Association of Selected Phenotypic Markers of Lymphocyte Activation and Differentiation with Perinatal Human Immunodeficiency Virus Transmission and Infant Infection

This study of a subset of women and infants participating in National Institutes of Health Pediatric AIDS Clinical Trials Group protocol 185 evaluated lymphocyte phenotypic markers of immune activation and differentiation to determine their association with the likelihood of human immunodeficiency virus (HIV) transmission from the women to their infants and the potential for early identification and/or prognosis of infection in the infants. Lymphocytes from 215 human immunodeficiency virus type 1 (HIV)-infected women and 192 of their infants were analyzed by flow cytometry with an extended three-color panel of monoclonal antibodies. Women who did not transmit to their infants tended to have higher CD4⁺ T cells. Most notably, levels of total CD8⁺ T cells and CD8⁺ CD38⁺ cells made significant independent contributions to predicting the risk of mother-to-child transmission. Adjusting for HIV-1 RNA level at entry, a one percentage-point increase in these marker combinations was associated with a nine percent increase in the likelihood of maternal transmission. Total as well as naïve CD4⁺ T cells were significantly higher in uninfected than infected infants. Total CD8⁺ cells, as well as CD8⁺cells positive for HLA-DR⁺, CD45 RA⁺ HLA-DR⁺, and CD28⁺ HLA-DR⁺ were elevated in infected infants. Detailed immunophenotyping may be helpful in predicting which pregnant HIV-infected women are at increased risk of transmitting HIV to their infants. Increasing differences in lymphocyte subsets between infected and uninfected infants became apparent as early as six weeks of age. Detailed immunophenotyping may be useful in supporting the diagnosis of HIV infection in infants with perinatal HIV exposure.     

Timing of lymphocyte activation in neonates infected with human immunodeficiency virus.

Human immunodeficiency virus (HIV) infection in children is associated with qualitative and quantitative changes in the peripheral lymphocyte surface phenotype beyond the normal maturational changes. Neonates, however, have been reported to have a delayed immune response to HIV compared to HIV-infected adults. We prospectively performed immunophenotyping of T lymphocytes by three-color immunofluorescent labeling and laser flow cytometry to determine the timing of phenotypic alterations in 112 neonates born to HIV-infected mothers. Serial testing was performed at birth (cord blood) and at 2, 6, and 12 weeks of age. Data were divided retrospectively for analysis into those for HIV-infected (n = 14) infants and those for exposed, uninfected infants. Our results show that both infected and uninfected infants had a decline in the percentages and numbers of CD4 cells beginning at 2 weeks of age but that the decline was greater in the HIV-infected group. The activation and differentiation of CD8 T cells in HIV+ infants were shown by a significant increase in CD45RA- CD45RO+ CD8+ cells by 6 weeks of age and by increases in CD8+ S6F1+ CD3+ cells and HLA-DR+ CD38+ CD8+ cells by 2 weeks of age. These results indicate that HIV-infected neonates show alterations in T-cell phenotype reflecting those reported for older HIV-infected children. Most importantly, neonatal T cells are able to respond to HIV within the first weeks of life.     

Function and phenotype of immature CD4+ lymphocytes in healthy infants and early lymphocyte activation in uninfected infants of human immunodeficiency virus-infected mothers.

The function and phenotypes of CD4+ lymphocytes in infants are different than in adults and are modulated by maturational changes and exposure to environmental antigens. Infants of non-human immunodeficiency virus (HIV)-infected mothers and uninfected infants of HIV-infected mothers, 0 to 6 months of age, were examined for CD4+ lymphocyte function by in vitro interleukin-2 (IL-2) production and for CD4+ phenotypes by three-color flow cytometry. A minority of these uninfected infants (28%) had functional responses similar to those of healthy adult women (IL-2 production in response to anti-CD3, alloantigen, and mitogen), while the remainder were capable of responding to alloantigen and mitogen but not to anti-CD3. We did demonstrate reduced phytohemagglutinin-stimulated IL-2 production in uninfected infants born to HIV-seropositive mothers compared to that in infants from seronegative mothers. The proportions of CD3+ CD4+, CD4+ HLA-DR- CD38+, and CD4+ CD45RA+ RO- (naive) lymphocytes were much higher in infants than in adults, and the proportions of CD4+ CD45RA- RO+ (memory) and CD4+ CD25+ (IL-2 receptor-bearing) lymphocytes were lower in infants than in adults. The proportions of activated (CD4+ HLA-DR+ CD38+) and memory (CD4+ CD45RA- RO+) lymphocytes were increased in uninfected infants of HIV-infected mothers compared to infants of uninfected mothers. Therefore, T-helper-cell function is immature in many infants, but the CD4+ lymphocytes of some HIV-exposed, uninfected infants have been stimulated by antigen at an early age.     

