Telomerase elevation in pancreatic ductal carcinoma compared to nonmalignant pathological states

OBJECTIVE: To assess the changes in the subpopulations of lymphocytes and in lymphocyte mitogenic activity in women with endometriosis receiving GnRH-agonist treatment. METHODS: Twenty-six women with advanced endometriosis from the National Cheng Kung University Medical College were studied. Each received a total of six doses of GnRH agonist at 4-week intervals. Immunologic responses at various times after receiving GnRH-agonist treatment, including numbers of peripheral blood lymphocytes subsets and the lymphocyte proliferative activity, were analyzed using a repeated measures analysis of variance. Twenty-six healthy women who visited our gynecologic clinics for routine Papanicolaou smear examination at the time of the recruitment were enrolled as controls. The responses for each patient receiving GnRH agonist were normalized with respect to those of her matched control at each of the time points. The differences between post- and pretreatment data were estimated using generalized estimating equations. RESULTS: There was no significant difference in the sizes of lymphocyte subsets between patients and controls before treatment. After GnRH-agonist treatment, there was a trend in the rise of natural killer cell numbers early in the treatment period, with P values of .05 and .07 at 1-2 weeks and 2-3 weeks, respectively. This rise in natural killer cell numbers was not significant until 3-4 weeks and the second month after the treatment. There were no significant changes in the CD4+ and CD8+ T-cell subsets and B cells, although a slight increase in total T cells (ie, CD3+ T) was observed 1-2 weeks after receiving GnRH agonist. The T-cell mitogenic activities at the end of 2 and 4 months after GnRH-agonist treatment were 1.5 and 1.8 times, respectively, of those before treatment. CONCLUSION: The increase in natural killer cell numbers and the upregulation of T-lymphocyte mitogenic activity, which might be caused by a direct effect of GnRH agonist or a consequence resulting from the depression of estradiol by GnRH agonist, may have implications in the clinical treatment of endometriosis.     

Effects of a chronic lithium treatment on cortical serotonin uptake sites and 5-HT1A receptors

Using confocal scanning laser microscopy of viable tissue sections, we have demonstrated organized lymphoid aggregates (LA), that have a unique structure, in the stratum basalis of uterine endometrium. These LA consist of a core of B cells surrounded by more numerous T cells and an outer halo of monocytes/ macrophages. The T cells in the LA were almost exclusively CD8+CD4-. These CD8+ LA, in terms of both their T cell and B cell components, were either small or absent during the early proliferative stage of the menstrual cycle, significantly larger in size at mid-cycle and during the secretory phase, and absent in post-menopausal women, suggesting that their development is hormonally influenced. This new finding of a menstrual cycle-dependent, phenotypically unique, organized immune cell structure may lead to new insights into the mechanisms by which the endometrium accepts a semiallogeneic graft while providing resistance to infectious organisms.     

Lymphocyte subsets and mitogen stimulation of blood lymphocytes in normal pregnancy

PROBLEM: In normal pregnancy the maternal immune system should be directed towards tolerance or suppression in order not to reject the partly foreign feto-placental unit. The aim of this investigation was to find hallmarks of systemic immunosuppression during normal pregnancy. METHODS: Five healthy primigravidae were examined during pregnancy and postpartum with flow cytometric analysis to define T and B lymphocyte subsets in peripheral blood. In addition, we studied the proliferative response of lymphocytes to mitogens or interleukin-2 (IL-2) alone or in combination with immunomodulating drugs or interleukin-4 (IL-4). The results were compared to healthy, non-pregnant women. RESULTS: During pregnancy and early puerperium we noted an immune balance in favour of suppression, as measured by increased numbers of T "helper/suppressor" (CD4+CD45RA+) and "suppressor"/effector T cells (CD8+S6F1-), and decreased numbers of T "helper/inducer" (CD4+CD29+), T "helper/memory" (CD4+CD45RO+), killer/effector T cells (CD8+S6F1+), and Natural Killer cells (CD56+), as well as decreased numbers of activated lymphocytes expressing IL-2 receptor (CD25+) and T cells expressing HLA-DR (HLA-DR+CD3+). During pregnancy, lymphocyte proliferation was impaired in autologous serum with concanavalin A (ConA), phytohemagglutinin (PHA), or IL-2. A difference in proliferative response to PHA or IL-2 between cultures with AB serum and autologous serum is suggestive of an immunosuppressor factor in serum during pregnancy. Indomethacin significantly increased lymphocyte proliferation in autologous serum with ConA, indicating PGE2 mediated suppressor activity during pregnancy. Chlorambucil and cimetidine modulated the proliferative response to ConA, indicating an alkylating agent sensitive and a histamine dependent suppressor activity during pregnancy. CONCLUSIONS: During normal pregnancy, a state of systemic suppression of the maternal immune system seems to be present.     

