Number Of Peripheral CD4 Research Articles

Immunomodulatory effect of mesenchymal stem cells-derived extracellular vesicles to modulate the regulatory T cells and Th1/Th2 imbalance in peripheral blood mononuclear cells of patients with allergic rhinitis.

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have shown promising immunomodulatory capabilities for a variety of clinical conditions. However, the potential regulatory mechanisms of MSC-EVs in allergic rhinitis (AR) remain unexplored. The present study was designed to investigate the immunomodulatory effect of MSC-EVs in patients with AR. Peripheral blood mononuclear cells (PBMCs) were isolated from AR patients. The number of peripheral CD4+Foxp3+IL-17+, CD4+Foxp3+IL-17- and CD4+Foxp3-IL-17+ T cells in healthy controls and AR patients were evaluated using flow cytometry. Therapeutic effect of MSC-EVs was determined by detecting IFN-γ, IL-4, IL-17 and IL-10 cytokines in supernatant by ELISA and flow cytometry. The mean fluorescence intensity (MFI) was calculated in PBMCs for IL-10, IL-17 and TGF-β on T cells after MSC-EVs treatment. Bioinformatic analysis of microRNA was performed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. CD4+Foxp3+IL-17+ T cells expression in PBMCs was higher in the AR group and the balance of Treg/Th17 was tilted towards Th17 cells. Supernatant from AR patients revealed that MSC-EVs treatment upregulated IL-10 and IFN-γ, and downregulated IL-4 and IL-17. EVs treatment effectively re-established Th1(CD4+IFN-γ+cells)/Th2(CD4+IL-4+cells) balance, reduced CD4+IL-17+ and increased CD4+IL-10+ and CD4+TGF-β+ cells. The MFI of IL-10 and TGF-β in CD4+CD25+CD127- T cells were higher, whereas lower levels of IL-17 were observed. Bioinformatic analysis revealed that the TGF-β, Wnt signalling pathways and STAT5 transcription factor might mechanistically support the immunomodulatory effect of MSC-EVs. This study presents the immunomodulatory effect of MSC-EVs in PBMCs from AR patients. The results provide a new therapeutic strategy for AR.

Paxbp1 is indispensable for the maintenance of peripheral CD4 T cell homeostasis.

The size and condition of the peripheral CD4 T cell population determine the capacity of the immune response. Under homeostatic conditions, the size of the peripheral CD4 T cell population is maintained through turnover and survival. However, the underlying mechanisms remain inadequately understood. Here, we observed a significant decrease in the percentage of CD4 T cells in the periphery following the targeted deletion of the Paxbp1 gene in mouse T cells. In the absence of Paxbp1, naïve CD4 T cells displayed reduced surface interleukin-7 receptor levels and a decreased capacity to respond to survival signals mediated by interleukin-7. In addition, naïve CD4 T cells deficient in Paxbp1 demonstrated impaired T cell antigen receptor signalling, compromised cell cycle entry, decreased proliferation, and increased apoptosis following stimulation, all of which contributed to the reduction in the number of peripheral CD4 T cells. Therefore, our study highlights the indispensable role of Paxbp1 in maintaining peripheral CD4 T cell homeostasis.

Two vicious circles associated with the aging of the immune system in the development of severe forms of COVID-19.

Background: The immune-inflammatory response is the basis of the pathophysiology of SARS-Cov-2 infection. In severe cases of COVID-19 uncontrolled systemic inflammatory response causes multiorgan dysfunction (MODS), as the most common immediate cause of death. Unfavorable outcome of the COVID-19 most often occurs in elderly patients. The aim of the study was to establish parameters with prognostic significance in severe cases of COVID-19 according to life years, laboratory markers of sepsis and MODS, as well as the number of peripheral CD4+ and CD8+T lymphocytes in 20 consecutively selected critically ill patients. Results: Eleven subjects were male, 9 female, mean age 73.45 ± 11.59, among which the oldest patient was 94 and the youngest 43years. All the patients met the sepsis and MODS criteria. Increased age and low CD4+ and CD8+T cell counts were identified as independent predictors of death. Only the two youngest patients (43 and 50years old) survived 28days, and they are the only ones with a CD4 lymphocyte count above 500 cells/mm3. Conclusion: Senescence of the immune system is mostly characterized by reduced regenerative capacity of adaptive immunity with diminished ability to respond to new antigens and a manifested proinflammatory phenotype. Additional reduction of protective capacity by further deterioration of T cell quantity and quality due to sepsis itself and mutual interaction of senescent T cells and vascular endothelial cells in the induction of cytokine storm represent two complementary vicious cycles in the development of sepsis-related multiorgan dysfunction.

