Long-lasting expansion of Vδ2neg γδ T cells is a hallmark of cytomegalovirus (CMV) infection in kidney transplant recipients. The ligands of these cells and their role remain elusive. To better understand their immune function, we generated γδ T cell clones from several transplanted patients. Numerous patient Vδ1+, Vδ3+, and Vδ5+ γδ T cell clones expressing diverse Vγ chains, but not control Vγ9Vδ2+ T clones, displayed strong reactivity against CMV-infected cells, as shown by their production of tumor necrosis factor-α. Vδ2neg γδ T lymphocytes could also kill CMV-infected targets and limit CMV propagation in vitro. Their anti-CMV reactivity was specific for this virus among herpesviridae and required T cell receptor engagement, but did not involve major histocompatibility complex class I molecules or NKG2D. Vδ2neg γδ T lymphocytes expressed receptors essential for intestinal homing and were strongly activated by intestinal tumor, but not normal, epithelial cell lines. High frequencies of CMV- and tumor-specific Vδ2neg γδ T lymphocytes were found among patients' γδ T cells. In conclusion, Vδ2neg γδ T cells may play a role in protecting against CMV and tumors, probably through mucosal surveillance of cellular stress, and represent a population that is largely functionally distinct from Vγ9Vδ2+ T cells.

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Cytomegalovirus (CMV) reactivation was analyzed in 92 recipients of allogeneic hematopoietic stem cell transplantation (HSCT) in relation to the proportion of CD4(+) lymphocytes in blood and a microsatellite polymorphism within the first intron of the interferon-gamma (IFNG) gene. CMV reactivation was found in 50% of the HSCT recipients; in 30% of these individuals, the level of CMV copies exceeded 100 per 10(5) peripheral blood (PB) cells on at least one occasion during the 100-day post-HSCT observation period. This high CMV copy level was most frequently found between 31 and 60 days post-HSCT (P = .021). Patients with > or = 100 CMV copies/10(5) cells were characterized by poorer overall survival (OS) compared with those lacking CMV copies or having < 100 CMV copies/10(5) cells (P = .04), and they suffered from severe post-HSCT complications, including acute graft-versus-host disease (aGVHD) and relapse. Thus, patients with > or = 100 CMV copies/10(5) cells were designated as having clinically significant CMV reactivation. Patients with < 10% CD4(+) lymphocytes had a higher number of CMV DNA copies than those with higher proportions of CD4(+) lymphocytes (0.62 vs 0.21, P = .001; mean +/- SEM, 4422 +/- 1667 vs 937 +/- 662 CMV copies/10(5) cells, P < .001, for the proportion of cases with reactivation and numbers of copies, respectively). Similarly, patients carrying 2 IFNG 13-CA-repeat alleles (homozygotes) had more frequent CMV reactivation (0.50 vs 0.26; P = .039) and a higher CMV load (4111 +/- 1699 vs 950+/-591 CMV copies/10(5) cells; P = .041) compared with those with other IFNG microsatellite allele constellations. Multivariate analysis demonstrated that the IFNG 13-CA-repeat homozygous genotype (odds ratio [OR] = 0.221; P = .044), a low proportion of CD4(+) lymphocytes (OR = 0.276; P = .050), and a lack of optimal (10/10 alleles) donor-recipient HLA match (OR = 15.19; P = .006) were independent risk factors for CMV reactivation with a high number of copies.

The interaction between CXCL12 and its receptor CXCR4 plays a crucial role in the homing and mobilization of haematopoietic progenitors. We investigated the putative association between a CXCL12 gene polymorphism, the G-A transition at position 801 in the 3 0 -untranslated region (3 0 UTR), and the yield of CD34 þ progenitors in 65 healthy allogeneic transplant donors who received G-CSF. Importantly, in this setting, the analysis was not biased by background disease or chemotherapy. The 3 0 UTR CXCL12 G801A polymorphism was detected using a PCR-RFLP technique with the MspI restriction enzyme and the frequency of CD34 þ progenitors was assessed by flow cytometry. The frequency as well as the number of CD34 þ progenitor cells in the first leukapheresis product was significantly higher from donors with the CXCL12-3 0 A allele compared to GG homozygotes (Po0.05 in both cases), especially for subjects with the CXCL12-3 0 AA homozygous genotype (Po0.01 in both cases). Moreover, more leukaphereses were needed to obtain the required number of CD34 þ progenitors for transplantation from CXCL12-3 0 GG homozygous donors compared to the CXCL12-3 0 A carriers (P ¼ 0.003). In conclusion, the CXCL12-3 0 A allele was associated with a higher yield of CD34 þ cells from healthy donors of PBPC for allogeneic haematopoietic SCT.