B-cell activation in vitro by helper T cells specific to a protein region that is recognized both by T cells and by antibodies

The effects of Trypanosoma evansi on efferent lymphocyte phenotypes draining from a lymph node primed with Pasteurella haemolytica vaccine were studied in sheep. The prefemoral efferent lymphatic ducts of the infected sheep along with those of two uninfected sheep were surgically cannulated. Lymph was collected and lymphocytes recovered from it analysed by two-colour indirect immunofluorescence staining and cytofluoremetry in a fluorescence activated cell analyser (FACSCAN). The study showed the appearance and persistence of T. evansi in the efferent lymph for a long period of time and the appearance of CD4+CD8+ (double positive, DP) T lymphocytes in the efferent lymph of infected animals. The infection also resulted in increases in CD5+ B cells in the prefemoral efferent lymph. In addition, there were decreases in the output of conventional B cells, CD5+ and CD4+ T cell subsets but large increases in CD8+ cells followed by terminal depletion of all cell subsets. In contrast, inoculation of sheep with pasteurella vaccine antigen alone produced little alterations in the proportions, but large increases in the numbers of all T cell subsets except that of CD8+ cells which also showed little variation; and there was a concurrent increase in the numbers and proportions of efferent B cells. In addition, the abnormal expression of DP and CD5+ B cells did not occur in the uninfected vaccinated sheep. It is concluded that these abnormal changes in the kinetics of efferent lymphocyte phenotypes are likely to play a role in the genesis of the generalized immunosuppression seen in trypanosome-infected hosts.     

Altered lymphocyte antigen expressions in HIV infection: a study by quantitative flow cytometry

To identify surface antigen changes that may contribute to the immune deficiency in infection with the human immunodeficiency virus (HIV), we quantified, by double-staining flow cytometry, the number of antigens of the main peripheral blood lymphocyte subsets from 30 HIV-positive persons and compared them with those of 19 HIV-negative healthy donors. Standard microbeads with different capacities to bind mouse immunoglobulins were used to convert the mean fluorescence intensity values into numbers of antigen molecules per cell, measured as antibody binding capacity. The level of expression of different lymphocyte antigens in HIV-infected patients differs from that seen in normal blood lymphocytes. Some of these surface markers are decreased, whereas others are increased, and their expression is modulated depending on the specific cell subset considered. The expression of CD3, CD4, and CD8 on T lymphocytes is significantly decreased; moreover, CD3 is down-regulated on activated and nonactivated T lymphocytes and on CD4 and CD8 cells. In contrast, the expression of CD2 on T cells is significantly increased. Natural killer cells exhibit down-regulation of CD7, normal levels of CD8 and CD56, and overexpression of CD2. Our results also identified, for most of these antigens, quantitative differences in membrane expression according to different disease stages, as assessed by the CD4 T-cell count. Quantitative flow cytometry therefore may provide useful insights into the lymphocyte functional defects characterizing HIV infection.     

