Interruptions of cART limits CD4 T-cell recovery and increases the risk for opportunistic complications and death.

BACKGROUND: A major goal of antiretroviral therapy (ART) for HIV-1-infected persons is the recovery of CD4 T lymphocytes, resulting in thorough protection against opportunistic complications. Interruptions of ART are still frequent. The long-term effect on CD4 T-cell recovery and clinical events remains unknown. METHODS: Immunological and clinical endpoints were evaluated in 2491 participants of the Swiss HIV Cohort Study initiating ART during a mean follow-up of 7.1 years. Data were analysed in persons with treatment interruptions (n = 1271; group A), continuous ART, but intermittent HIV-1 RNA at least 1000 copies/ml (n = 469; group B) and continuous ART and HIV-1 RNA constantly less than 1000 copies/ml (n = 751; group C). Risk factors for low CD4 T-cell counts and clinical events were analysed using Cox proportional hazards models. RESULTS: In groups A-C, CD4 T lymphocytes increased to a median of 427, 525 and 645 cells/μl at 8 years. In group A, 63.0 and 37.2% reached above 350 and 500 CD4 T cells/μl, whereas in group B 76.3 and 55.8% and in group C 87.3 and 68.0% reached these thresholds (P < 0.001). CD4 T-cell recovery directly depended on the cumulative duration of treatment interruptions. In addition, participants of group A had more Centers for Disease Control and Prevention B/C events, resulting in an increased risk of death. Major risk factors for not reaching CD4 T cells above 500 cells/μl included lower baseline CD4 T-cell count, higher age and hepatitis C virus co-infection. CONCLUSION: In persons receiving continuous ART larger CD4 T-cell recovery and a reduced risk for opportunistic complications and death was observed. CD4 T-cell recovery was smaller in persons with treatment interruptions more than 6 months.

HLA-Bw4 homozygosity is associated with an impaired CD4 T cell recovery after initiation of antiretroviral therapy.

We assessed the influence of human leukocyte antigen (HLA) alleles HLA-Bw4 and HLA-Bw6 on CD4 T cell recovery after starting successful combination antiretroviral therapy in 265 individuals. The median gains in the CD4 T cell count after 4 years were 258 cells/microL for HLA-Bw4 homozygotes, 321 cells/microL for HLA-Bw4/Bw6 heterozygotes, and 363 cells/microL for HLA-Bw6 homozygotes (P = .01, compared with HLA-Bw4 homozygotes). HLA-Bw4 homozygosity appears to predict an impaired CD4 T cell recovery after initiation of combination antiretroviral therapy.

CD4+ T cell count recovery in HIV type 1-infected patients is independent of class of antiretroviral therapy.

BACKGROUND: In recent years, treatment options for human immunodeficiency virus type 1 (HIV-1) infection have changed from nonboosted protease inhibitors (PIs) to nonnucleoside reverse-transcriptase inhibitors (NNRTIs) and boosted PI-based antiretroviral drug regimens, but the impact on immunological recovery remains uncertain. METHODS: During January 1996 through December 2004 [corrected] all patients in the Swiss HIV Cohort were included if they received the first combination antiretroviral therapy (cART) and had known baseline CD4(+) T cell counts and HIV-1 RNA values (n = 3293). For follow-up, we used the Swiss HIV Cohort Study database update of May 2007 [corrected] The mean (+/-SD) duration of follow-up was 26.8 +/- 20.5 months. The follow-up time was limited to the duration of the first cART. CD4(+) T cell recovery was analyzed in 3 different treatment groups: nonboosted PI, NNRTI, or boosted PI. The end point was the absolute increase of CD4(+) T cell count in the 3 treatment groups after the initiation of cART. RESULTS: Two thousand five hundred ninety individuals (78.7%) initiated a nonboosted-PI regimen, 452 (13.7%) initiated an NNRTI regimen, and 251 (7.6%) initiated a boosted-PI regimen. Absolute CD4(+) T cell count increases at 48 months were as follows: in the nonboosted-PI group, from 210 to 520 cells/muL; in the NNRTI group, from 220 to 475 cells/muL; and in the boosted-PI group, from 168 to 511 cells/muL. In a multivariate analysis, the treatment group did not affect the response of CD4(+) T cells; however, increased age, pretreatment with nucleoside reverse-transcriptase inhibitors, serological tests positive for hepatitis C virus, Centers for Disease Control and Prevention stage C infection, lower baseline CD4(+) T cell count, and lower baseline HIV-1 RNA level were risk factors for smaller increases in CD4(+) T cell count. CONCLUSION: CD4(+) T cell recovery was similar in patients receiving nonboosted PI-, NNRTI-, and boosted PI-based cART.