In HIV-infected patients, intestinal bacteria-derived products interfere with CD4<sup>+</sup>T cell regeneration

Despite successful suppression of viral replication by antiretroviral drugs there is no significant increase in the number of peripheral CD4+T lymphocytes in some HIV-infected patients (immune nonresponse to therapy). One of the crucial factors for immunodeficiency aggravation is immune activation developing in response to the bacterial products entry into the bloodstream through the damaged intestinal barrier. Additionally, the intestinal microflora produces various solutes that accumulate in the blood and exhibit toxic properties. This work aimed to evaluate the effect of intestinal microbial products (para-cresol sulfate and indoxyl sulfate) on the number of CD4+T lymphocytes in HIV-infected patients receiving antiretroviral therapy. The object of the study was the peripheral blood of HIV-infected subjects with different immune system restoration efficiency during the therapy. Uninfected donors were enrolled as healthy controls. Plasma concentrations of IL-6 (p = 0.012), IP-10 (p = 0.0004), and sCD14 (p = 0.003) in HIV-infected immune nonresponders were increased compared with those in individuals with effective restoration of CD4+Tcells (immune responders). Although both groups of HIV-positive subjects did not differ in plasma lipopolysaccharide and I-FABP levels, para-cresol sulfate (p = 0.001) and indoxyl sulfate (p = 0.042) concentrations were increased in immune non-responders. In vitro experiments showed a negative dose-dependent effect of para-cresol sulfate and indoxyl sulfate on the viability and mitotic activity of CD4+T lymphocytes. Thus, in HIV-infected patients with impaired regeneration of CD4+T lymphocytes during antiretroviral therapy, a higher level of systemic inflammation is noted than in subjects responding to treatment with an increase in the number of CD4+T cells. The severity of the intestinal barrier damage and the load of bacterial components released into the bloodstream are approximately the same in HIV-infected individuals with different efficiency of immune recovery in response to treatment. Simultaneously, the blood plasma of immune non-responders is significantly enriched with microbial products of intestinal origin: para-cresol sulfate and indoxyl sulfate. The significant decrease in the proliferative capacity of CD4+T cells stimulated in vitro and the induction of their death in the presence of these toxins may be a reason for the ineffective restoration of the number of CD4+T lymphocytes in HIV-infected individuals receiving antiretroviral therapy.

The Evaluation of Melatonin Effects on Mobilization and Engraftment in Autologous Hematopoietic Stem Cell Transplant Recipients; A Randomized, Double-blind and Placebo-controlled Trial.

Mobilization and engraftment of Hematopoietic Stem Cells (HSCs) are challenging issues in Autologous HSC transplantation (AHSCT) so several attempts such as colony-stimulating factors (CSF) and plerixafor have been used for enhancement of HSCs mobilization and engraftment. In this randomized, double-blind and placebo-controlled study, we evaluated the melatonin’s efficacy and safety, as endogenous CSF inducer, co-administered with Filgrastim in mobilizing and engraftment of HSC. AHSCT patients were randomized to receive either Melatonin or placebo plus filgrastim. Of Fifty-one patients, 26 patients received the melatonin (In mobilization phase 3 mg sublingual twice daily, then 9 mg single dose 30 min before apheresis session and then 3 mg twice daily from +1 until engraftment) and 25 patients received the placebo. The mean number of CD34 cells/kg × 106 in the melatonin group was 6.54 versus 4.22 in the placebo group (p = 0.025). The mean day to neutrophil engraftment in the melatonin group was 11.69 ± 2.093, whereas 12.68 ± 2.42 days in the placebo group (p = 0.021). In this study, the second apheresis session requirement, the use of plerixafor and hospital stay duration, were comparable between the two groups. Considering the result of the study, it could be suggested that melatonin plus Filgrastim can be effectively used in AHSCT patients to enhance the number of peripheral CD34 cells/kg × 106 and decrease the day number of neutrophil engraftment.

