Sub-optimal CD4 recovery on long-term suppressive highly active antiretroviral therapy is associated with favourable outcome

Objectives To examine risk factors for sub-optimal CD4 recovery on suppressive highly active antiretroviral therapy (HAART) and assess long-term clinical and immunological outcomes.
Methods Retrospective analysis of 286 HIV-positive patients from a university clinic who initiated HAART with CD4 count <350 cells/μL between January 1996 and July 2006 and achieved ≥52 weeks of viral suppression (VS). Sub-optimal and optimal CD4 count recovery were defined by gains of <150 and ≥150 cells/μL during the first year of VS, respectively. Risk factors were analysed by multivariate logistic regression and markers of immune maturation and activation were evaluated prospectively for a sub-group of patients with prolonged (>5 years) VS.
Results One hundred and two (36%) patients had sub-optimal CD4 recovery. Male gender, lower pre-HAART viral load, HAART toxicity and use of opportunistic infection (OI) prophylaxis were independent risk factors on multivariate analysis ( P <0.05). Outcomes of duration of VS on HAART (4 years), new OI events (1%) and mortality (5%) were similar between groups. Markers of immune maturation and activation were higher among patients with sub-optimal CD4 recovery ( P <0.05).
Conclusions Among HIV-positive patients with long-term VS, sub-optimal CD4 recovery was common but morbidity and mortality remained low. In addition, persistent CD4 T-cell activation appeared to blunt long-term CD4 gains.     

Serum leptin and CD4+ T lymphocytes in HIV+ children during highly active antiretroviral therapy

objective Because leptin, the adipocyte‐derived hormone, affects thymocyte survival, proliferation of naïve T lymphocytes and the production of proinflammatory cytokines, we aimed to investigate the role of this molecule in immunoreconstitution during highly active antiretroviral therapy (HAART). design Prospective longitudinal cohort study. A series of 20 HIV⁺ children were studied. The subjects were grouped by their increase in serum leptin levels after HAART. methods All participants were weight‐stable, free of endocrine disorders and opportunistic infections and equally distributed for sex (males, n= 10; females, n= 10). Body mass index (BMI), serum lipids, leptin, CD4⁺ T cells and HIV‐1 RNA were measured before initiation of HAART and after a 2‐year follow‐up. results Serum leptin concentration positively correlated with CD4⁺ lymphocyte number before treatment. HAART significantly reduced viraemia and increased serum levels of lipids in all patients, whereas a significant increase in CD4⁺ cells and serum leptin was observed in the majority of patients. Notably, in children where HAART was not effective in increasing CD4⁺ lymphocyte counts, serum leptin did not increase. conclusion To our knowledge, these findings reveal for the first time a novel link among CD4⁺ T lymphocytes, serum leptin and highly active anteretroviral theraphy.     

Increasing CD4+ T cells specific for tuberculosis correlate with improved clinical immunity after highly active antiretroviral therapy

Treatment advances have led to dramatic clinical improvements for patients with HIV-1 infection. These clinical improvements reflect treatment-related improvements in immune function, which are most striking in individuals who develop exaggerated immune inflammatory responses to occult opportunistic infections. The mechanisms accounting for these exaggerated immune responses are unknown. To gain insight into these mechanisms, we intensively studied a subject untreated for disseminated tuberculosis and HIV-1 coinfection who then began treatment for both diseases. We examined the changing frequencies of Mycobacterium tuberculosis (MTB)-specific CD4(+) T cells that produced interferon gamma (IFN-gamma) after short-term stimulation with MTB antigen, and we compared these frequencies with those in HIV-1-seronegative subjects with and without prior exposure to MTB antigens. For the HIV-1/MTB-coinfected subject, the proportion of peripheral blood CD4(+) T cells expressing MTB-specific IFN-gamma was 8.6% at 11 days, 11% at 33 days, and 33% at 95 days after starting treatment for HIV-1. CD4(+) IFN-gamma(+) T cells had a CD45RA(-)CD62L(-) (effector memory) phenotype and most coexpressed interleukin 2. Median frequencies of CD4(+) IFN-gamma(+) T cells from six subjects without and nine subjects with prior exposure to MTB antigens were 0.06 and 0.46%, respectively. We conclude that individuals starting treatment for disseminated tuberculosis and HIV-1 coinfection can accumulate remarkably large numbers of MTB-specific CD4(+) T cells in the peripheral blood. The rapid expansion of antigen-specific effector CD4(+) T cells is one mechanism to explain immediate improvements in clinical immunity after HIV-1 treatment. This mechanism provides a theoretical framework to understand the unusual inflammatory responses recently reported to occur after starting HIV-1 treatment.     

