Juana Gil

Quantitative Alterations of the Functionally Distinct Subsets of CD4 and CD8 T Lymphocytes in Asymptomatic HIV Infection: Changes in the Expression of CD45RO, CD45RA, CD11b, CD38, HLA-DR, and CD25 Antigens

We determined the representation in asymptomatic human immunodeficiency virus (HIV) infection of the CD45RO+ and CD45RO- CD45RA+ subsets of CD4+ and CD8+ T lymphocytes, CD11b+ and CD11b- subsets of CD8+ T cells, and activated populations of these subsets. Three-color flow cytometry was used to quantitate the different CD4+ and CD8+ T cell populations in 116 asymptomatic HIV+ individuals. In asymptomatic HIV+ infection there was a significant relative increase in the CD4+ CD45RO+ and CD8+ CD45RO+ T cell subsets, which express CD38 and DR antigens, that correlated strongly with the decline in total CD4+ T cells. In addition, we found a loss of CD4+ CD45RO- and CD8+ CD45RO- T cells associated with progression of HIV infection (as measured by the decline in total CD4+ T cells). Studies presented here also indicate that, with the progression of asymptomatic HIV infection, CD8+ CD11b- T lymphocytes showed a significant decrease, whereas CD8+ CD11b+ T cells were significantly increased. This study demonstrates that the progression of HIV infection in asymptomatic patients involves the increase in CD45RO+ subsets of CD4+ and CD8+ T cells, the increase in CD8+ CD11b+ T cells, the decrease in CD45RO- CD45RA+ subsets of CD4 and CD8 T cells, and the decline in CD8+ CD11b- T cells.

Increased levels of activated subsets of CD4 T cells add to the prognostic value of low CD4 T cell counts in a cohort of HIV-infected drug users.

ObjectiveTo identify subsets of CD4 T lymphocytes that can predict the development of AIDS and to assess whether increased levels of these cellular markers could provide additional independent prognostic information to the CD4 T cell count and plasma HIV-1-RNA levels. Design and methodsIn a prospective study, a cohort of 85 HIV-positive intravenous drug users [clinical categories of the CDC classification A (n = 48) and B (n = 37)] were followed for a period of 37 ± 13 months. Memory and activated CD4 and CD8 T cells were quantitated by three-colour flow cytometry at baseline and expressed as a percentage of total CD4 and CD8 lymphocytes. Clinical evaluations were performed at 6 month intervals. The relationships between these lymphocyte subsets and progression to AIDS were studied using Kaplan–Meier plots and proportional hazards regression models. ResultsAfter adjustment for the level of CD4 T cells and plasma HIV-1-RNA levels, the elevation in the subset CD4+CD38+DR+ was the marker within the functionally distinct subsets of CD4 T lymphocytes with additional prognostic value in bivariate Cox regression models. In multivariate models, increased percentages of CD4+CD38+DR+ T cells provided the strongest independent prognostic information for progression to AIDS (relative hazard, 1.07;P < 0.0001). ConclusionOur results suggest that high levels of CD4+CD38+HLA-DR+ T cells reflect the increasing degree of CD4 T cell activation during the progression of HIV infection, and could be used together with the CD4 T cell and HIV-RNA levels to evaluate more accurately the progressive cellular immune impairment associated with the risk of progression to AIDS.

Intravenous Immunoglobulin Treatment Increased Live Birth Rate in a Spanish Cohort of Women with Recurrent Reproductive Failure and Expanded CD56+ Cells

Natural killer (NK, CD3− CD56+/CD16+) and NKT‐like cells (CD3+ CD56+/CD16+) activity is considered among the key factors for reproductive success. In the absence of immunological screening, beneficial effects of intravenous immunoglobulin (IVIG) in preventing recurrent reproductive failure (RRF) have not been reported. Here, we analyse the IVIG influence on pregnancy success in women with RRF and circulating NK or/and NKT‐like cells expansion.

Experience in IVIg Therapy for Selected Women with Recurrent Reproductive Failure and NK Cell Expansion

Recurrent reproductive failure (RRF) has been associated with expansion of circulating NK cells, key cells for maternal tolerance, decidual vasculogenesis and embryo growth. This study reports our experience in intravenous immunoglobulin (IVIg) therapy of a large cohort of women with RRF with expanded circulating NK and/or NKT‐like cells (blood NKT cells are a heterogeneous subset of T cells that share properties of both T cells and NK cells).