Molecular Bases for Pharmacotherapy of COVID -19

The most large-scale challenge aroused at the beginning of Y2020 was the global spread of the coronavirus disease 2019 (COVID-19), caused by a zoonotic beta-coronavirus. One year after we have nearly 270 thousand confirmed cases with mortality rate 1.3% in Georgia, and almost 120 billion confirmed cases with mortality rate 2.2% worldwide. As it is known, COVID-19 is triggered by coronavirus species 2 or SARS-CoV-2, which inters in the human body by binding to the angiotensin-converting enzyme 2 (ACE2) molecule on the host cell membrane via the viral spike protein and expresses complex pathological changes in many organs linked with vascular injuries. The most severe expression of this disease exposed by microscopic examination is bilateral diffuse alveolar damage with fibroblasts exudates, indicating Acute Respiratory Distress Syndrome (ARDS). Immune system plays crucial role in tissue damage. As clinical researches showed, the number of peripheral CD4+ and CD8 + T cells were significantly reduced, while their activity was hyper-expressed as evidenced by the high proportions of HLADR (CD4 3•47%) and CD38 (CD8 39•4%) double-positive fractions. Moreover, there was identified an amplified concentration of highly pro inflammatory CCR6+ Th17 in CD4 T cells. This date explains that severe tissue injury in later stages of COVID-19 is depend on the immune system abnormalities, but not on SARS-CoV-2 direct cell destruction. In the same time the scientists and doctors found out abnormalities in coagulation function in most of the severe COVID-19 patients, which were expressed in elevation of D-Dimer level and prolongation of prothrombin time, some of whom terminated in disseminated intravascular coagulation (DIC), deep venous thrombosis (DVT) or fatal pulmonary thromboembolism (PTE). At the later stage in some severe patients it was identified thrombocytopenia as a result of excessive platelets consuming, which significantly affected on treatment and prognosis. More than 300 drugs are used for the treatment of COVID-19 worldwide. Now, the most popular treatments include Remdesivir, Hydroxychloroquine, Betamethasone, Tocilizumab, anti HIV drugs, and convalescent plasma. In the same time, WHO supports vaccines distribution for immunization. Currently, almost 8 vaccines are approved by different countries and more than 180 vaccines are under the clinical trails. Conclusion & Significance: Up till now it is challenging problem to combat SARS-CoV-2 with not well-defined origin and inexplicable biological characteristics as well as to control a pandemic of COVID-19 with such a high R0, a long incubation period and different disease outcomes. Unfortunately, we have limited understandings of particular mechanisms running to abnormal expression of immune system and coagulation processes. In the same time, we don’t have complete picture of vasculopathy leading to the tissue injury and patient death. Therefore, it is problematic to manage SARS-CoV-2 induced processes successfully using available drugs with no significant restoring effect on the organ damages in severe COVID-19 patients. So, we need new targets and new drugs for the prophylaxes and treatment of COVID-19 even we have vaccines available.

Non-Pulsatile Flow is Associated with Lower Levels of Circulating CD34+ Cells in LVAD-Supported Patients