趋化因子受体CCR4在活动期类风湿关节炎患者外周血CD4+T细胞表达的研究

目的 探讨活动期类风湿关节炎(aRA)患者趋化因子受体CCR4在外周血CD4+T细胞的表达及其意义,并对该表达与血清重要细胞因子水平的相关性进行研究.方法流式细胞计数方法对12例aRA患者和10名健康对照者外周血CD4+T细胞表面CCR4的表达情况进行检测;酶联免疫吸附试验(ELISA)方法检测患者血清肿瘤坏死因子(TNF)-α、白细胞介素(IL)-10及干扰素(IFN)-γ的水平并记录患者相关临床及实验室资料.分析及评价aRA患者外周血淋巴细胞中CD4+CCR4+T细胞百分数(CD4+CCR4+T%)与TNF-α、IL-10、IFN-γ的血清水平及临床指标的相关性.结果 aRA组外周血CD4+CCR4+T%明显高于健康对照组(P＜0.01).aRA组血清TNF-α(P＜0.01)、IL-10(P＜0.01)及IFN-γ(P＜0.01)水平明显高于健康对照组.在检测的细胞因子中,aRA患者血清IL-10水平与CD4+CCR4+T%呈明显正相关关系(r＝0.66,P＜0.05).在临床指标中,CD4+CCR4+T%与aRA患者Lunsbury关节指数、血沉、C反应蛋白及血小板计数呈明显正相关关系(P＜0.05).结论 CCR4在CD4+T细胞趋化至病变关节过程中可能发挥重要作用;外周血CD4+CCR4+T%与血清IL-10水平密切相关;该百分数可以作为临床评价RA活动性的一个敏感指标.     

Decreased recovery of CD4 lymphocytes in older HIV-infected patients beginning highly active antiretroviral therapy

Among virological responders, the area under the curve of the CD4 count minus baseline (AUCMB) after 3, 9, 15 and 18 months of highly active antiretroviral therapy (HAART) was less in individuals 55 years or older (P < 0.05). Fewer older individuals achieved increases of 50, 100, or over 150 CD4 cells/l. A random quadratic time course model estimated that the AUCMB decreased 35 cells/year for each 10 years of additional age during the first 12 months after HAART (P < 0.005).     

CD4+T细胞与支气管哮喘治疗研究新进展

在支气管哮喘(简称哮喘)中,Th2细胞及其细胞因子促使气道嗜酸粒细胞炎症浸润和气道高反应产生,是哮喘治疗的重要靶点.越来越多的研究结果显示,除Th2细胞外,其他CD4+T细胞[包括Th1、Th17及调节性T细胞(Treg)]也可以被招募至气道,共同参与哮喘发病.哮喘的免疫学治疗复杂,现将各亚群CD4+T细胞在哮喘治疗中的研究进展综述如下.     

Interleukin-2-associated viral breakthroughs induce HIV-1-specific CD4 T cell responses in patients on fully suppressive highly active antiretroviral therapy

The combination of intermittent subcutaneous IL-2 and highly active antiretroviral therapy in individuals infected with HIV-1 has been shown to have a beneficial quantitative effect on the CD4 T cell count. We observed IL-2-associated viral load 'blips' inducing HIV-1-specific lymphoproliferative responses at 24 weeks in such individuals. This immunotherapeutic approach, utilizing autologous virus as autovaccination, may be a viable, safer alternative to structured treatment interruption and potentially more efficacious than therapeutic vaccines.     

Interaction with activated monocytes enhances cytokine expression and suppressive activity of human CD4+CD45ro+CD25+CD127low regulatory T cells

Objective

Despite the high frequency of CD4+ T cells with a regulatory phenotype (CD25+CD127^low FoxP3+) in the joints of patients with rheumatoid arthritis (RA), inflammation persists. One possible explanation is that human Treg cells are converted into proinflammatory interleukin‐17 (IL‐17)–producing cells by inflammatory mediators and thereby lose their suppressive function. The aim of this study was to investigate whether activated monocytes, which are potent producers of inflammatory cytokines and are abundantly present in the rheumatic joint, induce proinflammatory cytokine expression in human Treg cells and impair their regulatory function.