Selective increase of activation antigens HLA-DR and CD38 on CD4+ CD45RO+ T lymphocytes during HIV-1 infection.

Infection with HIV results in a progressive depletion of CD4+ T cells and leads to significant in vivo lymphocyte phenotype changes. In this regard, the expression of HLA-DR and CD38 on CD8+ T cells has been shown to increase dramatically with disease progression. We investigated the expression of both activation markers on CD4+ T cells in HIV-1-infected subjects at different clinical stages of infection and compared the in vivo activation of CD4+ T cells with parameters of viral activity and CD8+ T cell activation. Fresh peripheral venous blood was obtained from 54 HIV-infected subjects and from 28 uninfected healthy controls. Three-colour immunophenotyping of the CD4+ T cell subset showed that the proportion of CD4+ T cells expressing HLA-DR (10% in HIV-negative controls) or CD38 (62% in HIV-negative controls) was higher in asymptomatic (P < 0.05 for CD38) and symptomatic (P < 0.001 for HLA-DR and CD38) HIV-infected subjects than in controls, whereas the proportion of CD4+ T cells expressing CD45RO (54% in controls) remained relatively unchanged. Simultaneous expression of HLA-DR and CD38 on CD4+ T cells increased from 2.3% in controls to 11% (P < 0.001) in asymptomatic and 22% (P < 0.001) in symptomatic HIV-infected subjects. This relative increase of CD38 and HLA-DR expression occurred mainly on CD4+ T cells co-expressing CD45RO. Changes in expression of HLA-DR and CD38 on CD4+ T cells correlated with similar changes on CD8+ T lymphocytes, with the presence of HIV antigen in the circulation, and with the disease stage of HIV infection.     

Study of CD4+CD8+ double positive T-lymphocyte phenotype and function in Indian patients infected with HIV-1

CD4+CD8+ double positive T cells represent a minor peripheral blood lymphocyte population. CD4+ expression on CD8+ T cells is induced following cellular activation, and as chronic HIV-1 infection is associated with generalized immune activation, double positive T cells studies have become necessary to understand the immunopathology of human immunodeficiency virus (HIV). The frequency of double positive T cells in persons infected with HIV was studied in comparison to uninfected controls. Further, the expression of CD38, HLA-DR, and programmed death (PD)-1 on these cells were ascertained. HIV-1 specific double positive T cells were also studied for their cytokine secretory ability and phenotype. A significantly higher double positive cell population was observed in the patients with advanced HIV disease (CD4+ T cell counts below 200 cells/μl), as compared to patients with CD4+ T cell counts above 500 cells/μl. Double positive T cells from patients with symptomatic HIV disease had a significantly increased activation and exhaustion levels, compared to asymptomatic subjects and to single positive T cells from the same subjects. HIV-1 specific double positive T cells showed further increase in CD38 and PD-1 expression levels. The proportion of CD38 and PD-1 expressing total and HIV-1 specific double positive T cells correlated positively with HIV-1 plasma viremia and negatively with CD4+ T cell counts. HIV infection results in a marked increase of double positive T cell population, and this cell population shows higher level of activation and exhaustion (increased PD-1 expression) compared to the single positive CD4+ and CD8+ T cells.     

Cell cycling in HIV infection: analysis of in vivo activated lymphocytes.