Hepatitis B virus infection is associated with impaired immunological recovery during antiretroviral therapy in the Swiss HIV cohort study.

Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected patients worldwide. It is unclear whether HIV-related outcomes are affected by HBV coinfection. We compared virological suppression and immunological recovery during antiretroviral therapy (ART) of patients of different HBV serological status in the Swiss HIV Cohort Study. CD4 cell recovery during ART was significantly impaired in hepatitis B surface antigen-positive patients and in those with anti-hepatitis B core antigen alone compared with HBV-uninfected patients, despite similar virological efficacy of ART. CD4 increase in patients with resolved HBV infection was similar to that in HBV-uninfected individuals.

Longer term clinical and virological outcome of sub-Saharan African participants on antiretroviral treatment in the Swiss HIV Cohort Study.

OBJECTIVES: Persons from sub-Saharan Africa (SSA) are increasingly enrolled in the Swiss HIV Cohort Study (SHCS). Cohorts from other European countries showed higher rates of viral failure among their SSA participants. We analyzed long-term outcomes of SSA versus North Western European participants. DESIGN: We analyzed data of the SHCS, a nation-wide prospective cohort study of HIV-infected adults at 7 sites in Switzerland. METHODS: SSA and North Western European participants were included if their first treatment combination consisted of at least 3 antiretroviral drugs (cART), if they had at least 1 follow-up visit, did not report active injecting drug use, and did not start cART with CD4 counts >200 cells per microliter during pregnancy. Early viral response, CD4 cell recovery, viral failure, adherence, discontinuation from SHCS, new AIDS-defining events, and survival were analyzed using linear regression and Cox proportional hazard models. RESULTS: The proportion of participants from SSA within the SHCS increased from 2.6% (<1995) to 20.8% (2005-2009). Of 4656 included participants, 808 (17.4%) were from SSA. Early viral response (6 months) and rate of viral failure in an intent-to-stay-on-cART approach were similar. However, SSA participants had a higher risk of viral failure on cART (adjusted hazard ratio: 2.03, 95% confidence interval: 1.50 to 2.75). Self-reported adherence was inferior for SSA. There was no increase of AIDS-defining events or mortality in SSA participants. CONCLUSIONS: Increased attention must be given to factors negatively influencing adherence to cART in participants from SSA to guarantee equal longer-term results on cART.

Autologous adult cortical cell transplantation enhances functional recovery following unilateral lesion of motor cortex in primates: a pilot study.

BACKGROUND:: Although cell therapy is a promising approach after cerebral cortex lesion, few studies assess quantitatively its behavioral gain in non-human primates. Furthermore, implantations of fetal grafts of exogenous stem cells are limited by safety and ethical issues. OBJECTIVE:: To test in non-human primates the transplantation of autologous adult neural progenitor cortical cells with assessment of functional outcome. METHODS:: Seven adult macaque monkeys were trained to perform a manual dexterity task, before the hand representation in motor cortex was chemically lesioned unilaterally. Five monkeys were used as control, compared to two monkeys subjected to different autologous cells transplantation protocols performed at different time intervals. RESULTS:: After lesion, there was a complete loss of manual dexterity in the contralesional hand. The five "control" monkeys recovered progressively and spontaneously part of their manual dexterity, reaching a unique and definitive plateau of recovery, ranging from 38% to 98% of pre-lesion score after 10 to 120 days. The two "treated" monkeys reached a first spontaneous recovery plateau at about 25 and 40 days post-lesion, representing 35% and 61% of the pre-lesion performance, respectively. In contrast to the controls, a second recovery plateau took place 2-3 months after cell transplantation, corresponding to an additional enhancement of functional recovery, representing 24 and 37% improvement, respectively. CONCLUSIONS:: These pilot data, derived from two monkeys treated differently, suggest that, in the present experimental conditions, autologous adult brain progenitor cell transplantation in non-human primate is safe and promotes enhancement of functional recovery.