The lack of pulsatility may be associated with altered angiogensis in LVAD patients. Since CD34+ cells represent an important regulator of angiogenesis in heart failure, we sought to investigate a potential correlation between flow pulsatility and circulating CD34+ cell levels in this patient population. In a single-center prospective cohort study we measured peripheral CD34+ cell numbers in patients undergoing LVAD support for at least 3 months. Patients with active infection, active hematologic disorders and history of chemotherapy were excluded. Pulsatile flow was defined as aortic valve opening in each cardiac cycle in the setting of optimized left ventricular unloading. Peripheral CD34+ cells were quantified by flow cytometry using the International Society of Hemotherapy and Graft Engineering protocol. Of 12 patients, pulsatile flow was established in 6 patients (Group A) and 6 patients failed to demonstrate flow pulsatility (Group B). The two groups did not differ in age (60±9 years in Group A vs. 59±6 years in Group B, P=0.97), gender (male; 83% vs. 83%, P=1.00), heart failure etiology (ischemic: 50% vs. 52%, P=0.84), serum creatinine (1.10±0.19 mg/dL vs. 0.97±0.17 μmol/L, P=0.35), NT-proBNP (926±587 pg/mL vs. 1562±1190 pg/mL, P=0.35), LDH levels (3.2±0.5 μmol/L vs. 3.4±3.2 μmol/L, P=0.79), length of LVAD support (932±369 days vs. 462±298 days, P=0.10), mean blood pressure (86±9 mmHg vs. 83±4 mmHg, P=0.43) or estimated pump flow (4.8±0.9 L/min vs. 4.3±0.6 L/min, P=0.32). Pulsatility index was higher in Group A than in Group B (5.6±1.2 vs. 3.6±0.6, P=0.006). Despite similar leukocyte counts (6.7±0.9x109/L in Group A vs. 7.3±0.8 x109/L in Group B, P=0.52), hemoglobin (12.6±7.3 g/dL vs. 13.5±1.6 g/dL, P=0.28) and serum iron (16±10 μmol/L vs. 14±5 μmol/L, P=0.66) we found significantly higher peripheral CD34+ cell count in Group A than in Group B (2.4±0.7x106/L vs. 1.6±0.8 x106/L, P=0.03). Overall, CD34+ cell count was inversely related to red cell distribution width (R2=0.-58 , P=0.05). Non-pulsatile flow appears to be associated with lower numbers of peripheral CD34+ cells in LVAD-supported patients. This suggests that hemodynamic changes after prolonged LVAD support may significantly alter angiogenesis and vasculogenesis pathways in chronic heart failure.

Expression of OX40 Gene and its Serum Levels in Neuromyelitis Optica Patients.

Neuromyelitis optica (NMO), also known as Devic's disease, is an autoimmune disorder of the central nervous system (CNS) in which immune system cells and antibodies primarily attack the optic nerves and the spinal cord. OX40 (CD134) is a tumor necrosis factor (TNF)-receptor family member expressed primarily on activated CD4+ and CD8+ T-cells. In an autoimmune disease, OX40 is typically up-regulated at sites of inflammation, and increases in the number of peripheral CD4+ T-cells expressing OX40. OX40 and its ligand OX40L are key TNF members that augment T-cell expansion, cytokine production, and promote T-cell survival. The aim of this study was to evaluate and compare of OX40 gene expression and its serum levels in patients with NMO and healthy controls. Twenty sex-/age-matched healthy controls (HC) (median age = 32 years, 15 females/5 males) were engaged for the present study. Expression of OX40 at the transcript level and serum protein levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assays, respectively. The results indicated OX40 expression in patients was significantly lower than in healthy controls (p = 0.001). However, the serum level of OX40 was not significantly different between groups (p = 0.37). In addition, the results indicated that CD134 expression was not age-related (p = 0.041). Overall, this study suggests to us that OX40 levels are not a suitable marker for diagnosis or treatment of NMO.

Increased numbers of peripheral blood CD34+ cells in dogs with canine atopic dermatitis.

The bone marrow may be involved in human atopic diseases, as shown by the release of CD34+ cells into the peripheral blood. The aim was to determine the numbers of CD34+ cells in atopic dogs. The following three groups of dogs were studied: 27 dogs with nonfood-induced atopic dermatitis (NFICAD); 16 dogs with nonallergic inflammatory diseases; and 13 healthy control dogs. Dogs with NFICAD were selected after fulfilment of Favrot's criteria and exclusion of other pruritic dermatoses, including flea infestation and adverse reaction to foods. The Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03 and a Visual Analog Scale (VAS) score for pruritus were used to quantify clinical signs. A phycoerythrin-conjugated anticanine CD34 antibody was used to stain peripheral blood CD34+ cells, and these were enumerated using a flow cytometer. The CD34+ cell counts were compared between groups and tested (in the NFICAD group) for correlation with the severity of clinical signs. The numbers of peripheral CD34+ cells in dogs with NFICAD (median 1.7) were statistically higher than in dogs with other nonallergic inflammatory diseases (median 1.0; P=0.01) and healthy control dogs (median 0.9; P=0.009). In dogs with NFICAD, there was no correlation between CD34+ cell numbers and CADESI-03 scores or owner-assessed pruritus (VAS score). The results of this study suggest the possible involvement of CD34+ cells in dogs with NFICAD. The role of CD34+ cells in the aetiopathogenesis of canine atopic dermatitis remains to be determined.

