Massive production of Th2 cytokines by human CD4+ effector T cells transiently expressing the natural killer cell marker CD57/HNK1

Changes of Th1/Th2 cytokines in patients with primary hepatocellular carcinoma after ultrasound-guided ablation

Liver cancer is a malignancy of the digestive system and has a high morbidity and mortality rate. Local intervention has become a viable option in identifying liver treatment. The aim of the present study was to analyze the changes of Th1/Th2 cytokines in patients with primary hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) treatment. 26 patients with stage III-IV liver cancers and 25 healthy controls were selected to participate in the study. HCC patients were initiated with RFA treatment and the serum levels of alpha fetoprotein (AFP) and Th1/Th2 cytokines were valued. We found that with the level of AFP decreased, the levels of Th1 cytokines including interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were significantly increased after treatment with RFA (P<0.05). Meanwhile, the levels of Th2 cytokines consist of interleukin-4 (IL-4), IL-6 and IL-10 were decreased markedly on the contrary, and the differences were statistically significant (P<0.05). In conclusion, the levels of Th1/Th2 cytokines were correlated with the change of AFP in patients of HCC after treatment with RFA, which might be an important guiding significance for the prognosis of HCC.

The distribution of immune cells and macrophages in the endometrium of women with recurrent reproductive failure I: Techniques

Recurrent miscarriage affects approximately 1% of the population and in half of these cases no cause is found. Abnormally functioning immunocompetent cells, including natural killer (NK) cells, in the endometrium, are thought to be responsible for many such cases and treatment trials including oral prednisolone and intravenous immunoglobulins are now underway. Despite these encouraging developments, there is neither adequate standardization of counting uterine NK cells nor consensus as to what constitutes an abnormal level. To address this issue, immunohistochemistry was used to examine the presence and distribution of selected immune cells and macrophages in the endometrium from 222 women who had a routine endometrial biopsy for investigation of recurrent miscarriage or IVF failure, at various stages of the menstrual cycle, and accessioned prospectively over a 7-month period. Biopsies were examined by H+E and immunostained for CD8(+) T-cells, CD163(+) macrophages, CD56(+) NK cells, and CD57(+) cells. Cell numbers (expressed as immunopositive cells per mm(2)) were determined in the stroma of the functional layer of endometrium and the relative concentrations of some cell types (CD163(+) macrophages, CD56(+) NK cells) were expressed as a percentage of all stromal cells. Routine H+E sections revealed 12 patients with focal "endometritis" without plasma cells. CD8(+) T-cells showed focal perivascular aggregates in most instances, and non-random but scattered cells in all cases, with a twofold increase in the luteal phase. CD163(+) cells were distributed evenly throughout the superficial endometrial stroma and also present as single or clustered macrophages within the lumens of superficial glands, mostly in the luteal phase. CD56(+) NK cells showed "diffuse" but variable distribution throughout the functional layer and perivascular aggregates of various sizes in two thirds of cases. Raw cell counts were low and relatively stable in the proliferative phase, but increased somewhat during the first half of the secretory phase, while in the second half of secretory phase they increased six to tenfold. Percentage counts rose from approximately 5% of stromal cells in the early part of the secretory phase of the cycle to over 35% in premenstrual endometrium. CD57(+) cells were present in very low numbers in most cases. The study illustrates the complexity and variability of immune cell infiltration of endometrium. We stress the need for strict counting protocols and attention to histological criteria if any immunological perturbations potentially responsible for recurrent reproductive failure are to be identified. Reference ranges for individual cell types are only valid for individual "days" of a normalized menstrual cycle.

Effects of the neuropeptide secretoneurin on natural killer cell migration and cytokine release

Secretoneurin has a widespread occurrence in airway mucosal innervation of patients with allergic diseases and may play an important role in the local traffic of immune cells in human airway mucosa. Whether secretoneurin affects natural killer cell migration and cytokine release in vitro was tested. Natural killer cells were obtained from venous blood of healthy donors. Cell migration was studied by micropore filter assays. Signalling mechanisms required for secretoneurin-dependent migration were tested using signalling enzyme blockers. Cytokine release was measured in natural killer cell supernatants by ELISA. Secretoneurin significantly stimulated natural killer cell chemotaxis via activation of phosphatidylinositol 3'-kinase and protein kinase C. IL-2 stimulated natural killer cells showed a stronger response toward secretoneurin than unstimulated cells. Moreover, secretoneurin increased the release of interleukin-5 in a dose-dependent manner but did not affect Th1 cytokine release by natural killer cells. Data suggest that secretoneurin stimulates directed migration of natural killer cells and may modulate Th1/Th2-response via affecting chemokine release. Thus, secretoneurin may play an important role in the early stages of allergic inflammation.

