage pool in recipient mice increased donor T cell expansion and aggravated GVHD mortality after allo-HCT. We also show that host macrophages that persist after allo-HCT engulf donor allogeneic T cells and inhibit their proliferation. Conversely, administration of the cytokine CSF-1 before transplant expanded the host macrophage pool, reduced donor T cell expansion, and improved GVHD morbidity and mortality after allo-HCT. This study establishes the unexpected key role of host macrophages in inhibiting GVHD and identifies CSF-1 as a potential prophylactic therapy to limit acute GVHD after allo-HCT in the clinic.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4616-4616
Author(s):  
Yi Wang ◽  
Hui Wang ◽  
Shumei Wang ◽  
Megan Sykes ◽  
Yong-Guang Yang

Abstract NKT cells from naïve mice are mainly CD4+ or CD4−CD8−. However, it has been reported that CD8+ NKT cells can be expanded in vitro from splenocytes, bone marrow cells and thymocytes of C57BL/6 (B6) mice by stimulation with anti-CD3 mAb and cytokines, and that the expanded CD8+ NKT cells mediate strong graft-vs.-leukemic (GVL) effects without severe GVHD after adoptive transfer into allogeneic mice. We now describe the presence of CD8+NK1.1+ cells in recipient livers (approximately 2–6%), but not in other tissues (spleen, lung, bone marrow, thymus and PBMC), in various allogeneic hematopoietic cell transplantation (allo-HCT) models. The generation of CD8+NK1.1+ cells is likely a consequence of alloresponses, as these cells were not detected in the liver of syngeneic HCT controls. Flow cytometric analysis confirmed that these cells are CD1d-independent, TCRαβ+ T cells with a memory phenotype (CD44+ and CD62L−), and do not express CD49b, Ly-49C/I, Ly-49G2, or Ly-49D. In a sublethally (6 Gy)-irradiated B6-to-B6D2F1 allo-HCT model, NK1.1+ CD8 T cells became detectable by week 2, increased in number until approximately week 8, and gradually declined thereafter but were still detectable in the liver at day 100 after allo-HCT. By using CD45.1 and CD45.2 congeneic donors, we determined that the majority of NK1.1+ CD8 T cells were derived from the donor splenocytes. Furthermore, depletion of CD8+, but not NK1.1+, cells from the donor splenocytes prior to transplantation prevented the generation of NK1.1+ CD8 T cells, indicating that these cells were derived from donor NK1.1−CD8+ splenic T cells. Our data demonstrate that donor CD8 T cells can acquire NK1.1 expression upon activation in allo-HCT recipients, and that these NK1.1+ CD8 T cells maintain a memory phenotype and persist in the recipients with preferential accumulation in the liver. Studies are currently in progress to determine the role of activated donor NK1.1+ CD8 T cells in GVHD and GVL effects.


Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3832-3839 ◽  
Author(s):  
Ming-Tseh Lin ◽  
Li-Hui Tseng ◽  
Haydar Frangoul ◽  
Ted Gooley ◽  
Ji Pei ◽  
...  

Lymphopenia and immune deficiency are significant problems following allogeneic hematopoietic cell transplantation (HCT). It is largely assumed that delayed immune reconstruction is due to a profound decrease in thymus-dependent lymphopoiesis, especially in older patients, but apoptosis is also known to play a significant role in lymphocyte homeostasis. Peripheral T cells from patients who received HCT were studied for evidence of increased cell death. Spontaneous apoptosis was measured in CD3+ T cells following a 24-hour incubation using 7-amino-actinomycin D in conjunction with the dual staining of cell surface antigens. Apoptosis was significantly greater among CD3+ T cells taken from patients 19-23 days after transplantation (30.4% ± 12.5%,P < .05), and 1 year after transplantation (9.7% ± 2.8%, P < .05) compared with healthy controls (4.0% ± 1.5%). Increased apoptosis occurred preferentially in HLA (human leukocyte antigen)-DR positive cells and in both CD3+/CD4+ and CD3+/CD8+ T-cell subsets, while CD56+/CD3− natural killer cells were relatively resistant to apoptosis. The extent of CD4+T-cell apoptosis was greater in patients with grade II-IV acute graft-versus-host disease (GVHD) (33.9% ± 11.3%) compared with grade 0-I GVHD (14.6 ± 6.5%, P < .05). T-cell apoptosis was also greater in patients who received transplantations from HLA-mismatched donors (39.5% ± 10.4%,P < .05) or HLA-matched unrelated donors (32.1% ± 11.4%, P < .05) compared with patients who received transplantations from HLA-identical siblings (19.6% ± 6.7%). The intensity of apoptosis among CD4+ T cells was significantly correlated with a lower CD4+ T-cell count. Together, these observations suggest that activation of T cells in vivo, presumably by alloantigens, predisposes the cells to spontaneous apoptosis, and this phenomenon is associated with lymphopenia. Activation-induced T-cell apoptosis may contribute to delayed immune reconstitution following HCT.


Blood ◽  
2011 ◽  
Vol 118 (11) ◽  
pp. 2951-2959 ◽  
Author(s):  
Krystel Vincent ◽  
Denis-Claude Roy ◽  
Claude Perreault

Abstract Allogeneic hematopoietic cell transplantation led to the discovery of the allogeneic GVL effect, which remains the most convincing evidence that immune cells can cure cancer in humans. However, despite its great paradigmatic and clinical relevance, induction of GVL by conventional allogeneic hematopoietic cell transplantation remains a quite rudimentary form of leukemia immunotherapy. It is toxic and its efficacy is far from optimal. It is therefore sobering that since the discovery of the GVL effect 3 decades ago, the way GVL is induced and manipulated has practically not changed. Preclinical and clinical studies suggest that injection of T cells primed against a single Ag present on neoplastic cells could enhance the GVL effect without causing any GVHD. We therefore contend that Ag-targeted adoptive T-cell immunotherapy represents the future of leukemia immunotherapy, and we discuss the specific strategies that ought to be evaluated to reach this goal. Differences between these strategies hinge on 2 key elements: the nature of the target Ag and the type of Ag receptor expressed on T cells.


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