Behavior of circulating CD4+CD25+Foxp3+ regulatory T cells in colon cancer patients undergoing surgery.

CD4+CD25+Foxp3+ regulatory T cells (Treg) specialize in suppressing immune responses. In this study, 47 consecutive colon cancer patients were subjected to circulating Treg frequency assessment by flow cytometry before and after cancer resection. Thirty-two healthy subjects served as controls. Circulating Treg frequencies were significantly higher in colon cancer patients with respect to healthy controls. When patients were subgrouped according to Dukes stages, a linear relationship was observed between Dukes stages and Treg frequencies. In radically resected patients, Treg frequencies were shown to have significantly dropped down. Patients with advanced colon cancer were more likely to have significantly higher proportions of circulating Treg frequencies than Dukes A and B patients when compared to healthy subjects. Of note, nonradically resected patients were found to display reductions in-but not normalization of-Treg frequencies. These results suggest that cancer itself may be able to drive Treg recruitment as a strategy of immunoevasion.

Posttranscriptional regulation of IL-13 in T cells: role of the RNA-binding protein HuR.

BACKGROUND: IL-13, a critical cytokine in allergy, is regulated by as-yet-elusive mechanisms. OBJECTIVE: We investigated IL-13 posttranscriptional regulation by HuR, a protein associating with adenylate-uridylate-rich elements in the 3' untranslated regions (UTRs) of mRNA, promoting mRNA stability and translation. METHODS: IL-13 mRNA decay was monitored in human T(H)2-skewed cells by using the transcriptional inhibitor actinomycin D. The IL-13 3'UTR was subcloned into an inducible beta-globin reporter transiently expressed in H2 cells in the absence or presence of overexpressed HuR. Association of HuR with IL-13 mRNA was detected by means of immunoprecipitation of ribonucleoprotein complexes and a biotin pull-down assay. The effects of HuR transient overexpression and silencing on IL-13 expression were investigated. RESULTS: IL-13 mRNA half-life increased significantly in restimulated T(H)2-skewed cells compared with baseline values. Decay of beta-globin mRNA was significantly faster in H2 cells transfected with the IL-13 3'UTR-containing plasmid than in those carrying a control vector. HuR overexpression increased the beta-globin IL-13 3'UTR reporter half-life. Significant enrichment of IL-13 mRNA was produced by means of immunoprecipitation of Jurkat cell ribonucleoprotein complexes with anti-HuR. HuR binding to the IL-13 3'UTR was confirmed by means of pull-down assay of biotin-labeled RNA probes spanning the IL-13 3'UTR. Two-dimensional Western blot analysis showed stimulus-induced posttranslational modification of HuR. In Jurkat cells mitogen-induced IL-13 mRNA was significantly affected by HuR overexpression and silencing. CONCLUSIONS: Mitogen-induced IL-13 expression involves changes in transcript turnover and a change in phosphorylation of HuR and its association with the mRNA 3'UTR.

A scleroderma-like cutaneous syndrome associated with a marked Th2-type immune response occurring after a prosthetic joint implant.

A scleroderma-like cutaneous syndrome, occurring after implantation of a prosthetic knee joint in an elderly woman, is reported. This case did not seem to typically fit into any of the known scleroderma-like disorders of the skin described to date. The patient was shown to be sensitized to metals contained in the prosthesis and to mount a Th2-type immune response concomitantly with development of skin fibrosis. In particular, eosinophilia, markedly elevated serum IgE levels, in vitro spontaneous production of interleukin (IL)-4 by T lymphocytes, and elevated serum levels of Th2 cytokines (namely, IL-4, IL-5, and IL-13) were observed during the acute phase of illness. Since eosinophils and such Th2 cytokines as IL-13 also have recognized fibrogenic properties, it is speculated that the pathogenesis of skin fibrosis in this case could have been the direct and/or indirect consequence of the coexisting Th2-type immune response.

Induction of CD95 upregulation does not render chronic lymphocytic leukemia B-cells susceptible to CD95-mediated apoptosis.