Primate adult brain cell autotransplantation produces behavioral and biological recovery in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonian St. Kitts monkeys.

The potential for "replacement cells" to restore function in Parkinson's disease has been widely reported over the past 3 decades, rejuvenating the central nervous system rather than just relieving symptoms. Most such experiments have used fetal or embryonic sources that may induce immunological rejection and generate ethical concerns. Autologous sources, in which the cells to be implanted are derived from recipients' own cells after reprogramming to stem cells, direct genetic modifications, or epigenetic modifications in culture, could eliminate many of these problems. In a previous study on autologous brain cell transplantation, we demonstrated that adult monkey brain cells, obtained from cortical biopsies and kept in culture for 7 weeks, exhibited potential as a method of brain repair after low doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) caused dopaminergic cell death. The present study exposed monkeys to higher MPTP doses to produce significant parkinsonism and behavioral impairments. Cerebral cortical cells were biopsied from the animals, held in culture for 7 weeks to create an autologous neural cell "ecosystem" and reimplanted bilaterally into the striatum of the same six donor monkeys. These cells expressed neuroectodermal and progenitor markers such as nestin, doublecortin, GFAP, neurofilament, and vimentin. Five to six months after reimplantation, histological analysis with the dye PKH67 and unbiased stereology showed that reimplanted cells survived, migrated bilaterally throughout the striatum, and seemed to exert a neurorestorative effect. More tyrosine hydroxylase-immunoreactive neurons and significant behavioral improvement followed reimplantation of cultured autologous neural cells as a result of unknown trophic factors released by the grafts. J. Comp. Neurol. 522:2729-2740, 2014. © 2014 Wiley Periodicals, Inc.

Regenerative cell injection in denervated muscle reduces atrophy and enhances recovery following nerve repair.

INTRODUCTION: Functional muscle recovery after peripheral nerve injury is far from optimal, partly due to atrophy of the muscle arising from prolonged denervation. We hypothesized that injecting regenerative cells into denervated muscle would reduce this atrophy. METHODS: A rat sciatic nerve lesion was performed, and Schwann cells or adipose-derived stem cells, untreated or induced to a "Schwann-cell-like" phenotype (dASC), were injected into the gastrocnemius muscle. Nerves were either repaired immediately or capped to prevent muscle reinnervation. One month later, functionality was measured using a walking track test, and muscle atrophy was assessed by examining muscle weight and histology. RESULTS: Schwann cells and dASC groups showed significantly better scores on functional tests when compared with injections of growth medium alone. Muscle weight and histology were also significantly improved in these groups. CONCLUSION: Cell injections may reduce muscle atrophy and could benefit nerve injury patients.

Aggregating Brain Cell Cultures as a Model to Study Ischaemia-induced Neurodegeneration.

Rotation-mediated aggregating brain cell cultures at two different maturational stages (DIV 11 and DIV 20) were subjected for 1 or 2 hours to ischaemic conditions by transient immobilization (arrest of media circulation). During recovery, cell damage was evaluated by measuring changes in cell type-specific enzyme activities and total protein content. It was found that in immature cultures (DIV 11), immobilization for 1 or 2 hours did not affect the parameters measured. By contrast, at DIV 20, ischaemic conditions for 1 hour caused a pronounced decrease in the activities of glutamic acid decarboxylase and choline acetyltransferase. A significant decrease in these neuron-specific enzyme activities was found at post-ischaemic days 1-14, indicating immediate and irreversible neuronal damage. The activity of the astrocyte-specific enzyme, glutamine synthetase, was significantly increased at 4 days post-treatment; equal to control values at 6 days; and significantly decreased at 14 days after the ischaemic insult. Immobilization of DIV 20 cultures for 2 hours caused a drastic reduction in all the parameters measured at post-ischaemic day 6. Generally, the ischaemic conditions appeared to be more detrimental to neurons than to astrocytes, and GABAergic neurons were more affected than cholinergic neurons.