Infection with HIV results in increased circulating levels of T lymphocytes expressing phenotypic markers of immune activation. In the present study, using three-colour immunofluorescence, we examined the cell cycle status of these activated cells. Activated (HLA-DR+, CD25+ and CD38+) CD4+ and CD8+ T lymphocytes in peripheral blood were analysed for DNA content in 15 HIV+ patients and 10 healthy age- and sex-matched control subjects. As expected, all HIV+ patients had elevated percentage levels of activated CD4+ HLA-DR+, CD4+ CD25+, CD8+ HLA-DR+, CD8+ CD25+ and CD8+ CD38+ T lymphocytes compared with control subjects (P < 0.001 for all). Percentage levels of CD4+ HLA-DR+ and CD8+ HLA-DR+T lymphocytes in the 'proliferative' (S-G2M) phase of the cell cycle were also higher in the HIV+ patients compared with controls (P < 0.001 for both). The percentage levels of proliferative CD4+ CD25+, CD8+ CD25+ and CD8+ CD38+ lymphocytes were, however, similar in HIV+ patients and controls, indicating that the proliferative fraction of cells in vivo was confined to the HLA-DR+ subset and absent from the CD25+ and CD38+ populations. Four HIV+ patients had grossly elevated levels of CD8+ lymphocytes which were CD38+ (> 95%) and confined to the pre-G0-G1 phase of the cell cycle, suggesting these may be cells committed to apoptosis. These observations indicate an increase in the proliferative capacity of HLA-DR+ T lymphocytes in HIV infection in vivo. The reduced DNA content in other populations (e.g. CD38+ CD8+ lymphocytes) of some patients with advanced HIV disease suggests that these cells are apoptotic. Thus our results define both proliferative and apoptotic processes as a spectrum of activation-related events in HIV infection.     

Evidence for circulating activated cytotoxic T cells in HIV-infected subjects before the onset of opportunistic infections

The activity of both cytotoxic T lymphocyte (CTL) and natural killer (NK) cells were measured cross-sectionally in 43 subjects seropositive for HIV, in 27 HIV- blood donors and in 24 HIV- persons from the Outpatients Clinic for sexually transmitted diseases. CTL activity was evaluated using the HL-60 cells coated with OKT3 as the targets and freshly separated peripheral blood lymphocytes as the effectors. In 20 out of 43 HIV+ subjects, CTL activity was significantly enhanced in comparison to the HIV- subjects. This lytic activity correlated positively with the percentages of CD3+ HLA-DR+, of CD8+ CR3- and of CD57+ CD16- lymphocytes, and was greatly reduced after elimination of CD8+, of HLA-DR+ or of CD57+ cells. The median CTL activity seemed to increase from CDC group II to CDC group IV (Centers for Disease Control classification), but to return back to control levels in those patients with a history of opportunistic infections. NK function in HIV+ subjects was not significantly different from that in the blood donors. In seropositive patients, NK activity correlated positively with the percentages of both CD16+ CD57+ and of CD8+ CR3+ cells and was strongly diminished after elimination of CD16+ or of CD57+ cells. There was no significant change in NK function according to the clinical stage. The data show that circulating CD8+ HLA-DR+ CD57+ T cells in HIV+ subjects are activated cytotoxic T cells and point to progressive (over) activation of this T cell compartment until the onset of opportunistic infections.     

HIV/AIDS患者CCR5、CXCR4的表达与疾病进展的关系

目的　了解HIV AIDS患者淋巴细胞表面第二受体CCR5、CXCR4的表达 ,分析其与疾病进展的关系 ,探讨HIV感染的免疫基础。方法　收集 33例HIV AIDS患者及 13例健康对照的抗凝全血 ,用流式细胞仪检测第二受体CCR5、CXCR4的表达 ,并分析第二受体表达与病毒载量、CD4 + T淋巴细胞绝对值及T淋巴细胞活化 (HLA DR+ CD38+ )的相关性。结果　艾滋病组CD4 + 、CD8+ T淋巴细胞表面CCR5表达高于无症状HIV 1感染组及健康对照 (P <0 .0 0 1) ;艾滋病组CD8+ T淋巴细胞表面CXCR4表达低于健康对照 (P <0 .0 1)。HIV AIDS患者CD4 + 、CD8+ T淋巴细胞表面CCR5的表达与病毒载量明显正相关 (P <0 .0 1) ;与CD4 + T淋巴细胞绝对值明显负相关 (P <0 .0 1) ,与T淋巴细胞活化(HLA DR+ CD38+ )水平明显正相关 (P <0 .0 0 1)。结论　HIV 1感染者第二受体CCR5的表达与机体对HIV的免疫反应及疾病进展密切相关。     

Concentrations of soluble Fas and soluble Fas ligand as indicators of programmed cell death among patients coinfected with Human Immunodeficiency Virus and Hepatitis C Virus

Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV) coinfections can affect mechanisms of programmed cell death and therefore influence acquired immunodeficiency syndrome (AIDS) development as well as the course of chronic hepatitis C. The aim of the study was to assess soluble Fas (sFas) and soluble Fas ligand (sFasL) concentrations in HIV- and HCV-coinfected patients and, moreover, to establish their relationships with HIV viral load, CD4+ T lymphocyte count, as well as liver function tests. Seventy-eight patients were included in the study, among them 30 coinfected with HIV and HCV, 10 infected only with HIV, and 38 infected only with HCV. HIV infection was confirmed by means of Western blot analysis; HIV viral load was measured by RTPCR; and CD3+, CD4+, and CD8+ T lymphocyte counts were established by means of flow cytometry. HCV infection was confirmed through HCV RNA isolation, using RT-PCR. sFas and sFasL concentrations were measured in duplicate by ELISA. The mean CD4+ T lymphocyte count decreased in HIV- and HCV-coinfected patients versus HIV-infected individuals (429 versus 279/ml). sFasL protein was detectable principally in HIV-infected individuals without HCV infection (90%), whereas in those with HCV infection it occurred only in 11% of cases. The highest sFas concentration was observed in HCV-infected patients (25.9 ng/ml) as well as in HIV- and HCV-coinfected individuals (20.3 ng/ml). This concentration was negatively proportional to sFasL prevalence. The results of our study suggest that HCV infection in HIV-positive individuals may suppress processes of programmed cell death. There was no correlation between sFas, sFasL, and HIV-1 viral load. On the other hand, sFas concentration and the presence of sFasL were related to CD4+ T lymphocyte count.     

Perivascular macrophages in the neonatal macaque brain undergo massive necroptosis after simian immunodeficiency virus infection

We previously showed that rhesus macaques neonatally infected with simian immunodeficiency virus (SIV) do not develop SIV encephalitis (SIVE) and maintain low brain viral loads despite having similar plasma viral loads compared to SIV‐infected adults. We hypothesize that differences in myeloid cell populations that are the known target of SIV and HIV in the brain contribute to the lack of neonatal susceptibility to lentivirus‐induced encephalitis. Using immunohistochemistry and immunofluorescence microscopy, we examined the frontal cortices from uninfected and SIV‐infected infant and adult macaques (n = 8/ea) as well as adults with SIVE (n = 4) to determine differences in myeloid cell populations. The number of CD206+ brain perivascular macrophages (PVMs) was significantly greater in uninfected infants than in uninfected adults and was markedly lower in SIV‐infected infants while microglia numbers were unchanged across groups. CD206+ PVMs, which proliferate after infection in SIV‐infected adults, did not undergo proliferation in infants. While virtually all CD206+ cells in adults are also CD163+, infants have a distinct CD206 single‐positive population in addition to the double‐positive population commonly seen in adults. Notably, we found that more than 60% of these unique CD206+CD163? PVMs in SIV‐infected infants were positive for cleaved caspase‐3, an indicator of apoptosis, and that nearly 100% of this subset were concomitantly positive for the necroptosis marker receptor‐interacting protein kinase‐3 (RIP3). These findings show that distinct subpopulations of PVMs found in infants undergo programmed cell death instead of proliferation following SIV infection, which may lead to the absence of PVM‐dependent SIVE and the limited size of the virus reservoir in the infant brain.     

Are there gender and race differences in cellular immunity patterns over age in infected and uninfected children born to HIV-infected women?

This study investigated whether age-related patterns of immunologic markers in 1488 uninfected (9789 measurements) and 186 infected (3414 measurements) children differed by gender and race. CD4+, CD8+, and absolute lymphocytes by HIV infection status, gender, and race were assessed using linear mixed-effects natural cubic spline models, allowing for prematurity and maternal CD4+ cell count. In uninfected children, levels of all 3 markers peaked twice in the first few months of life, declining to adult levels by around 8 years of age; uninfected boys and uninfected black children had significantly reduced CD4+ and absolute lymphocyte counts; the gender difference was especially pronounced in black children. Infected children had substantially lower levels and distinctly different patterns; with, e.g., by age 6 months CD4+ cell counts nearly 1200 per mm3 lower than in uninfected infants. Levels also significantly differed by gender and race for infected children, although for gender in the opposite direction. The gender and race differences in CD4+ levels were not explained by a general lymphocytosis nor were they confounded by treatment. These substantial differences in immunologic markers may reflect underlying genetic influence on the cellular immune system and may have implications for clinical decisions about therapeutic management.     

