A decreasing CD4/CD8 ratio over time and lower CSF-penetrating antiretroviral regimens are associated with a higher risk of neurocognitive deterioration, independently of viral replication.

Persistent immune activation is one of the suspected causes of HIV-associated neurocognitive disorders (HAND) in cART era. The CD4/CD8 ratio has been recently showed as a marker of immune activation and HAND. Our aim was to analyze if a decrease in the CD4/CD8 ratio over time could have an impact on neurocognitive deterioration. Randomly selected HIV-infected patients were followed for neuropsychological (NP) testing during a period of almost 2 years. Tests were adjusted for age, gender, and education. Patients were divided into 5 groups: normal tests (NT), neuropsychological deficit (ND, one impaired cognitive domain), asymptomatic neurocognitive disorders (ANI), mild neurocognitive disorders (MND), and HIV-associated dementia (HAD). Risk factors for neurocognitive deterioration were analyzed. Two hundred fifty-six patients underwent NP tests and 94 participated in the follow-up. The groups were comparable. Upon neuropsychological re-testing, six patients showed clinical improvement, 30 had worsened, and 58 were stable, resulting in 42 patients presenting with HAND (45 %). The majority of HAND cases consisted of ANI (26 %) and MND (16 %). In patients whose NP performance worsened, CPE 2010 score was lower at inclusion (7.13 vs 8.00, p = 0.003) and CD4/CD8 decrease more frequent (60 vs 31 %, p = 0.008) than in those who were stable or improved. Multivariate analysis confirmed these results. A decreasing CD4/CD8 ratio during a longitudinal follow-up of randomly selected HIV-infected patients and lower CSF-penetrating regimens were independently associated with cognitive decline. Monitoring trends in CD4/CD8 ratio could contribute to identifying patients at higher risk of neurocognitive deterioration.

Neuromyelitis optica: Contribution of therapeutic responses markers monitoring in patients given rituximab.

Neuromyelitis optica (NMO) is a central nervous system inflammatory autoimmune disease characterized by medullary and/or optical nerve damage. It is rare but life-threatening. Concerning the treatment of NMO, many drugs have been used in background therapy. Some studies have shown efficacy of rituximab (an antiCD20 monoclonal anti-body) either on the reduction of the annual number of exacerbation or the mean score EDSS. In 2013, a Korean team reported a new protocol during which they administered rituximab only when memory B lymphocytes CD27+ were detectable in the bloodstream. In our patient, institution of this protocol led to clinical benefit with a major decrease in the EDSS score over time (7 in August 2012 vs. 1 in October 2015), a reduction of the total administered dose (4g in 2013 vs. 1.375g in 2014 vs. 0g in 2015) and side effects. Compared with the rate of theoretical administration, health expenditure savings reached 1700 Euros per month over the 11-month treatment. Monitoring therapeutic response markers with memory B lymphocyte counts appear to be an efficient cost-effective way to measure clinical efficiency, reduce total doses, and limit side effects.

Virologically suppressed patients with asymptomatic and symptomatic HIV-associated neurocognitive disorders do not display the same pattern of immune activation.

OBJECTIVES: Inversion of the CD4:CD8 ratio is a marker of immune activation and age-associated disease. We measured the CD4:CD8 ratio as a marker of cognitive impairment in HIV-infected patients and explored differences according to clinical severity. METHODS: Post hoc analysis of data from two prospective cohorts of HIV-infected patients randomly selected to undergo neuropsychological tests was performed. Test scores were adjusted for age, gender and education. Inclusion criteria were undetectable viral load and stable treatment for at least 6 months. Subjects with HIV-associated dementia were excluded. Patients were divided into an unimpaired group, a group with asymptomatic neurocognitive disorder (ANI) and a group with symptomatic HIV-associated neurocognitive disorder (sHAND), represented by mild neurocognitive disorder (MND). Demographic and background parameters, immune activation markers and the CD4:CD8 ratio were recorded. RESULTS: Two hundred patients were included in the study. The mean age was 52 years, 78% were male, the mean CD4 count was 624 cells/µL, the mean nadir CD4 count was 240 cells/µL, 27% were hepatitis C virus (HCV)-coinfected, the mean duration of HIV infection was 16 years, and the mean time on current combination antiretroviral therapy (cART) was 2.9 years. Twenty-nine per cent of subjects had HAND (21% had ANI and 8% had MND). In multivariate analysis, a CD4:CD8 ratio < 1 was associated with a nadir CD4 count < 200 cells/µL [odds ratio (OR) 3.68] and with the presence of CD4(+) CD38(+) HLA(+) cells (OR 1.23). Multinominal logistic regression showed that, in comparison with the unimpaired group, diagnosis of sHAND was associated with a CD4:CD8 ratio < 1 (OR 10.62), longer HIV infection (OR 1.15) and longer current cART (OR 1.34), while the ANI group differed from the unimpaired group only for education level. CONCLUSIONS: Aviraemic patients with sHAND did not display the same pattern of immune activation as subjects with ANI, suggesting that the underlying pathophysiological mechanisms could be different.