Germinal centers regulate human Th2 development

In the present study we demonstrate that all CD4(+) T cells in human tonsil expressing the Th2-selective receptor chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) also 1) express high levels of CXCR5, and 2) display a transitional CD45RA/RO phenotype and consistently do not produce significant amounts of cytokines when immediately analyzed ex vivo. Hence, they represent precursors of Th2 effector cells, a conclusion confirmed by their robust production of IL-4, IL-5, and IL-13, but not IFN-gamma, after in vitro activation. CD4(+) T cells, which express only intermediate levels of CXCR5, instead develop into IFN-gamma-producing cells under identical culture conditions, thus establishing a correlation between relative levels of CXCR5 expression and the acquired cytokine profile. Because CXCR5 is critically involved in follicular localization, the results suggest that these CRTH2(+) Th2 cells preferentially develop their cytokine-producing phenotype within germinal centers (GCs), whereas extrafollicular differentiation instead promotes Th1 development. In support for this proposal, we show that T cells with an intermediate expression of CXCR5 can be forced to also produce IL-4 and IL-13 if cultured with allogenic GC B cells. Finally, we demonstrate that the previously described CD57(+) GC T cells also express high levels of CXCR5 but instead of comprising a Th2 precursor, they represent anergized T cells. Taken together, these data suggest that GCs and B cells regulate CD4(+) T cell differentiation in a finely tuned fashion, either by promoting differentiation of Th2 cells, which apparently leave the lymphoid tissue before evolving a cytokine-producing phenotype, or by furnishing T cell unresponsiveness.

Proliferation of T-cell subsets that contact tumour cells in colorectal cancer

We have investigated the proliferation rates of T-cell subsets in colorectal carcinomas using immunohistochemistry. It was found that the tumour-infiltrating T cells in contact with the tumour cells have a significantly higher frequency of proliferation than those in the stroma. In particular, the CD8+ intraepithelial lymphocytes (T-IEL) within the tumours have a significantly higher frequency of proliferation in comparison with CD8+ T cells in the stromal compartment or in any normal mucosal lymphoid tissues. It is possible that the proliferation of the CD8+ T-IEL may be driven by self-antigens expressed on the tumour cells. The proportion of CD3+ CD7- T cells is increased within carcinomas compared with the normal colon, and a population of CD57+ T cells was observed which is absent from the normal colon. It is possible that these phenotypes are acquired in situ due to repeated stimulation of the T cells by tumour antigens. Intact colorectal carcinoma explants were cultured, and the presence of tumour-infiltrating T cells analysed after 3 days of culture in isolation from the systemic compartments. CD3+ T cells were proliferating (at a low rate) within the explants after 3 days of culture, indicating that they may be sustained by factors present in the tumour microenvironment.

Expansion of CD4+ T cells with a cytotoxic phenotype in patients with B-chronic lymphocytic leukaemia (B-CLL)

Abnormal CD4/CD8 ratios and T-cell function have previously been shown in patients with B-chronic lymphocytic leukaemia (B-CLL). We have demonstrated that CD4+ T cells containing both serine esterase and perforin (PF) are increased in the blood of these patients. Using flow cytometry, we have shown that the CD4+ PF+ cells were CD57+ but lacked expression of CD28, suggesting a mature population. The same phenotype in CD8+ T cells is characteristic of mature cytotoxic T cells. However, in contrast to the CD8+ T cells, the CD4+ T cells were more frequently CD45RO positive than CD45RA positive, indicating prior antigen experience. In contrast, this population lacked expression of either CD69 or HLA-DR, arguing that they were not activated or that they are an abnormal population of T cells. Their constitutive cytokine levels showed them mainly to contain IL4 and not IFNgamma, suggesting a Th2 phenotype. The role of the CD4+ PF+ T-cell population is at present uncertain. However, this potentially cytotoxic T-cell population could contribute both to enhancing survival of the B-CLL tumour cells through production of IL4, and to the immunodeficient state frequently seen in patients with this tumour, independent of drug treatment.