Imbalance of Different Types of CD4+Foxp3+ T cells in renal transplant recipients

Aims: To determine the number of CD4+CD25-Foxp3+, CD4+CD25+Foxp3+ and CD4+CXCR5+Foxp3+ T cells in renal transplant recipients that are transplanted stable (TS), or experiencing accelerated rejection (ALR), or acute rejection (AR). Methods: Renal transplantation was conducted in 28 patients with end-stage renal failure (ESRF). The number of peripheral CD4+CD25-Foxp3+, CD4+CD25+Foxp3+, or CD4+CXCR5+Foxp3+ T cells and the serum levels of interleukin-10 (IL-10) were measured in pre- and post-transplant patients and these results were compared to 10 healthy controls (HC). Correlation between CD4+CD25+Foxp3+ and estimated glomerular filtration rate (eGFR), CD4+CD25-Foxp3+ and serum creatinine (Cr) levels, or Cr and IL-10 levels in TS patients was also determined. Results: The number of CD4+CD25-Foxp3+ T cells was significantly increased in patients with ESRF, as compared to HC. Stratification analysis demonstrated that TS patients contained greater numbers of CD4+CD25+Foxp3+ and CD4+CXCR5+Foxp3+ T cells, higher levels of serum IL-10, and fewer numbers of CD4+CD25-Foxp3+ T cells than ESRF patients. In contrast, ALR and AR patients contained fewer numbers of CD4+CD25+Foxp3+ and CD4+CXCR5+Foxp3+ T cells, greater numbers of CD4+CD25-Foxp3+ T cells, and lower levels of serum IL-10 than ESRF patients. In TS patients, the numbers of CD4+CD25+Foxp3+ and CD4+CD25-Foxp3+ T cells were positively correlated with eGFR and serum Cr levels, respectively. Conclusion: An imbalance of different types of CD4+Foxp3+ T cells might be involved in renal transplant rejection.

Allogeneic hematopoietic stem cell collection from elderly related donors: a retrospective multicenter study on mobilization and collection efficiency

Correspondence: Franco Maria Dallavalle Via Vochieri, 51 15121 Alessandria, Italy E-mail: fdallavalle@ospedale.al.it SUMMARY In literature several data are reported showing that CD34+ cell collection efficiency decreases gradually with the increasing in donor age. We have therefore retrospectively analyzed data on 81 healthy donors older than 65 years from eight Italian transplant centers undergoing a total of 142 apheresis procedures. Data related to CD34+ cell mobilization in peripheral blood, collection and complication during procedures were recorded. Standard mobilization regimen was granulocyte colony-stimulating factor at 10 μg/kg/die for 4 days. On Day 5, median number of peripheral CD34+ cells was 42/ mL. Median number of total CD34+ cells collected was 3.35x106/kg in a median of 2 aphereses. Adverse events were recorded in 34.8% of procedures but were mostly mild. Our data show that mobilization of donors older than 65 can be safe and effective in the majority of cases. Allogeneic hematopoietic stem cell collection from elderly related donors: a retrospective multicenter study on mobilization and collection efficiency

Who should be really considered as a poor mobilizer in the plerixafor era?