Role of T lymphocyte subsets in immunity to spotted fever group Rickettsiae

To evaluate the roles of CD4 and CD8 T lymphocytes in immunity to disseminated endothelial infection with Rickettsia conorii (Malish 7 strain), these T cell subsets were depleted or adoptively transferred into subsequently infected C3H/HeN mice. CD4 T lymphocyte-depleted and sham-depleted mice underwent a similar course of illness with a sublethal rickettsial dose, cleared the infection by day 10, and recovered on days 10 to 11. In contrast, mice depleted of CD8 lymphocytes or CD4 and CD8 lymphocytes died or remained persistently infected through day 15 with the ordinarily sublethal dose. Endothelium was the major site of rickettsial persistence, including sites in the vital organs, brain, and lungs of CD8 lymphocyte-depleted mice. In nondepleted animals, CD8 T lymphocytes were observed in apposition to endothelial cells on day 10 at the time of rickettsial clearance. Adoptive transfer of immune CD4 or CD8 T lymphocytes protected mice against a lethal dose of R. conorii in the disseminated endothelial target model. Nonimmune CD4 or CD8 lymphocytes and immune lymphocytes that had passed through columns that depleted both CD4 and CD8 lymphocytes failed to protect mice against R. conorii. These studies represent the first analysis of the role of T lymphocyte subsets in immunity to spotted fever group rickettsiae and the first demonstration that clearance of spotted fever group rickettsiae from endothelial cells requires immune CD8 T lymphocytes.     

Age-related changes in blood lymphocyte subsets of Saudi Arabian healthy children

The age-related changes in absolute and percentage values of lymphocyte subsets in the peripheral blood of healthy children of different ages (1 month to 13 years) were studied by flow cytometry. The absolute and percentage values for most lymphocyte subpopulations differed substantially with age. Comparisons among age groups from infants through adults revealed progressive declines in the absolute numbers of leukocytes, total lymphocytes, and T, B, and natural killer (NK) cells. The percentages of T cells increased with age. Within the T-lymphocyte population, the CD8(+) subset increased but the CD4(+) subset decreased, resulting in a declining CD4(+)/CD8(+) ratio. The percentage of B cells declined, but that of NK cells remained unchanged. The percentage of HLA-DR+ T cells increased over time, but their number changed inconsistently. Our findings confirm and extend earlier reports on age-related changes in lymphocyte subpopulations. These data should be useful in the interpretation of disease-related changes, as well as therapy-dependent alterations, in lymphocyte subsets in children of different age groups.     

The use of biochemical markers in the diagnosis of pelvic endometriosis

The aim of this study was to evaluate CA 125 II, C-reactive protein (CRP) and serum amyloid A (SAA) and anticardiolipin antibody (aCL) concentrations for the diagnosis of pelvic endometriosis. The study population consisted of 15 women without endometriosis, as confirmed by laparoscopy (group A), and 35 patients with pelvic endometriosis diagnosed by laparoscopy or laparotomy (group B). Group B patients were divided into those at stages I and II of the disease (BI/II) and those at stages III and IV (BIII/IV). Blood samples were obtained twice during the menstrual cycle: on day 1, 2 or 3 of the cycle and on day 8, 9 or 10 of the cycle. CA 125 II and CRP concentrations were higher in group III/IV patients compared with healthy controls, mainly during the first 3 days of the menstrual cycle; SAA concentrations were also higher in this group of patients compared with healthy controls, but only during the first 3 days of the menstrual cycle. Immunoglobulin (Ig) M aCL concentrations were higher in all patients with endometriosis compared with healthy controls, mainly during the first 3 days of the menstrual cycle. It is concluded that these determinations may contribute to the diagnosis and the indication of treatment for pelvic endometriosis. Determination of CA 125 II concentrations at the beginning of the menstrual cycle may aid the diagnosis of stage III and IV endometriosis. IgM aCL appears to be associated with the presence of all stages of the disease, while SAA values are elevated in severe situations. Measurement of these molecules may therefore provide a valuable tool in the diagnosis and management of endometriosis.     