Methods

The presence and phenotype of CD4+CD45RO+CD25+CD127^low T cells (memory Treg cells) and CD14+ monocytes in the peripheral blood (PB) and synovial fluid (SF) of patients with RA were investigated by flow cytometry. Memory Treg cells obtained from healthy control subjects underwent fluorescence‐activated cell sorting and then were cocultured with autologous activated monocytes and stimulated with anti‐CD3 monoclonal antibodies. Intracellular cytokine expression, phenotype, and function of cells were determined by flow cytometry, enzyme‐linked immunosorbent assay, and proliferation assays.

Results

In patients with RA, the frequencies of CD4+CD45RO+CD25+CD127^low Treg cells and activated CD14+ monocytes were higher in SF compared with PB. In vitro–activated monocytes induced an increase in the percentage of IL‐17–positive, interferon‐γ (IFNγ)–positive, and tumor necrosis factor α (TNFα)–positive Treg cells as well as IL‐10–positive Treg cells. The observed increase in IL‐17–positive and IFNγ‐positive Treg cells was driven by monocyte‐derived IL‐1β, IL‐6, and TNFα and was mediated by both CD14+CD16− and CD14+CD16+ monocyte subsets. Despite enhanced cytokine expression, cells maintained their CD25+FoxP3+CD39+ Treg cell phenotype and showed an enhanced capacity to suppress T cell proliferation and IL‐17 production.

Conclusion

Treg cells exposed to a proinflammatory environment show increased cytokine expression as well as enhanced suppressive activity.

     

CD4+ T cell recovery beyond the first year of complete suppression of viral replication during highly active antiretroviral therapy is not influenced by CD8+ T cell activation

CD38 expression on CD8(+) T cells was longitudinally assessed in 31 human immunodeficiency virus (HIV)-infected persons with undetectable plasma viremia who had undergone highly active antiretroviral therapy (HAART) for 12 months and were followed for a mean of 30 months thereafter. Overall, CD4(+)T cell counts increased during follow-up, whereas CD38 expression remained stable. However, a subset of patients showed declines in CD38 expression, and, conversely, another subset showed increases in CD38 expression. No association could be found between long-term gains in CD4(+) T cells and evolution of CD38 expression. Thus, activation of CD8(+) T cells does not seem to be associated with the extent of CD4(+) T cell recovery beyond the first year of successful HAART.     

Early highly active antiretroviral therapy for acute HIV-1 infection preserves immune function of CD8+ and CD4+ T lymphocytes

Highly active antiretroviral therapy (HAART) has been advocated for the management of primary HIV-1 infection without clear understanding of its immunological effects. Here, we demonstrate that early use of HAART during primary infection preserves HIV-specific CD8(+) T cells physically and functionally while HIV-specific T cell help is sustained. We also show that even transient administration of HAART at seroconversion can preserve HIV-specific immunity. In contrast, delayed initiation of HAART is associated with a progressive loss of HIV-specific CD8(+) T cells and absent HIV-specific T cell help. These results imply that HIV-specific T help is damaged during primary HIV-1 infection. Early drug treatment, which preserves this immunity, also preserves HIV-specific CD8(+) T cells. These results have implications for understanding the early pathogenesis of HIV-1 infection and suggest that acute HIV infection should be treated aggressively and as early as possible.     

Severe immune dysregulation affects CD4(+)CD25(hi)FoxP3(+) regulatory T cells in HIV-infected patients with low-level CD4 T-cell repopulation despite suppressive highly active antiretroviral therapy

We hypothesized that CD4(+)CD25(hi)FoxP3(+) regulatory T cells (Tregs) could be involved in the high immune activation existing in patients with low-level CD4 T-cell repopulation under suppressive high active antiretroviral therapy (hereafter, "LLR patients"). Sixteen LLR patients, 18 human immunodeficiency virus (HIV)-infected controls (hereafter, "HIV controls"), and 16 healthy subjects were included. The frequency of CD4(+)CD25(hi)FoxP3(+) and HIV-specific Treg suppressive function were assessed. Relationships between Treg and CD4/CD8 activation (HLA-DR/CD38) and the frequency of naive CD4 T-cells were assessed. Low-level patients showed a higher Treg frequency but reduced HIV-specific immunosuppressive functions than HIV controls. Whereas in healthy subjects a strong negative correlation between Tregs and activated CD8 T cells emerged (r?=?-0.75, P?相似文献   

Antigen-driven CD4+ T cell and HIV-1 dynamics: residual viral replication under highly active antiretroviral therapy

Antigen-induced stimulation of the immune system can generate heterogeneity in CD4+ T cell division rates capable of explaining the temporal patterns seen in the decay of HIV-1 plasma RNA levels during highly active antiretroviral therapy. Posttreatment increases in peripheral CD4+ T cell counts are consistent with a mathematical model in which host cell redistribution between lymph nodes and peripheral blood is a function of viral burden. Model fits to patient data suggest that, although therapy reduces HIV replication below replacement levels, substantial residual replication continues. This residual replication has important consequences for long-term therapy and the evolution of drug resistance and represents a challenge for future treatment strategies.     