TH1 cytokine response of CD57+ T-cell subsets in healthy controls and patients with alcoholic liver disease

Patients with chronic inflammatory diseases, including Crohn's disease and rheumatoid arthritis, as well as those with certain viral infections, and patients who are transplant recipients or who have certain hematologic malignancies have been observed to have CD57+ T cell expansion in both CD4+ and CD8+ subsets. We have reported previously that alcoholic patients also have CD57+ T cell expansion. Because many alcoholics become seriously deficient in cell-mediated immunity, it is of interest to determine whether the expanded CD57+ subsets can respond to stimulation with normal T helper cell subtype 1 (TH1) cytokine production. We report evaluation of the CD57 T-cell subsets of patients with alcoholic liver disease (ALD) with the use of cytoplasmic staining after stimulation through the T-cell receptor (TCR). The CD57+ subsets of the T cells of both healthy individuals and patients with ALD express significantly higher amounts of cytoplasmic tumor necrosis factor-alpha (TNF-) and interferon-gamma (IFN-) after 6 h of stimulation than do the CD57- subsets. This increased production can persist up to 46 h of continuous stimulation. Under these assay conditions, very little cytoplasmic interleukin (IL)-4 is observed in the T cells of either healthy control subjects or patients with ALD. Measurement of cytokine secretion by sort-purified CD57 T-cell subsets with the use of enzyme-linked immunosorbent assay (ELISA) shows that the CD57+ T-cell subset produces 18- to 30-fold more TNF- and IFN-, respectively, than does the CD57- subset in the first 12 h of stimulation. This response requires only stimulation through the TCR for the CD57+ subset, whereas significant secretion by the CD57- subset requires added IL-2 or anti-CD28 antibody. These results are consistent with the concept of the CD57+ T-cell subset as a differentiated effector cell and demonstrate that patients with ALD who are not drinking at the time of evaluation have normal or increased immediate TH1 T-cell responses.

Human T cells with a type-2 cytokine profile are resistant to apoptosis induced by primary activation: consequences for immunopathogenesis

The mechanisms leading to a relative dominance of T cells producing type 2 cytokines in certain human immune disorders are still unclear. We investigated the relative susceptibility to apoptosis induced by primary in vitro activation of human type 1 (producing interferon-gamma (IFN-gamma)) or type 2 (producing IL-4) T cells. Peripheral blood lymphocytes were isolated from patients with immune disorders characterized by expansion of type 2 cells (four with AIDS and hyper-IgE/hypereosinophilia, one with Churg-Strauss syndrome, and one with idiopathic hypereosinophilic syndrome) or from individuals with normal cytokine balances. Cells were stimulated for 16 h with ionomycin and phorbol ester, and apoptosis of cytokine-producing cells was assessed by flow cytometry. T cells with a type-2 cytokine profile, i.e. producing IL-4 alone, were significantly more resistant to activation-induced apoptosis than those producing IFN-gamma alone. This was observed in AIDS patients, whose type 2 cells were mostly CD8+, as well as in the patients with Churg-Strauss and with hypereosinophilic syndrome. CD4+ and CD8+ IL-4-producing cells were equally resistant to apoptosis. Lower susceptibility to apoptosis of type-2 T cells was also observed in subjects with normal cytokine balances. Bcl-2 expression was high in type-2 cells and in viable type-1 cells, whereas it was low in apoptotic type-1 cells. Resistance to activation-induced apoptosis may explain the expansion of cells producing type-2 cytokines in certain immune disorders.

Strategies to evaluate metabolic stress and catabolism by means of immunological variables

In this article, we outline how metabolic stress and catabolism are set off and influenced by the neuroendocrine network that interacts intensely with the immune system. When evaluating metabolic stress in individuals, the vast ocean of mediators, cell-surface markers and intracellular components that participate in metabolism and catabolic or anabolic changes make it necessary to focus on specific entities that may best mirror all these events. T cell responsiveness and factors that orchestrate the T helper type 1 and type 2 balance form an immunological mirror that can competently reflect catabolism and metabolic stress.