Expression of the CD8alpha beta-heterodimer on CD8(+) T lymphocytes in peripheral blood lymphocytes of human immunodeficiency virus- and human immunodeficiency virus+ individuals

CD8(+) T lymphocytes play a pivotal role in controlling human immunodeficiency virus (HIV)-1 replication in vivo. We have performed four-color flow cytometric analysis of CD8(+) peripheral blood lymphocytes (PBL) from 21 HIV-1 seronegative and 103 seropositive individuals to explore the phenotypic heterogeneity of CD8beta-chain expression on CD8(+) T lymphocytes and to clarify how its expression on CD8(+) T lymphocytes may relate to acquired immunodeficiency syndrome (AIDS) clinical progression. We showed that the single monoclonal antibody (MoAb) 2ST8-5H7, directed against the CD8alpha beta-heterodimer, identifies CD8(+) T lymphocytes as effectively as the conventional combination of anti-CD3 and anti-CD8alpha antibodies. However, we detected a significantly lower mean fluorescence (MF) of anti-CD8alpha beta staining on PBL from HIV-1 seropositive donors as compared with seronegative donors. In fact, CD8(+) T lymphocytes from HIV-1-infected individuals with the lowest CD4 counts showed the lowest levels of CD8alpha beta MF. To explore further this change in CD8alpha beta expression, we assessed the expression of 14 different cell surface molecules on CD8alpha beta+ T lymphocytes of PBL from 11 HIV-1 seronegative and 22 HIV-1 seropositive individuals. The MF of anti-CD8alpha beta staining was significantly reduced on CD8(+) T lymphocyte subsets that showed immunophenotypic evidence of activation. The subset of lymphocytes expressing low levels of CD8alpha beta expressed higher levels of activation, adhesion, and cytotoxic-associated molecules and was predominantly CD45RO+ and CD28(-). Finally, we monitored the expression of the CD8alpha beta-heterodimer on PBL of eight HIV-1-infected individuals over a 16-week period after the initiation of highly active antiretroviral therapy (HAART), including zidovudine (ZDV), lamivudine (3TC), and indinavir (IDV), and found a significant increase in the expression of the CD8alpha beta-heterodimer. These results suggest that antibodies recognizing the CD8alpha beta-heterodimer are useful tools to specifically identify CD8(+) T lymphocytes. Moreover, the quantitative monitoring of CD8alpha beta expression allows the detection of discrete CD8(+) T lymphocyte subsets and may be useful for assessing the immune status of individuals infected with HIV-1.     

Peritoneal interleukin-10 increases with decrease in activated CD4+ T lymphocytes in women with endometriosis

This study was performed to determine whether peritoneal T cells are suppressed in the CD4+ or CD8+ T cell subpopulation and whether they are Th1 or Th2 predominant in women with endometriosis. Immune cells in the peritoneal fluid (PF) were obtained from women undergoing laparoscopy for endometriosis or tubal ligation. Three-colour flow cytometry was utilized for immunophenotyping of peritoneal fluid mononuclear cells (PFMC). Concentrations of interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma) produced by PFMC with and without mitogen stimulation and concentrations of IL-10 and IL-12 were measured in PF. The peritoneal T lymphocytes were predominantly of the Th1 type that produced much more IFN-gamma but less IL-4 or IL-5 in women with or without endometriosis. The decrease in peritoneal lymphocytes was significant in the HLA-DR+ CD4+ CD3+ subpopulation and the concentrations of peritoneal IL-10 and IL-12 were significantly elevated in women with early stage endometriosis. There was impaired IL-5 production by PFMC after phytohaemagglutinin stimulation in women with advanced stage endometriosis. We concluded that the activated peritoneal CD4+ Th1 cells from the women with endometriosis were decreased in number. The suppression of these T cells may be due to the elevation of IL-10 and IL-12 in the peritoneal fluid.     