Patients with a number of peripheral CD34+ cells ⩽20/μL have recently been defined in the literature as “poor mobilizers”. We retrospectively reviewed medical records from a total of 248 patients affected by hematological malignancies or solid tumors undergoing peripheral blood stem cell collection following chemotherapy plus G-CSF. On the basis of the CD34+ cell peak in peripheral blood following mobilization therapy, patients were defined as good mobilizers (group A, CD34+ cells ⩾20/μL), relative poor mobilizers (group B, CD34+ cells <20 and ⩾8/μL) and absolute poor mobilizers (group C, CD34+ cells <8/μL). One hundred and seventy-seven (71%) patients resulted good mobilizers, 35 (14%) patients relative poor mobilizers and 36 (15%) patients absolute poor mobilizers. Target of stem cell collection was ⩾2.0×106 CD34+cells/kg for each transplantation procedure. All patients in group A, 20 patients in group B (57%) and 1 patient in group C (2.7%) were able to collect ⩾2.0×106 CD34+cells/kg. The multivariate analysis confirmed that more than three lines of previous chemotherapy and a previous autologous PBSC transplantation negatively affect mobilization of CD34+ cells in peripheral blood. Our data suggest that a number of CD34+ cells ⩽20/μL does not always result in a failed stem cell collection and in fact in our patient series more than 70% of the patients defined as poor mobilizers have indeed collected the minimum number of 2.0×106 CD34+cells/kg required for a successful transplantation. The use of new agent such as CXCR4 antagonist plerixafor might further improve mobilization efficacy in such patients.

Toward a B-cell signature of tolerance?

Operational tolerance is a rare and still unexplained phenomenon in organ transplantation. Pallier et al. analyzed the peripheral B-cell compartment of 12 renal transplant patients with drug-free long-term graft function and found a peculiar blood B-cell phenotype, with an expansion of memory activated B cells and increased expression of inhibitory molecules, suggesting a role of B cells in maintaining graft tolerance.

Low MHC-I density impairs the homeostatic proliferation of CD8 T cells after HSCT

We hypothesise that the modifications in the Major Histocompatibility Class I (MHC-I) expression after Hematopoietic Stem Cell Transplantation (HSCT) might impact on CD8 T cell recovery. To evaluate our proposal, we measured the number of peripheral CD8 T cells and the MHC-I expression on the monocytes from the patients who underwent allogenic or autologous HSCT. Three months after transplantation, almost all of the autologous recipients showed a high density of MHC-I and the CD8 T cell counts were within the normal range. In contrast, allogeneic recipients had low or heterogeneous expression of MHC-I and low numbers of CD8 T cells. Similar patterns were observed even after 6 to 20 months after transplantation. Recent thymic emigrants and serum levels of IL-7 and IL-15 were similar within both groups of patients. Together, our results indicate that Homeostatic Peripheral Expansion (HPE) is the main mechanism to reach the normal numbers of CD8 T cells immediately after HSCT. A high and homogenous expression of MHC-I molecules is required for an optimal HPE.

HLA-DR Expressing Peripheral T Regulatory Cells in Newly Diagnosed Patients with Different Forms of Autoimmune Thyroid Disease

Several reports have claimed a role for T regulatory cells (Tregs) in the pathogenesis of various autoimmune diseases, including autoimmune thyroid disease (AITD). The aim of the present study was to examine whether changes in the number of peripheral CD4 + CD25highHLA-DR + lymphocytes, a subpopulation of Tregs, occur in patients with AITD. Three-color flow cytometry was used to detect the proportion of CD4 cells expressing CD25, CD25high, and HLA-DR in 70 newly diagnosed and untreated AITD patients and 20 controls. The intensity of CD25 expression on these cells was also examined. The proportion of CD4 + CD25 + cells as well as the proportion of CD4 + CD25high cells among the population of CD4 lymphocytes was not different in AITD patients relative to controls. However, a significant increase in the proportion of CD4 + CD25highHLA-DR + cells among the population of CD4 lymphocytes was found in patients with Hashimoto's thyroiditis (HT) compared to controls. In HT patients there is a quantitative increase of CD4 + CD25highHLA-DR + cells that may indicate a compensatory expansion of this subpopulation of Tregs in an attempt to suppress the immune response.

