Laura Montiel-Cervantes

Role of CD4+CD25+highFoxp3+CD62L+ regulatory T cells and invariant NKT cells in human allogeneic hematopoietic stem cell transplantation.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for some hematological diseases; however, graft-versus-host disease (GVHD) is still one of the most important and deleterious complications. Regulatory T cells and iNKT cells can decrease the incidence and severity of GVHD, while preserving the graft-versus-tumor response. In order to analyze the relationship between the transfused dose of these cells, the presence of GVHD and survival, 15 normal donors and 15 patients with hematological diseases who underwent allogeneic HSCT from HLA-identical siblings were studied. The mobilization and infused doses of valpha24-vbeta11(iNKT cells) lymphocytes and CD4+CD25+FoxP3+, CD4+CD25+FoxP3+CD62L+, regulatory T cells were analyzed. All patients were conditioned with busulfan and cyclophosphamide and received cyclosporine and methotrexate as GVHD prophylaxis. iNKT and FoxP3 cells were mobilized after G-CSF administration. Acute GVHD was present in 9 of 15 (60%) and cGVHD in 7 of 13 (54%) patients. Patients who received a dose <0.6 x 10(6)/kg of iNKT cells and >4 x 10(6)/kg of FoxP3 had better disease-free survival and overall survival. Individuals transfused with >1.1 x 10(6)/kg of FoxP3+ CD62L+ Treg cells had better overall survival. In conclusion, iNKT and Treg cells are mobilized with G-CSF in healthy donors and the dose of iNKT cells and FoxP3 and CD62L+ regulatory T cells is of clinical importance in human HSCT.

Clinical relevance of NK, NKT, and dendritic cell dose in patients receiving G-CSF-mobilized peripheral blood allogeneic stem cell transplantation

To analyze the relationship between the cellular composition of peripheral blood allografts and clinical outcome, we performed a prospective study in 45 adult patients who underwent allogeneic peripheral blood hematopoietic stem cell transplantation (HSCT) from a histocompatibility leukocyte antigen identical sibling donor for different hematological malignancies. The dose of CD34+, CD3+, CD4+, CD8+, and CD19+ lymphocytes, natural killer (NK) cells, natural killer T (NKT) cells, type 1 and type 2 dendritic cells (DC1 and DC2), as well as regulatory T (Treg) lymphocytes was analyzed. All patients were conditioned with busulphan and cyclophosphamide (BuCy2) ± VP-16 and received a short course of methotrexate and cyclosporin-A as graft-versus-host disease (GVHD) prophylaxis. Acute GVHD (aGVHD) was present in 9 of 43 (21%) patients, and chronic GVHD (cGVHD) developed in 18 of 39 (46%) patients. There was a significantly higher incidence of aGVHD in patients receiving more than 6×106/kg CD34+ cells. In univariate analysis, variables associated with better survival were as follows: a dose of less than 1.5×107/kg NKT cells and less than 1.7×106/kg DC2 for disease-free survival (DFS), and a dose of less than 3×107/kg NK cells, less than 1.5×107/kg NKT cells, less than 3×106/kg DC1, and less than 1.7×106/kg DC2 for overall survival (OS). In the Cox regression analysis, the dose of NKT cells was the only variable associated with better DFS, while the doses of NK, NKT, and CD34+ cells (less than 8×106/kg) were associated with better OS. In conclusion, different circulating cell populations, other than CD34+ cells, are also of relevance in predicting the clinical outcome after allogeneic peripheral blood HSCT.

Granulocyte colony-stimulating factor produces a decrease in IFNγ and increase in IL-4 when administrated to healthy donors

Hematopoietic stem cells transplantation (HSCT) is the leading curative therapy for a variety of hematological and hereditary diseases; however, graft versus host disease (GVHD), an immunologic phenomenon that is favored by Th1 cytokines and cytotoxic cells from donors, is present frequently and is one of the most important causes of transplant related mortality. Peripheral blood HSCT is the preferred source of stem cells in almost 100% of the cases of autologous HSCT and in 70% of allogeneic transplants. The best mobilizing agent to get the stem cells out from the bone marrow is the Granulocyte‐Colony Stimulating Factor (G‐CSF). In this work, our main objective was to study a possible correlation between the graft cell dose and the patients clinical outcome. We evaluated the immunologic changes produced by G‐CSF in the lymphocyte and cytokine profiles in allogeneic HSC donors. HSC from twelve donors were mobilized with G‐CSF at 16 μg/kg/day, for 5 days. Basal Peripheral Blood (BPB), Mobilized Peripheral Blood (MPB), and aphaeresis mononuclear cells (G‐MNC) samples were taken from all donors. Using flow cytometry, we quantified CD19+, CD3+, CD3+CD4+, CD3+CD8+, NK, NKT, DC1, and DC2 cells. Cytokines were determined by ELISA in culture supernatants. CD19+ (p = 0.001), DC1 (p < 0.002) and DC2 (p < 0.001) cells were increased in MPB with respect to BPB. An increase in Th2 cytokines such as (IL‐4) and a decrease in Th1 cytokines (IFNγ, IL‐2) were also found in MPB samples. In conclusion, Th1 and Th2 cytokines are relevant in predicting the clinical outcome after allogeneic peripheral blood HSCT. J. Clin. Apheresis 25:181–187, 2010.