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by a progressive accumulation of long-lived and well-differentiated clonal B-lymphocytes in peripheral blood, lymphoid tissue and bone marrow. Although B-CLL pathogenesis is not entirely understood, the progressive increase in lymphocyte counts coupled with the very low proportion of proliferating cells suggests that B-CLL may be primarily determined by defective apoptosis. Consistently, freshly analyzed CLL B-cells express very low levels of membrane CD95, one of the best-known receptors involved in triggering apoptosis. In this study, CD95 upregulation on CLL B-cells was induced by culturing clonal B-cells in the presence of supernatants from preactivated autologous T-lymphocytes. Intracellular cytokine staining of preactivated autologous T-lymphocytes using monoclonal antibodies (moAbs) specific for Th1 or Th2 cytokines, namely interleukin (IL)-2, IL-4, IL-5, IL-10 and interferon (IFN)-gamma, showed these cells to be positive for IL-2 and IFN-gamma. Blocking experiments using moAbs specific for IL-2 and/or IFN-gamma revealed that CD95 upregulation on CLL B-cells was mainly driven by IFN-gamma. However, CD95-expressing CLL B-cells were demonstrated to be resistant to CD95-mediated apoptosis, thus arguing against strategies aimed at exploiting CD95-mediated apoptosis for immunotherapy of B-CLL.

Effects of stress hyperglycemia on acute myocardial infarction: role of inflammatory immune process in functional cardiac outcome.

OBJECTIVE: Stress hyperglycemia has been associated with increased mortality in patients with myocardial infarction (MI). We examined the association between plasma glucose levels, circulating inflammatory markers, T-cell activation, and functional cardiac outcome in patients with first MI. RESEARCH DESIGN AND METHODS: Echocardiographic parameters, circulating levels of interleukin-18 (IL-18), C-reactive protein (CPR), and the percent of CD16-CD56, CD4/CD8, CD152, and HLA-DR expression were investigated in 108 patients with acute MI on admission to the emergency ward. RESULTS: Our review found that 31 new hyperglycemic patients (glycemia >or=7 mmol/l) had higher infarct segment length (P < 0.05) and myocardial performance index (P < 0.02) and reduced transmitral Doppler flow (P < 0.05), pulmonary flow analysis (P < 0.02), and ejection fraction (P < 0.05) compared with 36 hyperglycemic diabetic patients and 41 normoglycemic patients. Plasma IL-18 and CRP were higher in the hyperglycemic than in the normoglycemic patients (P < 0.005), with the highest values in patients with new hyperglycemia (P < 0.05). Hyperglycemic patients had a higher percent of CD16+/CD56+ cells and CD4/CD8 ratio (P < 0.01), whereas they had lower CD152 expression (which has a negative regulatory function in T-cell activation) compared with normoglycemic patients (P < 0.001). CONCLUSIONS: During MI, hyperglycemia is associated with increased levels of inflammatory markers, enhanced expression of cytotoxic T-cells, and reduced expression of T-cells, which are implicated in limiting the immune process. An increased inflammatory immune process seems a likely mechanism linking acute hyperglycemia to poor cardiac outcome in MI patients.

Clinical and phenotypic features of CD5-negative B cell chronic lymphoproliferative disease resembling chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) B cells are phenotypically identified by surface expression of CD5 and CD23 antigens. Infrequently, patients with a monoclonal B cell lymphocytosis clinically resembling classic B-CLL have been found to harbor leukemic B cells lacking expression of the CD5 antigen. Little information is available concerning such CLL-like lymphoproliferative syndromes. Here, we provide phenotypic and clinical characteristics of 13 patients with CD5-negative chronic lymphoproliferative disorders selected from among 400 B-CLL patients followed up at a single academic center. Phenotypic analysis was carried out by flow cytometry using a broad panel of monoclonal antibodies including activation, costimulatory, adhesion, and growth factor receptor molecules. Moreover, intracellular staining and stimulation experiments were performed to investigate whether CD5 antigen was either retained in the cytoplasm of clonal B cells or not expressed due to defective cellular activation, respectively. Overall, CD5-negative leukemic cells were found to express significantly different levels of several membrane molecules, including CD95, CD69, CD23, CD25, CD80, and CD20, compared to "classic" CLL B cells. CD5 antigen was not detected in the cytoplasm of CD5-negative clonal B cells, nor could it be induced following in vitro activation. CD3+ T cell proportions were found to be less affected in CD5-negative patients than in classic B-CLL. Although these data suggest that CD5-negative clonal B cells are phenotypically different from classic B-CLL, clinical outcomes were similar to those shown by B-CLL patients, with most of the patients experiencing a long-lasting disease requiring chemotherapeutic intervention at some time during the disease course.