Differential activity of P-glycoprotein in normal blood lymphocyte subsets

To better understand the phenomenon of P-glycoprotein (P-170) expression we investigated lymphocyte subpopulations for P-170 function in healthy volunteers. Studies were based on three-colour flow cytometry including the fluorescent probe rhodamine 123 (Rh123), which is transported by P-170. Marked Rh123 efflux was detected in CD8+ T lymphocytes with CD8+/CD45RA+ T cells (naive cells) showing significantly higher P-170 activity as compared with CD8+/CD45RA- cells (P<0.04). Vice versa, CD8+/CD45RO+ T cells (memory cells) demonstrated less P-170 activity than CD8+/CD45RO- cells (P<0.04). P-170 function was less prominent in CD4+ T cells, however, Rh123 efflux was higher in the CD4+/CD45RA+ and CD4+/CD45RO- subpopulations (P<0.025) corresponding to the CD8+ results. Dye efflux differed significantly between activated and non-activated CD8+ and CD4+ as well as CD8+/CD11b+ and CD8+/CD11b- T lymphocytes. Since CD16+ natural killer cells (NK) expressed the highest level of P-170, the NK cytotoxicity against 51Cr-labelled K562 target cells was assayed in the presence or absence of P-170 inhibitors. NK related cytotoxicity was significantly reduced in the presence of R-verapamil and dexnigaldipine-HCP in a dose-dependent manner. The differential expression of P-170 activity in naive and memory T cells together with the reduced NK related cytotoxicity in the presence of MDR-modulators suggest a physiological role of P-170 in immunological functions of these lymphocyte subsets. Consequently, the addition of MDR modulators to conventional chemotherapy as a strategy to overcome drug resistance should consider possible adverse immunosuppressive effects.     

Nitric oxide and low-density lipoprotein oxidation

Immune status was determined in a representative sample of elderly people by measuring lymphocyte subsets in whole-blood samples as part of an epidemiological study of the population aged 65 and over. Venepuncture was undertaken in more than 500 individuals who took part in an extensive interview that focused on the lifestyle and psychosocial determinants of healthy aging. The results show that median levels of all lymphocyte subsets tend to decline as the age of the sample increases. In the total sample there were significant age effects (p < 0.05) on total lymphocytes, CD3, CD4, and CD19 (B cells); age differences did not reach significance for CD8 and CD57. There were also significant sex differences (p < 0.05) on CD3, CD4, and CD19, and in all cases women had higher values than men. When we selected a particularly healthy subsample who did not report any illness and took no medication, the findings were unchanged. We conclude that the peripheral expression of lymphocytes appears little affected by aging-related illnesses in the general population, but is affected by aging itself. The study provides reference values for the lymphocyte measures, which can be regarded as having greater validity than the values usually cited.     

Healthy women and patients with endometriosis show high concentrations of inhibin A, inhibin B, and activin A in peritoneal fluid throughout the menstrual cycle

Inhibin A, inhibin B, and activin A are growth factors which play local autocrine/paracrine roles in reproductive tissues. Since peritoneal fluid hormone content may reflect in part ovarian and endometrial secretory activities, the present study aimed to evaluate: (i) whether inhibin alpha-, activin betaA- and betaB-subunits, and activin receptor type II and type IIB mRNA are expressed in peritoneal tissues; (ii) expression and secretion of inhibin A and B, and activin A in cultured endometriotic cells; and (iii) concentrations of inhibin A and B, and activin A in serum and in peritoneal fluid in healthy women and in patients with endometriosis throughout the menstrual cycle. A group of women (n = 72) was recruited at laparoscopy for infertility investigation and divided into two groups: (i) control healthy women (n = 35), (ii) women with endometriosis (n = 37). Both groups were subdivided according to the follicular and luteal phase of the menstrual cycle. At the time of laparoscopy, specimens of peritoneal tissues were collected from three healthy women, while endometriotic tissue samples were collected and cultured from three women with endometriosis. Peritoneal tissues and cultured endometriotic cells expressed inhibin alpha-, activin betaA-, and betaB-subunits, and activin receptors mRNAs; in addition, inhibin-related proteins were measurable in culture medium. In healthy women, inhibin A and B, and activin A concentrations in peritoneal fluid were significantly higher than in serum (P < 0.001), at both phases of the menstrual cycle. Peritoneal inhibin A and B, and activin A concentrations were not significantly different between healthy women and patients with endometriosis, either when evaluated according to the degree of the disease and/or to the phase of the menstrual cycle. In conclusion, the findings that high concentrations are present in peritoneal fluid and that menstrual cycle-related changes occur suggest that reproductive organs may contribute to inhibin-related proteins in peritoneal fluid.     