Functional assessment of perforin C2 domain mutations illustrates the critical role for calcium-dependent lipid binding in perforin cytotoxic function

Perforin-mediated lymphocyte cytotoxicity is critical for pathogen elimination and immune homeostasis. Perforin disruption of target cell membranes is hypothesized to require binding of a calcium-dependent, lipid-inserting, C2 domain. In a family affected by hemophagocytic lymphohistiocytosis, a severe inflammatory disorder caused by perforin deficiency, we identified 2 amino acid substitutions in the perforin C2 domain: T435M, a previously identified mutant with disputed pathogenicity, and Y438C, a novel substitution. Using biophysical modeling, we predicted that the T435M substitution, but not Y438C, would interfere with calcium binding and thus cytotoxic function. The capacity for cytotoxic function was tested after expression of the variant perforins in rat basophilic leukemia cells and murine cytotoxic T lymphocytes. As predicted, cells transduced with perforin-T435M lacked cytotoxicity, but those expressing perforin-Y438C displayed intact cytotoxic function. Using novel antibody-capture and liposome-binding assays, we found that both mutant perforins were secreted; however, only nonmutated and Y438C-substituted perforins were capable of calcium-dependent lipid binding. In addition, we found that perforin-Y438C was capable of mediating cytotoxicity without apparent proteolytic maturation. This study clearly demonstrates the pathogenicity of the T435M mutation and illustrates, for the first time, the critical role of the human perforin C2 domain for calcium-dependent, cytotoxic function.

Frequency of BCL2 and BCL6 translocations in follicular lymphoma: relation with histological and clinical features.

Follicular lymphomas (FLs) usually carry BCL2 translocations although BCL6 translocations are also present. We explored relationships between translocations status and clinical or histological parameters at diagnosis in 182 patients stratified in four groups: BCL2−/BCL6−, BCL2+/BCL6−, BCL2−/BCL6+ and BCL2+/BCL6+. BCL2−/BCL6− and BCL2+/BCL6−. Double negative cases were ascribed to lower histological grades. In contrast, BCL2−/BCL6+ cases corresponded to higher grades. However, a majority of BCL2+/BCL6+ tumours were classified as lower grades. These results were reinforced by the finding that double positive patients had lower LDH levels and PS than those with solitary BCL6 rearrangements. Bone marrow involvement was more frequent in BCL2+/BCL6+ compared with BCL2−/BCL6+ tumours. Our data confirm the presence of a relationship between histological grade and translocation status, suggesting that FLs carrying BCL6 translocations probably constitute a special biological subtype. Clinical and histological differences between BCL2−/BCL6+ and BCL2+/BCL6+ tumours could reflect an interplay between both translocations.

The potential role of the HIV-1 immunogen (Remune) as a therapeutic vaccine in the treatment of HIV infection.

Immune-based therapies, such as therapeutic vaccination, that might preserve, restore, enhance and induce new HIV-specific immunologic responses are currently being explored. HIV-specific immunotherapy with Remune® (The Immune Response Corp.) offers the opportunity to boost immune responses against HIV-1. The clinical trial program in a wide range of subjects has established the efficacy of Remune in stimulating an appropriate immune response in HIV-positive individuals. Furthermore, a recent unblinded study conducted in Europe has documented a significant effect of Remune on viral load. Evidence regarding clinical end points is more difficult to collect. The same studies have revealed no serious safety issues in a total of more than 2000 Remune-treated patients. It is therefore reasonable to suggest that the risk–benefit ratio of Remune could be positive.

Sublingual therapeutic immunization with a polyvalent bacterial preparation in patients with recurrent respiratory infections: immunomodulatory effect on antigen-specific memory CD4+ T cells and impact on clinical outcome