Early infectious acute respiratory distress syndrome is characterized by activation and proliferation of alveolar T-cells.

Acute respiratory distress syndrome (ARDS) in humans is characterized by the infiltration of polymorphonuclears in the alveolar spaces. However, the role of T-cells in ARDS is unknown. Our aim was to characterize the T-cell phenotype in bronchoalveolar lavage (BAL) during the early phase of acute lung infection(ALI)/ARDS-infected patients in comparison to a control group (CG). BAL lymphocyte phenotypes of two ALI, 16 ARDS, and eight CG were examined by flow cytometry. ALI/ARDS showed a significant increase in CD4 and CD8 T-cell activation as compared to CG. Moreover, a significant level of proliferation was observed using the Ki67 marker in ARDS patients as compared to controls (median): 37 versus 6 % for CD4 T-cells (p = 0.022) and 34 versus 2 % for CD8 T-cells (p = 0.009). In contrast, the percentage of T-regulatory cells and apoptotic T-cells were similar in both groups. Among costimulatory molecules, we observed an overexpression of CTLA-4/CD152 on CD4 T-cells in ALI/ARDS as compared to CG: 30 versus 7 %, respectively (p = 0.063). In further characterizing T-cell subsets expressing high levels of CD152, we found the presence of IL-17 secreting CD4 T-cells in ALI/ARDS. In humans, ALI/ARDS due to infection is associated with a high level of T-cell activation and proliferation, along with the presence of Th17 cells, which are known to attract polymorphonuclears.

T cells from chronic bone infection show reduced proliferation and a high proportion of CD28⁻ CD4 T cells.

Chronic bone infection is associated with bone resorption. From animal studies, CD3/CD28-activated T cells are known to enhance osteoclastogenesis and bone resorption. Because CD28 is expressed constitutively on T cells and its expression is down-regulated by chronic exposure to the inflammatory environment, we characterized co-stimulatory molecule expression on T cells from chronically infected patients. We used cytofluorometric techniques to phenotypically characterize T cells, its co-stimulatory molecules and perforin secretion from infected and non-infected human bones. Chronic bone infection was defined as infection lasting for more than a month. We show a higher T cell activation [human leucocyte antigen D-related (HLA-DR⁺)] in infected compared to non-infected bones: median being 16 versus 7%, P = 0·009 for CD4 T cells, and 33 versus 15%, P = 0·038 for CD8 T cells, respectively. However, T cell proliferation (Ki67⁺) was lower for CD8 T cells in infected bones: 26 versus 34%, P = 0·045. In contrast, we detected no difference in apoptosis and regulatory T cells. In infected bone, we found higher CD28-negative CD4⁺ T cells compared to non-infected bone: 20 versus 8%, respectively (P = 0·005); this T cell subset had higher CD11b expression and perforin secretion. Chronically infected human bones are characterized by an increase of CD28-negative CD4⁺ T cells, indicating long-term activated cells with cytotoxic ability. Therefore, this alteration of co-stimulatory molecules may modify interactions with osteoclasts and impact bone resorption.

Blastic plasmacytoid dendritic cell neoplasm: a report of four cases and review of the literature.