Omalizumab for difficult-to-treat dermatological conditions: clinical and immunological features from a retrospective real-life experience.

BACKGROUND: Omalizumab, a therapeutic monoclonal antibody specific for human IgE, has thus far been used as add-on therapy for moderate-to-severe allergic asthma in adults and children. OBJECTIVE: The objective of this study was to test omalizumab efficacy in other conditions in which the IgE-mast cell axis is supposed to play a role. METHODS: Nine patients with dermatological manifestations possibly related to activation of the IgE-mast cell axis (six chronic spontaneous urticaria and three atopic dermatitis patients) were administered off-label omalizumab because of refractoriness to standard therapy. All patients were subjected to strict clinical, laboratoristic, and imaging follow-up to monitor for possible adverse effects. In addition, to further assess the role of omalizumab on T cells, mast cells, and eosinophils, T-cell immune polarisation as well as eosinophil cationic protein and tryptase serum levels were determined before and during omalizumab administration. RESULTS: Therapy was effective in seven out of nine patients (six complete responses, one partial response, and two no responses). Interestingly, omalizumab appeared to induce lymphocyte polarisation toward a type 2 immune response and to be able to quench eosinophil-mediated inflammation, particularly in atopic dermatitis patients. Tryptase serum levels were generally low and remained unchanged during omalizumab treatment. Despite treatment spanning over several years in most of the patients, no adverse effects nor new ensuing medical conditions have thus far been observed (median follow-up: 42 months). CONCLUSIONS: Off-label omalizumab was safe and effective in our patients. The novel immunologic features recorded in our patients add further complexity to the mechanism of action of omalizumab.

Effects of preactivated autologous T lymphocytes on CD80, CD86 and CD95 expression by chronic lymphocytic leukemia B cells.

Profound immune dysfunction is a constant feature in B-cell chronic lymphocytic leukemia (B-CLL) patients. Immunological abnormalities include hypogammaglobulinemia, impaired immunoglobulin class switching and diminished germinal center formation. This state of immune suppression renders B-CLL patients highly susceptible to infections, which contribute greatly to morbidity and mortality in this disease. Impaired T cell function in B-CLL is well-documented and has been suggested to result from inhibitory effects exerted by malignant B lymphocytes. Because the presence of leukemic cells may represent a major obstacle to efficient T cell activation, T lymphocytes were separated from CLL B cells, stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin for 4h, and then cocultured with autologous leukemic B cells both at a 1:1 ratio or at the same ratio as in vivo for 24-40 h. CLL B cell expression of CD86 and CD95 was markedly upregulated using this approach, whereas CD80 expression was augmented only in a minority of patients; these effects were partially preserved even when preactivated T cells were rechallenged with CLL B cells at the same low T/B cell ratio as that observed in vivo. Finally, CD80 upregulation on CLL B cells appeared to be mainly dependent on CD40L-mediated stimulation, whereas CD86 and CD95 expression was efficiently augmented by soluble factors released by preactivated T lymphocytes. In conclusion, efficient activation of T lymphocytes in B-CLL may be achieved which, in turn, may result in enhanced antigen-presenting capacity and susceptibility to apoptosis of leukemic cells via CD86 and CD95 upregulation, respectively.