SHP-1 phosphatase activity counteracts increased T cell receptor affinity.

Anti-self/tumor T cell function can be improved by increasing TCR-peptide MHC (pMHC) affinity within physiological limits, but paradoxically further increases (K(d) < 1 μM) lead to drastic functional declines. Using human CD8(+) T cells engineered with TCRs of incremental affinity for the tumor antigen HLA-A2/NY-ESO-1, we investigated the molecular mechanisms underlying this high-affinity-associated loss of function. As compared with cells expressing TCR affinities generating optimal function (K(d) = 5 to 1 μM), those with supraphysiological affinity (K(d) = 1 μM to 15 nM) showed impaired gene expression, signaling, and surface expression of activatory/costimulatory receptors. Preferential expression of the inhibitory receptor programmed cell death-1 (PD-1) was limited to T cells with the highest TCR affinity, correlating with full functional recovery upon PD-1 ligand 1 (PD-L1) blockade. In contrast, upregulation of the Src homology 2 domain-containing phosphatase 1 (SHP-1/PTPN6) was broad, with gradually enhanced expression in CD8(+) T cells with increasing TCR affinities. Consequently, pharmacological inhibition of SHP-1 with sodium stibogluconate augmented the function of all engineered T cells, and this correlated with the TCR affinity-dependent levels of SHP-1. These data highlight an unexpected and global role of SHP-1 in regulating CD8(+) T cell activation and responsiveness and support the development of therapies inhibiting protein tyrosine phosphatases to enhance T cell-mediated immunity.

Persistence of EBV Antigen-Specific CD8 T Cell Clonotypes during Homeostatic Immune Reconstitution in Cancer Patients.

Persistent viruses are kept in check by specific lymphocytes. The clonal T cell receptor (TCR) repertoire against Epstein-Barr virus (EBV), once established following primary infection, exhibits a robust stability over time. However, the determinants contributing to this long-term persistence are still poorly characterized. Taking advantage of an in vivo clinical setting where lymphocyte homeostasis was transiently perturbed, we studied EBV antigen-specific CD8 T cells before and after non-myeloablative lympho-depleting chemotherapy of melanoma patients. Despite more advanced T cell differentiation, patients T cells showed clonal composition comparable to healthy individuals, sharing a preference for TRBV20 and TRBV29 gene segment usage and several co-dominant public TCR clonotypes. Moreover, our data revealed the presence of relatively few dominant EBV antigen-specific T cell clonotypes, which mostly persisted following transient lympho-depletion (TLD) and lymphocyte recovery, likely related to absence of EBV reactivation and de novo T cell priming in these patients. Interestingly, persisting clonotypes frequently co-expressed memory/homing-associated genes (CD27, IL7R, EOMES, CD62L/SELL and CCR5) supporting the notion that they are particularly important for long-lasting CD8 T cell responses. Nevertheless, the clonal composition of EBV-specific CD8 T cells was preserved over time with the presence of the same dominant clonotypes after non-myeloablative chemotherapy. The observed clonotype persistence demonstrates high robustness of CD8 T cell homeostasis and reconstitution.

Effect of Platinum-Based Chemoradiotherapy on Cellular Proliferation in Bone Marrow and Spleen, Estimated by 18F-FLT PET/CT in Patients with Locally Advanced Non-Small Cell Lung Cancer.

Historically, it has been difficult to monitor the acute impact of anticancer therapies on hematopoietic organs on a whole-body scale. Deeper understanding of the effect of treatments on bone marrow would be of great potential value in the rational design of intensive treatment regimens. 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) is a functional radiotracer used to study cellular proliferation. It is trapped in cells in proportion to thymidine-kinase 1 enzyme expression, which is upregulated during DNA synthesis. This study investigates the potential of (18)F-FLT to monitor acute effects of chemotherapy on cellular proliferation and its recovery in bone marrow, spleen, and liver during treatment with 2 different chemotherapy regimens.

A flow cytometry based oligotrophic pollutant exposure test to detect bacterial growth inhibition and cell injury.