BACKGROUND: Blastic plasmacytoid dendritic cell neoplasm (BPDCN), formerly known as agranular CD4(+) /CD56(+) haematodermic neoplasm (CD4/CD56 HN), is a rare distinct form of lymphoma-like entity known of dermatologists because of its marked predilection for cutaneous involvement, and its aggressive behaviour. Moreover, the association or the evolution to an acute leukaemia entity that still expresses CD4 and CD56 markers is almost systematic. This new described entity of 'CD4(+) /CD56(+) leukaemia' or 'leukaemia of plasmacytoid dendritic cell lineage' has a poor prognostic and may lead to include haematopoietic stem cell transplantation in the treatment strategy as early as possible. REPORT OF CASES: We report here four cases presenting with skin lesions and haematological signs. One of the patients underwent allogeneic stem cell transplantation, with a relapse-free survival of 40 months. We discuss the diagnosis features as well as the treatment options. CONCLUSION: A collaborative work between dermatologists and onco-haematologists is essential to give patients the best chance of complete and long-term response.

The suppression of immune activation during enfuvirtide-based salvage therapy is associated with reduced CCR5 expression and decreased concentrations of circulating interleukin-12 and IP-10 during 48 weeks of longitudinal follow-up.

BACKGROUND: It has been suggested that patients who initiate highly active antiretroviral therapy (HAART) late in their course of infection may have suboptimal CD4 T-cell gains, persistent alterations in T-cell subsets and residual inflammation. To address this issue, we carried out a comprehensive 48-week immunological study in HIV-infected patients who had experienced failures of prior therapies, had low CD4 cell counts, and were receiving enfuvirtide-based salvage therapy. METHODS: Immunological monitoring of peripheral lymphocytes from enfuvirtide-responder patients was performed over a 48-week period. A detailed assessment of immune cell subsets, their activation state [CD38 and human leucocyte antigen (HLA)-DR expression] and homeostasis [activation-induced cell death (AICD) and Ki67 expression], and the expression of co-receptors was performed by flow cytometry. Cytokine and chemokine signatures were assessed using multianalyte profiling technology. RESULTS: Enfuvirtide-based salvage therapy induced a progressive restoration of naïve and central memory CD4 T cells, associated with a decrease in their activation state, suppression of premature priming for AICD and increased expression of Ki67. In addition, a significant decrease in C-C chemokine receptor 5 (CCR5) expression was detected on CD4 T cells, which was strongly correlated with the suppression of immune activation. Changes in circulating proinflammatory molecules occurred; i.e. there were decreases in the concentrations of interleukin (IL)-12, macrophage inflammatory protein MIP-1α, MIP-1ß, monokine induced by IFNγ (MIG) and interferon-γ-inducible protein-10 (IP-10). The decline in circulating IL-12 and IP-10 was correlated with both the reduction in the viral load and CD4 T-cell restoration. CONCLUSIONS: This study shows that suppression of HIV-1 replication with enfuvirtide-based salvage therapy in patients with low CD4 cell counts may result in an immunological benefit, characterized by the restoration of CD4 T-cell subsets associated with decreased immune activation and suppression of inflammation.

Immune changes in post-menopausal osteoporosis: the Immunos study.

UNLABELLED: The phenotypic and functional characteristics of immune cells of osteoporotic women compared to healthy controls similar for age and estrogen level showed for the first time significant changes in several B lymphocytes populations in postmenopausal osteoporosis, related to bone mineral density (BMD) and fractures, and a significant lower basal secretion of interferon-gamma (IFN-gamma) by CD4(+). INTRODUCTION: To investigate the interactions between bone and immune system, we studied the phenotypic and functional characteristics of immune cells of 26 postmenopausal women with osteoporotic (OP) fractures compared to 24 healthy controls. METHODS: We analyzed surface markers of peripheral B, CD4(+) and CD8(+) lymphocytes and cytokine secretion in supernatants of these cells cultured with or without stimulation. Body composition was assessed by dual energy X-ray absorptiometry. RESULTS: The two groups were similar for age and estrogen level. OP women had a significantly lower body mass index, fat mass, and lean mass. The number of CD19(+), CD19(+)/CD27(+), CD19(+)/CD27(+)/CD5(-)/CD38(+) and CD19(+)/CD27(+)/RANK(+), CD4(+)/CD27(+)/CD45RA(-)/RANK(+), and CD4(+)/CD27(+)/CD45RA(-)/CD28(+) was lower in OP women and positively correlated to BMD. In OP women, under basal conditions, CD4(+) secreted less IFN-gamma and B lymphocytes more granulocyte macrophage colony-stimulating factor (GM-CSF). GM-CSF was positively correlated to fracture rate and negatively to BMD. CONCLUSIONS: Our results suggest that, regardless of age and estrogen status, postmenopausal OP is associated with immune changes, highlighting a possible role of IFN-gamma in the pathophysiology of OP and reporting, for the first time, changes in several B lymphocyte populations. These alterations may reflect the frailty observed after fracture, providing new insight into the mechanisms of morbidity and mortality associated with OP fractures.