Recurrent respiratory tract infections (RRTIs) are common clinical conditions in individuals with alterations of the immune function. A prospective open pilot study in a cohort of patients with RRTIs has been performed to assess whether sublingual immunization with a polyvalent bacterial vaccine could exert an immunomodulatory effect on the antigen‐specific immunological responses and have an impact on the clinical outcome. Seventeen patients with RRTIs were recruited. An oral polyvalent bacterial preparation (Bactek®) was administered to all patients daily for 6 months. Immunological assessment was performed at baseline and at the end of immunization. Immunological measurements included: T cell‐specific proliferations of CD3+CD4+ and CD3+CD8+ to Bactek® antigens, total immunoglobulin levels, antibodies to pneumococcal polysaccharide and tetanus toxoid and B, T and natural killer (NK) cell subsets. There was a significant increase in the proliferative capacity of CD3+CD4+ T cells specific to Bactek® antigens at month 6 in comparison to baseline (P < 0·0001). A significant increase in total CD3+ T cells was also observed (P < 0·05). No significant differences were observed between baseline and month 6 in levels of total immunoglobulins, specific antibodies and B, T or NK cell subsets. A significant reduction in the patients rate of RRTIs was observed compared with 1 year prior to initiation of therapy (P < 0·0001). The results demonstrate that long‐term administration of a sublingual polyvalent bacterial preparation in patients with RRTIs exerts an immune stimulating effect on CD4+ T helper cell responses to bacterial antigens which could be associated with clinical benefit.

HLA-C matching and liver transplants: donor-recipient genotypes influence early outcome and CD8+KIR2D+ T-cells recuperation.

Background. Fully human leukocyte antigens (HLA)-mismatched liver grafts are well accepted, but the HLA influence on acceptance or rejection is unclear and much less so the impact of HLA-C, which may be conditioned by the fact that HLA-C-encode molecules are the major ligands for killer cell immunoglobulin-like receptors (KIR). Methods. The HLA-C allele compatibility and the effect of donor and recipient HLA-C genotype on early liver graft acceptance and on CD8+KIR+ T-cells recuperation were analyzed in a series of 431 primary liver transplants. Standard polymerase chain reaction PCR-SSO was used for HLA-C typing and flow cytometry to identify T cells KIR positives. Transplants were classified into two groups: acute rejection and nonacute rejection, and individual HLA-C genotypes as C1/C1, C2/C2, and C1/C2. Results. A favorable effect of HLA-C allelic compatibility on early liver graft acceptance was found because acute rejection significantly increased in transplants performed with 2 HLA-C allele mismatches (P=0.02). Considering the HLA-C groups, it was observed that C1/C2 heterozygous donors were best accepted in C1/C1 patients than in C2/C2 recipients, who experienced a high rate of acute rejection (P<0.004 and P<0.005, respectively). In addition, after transplantation CD3+CD8+KIR2D+ T-cells repertoires significantly increased in C1/C1 and C1/C2, but not in C2/C2 patients. Conclusions. This study confirms the benefit of HLA-C allele matching on early liver transplant outcome and shows that donor HLA-C heterozygosis influences the alloresponse of C1 and C2 homozygous patients and the recuperation of CD3+CD8+KIR2D+ T cells, suggesting an involvement in liver graft tolerance.

Hematopoietic Stem Cell Transplantation for CD3δ deficiency

BACKGROUND CD3δ deficiency is a fatal form of severe combined immunodeficiency that can be cured by hematopoietic stem cell transplantation (HSCT). The presence of a thymus loaded with T-cell progenitors in patients with CD3δ deficiency may require special considerations in choosing the regimen of conditioning and the type of HSCT. OBJECTIVES To study the outcome of CD3δ deficiency by using various modalities of stem cell transplantation. METHODS We analyzed data on 13 patients with CD3δ deficiency who underwent HSCT in 7 centers. HSCT was performed by using different sources of donor stem cells as well as various conditioning regimens. RESULTS One patient received stem cells from a matched related donor and survived after a second transplant, needing substantial conditioning in order to engraft. Only 2 of 7 other patients who received a mismatched related donor transplant survived; 2 of them had no conditioning, whereas the others received various combinations of conditioning regimens. Engraftment of T cells in the survivors appears incomplete. Three other patients who received stem cells from a matched unrelated donor survived and enjoyed full immune reconstitution. Two patients received unrelated cord blood without conditioning. One of them has had a partial but stable engraftment, whereas the other engrafted well but is only 12 months after HSCT. We also report here for the first time that patients with CD3δ deficiency can present with typical features of Omenn syndrome. CONCLUSIONS HSCT is a successful treatment for patients with CD3δ deficiency. The small number of patients in this report prevents definitive statements on the importance of survival factors, but several are suggested: (1) HLA-matched donor transplants are associated with superior reconstitution and survival than are mismatched donor transplants; (2) substantial conditioning appears necessary; and (3) early diagnosis and absence of opportunistic infections may affect outcome.