Mucosal lymphocyte subsets and HLA-DR antigen expression in paediatric Helicobacter pylori-associated gastritis

Paediatric studies may provide important insights into the immunopathology of Helicobacter pylori-associated gastritis, as mucosal changes reflect different stages of the immunoinflammatory response. We characterized, by quantitative immunohistochemistry, gastric mucosal lymphocyte phenotype and HLA-DR antigen expression and evaluated correlation with histopathology, in H. pylori-infected (Hp+ve) and uninfected children (Hp-ve). In the infected group, lamina propria CD3+ and IgA plasmocyte cell numbers were significantly higher and a trend for predominance of CD8+ over CD4+ was observed both in epithelium and lamina propria. A correlation of inflammation score with lamina propria CD3+ and CD4+ cell numbers and of CD45RO+ T lymphocytes with density of colonization was observed. The proportion of epithelial cells expressing HLA-DR antigen was significantly higher in the Hp+ve group and furthermore, glandular HLA-DR expression correlated with lamina propria CD3+ cell numbers, emphasizing the potential role of epithelial cells as antigen-presenting cells at this stage of infection.     

Functional Characterization of Human Tc0, Tc1 and Tc2 CD8+ T Cell Clones: Control of X4 and R5 HIV Strain Replication

CD8(+) T lymphocytes have the potential ability to inhibit human immunodeficiency virus (HIV) replication, by secreting soluble(s) factor(s) known as CD8(+) T lymphocyte antiviral factor (CAF). A panel of CD8(+) and CD4(+) T cell clones from HIV1-infected and uninfected donors were generated to better define the phenotype of CAF-producing cells. We first verified that the different CD4(+) T cell subsets (Th0, Th1, and Th2) were productively infected by X4 and R5 virus strains. X4 viral replication in CD4(+) T cells was controlled by the three CD8(+) T cell subsets (Tc0, Tc1, and Tc2); however, the frequency of Tc clones controlling R5 strain was much lower with a dramatic absence of this activity among Tc clones from uninfected donor. Finally, capacity to control viral replication showed an heterogeneity: some clones could control both virus strains, some controlled only the X4 virus, whereas the majority exerted no suppressive activity.     

Phenotypic distribution of T cells of patients who have subsequently developed AIDS

In a previous study of asymptomatic homosexual men, we found that CD8+ T-cell levels were higher in homosexual men infected with the human immunodeficiency virus (HIV) than in uninfected homosexual men because of higher numbers of CD8+ T cells that do not express the Leu15 marker, a phenotype associated with cytotoxic function. Among infected men, there was a positive correlation between the number of CD8+Leu15- T cells and the number of CD4+ T cells. If CD4+ T-cell levels are taken as a measure of severity of HIV infection and immunodeficiency, these results suggested that higher CD8+Leu15- cells may represent a phenotypic profile associated with less severe infection or better control of infection. In the present study, we extend the analysis to include a group of men who progressed to AIDS but were studied well before the onset of AIDS, and we compare results of CD8 subset analyses with results of infected men who have not progressed to AIDS. Phenotypic subsets associated with helper, suppressor, cytotoxic, and natural killer cell function were determined by two-color immunofluorescence. The only phenotypic subset that distinguished men who progressed to AIDS from those who have not was lower numbers of CD4+ T cells in the former group. If CD8+Leu15- cell numbers (or other phenotypic subsets examined) reflect effective control of HIV infection, the relationship is not strong enough to be of prognostic or predictive value with respect to outcome of infection.     