Cellular immune responses in hepatitis B virus e antigen negative chronic hepatitis B

The immunopathogenesis of hepatitis B e antigen (HBeAg) negative chronic hepatitis B (CHB) virus (HBV) infection has not been adequately investigated. We studied the cellular immune responses of peripheral lymphocytes using proliferating assays, intracellular cytokine staining (ICS) and ELISPOT interferon-gamma (IFN-gamma) assays after non-specific and specific stimulation with whole HBV proteins and synthetic peptides. Thirty patients with HBeAg negative CHB, eleven HBsAg inactive carriers, nine patients with acute hepatitis B and 22 healthy controls were included in the study. Patients with HBeAg negative CHB demonstrated an increased number of peripheral CD8+ T cells while their peripheral blood mononuclear cells showed increased proliferation after in vitro stimulation with overlapping hepatitis B core derived peptides and an envelope derived epitope (HBs 182-191 aa), similar to those observed in acute hepatitis B. Using ICS, we found an expanded population of IFN-gamma producing T lymphocytes, CD4+ and CD8+, after non-specific stimulation, in HBeAg negative CHB compared to all other groups. HBeAg negative CHB and acute hepatitis B patients had a similarly increased number of core specific T cells measured by the IFN-gamma assays. Inactive HBsAg carriers showed minimal proliferative responses overall while they exhibited an increased number of envelope specific effector T cells (measured by ICS). In conclusion, we showed that overall CD4+ T cell responses from patients with HBeAg negative CHB were comparable to those of acute hepatitis B, while inactive HBsAg carriers despite their limited proliferative capacity the effector activity of their peripheral T cells was maintained.

Factors Associated with Successful Mobilization of Progenitor Hematopoietic Stem Cells Among Patients with Lymphoid Malignancies

PurposeThis study's main aim was to assess the effect of 2 mobilization regimens (granulocyte colony-stimulating factor [G-CSF] and chemotherapy vs. G-CSF alone) on the yield of CD34+ cells in the apheresis components of patients with lymphoid malignancy. We also sought to identify possible predictors of CD34+ cell yield in the apheresis components. Patients and MethodsCD34+ cells were mobilized and harvested from 89 patients with non-Hodgkin lymphoma (n = 62) or Hodgkin disease (n = 27). Forty-one patients (46.1%) were mobilized with G-CSF, and 48 (53.9%) were mobilized with chemotherapy and G-CSF. Univariate and multivariate analyses were used to examine potential predictors of the CD34+ cell yield (collection of > 2.7 > 106 cells/kg), such as the number of peripheral CD34+ cells, age, sex, diagnosis, disease stage, weight, bone marrow status at baseline, mononuclear cells, white blood cells, and platelet counts. ResultsThe median patient age was 41 years (range, 12-66 years), and the median patient weight was 72 kg (range, 44-123 kg). Mobilization of peripheral blood progenitor cells (PBPCs) was superior when using chemotherapy and G-CSF versus G-CSF alone (3.6 > 106 cells/kg vs. 2.2 > 106 cells/kg; P = .001). CD34+ cell counts and platelet counts in the peripheral blood significantly correlated with CD34+ yield (P < .01 and P = .009, respectively). The yield was also significantly affected by weight, diagnosis, mobilization regimen, and baseline bone marrow status (P = .021, P = .05, P = .002, and P = .043, respectively). ConclusionMany factors influence harvesting of PBPCs, including diagnosis, bone marrow status at baseline, patient weight, and the type of mobilization regimen. The number of CD34+ cells in the peripheral blood can be used to predict the timing of apheresis and optimize yield.

Abstract 1175: Critical Role of Bone Marrow ASC (Apoptosis-associated Speck-like Protein Containing a CARD) in Neointimal Formation After Vascular Injury in Mice