Extensively calcified synovial sarcoma

OBJECTIVE: To determine the changes of T lymphocyte subsets, natural killer (NK) cell and serum interleukin-2 receptor (SIL-2R) in peripheral blood of the pregnant women with systemic lupus erythematosus (SLE). METHODS: T lymphocyte subsets NK cell, and SIL-2R in peripheral blood were detected by flow cytometry (FCM) and enzyme-labeled immunosorbent assay (ELISA) in 14 cases of pregnant women complicated by SLE (SLE+NP), 18 cases of stationary phase SLE (SLE), 20 cases of normal non-pregnant women (NNP) and 20 cases of normal pregnant women (NP). RESULTS: The percentages of CD4+ cell were decreased significantly in SLE+NP group as compared with the other three groups (P < 0.01); and the ratio of CD4+/CD8+ was decreased significantly in SLE+NP group, as compared that in SLE group and in NNP group (P < 0.01). There were no difference in the number of NK cells among the four groups. The SIL-2R values were found to be increased significantly in the SLE+NP group, as compared with that of other three groups (P < 0.01). CONCLUSION: The observation on the changes of peripheral T lymphocyte subsets and SIL-2R may be helpful for monitoring progress of SLE during pregnancy.     

Ovarian steroid regulation of vascular endothelial growth factor in the human endometrium: implications for angiogenesis during the menstrual cycle and in the pathogenesis of endometriosis

The human endometrium undergoes a complex process of vascular and glandular proliferation, differentiation, and regeneration with each menstrual cycle in preparation for implantation. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific angiogenic protein that appears to play an important role in both physiological and pathological neovascularization. To investigate whether VEGF may regulate human endometrial angiogenesis, we examined VEGF messenger ribonucleic acid (mRNA) and protein throughout the menstrual cycle and studied the regulation of VEGF by reproductive steroids in isolated human endometrial cells. By ribonuclease protection analysis, VEGF mRNA increased relative to early proliferative phase expression by 1.6-,2.0-, and 3.6-fold in midproliferative, late proliferative, and secretory endometrium, respectively. In histological sections, VEGF mRNA and protein were localized focally in glandular epithelial cells and more diffusely in surrounding stroma, with greatest VEGF expression in secretory endometrium. Consistent with these in vivo results, the treatment of isolated human endometrial cells with estradiol (E2), medroxyprogesterone acetate (MPA), or E2 plus MPA significantly increased VEGF mRNA expression over the control value by 3.1-, 2.8-, and 4.7-fold, respectively. The VEGF response to E2 was rapid, with steady state levels of VEGF mRNA reaching 85% maximum 1 h after the addition of steroid. E2 also caused a 46% increase in secreted VEGF protein, and the combination of E2 and MPA caused an 18% increase. VEGF expression in endometriosis, an angiogenesis-dependent, estrogen-sensitive disease was similar to that seen in eutopic endometrium. Peritoneal fluid concentrations of VEGF were significantly higher in women with moderate to severe endometriosis than in women with minimal to mild endometriosis or no disease. VEGF, therefore, may be important in both physiological and pathological angiogenesis of human endometrium, as it is an estrogen-responsive angiogenic factor that varies throughout the menstrual cycle and is elevated in women with endometriosis.     