Differences in constitutive and activation-induced expression of CD69 and CD95 between normal and chronic lymphocytic leukemia B cells.

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by a sustained accumulation of long-lived and well-differentiated B lymphocytes in lymphoid tissues, peripheral blood and bone marrow. Although the pathogenesis of this disease is not entirely understood, altered apoptosis is believed to play a relevant role in B-CLL. In this study, we compared the expression of CD95, the best characterized surface molecule involved in triggering the apoptotic machinery, on normal and CLL B cells before and after in vitro activation with polyclonal stimulators. Cell activation was monitored by verifying the induced expression of the early activation antigen CD69. Freshly analyzed CLL B cells showed significantly lower levels of CD95 than normal B cells. Moreover, following in vitro culture with phorbol 12-myristate 13-acetate (PMA) + ionomycin, phytohemagglutinin, or pokeweed mitogen, CLL B cells failed to upregulate CD95 expression as efficiently as normal B cells. Impairment of CD95 upregulation was mainly observed following PMA + ionomycin treatment. In contrast, CLL B cells were shown to express CD69 as well as normal B cells, regardless of the activator used, indicating that CLL B cells retain the ability to respond to activating stimuli but are unable to efficiently implement the CD95-mediated activation-induced cell death (AICD) program. In conclusion, these results suggest that prolonged survival of CLL B cells may be contributed to by alterations in AICD mechanisms.

T-lymphocytes expressing CC chemokine receptor-5 are increased in frail older adults.

OBJECTIVES: To evaluate the frequencies of T-lymphocytes expressing CC chemokine receptor-5 (CCR5(+) T-cells) and their relationship with frailty in older adults. DESIGN: Case-control study with an age-, race-, and sex-matched design. SETTING: General Clinical Research Center. PARTICIPANTS: Community-dwelling adults aged 72 and older from Baltimore, Maryland. METHODS: Frailty was determined using five validated criteria: weakness, slow walking speed, fatigue, low physical activity, and weight loss. Those meeting three or more of these five criteria were defined as frail and those with none as nonfrail. Complete blood counts were performed to obtain peripheral lymphocyte counts using an automated (Coulter) counter. Peripheral blood was collected for surface immunofluorescent staining of CCR5 and other T-cell markers. RESULTS: Twenty-six frail and matched nonfrail participants (mean age+/-standard deviation 83.8+/-5.3, range 72-94) completed the study. Frail participants had higher CCR5(+), CCR5(+)CD8(+), and CCR5(+)CD45RO(-) T-cell counts than matched nonfrail controls (349+/-160/mm(3) vs 194+/-168/mm(3), P=.02; 208+/-98/mm(3) vs 105+/-62/mm(3), P=.02; and 189+/-149/mm(3) vs 52+/-36/mm(3), P=.01; respectively). Furthermore, there was a trend toward graded increase in these T-cell counts across the frailty scores in frail participants (e.g., CCR5(+)CD8(+) counts of 123+/-52/mm(3), 248+/-115/mm(3), and 360+/-215/mm(3) for those with frailty scores of 3, 4, and 5, respectively). CONCLUSION: These initial results suggest an expansion of the CCR5(+) T-cell subpopulation in frailty. They provide a basis for further characterization of CCR5(+) T-cells and their role in frailty, with potential therapeutic implications.

T cell polarization identifies distinct clinical phenotypes in scleroderma lung disease.