Patients with Covid-19 exhibit different immunological profiles according to their clinical presentation.

OBJECTIVES: A novel beta coronavirus has been identified as responsible for the 2019 coronavirus infection (Covid-19). Clinical presentations range from asymptomatic cases to acute respiratory distress syndrome with fatal outcome. Such a broad spectrum of disease expression calls for an investigation of immune response characteristics. METHODS: We identified subjects admitted for Covid-19 in whom a large panel of immunological markers were measured, including B- and T- and NK-lymphocyte phenotypes, T-lymphocyte subpopulation cells and plasma cytokines. Patients were divided according to symptom severity during hospitalisation, in those with uncomplicated and complicated infection. Differences between groups were analyzed. RESULTS: Seventeen patients were included (mean age: 83 years; 9 women; mean delay of symptoms onset: 4 days). Six had uncomplicated infection, while 11 developed complicated forms during hospitalization. CD10 + B lymphocyte levels were inversely correlated with clinical severity (5.8% vs 2.0%, p = 0.04) and CD10+ levels above 3% were independently associated with uncomplicated forms [Odds Ratio 0.04 (CI 0.002-0.795, p = 0.034)]. TNF-alpha, IL-1, Il-6 and Il-8 measurements upon admission differed between patients who died and those who survived (p < 0.01 for all comparisons). CONCLUSIONS: In a population of elderly patients recently infected with Covid-19, CD10 + B cell levels were inversely correlated with clinical severity. Cytokine values upon admission were highly predictive of fatal outcome during hospitalisation. These findings could explain differences in the clinical presentation and allow rapid identification of patients at risk for complications.

Endocytosis of GPI-anchored proteins in human lymphocytes: role of glycolipid-based domains, actin cytoskeleton, and protein kinases.

GPI-anchored surface proteins mediate many important functions, including transport, signal transduction, adhesion, and protection against complement. They cluster into glycolipid-based membrane domains and caveolae, plasmalemmal vesicles involved in the transcytosis and endocytosis of these surface proteins. However, in lymphocytes, neither the characteristic flask shaped caveolae nor caveolin, a transmembrane protein typical of caveolae, have been observed. Here, we show that the GPI-anchored CD59 molecule on Jurkat T cells is internalized after cross-linking, a process inhibited by nystatin, a sterol chelating agent. Clustered CD59 molecules mostly accumulate in non-coated invaginations of the lymphocyte membrane before endocytosis, in marked contrast with the pattern of CD3-TCR internalization. Cytochalasin H blocked CD59 internalization in lymphocytes, but neither CD3 internalization nor transferrin uptake. Confocal microscopy analysis of F-actin distribution within lymphocytes showed that CD59 clusters were associated with patches of polymerized actin. Also, we found that internalization of CD59 was prevented by the protein kinase C inhibitor staurosporine and by the protein kinase A activator forskolin. Thus, in lymphocytes, as in other cell types, glycolipid-based domains provide sites of integration of signaling pathways involved in GPI-anchored protein endocytosis. This process, which is regulated by both protein kinase C and A activity, is tightly controlled by the dynamic organization of actin cytoskeleton, and may be critical for polarized contacts of circulating cells.

Laminin 5 in the human thymus: control of T cell proliferation via alpha6beta4 integrins.