Dispensability of p53 degradation for tumorigenicity and decreased serum requirement of human papillomavirus type 16 E6

Tonsils and adenoids are secondary lymphoid organs exposed to the environment. The most important classifications of AIDS include the lymphocyte subsets of peripheral blood. We have studied the lymphocyte subsets in peripheral blood and secondary lymphoid organs in a control group of children suffering adenotonsillar pathology and in five children with AIDS and the same adenotonsillar pathology. The antigen surface markers were determined by flow cytometry in lymphocytes isolated from peripheral blood, and from tonsils and adenoids after tonsillectomy and adenoidectomy, in the control group and in children diagnosed with AIDS. The most important findings in tonsils and adenoids were a decrease of the total T lymphocytes, helper T lymphocytes and CD4/CD8 ratio; an increase of cytotoxic T lymphocytes and B lymphocytes, as well as a 200% increase in monocytes of AIDS-affected children. These observations show the value of analyzing the lymphocyte subsets of the tonsils and adenoids of AIDS-affected children, and establishing an earlier relation to clinical symptoms.     

Immunophenotypic analysis of peripheral blood mononuclear cells undergoing in vitro apoptosis after isolation from human immunodeficiency virus-infected children

Lymphocytes of human immunodeficiency virus (HIV)-infected individuals undergo accelerated apoptosis in vitro, but the subsets of cells affected have not been clearly defined. This study examined the relationship between lymphocyte phenotype and apoptotic cell death in HIV-infected children by flow cytometry. Direct examination of the phenotype of apoptotic lymphocytes was accomplished using a combination of surface antigen labeling performed simultaneously with the Tdt mediated Utp nick end-labeling (TUNEL) assay. In comparison to live cells, apoptotic lymphocytes displayed an overrepresentation of CD45RO and HLA-DR expressing cells, while CD28 and CD95 expressing cells were underrepresented. Lymphocytes expressing CD4, CD8, and CD38 were equally represented in apoptotic and live populations. When percent lymphocyte apoptosis follow- ing culture was examined independently with lymphocyte subsets in fresh blood, apoptosis was negatively correlated with the percentage of CD4 cells, but not with specific CD4 T-cell subsets. Although not correlated with the percentage of total CD8 cells, apoptosis was positively correlated with specific CD8 T-cell subsets expressing CD45RO and CD95 and negatively correlated for CD8 T cells expressing CD45RA. These results provide direct evidence that a population of activated lymphocytes with the memory phenotype lacking the costimulatory molecule CD28 are especially prone to undergo apoptosis. The findings related to CD95 expression in fresh and apoptotic cells implicate Fas-dependent and Fas-independent pathways of apoptosis in HIV disease in children.     

The role of gammadelta T lymphocytes in lipopolysaccharide-induced eosinophil accumulation into the mouse pleural cavity

LPS induces an accumulation of eosinophils in the pleural cavity that requires resident macrophages and lymphocytes, but is independent of IL-5 production. In the present study we investigated the involvement of different T lymphocyte subsets on the modulation of LPS-induced eosinophil accumulation into the pleural cavity of mice. Within 4 h after LPS injection the number of neutrophils in the pleural cavity increased significantly. Mononuclear cell counts increased after 12 h, while a significant rise on eosinophil counts was observed only after 24 h. T lymphocytes counts were increased in the pleural cavity 24 and 48 h after LPS administration. This T lymphocyte accumulation was accounted for by an influx of the gammadelta+ subset, while CD4+ and CD8+ subsets did not accumulate in the pleural cavity after LPS stimulation. All those changes had resolved 96 h after LPS injection. Depletion of T lymphocytes by treatment with mAb anti-Thy 1.0 inhibited the eosinophil accumulation triggered by LPS. Aiming to clarify which T lymphocyte subset would be involved in the LPS-induced eosinophil accumulation, we depleted mice of various T lymphocyte subpopulations using specific Abs. Depletion of either CD4+ or CD8+ subsets failed to inhibit LPS-induced eosinophil migration. In contrast, when mice were treated with anti-gammadelta+ T lymphocyte mAb, a significant reduction of LPS-induced eosinophil accumulation was observed. Similarly, the administration of LPS in BALB/c-nu/nu mice induced the expected significant influx of eosinophils into the pleural cavity. Our results indicate that the gammadelta+ T lymphocytes are centrally involved in LPS-induced eosinophil accumulation in mice.     