In this work, association between the presence and membrane density of CXCR4 and the effectiveness of mobilization was studied. Ninety G-CSF mobilized PBPC and 28 native BM (nBM) preparations obtained from healthy individuals for transplantation and BM obtained after G-CSF mobilized PBPC collection in 10 donors were investigated. Positivity for CD34, HLA-DR and CXCR4 were analysed in the three colour fluorescence. The cellular profile of PBPC differed from nBM preparations with respect to lower: (i) proportion of CD34 þ cells (0.64%70.04 vs 0.9270.07) and CD34 þ CXCR4 þ cells (0.30%70.02 vs 0.6170.07); (ii) contribution of CXCR4 þ cells to CD34 þ cells (52.2%72.5 vs 62.2%74.2); (iii) CXCR4 epitope density in CD34 þ cells (48.975.5 vs 94.7710.4). PBPC yield for CD34 þ cells was correlated with the content of CD34 þ cells lacking CXCR4 in the leukapheresis product (R ¼ 0.38). In contrast, nBM harvested for transplantation was poor in CD34 þ cells if these cells were frequently CXCR4À (R ¼ À0.49). The present study shows that CD34 þ cells mobilized to blood were characterized with a low proportion of CXCR4 and this associated with CD34 þ cell content in PBPC.

Hematopoietic stem cell transplantation from anti-cytomegalovirus immunoglobulin G (anti-CMV-IgG) positive donors facilitated immunological recovery post-transplant, which may indicate that chronic CMV infection has an effect on the immune system. This can be seen in the recipients after reconstitution with donor lymphocytes. We evaluated the composition of lymphocytes at hematologic recovery in 99 patients with hematologic malignancies post hematopoietic stem cell transplantation (HSCT). Anti-CMV-IgG seropositivity of the donor was associated with higher proportions of CD4+ (227.963 ± 304.858 × 106 vs. 102.050 ± 17.247 × 106 cells/L, p = 0.009) and CD4+CD25high (3.456 ± 0.436 × 106 vs. 1.589 ± 0.218 × 106 cells/L, p = 0.003) lymphocytes in the blood at hematologic recovery. The latter parameter exerted a diverse influence on the risk of acute graft-versus-host disease (GvHD) if low (1.483 ± 0.360 × 106 vs. 3.778 ± 0.484 × 106 cells/L, p < 0.001) and de novo chronic GvHD (cGvHD) if high (3.778 ± 0.780 × 106 vs. 2.042 ± 0.261 × 106 cells/L, p = 0.041). Higher values of CD4+ lymphocytes in patients who received transplants from anti-CMV-IgG-positive donors translated into a reduced demand for IgG support (23/63 vs. 19/33, p = 0.048), and these patients also exhibited reduced susceptibility to cytomegalovirus (CMV), Epstein–Barr virus (EBV) and/or human herpes 6 virus (HHV6) infection/reactivation (12/50 vs. 21/47, p = 0.032). Finally, high levels (≥0.4%) of CD4+CD25high lymphocytes were significantly associated with better post-transplant survival (56% vs. 38%, four-year survival, p = 0.040). Donors who experience CMV infection/reactivation provide the recipients with lymphocytes, which readily reinforce the recovery of the transplanted patients’ immune system.

Abstract: Abstract: The migration, survival and proliferation of cells is the basis for all physiologic and pathologic processes in the human body. All these reactions are regulated by a complex chemokine network that guides lymphocytes homing, chemotaxis, adhesion and interplay between immunologic system response cells. Chemokines are also responsible for metastatic dissemination of cancers, including Hodgkin's and non-Hodgkin's lymphomas. The purpose of this study was to determine chemokine gene expression (CXCL8, CXCL10, CCL2, CCL3, CCL4 and CCL5) in lymphoma lymph nodes compared to their expression in reactive lymph nodes. We also analyzed the influence of chemokine gene expression on the survival of lymphoma patients. Chemokine gene expression was evaluated in 37 lymphoma lymph nodes and in 25 samples of reactive lymph nodes. Gene expression of chemokines CXCL8, CXCL10, CCL2, CCL3, CCL4 and CCL5 was measured using the PCR method. Statistical analysis was performed using CSS Statistica for Windows (version 7.0) software. Probability values < < 0.05 were considered statistically significant and those between 0.05 and 0.1 as indicative of a trend. We found lower CXCL8 and CXCL10 gene expression in lymphoma lymph nodes compared to reactive lymph nodes. In the cases of CCL2 and CCL3, expression in lymphomas was higher than in reactive lymph nodes. Patients with high expression of CCL2 and CXCL10 had shorter survival.

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