中国HIV/AIDS患者T细胞及调节性T细胞CTLA-4表达与疾病进展关系研究

目的 对中国HIV感染者T细胞及凋节性T细胞CTLA-4表达与HIV疾病进展的相关性进行研究,探讨CTLA-4在HIV感染中的作用.方法 选取58名HIV/AIDS患者(长期不进展组、无症状HIV组、AIDS组),应用流式细胞仪胞内染色技术检测T细胞及CD4+CD25+Foxp3+调节性T细胞内CTLA-4表达水平,分析其与CD4+T细胞、病毒载量、淋巴细胞活化凋亡水平的相关性.结果 长期不进展组、无症状HIV组、AIDS组CD4+T细胞内CTLA-4表达水平依次增岛(P<0.05);与CD+T细胞显著负相关(P<0.01),与CD8+T细胞活化(CD38表达)、凋亡水平(CD95表达)及CD4+T细胞凋亡水平显著相关(P<0.05),与病毒载量无显著相关性.长期不进展组、无症状HIV组、AIDS组CD8+T细胞内CTLA-4表达水平差异无统计学意义;与CD4+T细胞、病毒载量、CD4,'+>、CD8+T细胞活化及凋亡水平均无显著相关性.CD4+CD25+Foxp3+T细胞内CTLA-4表达水平长期不进展组明显低于无症状HIV组及AIDS纽(P<0.05);与CD4+T细胞显著负相关(P<0.05);与CD4+、CD8+T淋巴细胞活化(HLA-DR表达)显著相关(P<0.01).结论 中国HIV感染者CD4+T细胞及CD4+CD25+Foxp3+调节性T细胞内CTLA-4表达水平与疾病进展及免疫活化状态显著相关,参与HIV感染免疫平衡的调节.     

Effect of pregnancy and human immunodeficiency virus infection on intracellular interleukin-2 production patterns

Human immunodeficiency virus type 1 (HIV-1) infection decreases the production of interleukin-2 (IL-2) from CD4+ and CD8+ T cells. Recombinant IL-2 (rIl-2) has been given to HIV-infected individuals to generate significant increases in CD4+ T-cell counts. There are limited data regarding the effects of pregnancy and HIV infection on IL-2 production in humans. To investigate the effects of human pregnancy, HIV infection, and HIV therapy on IL-2 production, we evaluated 61 women. Intracellular IL-2 production by CD4+ T cells from nonpregnant HIV-infected women was significantly lower than in that in uninfected women (45% +/- 8% versus 52% +/- 8%, P = 0.04). In contrast, there was no difference in levels of intracellular IL-2 production between HIV-infected and uninfected pregnant women. These observations suggest that pregnancy may down-regulate IL-2 production regardless of HIV infection status. Future studies should evaluate IL-2 production patterns in larger cohorts of women so that the physiological significance of IL-2 down-regulation in pregnancy can be further evaluated. This information is essential to assess the possible use of IL-2 supplementation therapy as a means of enhancing immune responses among HIV-infected pregnant women.     

Immunity in the Female Lower Genital Tract and the Impact of HIV Infection

This study investigates the distribution of immunocompetent cells in the ectocervix, and cytokine and immunoglobulin (Ig) levels in cervicovaginal secretions to determine whether they are altered in asymptomatic human immunodeficiency virus (HIV) infection. Ectocervical biopsies from 10 HIV+ and 10 presumed HIV-ve women were studied by immunocytochemistry. Levels of Igs in cervicovaginal secretions were quantified by radial immunodiffusion (RID) and cytokine levels by ELISA. HIV+ women had significantly increased numbers of CD8+ lymphocytes resulting in reversal of the CD4:CD8 ratio. There was a significant increase in the proportion of activated CD8+ HLA-DR+ and CD4+ HLA-DR + lymphocytes, but not in CD8+ TIA-1+ cells. The epithelium of the cervix from HIV+ subjects showed a significant increase in both numbers of macrophages (CD68+) and proportions of activated macrophages (CD68+ HLA-DR+) compared to normal. The stroma contained increased proportions of inductive (D1+) and suppressive (D1+ D7+) macrophages but a decrease in effector phagocyte (D7+) proportions and Langerhans' cells. Significantly lower tumour necrosis factor (TNF)-alpha levels were observed in cervicovaginal secretions from HIV+ subjects. IgG levels were 4 times higher and IgM levels twice higher in cervicovaginal secretions from HIV+ women, compared to results from normal subjects. These results suggest a response within the CD8+ cells in HIV+ women, yet these cells may have a low cytolytic capacity. The raised proportions of HLA-DR+ and D1+ CD4+ macrophages could act as antigen-presenting cells (APC) for CD4+ CD45RO+ lymphocytes, and represent a local acquired response. However, the close juxtaposition of these cells offers the potential for them to act as a local reservoir of virus and promote its proliferation. The increase of IgG over sIgA in secretions of HIV+ subjects provides evidence suggesting a dysregulation of local humoral immunity.     