Lymphocyte subpopulations of workers in a plant producing plastic materials (preliminary study)

Lymphocyte subpopulations were studied in 31 men working in a plant producing plastic materials in relation with control groups of similar age and smoking habit. 8 workers (group A) were exposed to solvents (mainly methylethylketone and dimethylformamide), 8 men (group B) to dust containing particles of calcium carbonate, polyvinylchloride, phtalates, unsaturated oils, paraffin wax, iron oxides, titanium bioxides, barium, zinc and lead and 15 men (group C), working in the same department as group B, were studied after a period of 16 months during which lead chromate was employed in the preparation of colors. The lymphocyte subpopulations were normal in group A, while in B there was a significant increase of HLA-DR + cells (monocytes, B and activated T lymphocytes). In group C, T helper/inducer lymphocytes (mainly CD4(+)-CD45RO- "virgin" lymphocytes), CD19+ B lymphocytes, CD3-HLADR+ and CD3-CD25+ (activated B lymphocytes and monocytes) were significantly reduced without changes of serum IgM, IgG and IgA. Highly significant correlation was found between B lymphocytes (reduced in the workers about 40%) and CD4(+)-CD45R0+ "memory" lymphocytes (reduced about 20%). Moreover, blood lead (correlated with urinary chromium) showed a highly significant negative correlation with the B lymphocytes. This study demonstrates that combined exposure to toxic agents produces specific modifications in the lymphocyte subsets without changes in immunoglobulins and confirms the results of previous researches showing that the exposure to lead or chromate induces reduction of lymphocytes in the peripheral blood.     

Lymphocyte subpopulations in healthy 1-3-day-old infants

The primary objective of this study was to establish reference ranges for the major (B, T, and natural killer; NK) and clinically relevant minor lymphocyte subsets in the peripheral blood of healthy 1-3-day-old infants and then to compare the results with those obtained in a group of healthy adults analyzed simultaneously. Forty-three infants aged 1-3 days and 38 healthy adults were recruited to the study to establish the median, 10th, and 90th percentiles of the proportions and absolute numbers of relevant lymphocyte subsets. The samples obtained from the healthy adults served as a flow cytometry process control in addition to providing a group comparator. The peripheral blood of the newborns (vs. adults) contained elevated proportions of total T cells (83% vs. 77%) and T helper cells (63% vs. 46%), with decreased proportions of T suppressor/cytotoxic cells (23% vs. 28%) and NK cells (4% vs. 10.5%). The newborns had a higher proportion (P < 0.0001) of immature B lymphocytes compared with those of adults (CD10+CD19+, 1.5% vs. 0% and CD20+CD5+, 13% vs. 6%), and the proportion of activated T cells was significantly lower (P < 0.0001; CD3+CD25+, 7.0% vs. 15%;CD3+HLA-DR+, 2.0% vs. 6% and CD8 and CD57, 0.0% vs. 8.0%). In contrast, the proportions of neonatal CD8 cells expressing CD28 (90.2% vs. 67.7%) and CD38 (96.6% vs. 70.9%) were significantly higher (P < 0.0001). The reference ranges for 1-3-day-old healthy newborns generated in this study provides a valuable tool for the assessment of immune abnormalities in very young infants.