Reduced CD4+,CD25- T cell sensitivity to the suppressive function of CD4+,CD25high,CD127 -/low regulatory T cells in patients with active systemic lupus erythematosus

OBJECTIVE: CD4+,CD25high regulatory T (Treg) cells play a crucial role in the maintenance of self tolerance and prevention of organ-specific autoimmunity. The presence of many in vivo-preactivated CD4+,CD25++ T cells in patients with systemic lupus erythematosus (SLE) poses a difficulty in discriminating CD25++ activated T cells from CD25high Treg cells. To overcome this problem, we analyzed the phenotype and function of CD4+,CD25high,CD127(-/low) natural Treg (nTreg) cells isolated from the peripheral blood of patients with SLE. METHODS: CD4+,CD25high,CD127(-/low) nTreg cells and CD4+,CD25- responder T (Tresp) cells from patients with SLE and normal donors were separated by fluorescence-activated cell sorting. Cell proliferation was quantified by 3H-thymidine incorporation, and immunophenotyping of the cells was done using FACScan. RESULTS: Comparable percentages of CD4+,CD25high,FoxP3+ T cells were observed in patients with SLE and normal donors. Proliferation of SLE nTreg cells sorted into the subset CD4+,CD25high,CD127(-/low) was significantly decreased compared with that of SLE nTreg cells sorted into the subset CD4+,CD25high (mean +/- SEM 2,223 +/- 351 counts per minute versus 9,104 +/- 1,720 cpm, respectively), while in normal donors, these values were 802 +/- 177 cpm and 2,028 +/- 548 cpm, respectively, confirming that effector cell contamination was reduced. Notably, the suppressive activity of nTreg cells was intact in all groups. However, CD4+,CD25- Tresp cells isolated from patients with active SLE were significantly less sensitive than those from patients with inactive SLE to the suppressive function of autologous or normal donor CD4+,CD25high,CD127(-/low) nTreg cells. Furthermore, a significant inverse correlation was observed between the extent of T cell regulation in suppressor assays and the level of lupus disease activity. CONCLUSION: This study is the first to show that, in human SLE, impaired sensitivity of Tresp cells to the suppressive effects of a comparably functional, highly purified nTreg cell population leads to a defective suppression of T cell proliferation in active SLE. Studies aiming to define the mechanisms leading to Tresp cell resistance might help in the development of highly specific, alternative immunotherapeutic tools for the control of systemic autoimmune diseases such as SLE.     

AIDS患者高效抗逆转录病毒联合治疗后外周血CD+8 CD+38T细胞与病毒载量同步变化

目的了解艾滋病(AIDS)患者高效抗逆转录病毒联合治疗(HAART)前后外周血CD+38抗原在CD+8T淋巴细胞上的表达情况.方法应用流式细胞仪采用双色荧光抗体检测技术检测CD+8 CD+38 T细胞;用罗式核酸扩增荧光定量聚合酶链反应(PCR)法检测血浆病毒载量(VL).结果 HAART后2周内CD+8 CD+38 T细胞数与VL开始同步下降,12周后83%AIDS患者的VL降至＜500拷贝/ml,同时CD+8 CD+38 T细胞计数与治疗前相比非常明显地降低(P＜0.001).而且63%的AIDS患者在血浆VL低于检测水平时,其CD+8 CD+38 T细胞数仍继续下降(与VL开始达到检测水平以下时相比,P＜0.001).结论 AIDS患者在HAART开始后,CD+8 CD+38 T细胞数与VL快速下降,在24周左右降至正常水平;并且CD+8 CD+38 T细胞数在VL达到检测不到时仍继续下降,提示在血浆VL低于检测水平时,CD+8 CD+38 T细胞数能够作为判断病毒是否复制的标记.     