Activated CD4+ and CD8+ T Cell Proportions in Multiple Sclerosis Patients

The goal of this study was to trace the course of multiple sclerosis (MS) by evaluating the lymphocyte subpopulation counts and the levels of CD4+ and CD8+ T cell activation using flow cytometry. Samples obtained from healthy subjects (N?=?40) and patients with MS (N?=?290) were analyzed. Lymphocytes were labeled for the surface markers CD4+, CD8+, CD3+, CD16+, CD19+, CD45+, and CD53+ and the activation marker HLA-DR+. Cell counts were then determined using flow cytometry. A high degree of inter-individual variability was observed in the counts of all lymphocyte subtypes in the MS group. A significantly lower proportion of CD3+ T cells (69?±?14 % in healthy subjects and 60?±?17 % as a percent of total lymphocytes in MS patients), CD4+ T cells (41?±?11 and 28?±?18 %, respectively), and a significantly higher proportion of NK T cells (12?±?5 and 25?±?21 %, respectively) were observed in patients with MS than in healthy subjects. These differences led to a lowered CD4+/CD8+ T cell ratio. Furthermore, a significantly lower proportion of activated CD4+ T cells (HLA-DR+ CD4+; from 48?±?10 to 38?±?15 % as a percent of CD4+ cells) was observed in patients with MS than in healthy subjects. The high level of inter-individual variability in lymphocyte cell counts and the counts of activated T cells suggest that MS is a complex and heterogeneous disease.     

Increasing circulating T-cell activation markers are linked to subsequent implantation failure after transfer of in vitro fertilized embryos

PROBLEM: Implantation determines success of in vitro fertilization (IVF) and embryo transfer (ET) cycles. Data are accumulating to support a role of the immune system in implantation. Most of the literature addresses the importance of natural killer (NK) cells in this process. The purpose of the current study is to examine the role of circulating T cells in implantation failure. METHOD OF STUDY: Blood from 22 women undergoing IVF/ET during November, 2001, was drawn on cycle day 9 and analyzed for the percentage of circulating T cells expressing the activation markers CD69+ and human leukocyte antigen (HLA)-DR and the suppressor marker CD11b using immunofluorescence and flow cytometry. These results were compared with total percentage circulating CD3, CD4 and CD8 cells as well as NK cells and pregnancy outcome that cycle. RESULTS: Infertile women had significantly greater expression of the activation marker of CD69+ among CD8+ and CD4+ T cells and HLA-DR among CD4 cells than fertile women. No difference in expression of T cell suppressor marker of CD11b was noted when infertile and fertile women were compared. No correlations were observed when activated T cells were compared with circulating CD3+, CD4+, CD8+, activated NK cells and NK cytotoxicity. CD3+ 4+ HLA-DR+ was expressed significantly less among successfully pregnant compared with unsuccessfully pregnant women. CONCLUSION: T-cell activation markers CD 69+ and HLA-DR+ are associated with increased implantation failure after IVF/ET.     

HIV/AIDS患者CD28在外周血CD4+、CD8+ T细胞上的表达变化

目的　研究国内HIV AIDS患者CD2 8在外周血CD4 + 、CD8+ T淋巴细胞上表达的变化 ,并探讨这些变化的临床意义。方法　用流式细胞仪检测 5 1例正常对照、14例HIV感染者和 36例AIDS患者的外周血CD4 + 、CD8+ T淋巴细胞表面的CD2 8分子的表达 ,用bDNA法检测 11例HIV感染者和 18例AIDS患者的血浆病毒载量。结果　CD4 + CD2 8+ T细胞的绝对计数与百分比、CD8+ CD2 8+T细胞的百分比均显示为正常对照组 >HIV感染组 >AIDS组 ;而CD8+ CD2 8+ T细胞的绝对计数显示HIV感染组和对照组显著大于AIDS组 ,HIV感染组与对照组间差异无显著性。CD4 + 、CD2 8+ CD4 + T淋巴细胞计数与血浆病毒载量显著负相关。结论　HIV AIDS患者外周血CD2 8在CD4 + 、CD8+ T淋巴细胞上表达随着病情进展而降低 ,反映了细胞免疫功能随着疾病进展损害逐渐加重 ,是判断病情进展的指标。