Laminin 5 (alpha3beta3gamma2) distribution in the human thymus was investigated by immunofluorescence on frozen sections with anti-alpha3, -beta3, and -gamma2 mAbs. In addition to a linear staining of subcapsular basal laminae, the three mAbs give a disperse staining in the parenchyma restricted to the medullary area on a subset of stellate epithelial cells and vessel structures. We also found that laminin 5 may influence mature human thymocyte expansion; while bulk laminin and laminin 2, when cross-linked, are comitogenic with a TCR signal, cross-linked laminin 5 has no effect. By contrast, soluble laminin 5 inhibits thymocyte proliferation induced by a TCR signal. This is accompanied by a particular pattern of inhibition of early tyrosine kinases, including Zap 70 and p59(fyn) inhibition, but not overall inhibition of p56(lck). Using a mAb specific for alpha6beta4 integrins, we observed that while alpha3beta1 are known to be uniformly present on all thymocytes, alpha6beta4 expression parallels thymocyte maturation; thus a correspondence exists between laminin 5 in the thymic medulla and alpha6beta4 on mature thymocytes. Moreover, the soluble Ab against alpha6beta4 inhibits thymocyte proliferation and reproduces the same pattern of tyrosine kinase phosphorylation suggesting that alpha6beta4 is involved in laminin 5-induced modulation of T cell activation.

Homeostatic chemokines increase survival of B-chronic lymphocytic leukemia cells through inactivation of transcription factor FOXO3a.

B-chronic lymphocytic leukemia (B-CLL) cell is characterized by the accumulation of long-lived CD5+ B lymphocytes, whose survival in vivo is in part dependent on exogenous factors such as cytokines and/or extracellular matrix proteins. Homeostatic chemokines are critical mediators of lymphoid cell trafficking. However, how they function in cell signaling and survival remains ill-defined. In this study, we have investigated the role of the homeostatic chemokines, CXCL12, CCL21, CCL19 and CXCL13, in B-CLL cell survival. Using primary leukemic cells isolated from 26 patients, we observed that each chemokine enhances cell survival. Chemokines induced the phosphorylation of ERK1/2 and p90RSK, and of Akt and its effectors GSK3 and FOXO3a. Consistently, inhibitors against mitogen-activated protein kinase/extracellular signal-regulated kinase and phosphatidylinositol 3-kinase inhibited chemokine-induced survival. Moreover, using a constitutively active mutated form of FOXO3a or siRNAs against FOXO3a in transfection experiments performed in primary B-CLL cells, we directly demonstrated the critical role of FOXO3a in both spontaneous and chemokine-induced B-CLL cell survival. Overall, our data support the notion that homeostatic chemokines contribute to B-CLL resistance to cell death through inactivation of the transcription factor FOXO3a, which may represent a novel therapeutic target in this hematopoietic malignancy.

Monitoring CD27+ memory B-cells in neuromyelitis optica spectrum disorders patients treated with rituximab: Results from a bicentric study.

BACKGROUND: Rituximab (RTX) is increasingly used in the treatment of neuromyelitis optica spectrum disorder (NMO-SD). Administration regimen is not consensual as there is no reliable biomarker of RTX efficacy. In most cases, after induction, RTX is administered systematically every 6months. OBJECTIVE: To assess efficacy and safety of a maintenance regimen based on CD19+ CD27+ memory B-cell (mBc) detection. METHODS: We conducted a study in two French centers, including patients with NMO-SD who received an induction therapy with RTX. We compared the number of administered infusions, relapses and EDSS depending on two maintenance schemes (S1: administration of 1g RTX infusion every 6months or S2: a scheme based on regular mBc detection. 1g RTX was administered if mBc was >0.05%) RESULTS: 40 patients were included (mean age: 40.2years, F/M sex ratio: 5/1). Aquaporin-4 antibodies were positive in 75% patients. Under S1 regimen, all patients received 2 infusions per year, whereas under S2, they received 1.62 infusion per year. The mean interval between infusions under S2 was 7.4months, without decrease of clinical efficacy. CONCLUSION: In our study, mBc-based administration of RTX allowed personalizing treatment administration and in several cases to lower the cumulative dose without loss of efficacy.

Inhibition of T cell activation with a humanized anti-beta 1 integrin chain mAb.