Toxoplasma gondii: effect of maternal infection in the development of lymphoid organs of BALB/c neonates.

Toxoplasmosis is one of the worldwide parasitic zoonoses. Alterations in the lymphopoietic system are still poorly studied. We analyzed lymphoid organs of BALB/c mice neonates from Toxoplasma gondii-intraperitoneally-infected mothers on 19th day of gestation, with 30 tachyzoites of strain RH. Normal non-infected pregnant females were used as controls. At 7 days after birth, animals were classified as neonates from infected (NIM) and neonates from non-infected mothers (NNIM). Weight of the thymus and number of thymic cells in NIM were decreased, percentage of apoptosis was significantly increased. Decrease in lymphocytes and monocytes and an increase of plasma cells were observed in bone marrow of NIM. Peripheral blood of NIM showed an increase of monocytes and neutrophils and a decrease in lymphocytes. Infection of the mother during the last day of gestation provokes in the neonates changes in the lymphoid organs that could explain survival of 75% of them.

Role of CD8 Regulatory T Cells versus Tc1 and Tc17 Cells in the Development of Human Graft-versus-Host Disease

CD8+ T cells that secrete proinflammatory cytokines play a central role in exacerbation of inflammation; however, a new subpopulation of CD8 regulatory T cells has recently been characterized. This study analyzes the prominent role of these different subpopulations in the development of graft-versus-host disease (GVHD). Samples from 8 healthy donors mobilized with Filgrastim® (G-CSF) and 18 patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) were evaluated by flow cytometry. Mobilization induced an increase in Tc1 (p < 0.01), Th1 (p < 0.001), Tc17 (p < 0.05), and CD8+IL-10+ cells (p < 0.05), showing that G-CSF induces both pro- and anti-inflammatory profiles. Donor-patient correlation revealed a trend (p = 0.06) toward the development of GVHD in patients who receive a high percentage of Tc1 cells. Patients with acute GVHD (aGVHD), either active or controlled, and patients without GVHD were evaluated; patients with active aGVHD had a higher percentage of Tc1 (p < 0.01) and Tc17 (p < 0.05) cells, as opposed to patients without GVHD in whom a higher percentage of CD8 Treg cells (p < 0.01) was found. These findings indicate that the increase in Tc1 and Tc17 cells is associated with GVHD development, while regulatory CD8 T cells might have a protective role in this disease. These tests can be used to monitor and control GVHD.

Maternal obesity associated with increase in natural killer T cells and CD8+ regulatory T cells in cord blood units

One of the major limitations of umbilical cord blood (UCB) as hematopoietic stem cell source is its restricted cell number. In mothers who are candidates for stem cell donation, there are variables that affect the quantity and quality of UCB units. The aim of this study was to determine if obstetric, maternal, and fetal factors modify the number of lymphocyte subsets in UCB units.

Determination of Th1/Th2/Th17 Cytokines in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Allogeneic hematopoietic cell transplantation emerges as a therapy option to treat the sequels of exposure to radiation, a great concern at the beginning of the atomic age and cold war (Welniak et al., 2007). Hematopoietic cell transplantation emerged as a rescue strategy since there were already antecedents, like the study of Lorenz et al. in 1952 (as cited by Welniak et al., 2007), who showed that infusion of the bone marrow after lethal irradiation healed radiation disease in mice. This lay the foundations for the current consideration of allogeneic hematopoietic cell transplantation as the first-line therapy for many lifethreatening oncological and hematological diseases. Today, it is primarily used to treat patients with hereditary anemias or immunological deficiencies through replacement of the hematopoietic system with cells from a healthy individual. It also allows cancer patients to be treated with myeloablative radiation and/or chemotherapy (known as myeloablative conditioning) in an attempt to eliminate tumoral cells, and although this strategy brings loss of bone marrow function, the latter can be recovered with infusion of normal hematopoietic cells (Jenq & Van den Brink, 2010).

Description of CD8

Gershon and Kondo described CD8+ Treg lymphocytes as the first ones with regulating activity due to their tolerance ability to foreign antigens and their capacity to inhibit the proliferation of other lymphocytes. Regardless, CD8+ Treg lymphocytes have not been fully described—unlike CD4+ Treg lymphocytes—because of their low numbers in blood and the lack of specific and accurate population markers. Still, these lymphocytes have been studied for the past 30 years, even after finding difficulties during investigations. As a result, studies have identified markers that define their subpopulations. This review is focused on the expression of cell membrane markers as CD25, CD122, CD103, CTLA-4, CD39, CD73, LAG-3, and FasL as well as soluble molecules such as FoxP3, IFN-γ, IL-10, TGF-β, IL-34, and IL-35, in addition to the lack of expression of cell activation markers such as CD28, CD127 CD45RC, and CD49d. This work also underlines the importance of identifying some of these markers in infections with several pathogens, autoimmunity, cancer, and graft-versus-host disease as a strategy in their prevention, monitoring, and cure.