OBJECTIVE: Lung involvement is the leading cause of morbidity and mortality in systemic sclerosis (SSc; scleroderma), and interstitial lung disease (ILD) is the most common pulmonary manifestation. An abnormal profibrotic Th2/Tc2-polarized T cell response is postulated to mediate tissue damage and fibrosis. The aim of this study was to investigate whether a polarized T cell phenotype in SSc is associated with lung disease or other clinical manifestations of SSc. METHODS: Circulating T cells were characterized by flow cytometry in 62 patients with SSc and 36 healthy control subjects, using antibodies against CD3, CD4, CD8, chemokine receptor CCR5 (Th1/Tc1-specific), and prostaglandin D2 receptor CRTH2 (Th2/Tc2-specific). The ratio between CCR5 and CRTH2 T cell frequencies was used to quantify type 1 (high-ratio) or type 2 (low-ratio) immune polarization. RESULTS: Patients with SSc exhibited lower CCR5/CRTH2 T cell ratios than those exhibited by control subjects (P<0.0001), indicating a Th2/Tc2-polarized phenotype. Markedly reduced CCR5/CRTH2 T cell ratios were observed in SSc patients with ILD compared with SSc patients without ILD (P<0.0001), particularly in patients with active ILD (P<0.0001) compared with those with stable lung function. Lower CCR5/CRTH2 ratios were strongly associated with a lower value for the percent predicted forced vital capacity (P<0.0001). In patients with an estimated right ventricular systolic pressure>35 mm Hg, suggestive of pulmonary vascular disease, a lower value for the percent predicted diffusing capacity (DLCO) was associated with higher CCR5/CRTH2 T cell ratios (Th1/Tc1) (P=0.009), while in those with right ventricular systolic pressure<35 mm Hg, a lower value for the percent predicted DLCO correlated with lower ratios (Th2/Tc2) (P<0.0001), as observed for ILD. CONCLUSION: T cell polarization in SSc is strongly associated with specific manifestations of lung disease. Measurement of T cell polarization may represent a valuable tool to monitor disease activity and predict clinical outcomes in SSc patients with lung disease.

GATA3 up-regulation associated with surface expression of CD294/CRTH2: a unique feature of human Th cells.

GATA-3 and T-box expressed in T cells (T-bet) play central roles in Th-cell development and function. Consistently, studies in mice document their selective expression in Th1 and Th2 cells, respectively. In contrast, it is not clear whether these genes are regulated in human Th cells. Here we show that T-bet expression is polarized to a comparable degree in human and mouse Th-cell cultures, while only mouse GATA3 is subject to substantial regulation. This did not reflect differential skewing efficiency in human versus mouse cultures, as these contained similar frequencies of IFN-gamma- and IL-4-producing cells. However, GATA-3 was expressed at significantly higher levels in human IL-4-producing cells enriched via capture with monoclonal antibodies (mAbs) against the PGD(2) receptor, CRTH2, the best selective Th2-cell surface marker to date. Along with increased IL-4 and GATA-3, CRTH2(+) Th cells isolated from Th2-skewed cultures or the circulating memory pool exhibited markedly decreased IFN-gamma and T-bet expression. Thus, the human GATA-3 gene is not regulated in response to polarizing signals that are sufficient to direct Th2-specific expression in mouse cells. This postulates the involvement of an additional level of complexity in the regulation of human GATA-3 expression and stresses the existence of nontrivial differences in the regulation of human versus mouse T-cell function.

Altered constitutive and activation-induced expression of CD95 by B- and T-cells in B-cell chronic lymphocytic leukemia.

Expression of CD95, a molecule involved in activation-induced cell death (AICD), might contribute to explain accumulation of leukemic B-cells and functional impairment of T-cells in B-cell chronic lymphocytic leukemia (B-CLL). There-fore, we compared constitutive and activation-induced expression of CD95 and CD69 by B- and T-cells in CLL patients and in healthy donors.

Primary cardiac T-cell lymphoma.

Primary cardiac lymphoma (PCL), defined as a lymphoma clinically mimicking cardiac disease, with the bulk of the tumor located intrapericardially, is extremely rare in immunocompetent patients. Clinical manifestations vary depending on sites of involvement in the heart and include chest pain, arrhythmias, pericardial effusion, and heart failure. Diagnosis is often difficult and may require invasive procedures; in some cases, diagnosis is not made until autopsy. Histologically, nearly all cases of PCL reported thus far have been of B-cell origin. In this report, we describe a case of PCL of T-cell origin in an adult immunocompetent patient, the second reported in the literature to the best of our knowledge, and provide a brief overview of the features of previously published PCL cases.