The murine anti-CD29 mAb K20 (Mu-K20) is known to bind to the beta 1 chain of the human integrins and to inhibit activation and proliferation of T cells, implying an important potential for in vivo immunosuppression. However, use of K20 as an immunosuppressant drug would be impaired by the immunogenicity of mouse mAbs in man. We have therefore engineered K20 into (1) a mouse/human chimeric mAb (Ch-K20) that comprises the human kappa/gamma 1C regions and the K20 V regions; and (2) a humanized mAb (Hu-K20) combining the complementarity-determining regions (CDRs) of the K20 mAb with human framework (FR) and kappa/gamma 1 C regions. Both chimeric and humanized Abs were able to reproduce a range of functional properties of the original mouse mAb K20 (Mu-K20), namely, specific binding of CD29, inhibition of T cell proliferation and elevation of second messenger phosphatidic acid (PA) induced via CD3 in a soluble form, and activation of T cell proliferation in a cross-linked form. When compared to Ch-K20, the avidity of Hu-K20 was only slightly reduced. This demonstrates the feasibility of a successful humanization performed on the sole basis of the primary amino acid sequence analysis of the original mouse antibody V regions.

CD3-stimulated Jurkat T cells mediate IL-1 beta production in monocytic THP-1 cells. Role of LFA-1 molecule and participation of CD69 T cell antigen.

In this study we investigated the T cell signals required for monocyte activation. We used an in vitro co-culture system involving two human cell lines: Jurkat T cells and THP-1 monocytes. Monocyte activation was monitored by measuring IL-1 beta production, whereas IL-2 secretion reflected Jurkat activation. We showed that CD-3 -stimulated Jurkat cells delivered an IL-1-inductive signal to THP-1 cells through a cellular contact which was independent of THP-1 Fc receptors cross-linking. Stimulation of IL-1 beta production did not appear to require lymphokine secretion by T cell since a lymphokine defective mutant of Jurkat cell was able to deliver the stimulatory signal. The LFA-1 molecule was clearly shown to participate in the cooperation process, but its role was likely to be restricted to mediating initial adhesive interaction rather than to transducing the IL-1 -inductive signal. Interestingly, the co-culture stimulated by (Fab')2 fragments of CD3 mAb displayed an enhanced IL-1 beta production without any increase of IL-2 secretion. This result indicated that Jurkat cells could stimulate THP-1 cells even when they were only partially activated. The kinetics and conditions of IL-1 beta production called our attention to the early T cell activation antigen CD69. We then showed that CD69 mAb interfered with transmission of the IL-1 inductive signal (40-50% inhibition of IL-1 production). Our results are suggestive of a new role for CD69 molecule intervening in the T lymphocyte-dependent monocyte activation process.

[Lymphocytic molecules implicated in rosette phenomenon. Differential effect of antilymphocyte serum on T (CD2+E2+) and B (CD2-E2+) lymphocytes]. / Molécules lymphocytaires impliquées dans le phénomène des rosettes. Effet différentiel du sérum anti-lymphocytaire sur les lymphocytes T (CD2+E2+) et B (CD2-E2+).

The molecule E2 is present on T lymphocytes and thymocytes and is implicated in rosette phenomenon most probably via interaction with CD2. The discrepancy observed between rosette levels and lymphocyte phenotypes in the follow-up of kidney-transplanted patients treated with antilymphocyte globulins (ALG), methylprednisolone and azathioprine leaded us to study the effect of ALG on E2 molecule.

[Jacobsen's syndrome, thrombopenia and humoral immunodeficiency]. / Syndrome de Jacobsen, thrombopénie et déficit immunitaire humoral.

BACKGROUND: Clinical features of Jacobsen syndrome include facial dysmorphism, congenital heart defects, digit anomalies and mild to moderate psychomotor retardation. Thrombocytopenia or pancytopenia is observed in one half of patients. PATIENTS: Two unrelated children, a 6-month- and a 12-year-old, presented with a moderate thrombocytopenia associated with the clinical features of Jacobsen syndrome. Bone marrow aspirates showed, in both patients, normal cellularity with an increased number of micromegacaryocytes. Chromosome analysis showed a partial deletion of the long arm of chromosome 11. The 12-year-old patient had a history of upper respiratory airways infections with immune humoral deficiency (decreased level of IgA and IgM) which, to our knowledge, has never been reported. CONCLUSION: Jacobsen syndrome is a cause of inherited thrombocytopenia in children. Humoral immune functions must be explored in patients with a history of repeated infections.