Background: ASC is an adaptor protein that forms inflammasome complex and regulates caspase-1-dependent interleukin (IL)-1β and IL-18 generation; however, the role of ASC in the pathophysiology of cardiovascular diseases remains undefined. Here, we investigated the contribution of ASC to neointimal formation after vascular injury in ASC-deficient (ASC −/− ) mice. Methods and Results: Wire-mediated vascular injury was produced in the femoral artery of ASC −/− and wild-type (WT: C57BL/6) mice. Immunohistochemical analysis revealed that ASC was markedly expressed in the infiltrated macrophages in the neointima. Histological analysis revealed that neointimal formation was significantly reduced in ASC −/− mice as compared to that in the WT mice (I/M ratio, p = 0.007). IL-1β and IL-18 were clearly expressed in the neointimal lesion of the WT mice but showed decreased expression in the lesion of ASC −/− mice. However, TUNEL staining showed no significant difference in apoptotic cells of the media between these mice. Further, no significant differences were observed in early reendothelialization (CD31) and the number of macrophages (F4/80) and smooth muscle cells (SMCs: αSMA) per unit of the neointima. Flow cytometry analysis also showed no difference in the number of peripheral CD34 + /Flk-1 + cells (EPCs) after injury. To determine the contribution of bone marrow cells, we developed 3 types of bone marrow transplantation (BMT Wild+Wild , BMT Wild+ASC−/− , and BMT ASC−/− → Wild ) mice. The neointimal formation in BMT ASC−/−+Wild mice mice was remarkably reduced as compared to that in BMT Wild+Wild (I/M ratio, p = 0.0003) and BMT Wild+ASC−/− mice (p = 0.015), indicating that bone marrow ASC is critical for neointimal formation. In vitro experiments showed that the lipopolysaccharide-induced production of inflammatory cytokines such as IL-1β, IL-6, MCP-1, and IFN-γ, but not TNF-α, in ASC −/− bone marrow cells was significantly decreased. Further, serum-stimulated proliferation activity and MAP kinase (ERK1/2 and p38) activation of ASC −/− SMCs were not impaired. Conclusions: These findings suggest that bone marrow-derived ASC is critical for the neointimal formation after vascular injury and identify ASC as a novel therapeutic target for cardiovascular diseases.

FoxP3+CD25+CD8+T-Cell Induction during Primary Simian Immunodeficiency Virus Infection in Cynomolgus Macaques Correlates with Low CD4+T-Cell Activation and High Viral Load

The early immune response fails to prevent the establishment of chronic human immunodeficiency virus (HIV) infection but may influence viremia during primary infection, thereby possibly affecting long-term disease progression. CD25(+) FoxP3(+) regulatory T cells may contribute to HIV/simian immunodeficiency virus (SIV) pathogenesis by suppressing efficient antiviral responses during primary infection, favoring high levels of viral replication and the establishment of chronic infection. In contrast, they may decrease immune activation during chronic infection. CD4(+) regulatory T cells have been studied in the most detail, but CD8(+) CD25(+) FoxP3(+) T cells also have regulatory properties. We monitored the dynamics of CD25(+) FoxP3(+) T cells during primary and chronic SIVmac251 infection in cynomolgus macaques. The number of peripheral CD4(+) CD25(+) FoxP3(+) T cells paralleled that of memory CD4(+) T cells, with a rapid decline during primary infection followed by a rebound to levels just below baseline and gradual depletion during the course of infection. No change in the proportion of CD25(+) FoxP3(+) T cells was observed in peripheral lymph nodes. A small number of CD4(+) CD25(+) FoxP3(+) T cells at set point was associated with a high plasma viral load. In contrast, peripheral CD8(+) CD25(+) FoxP3(+) T cells were induced a few days after peak plasma viral load during primary infection. The number of these cells was positively correlated with viral load and negatively correlated with CD4(+) T-cell activation, SIV antigen-specific proliferative responses during primary infection, and plasma viral load at set point, with large numbers of CD8(+) CD25(+) FoxP3(+) T cells being indicative of a poor prognosis.

CD4+ CD8+ T cells in young and elderly humans. Comment on Macchia I, Gauduin MC, Kaur A, Johnson RP. Expression of CD8α identifies a distinct subset of effector memory CD4+ T lymphocytes. Immunology 2006; 119:232–42

Peripheral CD4(+) CD8(+) T cells have been described in animals as well as in humans. Two distinct populations can be distinguished, namely CD4(lo) CD8(hi) and CD4(hi) CD8(lo) T cells. We demonstrate here that the increase in the number of peripheral CD4(+) CD8(+) T cells in the elderly is the result of an increase of the CD4(lo) CD8(hi) T-cell population. While the phenotype of CD4(lo) CD8(hi) and CD4(hi) CD8(lo) T cells was very similar in young persons, CD4(hi) CD8(lo), T cells from elderly subjects expressed a more differentiated phenotype and produced less interleukin-2 compared to CD4(lo) CD8(hi) T cells. In conclusion, our results suggest that aging leads to a phenotypic and functional difference between CD4(+) CD8(+) T-cell subsets. It may therefore be of relevance to distinguish between these subsets before assessing their functional significance in elderly humans.