HAART未能恢复CD4+ T细胞数的原因

长期进行高效抗反转录病毒治疗(HAART)的艾滋病病毒(HIV)感染者中,高达30%的病人其HIV载量被完全抑制,但CD4+T细胞数并没有显著增加(称其为免疫无应答)。临床医生在治疗这些病人时,遇到许多问题,包括与持久免疫缺陷相关的临床风险,以及如何提供有效的治疗方案等。为了解答这些问题,需要研究免疫恢复缺陷的机制,为临床提供高效且特异性的治疗方案。该文将从全面评估免疫无应答病人CD4+T细胞增加缺陷的临床意义,检测CD4+T细胞恢复受限的免疫学机制,以及描述可能的治疗途径进行综述。     

Dysregulation of CD28 and CTLA-4 expression by CD4 T cells from previously immunodeficient HIV-infected patients with sustained virological responses to highly active antiretroviral therapy

OBJECTIVES: Current guidelines recommend commencing highly active antiretroviral therapy (HAART) in HIV-infected patients when CD4 T-cell counts reach 350 cells/microL. However, late-presenting HIV-infected patients with CD4 T-cell counts<50 cells/microL are still common. The ability of long-term HAART to normalize immune dysregulation in severely immunodeficient HIV-infected patients remains unclear. Here we address indices of immune dysregulation in previously severely immunocompromised HIV-infected patients treated with long-term HAART who had achieved increased CD4 T-cell counts and complete suppression of HIV viraemia. METHODS: We examined expression of CD28, cytotoxic T-lymphocyte antigen-4 (CTLA-4) and intracellular perforin by CD4 and CD8 lymphocytes from 25 highly selected HIV-infected patients [nadir CD4 T-cell counts <50 cells/microL, >4 years on HAART and >6 months of complete viral suppression (<50 HIV-1 RNA copies/mL)] and 18 HIV-seronegative age- and sex-matched controls. RESULTS: HIV-infected patients had lower percentages of CD28-expressing CD4 lymphocytes and higher percentages of CTLA-4-expressing CD4 lymphocytes than controls. The percentage of CTLA-4-expressing CD4 lymphocytes correlated inversely with that of CD28-expressing CD4 lymphocytes. The proportion of CD4 lymphocytes expressing perforin was generally low. However, more HIV-infected patients than controls had >1% of CD4 lymphocytes expressing perforin [11 of 25 (44%) vs. one of 18 (5.5%)]. The percentage of CD8 lymphocytes expressing perforin did not differ between HIV-infected patients and controls. Amongst HIV-infected patients, the percentage of perforin-expressing CD8 lymphocytes correlated inversely with nadir but not current CD4 T-cell count. CONCLUSIONS: Expression of CD28, CTLA-4 and perforin by CD4 lymphocytes remain dysregulated in HIV-infected patients with previous severe immunodeficiency, despite increased CD4 T-cell counts and control of HIV viraemia by HAART.     

Effects of highly active antiretroviral therapy on thymical reconstitution of CD4 T lymphocytes in vertically HIV-infected children

CD4 T-cell percentages, viral load and thymic function measured as T-cell receptor rearrangement excision circle (TREC) levels were determined every 2-3 months in six treated HIV-infected children for 4 years. All children experienced a marked increase in CD4 cell count after therapy, accompanied by a concomitantly marked increase in TREC levels. In children, the decrease in viral load caused by antiviral therapy leads to an increase in CD4 T cells, mainly because of a recovery in the thymic production of new T cells.     

Impact of HIV-1 infection and highly active antiretroviral therapy on the kinetics of CD4+ and CD8+ T cell turnover in HIV-infected patients

To evaluate the effects of HIV infection on T cell turnover, we examined levels of DNA synthesis in lymph node and peripheral blood mononuclear cell subsets by using ex vivo labeling with BrdUrd. Compared with healthy controls (n = 67), HIV-infected patients (n = 57) had significant increases in the number and fraction of dividing CD4(+) and CD8(+) T cells. Higher percentages of dividing CD4(+) and CD8(+) T cells were noted in patients with the higher viral burdens. No direct correlation was noted between rates of T cell turnover and CD4(+) T cell counts. Marked reductions in CD4(+) and CD8(+) T cell proliferation were seen in 11/11 patients 1-12 weeks after initiation of highly active antiretroviral therapy (HAART). These reductions persisted for the length of the study (16-72 weeks). Decreases in naive T cell proliferation correlated with increases in the levels of T cell receptor rearrangement excision circles. Division of CD4(+) and CD8(+) T cells increased dramatically in association with rapid increases in HIV-1 viral loads in 9/9 patients 5 weeks after termination of HAART and declined to pre-HAART-termination levels 8 weeks after reinitiation of therapy. These data are consistent with the hypothesis that HIV-1 infection induces a viral burden-related, global activation of the immune system, leading to increases in lymphocyte proliferation.