Toxicity of chemical pollutants in aquatic environments is often addressed by assays that inquire reproductive inhibition of test microorganisms, such as algae or bacteria. Those tests, however, assess growth of populations as a whole via macroscopic methods such as culture turbidity or colony-forming units. Here we use flow cytometry to interrogate the fate of individual cells in low-density populations of the bacterium Pseudomonas fluorescens SV3 exposed or not under oligotrophic conditions to a number of common pollutants, some of which derive from oil contamination. Cells were stained at regular time intervals during the exposure assay with fluorescent dyes that detect membrane injury (i.e., live-dead assay). Reduction of population growth rates was observed upon toxicant insult and depended on the type of toxicant. Modeling and cell staining indicate that population growth rate decrease is a combined effect of an increased number of injured cells that may or may not multiply, and live cells dividing at normal growth rates. The oligotrophic assay concept presented here could be a useful complement for existing biomarker assays in compliance with new regulations on chemical effect studies or, more specifically, for judging recovery after exposure to fluctuating toxicant conditions.

Disseminated Rhizopus microsporus infection cured by salvage allogeneic hematopoietic stem cell transplantation, antifungal combination therapy, and surgical resection.

O. Lebeau, C. Van Delden, J. Garbino, J. Robert, F. Lamoth, J. Passweg, Y. Chalandon. Disseminated Rhizopus microsporus infection cured by salvage allogeneic hematopoietic stem cell transplantation, antifungal combination therapy, and surgical resection. Transpl Infect Dis 2010. All rights reserved Abstract: Invasive Zygomycetes infection complicating prolonged neutropenia is associated with high mortality in the absence of immune recovery. We report a patient who developed disseminated zygomycosis due to Rhizopus microsporus during induction chemotherapy for acute myeloid leukemia. Rescue allogeneic hematopoietic stem cell transplantation (allo-HSCT) was performed as her only chance of cure of this infection and to treat refractory leukemia. Posaconazole combined with liposomal amphotericin B contained the zygomycosis during prolonged neutropenia due to allo-HSCT followed by intense immunosuppression for grade IV acute graft-versus-host disease. Surgical removal of all infected sites after immune recovery, with prolonged posaconazole treatment, ultimately cured the infection. New combination antifungal therapies might sufficiently control disseminated zygomycosis to allow allo-HSCT to be performed, assuring life-saving immune recovery. Surgery appears to be necessary for definite cure of these infections.

Dose-dependent influence of didanosine on immune recovery in HIV-infected patients treated with tenofovir.

BACKGROUND: Antiretroviral therapy (ART) containing tenofovir disoproxil fumarate (TDF) and didanosine (ddI) has been associated with poor immune recovery despite virologic success. This effect might be related to ddI toxicity since ddI exposure is substantially increased by TDF. OBJECTIVE: To analyze whether immune recovery during ART with TDF and ddI is ddI-dose dependent. DESIGN AND METHODS: A retrospective longitudinal analysis of immune recovery measured by the CD4 T-cell slope in 614 patients treated with ART containing TDF with or without ddI. Patients were stratified according to the tertiles of their weight-adjusted ddI dose: low dose (< 3.3 mg/kg), intermediate dose (3.3-4.1 mg/kg) and high dose (> 4.1 mg/kg). Cofactors modifying the degree of immune recovery after starting TDF-containing ART were identified by univariable and multivariable linear regression analyses. RESULTS: CD4 T-cell slopes were comparable between patients treated with TDF and a weight-adjusted ddI-dose of < 4.1 mg/kg per day (n = 143) versus TDF-without-ddI (n = 393). In the multivariable model the slopes differed by -13 CD4 T cells/mul per year [95% confidence interval (CI), -42 to 17; P = 0.40]. In contrast, patients treated with TDF and a higher ddI dose (> 4.1 mg/kg per day, n = 78) experienced a significantly impaired immune recovery (-47 CD4 T cells/microl per year; 95% CI, -82 to -12; P = 0.009). The virologic response was comparable between the different treatment groups. CONCLUSIONS: Immune recovery is impaired, when high doses of ddI (> 4.1 mg/kg) are given in combination with TDF. If the dose of ddI is adjusted to less than 4.1 mg/kg per day, immune recovery is similar to other TDF-containing ART regimen.