Increased interleukin-4 production by NK T cells in systemic lupus erythematosus

It has been reported that production of interleukin (IL)-4, a T helper (Th)-2-type cytokine, might play an important role in the pathogenesis of systemic lupus erythematosus (SLE). On the other hand, it is known that NK1.1(+) cells which belong to CD4, CD8 double-negative, or CD4(+) cells are associated with initial IL-4 production and Th2 differentiation in mice although human equivalent cells are unknown. In order to study the profile of IL-4-producing cells in SLE, cytoplasmic IL-4 and various surface antigens on peripheral mononuclear cells were analyzed. Peripheral mononuclear cells were stimulated for 5 h by phorbol ester and ionomycin in the presence of monensin, fixed, and permeabilized with paraformaldehyde and saponin solution. Then cytoplasmic IL-4 and various surface antigens were analyzed by flow cytometry. IL-4-producing cells in SLE were phenotypically the same as those which produce IL-4 normally and frequently bore activated T-cell (CD7, CD25, CD28, CD29) and NK-cell markers (CD56, CD57). Double-negative T cells and CD57(+) T cells were increased in number and were more frequently positive for cytoplasmic IL-4 in SLE compared with normal controls and various infectious diseases. It was suggested that T cells with NK cell markers, CD57(+) T cells, which are known to extrathymically differentiate, might be involved in the pathogenesis of SLE as a counterpart of mouse NK1.1(+) cells.

A human whole-blood assay for analysis of T-cell function by quantification of cytokine mRNA

A whole blood assay was developed for T-lymphocyte analysis which allows the quantification of induced cytokine mRNA expression. We applied a novel kinetic reverse transcription polymerase chain reaction method which directly measures product accumulation using Taqman technology. Quantitative results were obtained by using beta-actin and cytokine standard curves generated from synthetic external standards. Since quantification relies on threshold cycles for fluorescence detection (Ct), this technique proved to be accurate over a dynamic range of at least five orders of magnitude. To evaluate the method a study was undertaken to find optimal conditions for whole-blood stimulation with soluble anti-CD3 monoclonal antibodies in the presence of a costimulatory signal mediated by anti-CD28 monoclonal antibody. Therefore, whole blood was taken from healthy individuals (n = 10) and aliquots for mRNA measurement were withdrawn after 0, 4, 8 and 24 h of stimulation. Optimal assay conditions were reached with 1 : 10 diluted heparinized whole blood and after stimulation with equimolar amounts of anti-CD3 and anti-CD28 monoclonal antibodies (1 microgram/ml). Interferon-gamma and tumour necrosis factor-alpha proved to be early response cytokines with peak expression at 4 h. In contrast, interleukin (IL)-2, IL-4 and IL-10 required 8 h of stimulation. This novel whole-blood assay is potentially useful for monitoring T-cell-specific immune functions in a variety of clinical settings. Using whole blood obviates the need for T-cell purification and may therefore closely approximate the state of responsiveness of circulating T cells in vivo.

Immune escape mechanisms in Hodgkin's disease

BACKGROUND

The nodular sclerosis and mixed cellularity subtypes of Hodgkin's disease are histologically characterised by a small population of neoplastic cells, the so-called Reed-Sternberg cells and their mononuclear variants (RS cells) and an extensive admixture of other cell types including lymphocytes, plasma cells, eosinophils, and histiocytes. The nature of this infiltrate is largely known, but the mechanisms and functional effects are not. The small lymphocytes immediately surrounding the RS cells are mostly CD4+ T cells that express early activation markers. The absence of prominent specific cytotoxic T cell or natural killer (NK) cell populations seems to argue against a Th1-type response, whereas the sometimes prominent admixture of plasma cells and eosinophils is suggestive of a Th2-type response. Enrichment of the CD4 T-cell population may result from selective influx of CD4 T cells or from selective depletion of CD8 and NK cells.

RESULTS AND DISCUSSION

The T cells surrounding RS cells have an immuno-phenotype and cytokine production capability consistent with a Th2-type response. RS cells express several members of the TNF receptor family such as the FAS ligand (CD95L) that may induce apoptosis of activated, FAS expressing, CD8+ T cells and NK cells. The RS cells also produce TGF beta and interleukin-10 that may downmodulate the Th1 response. In addition, the Reed-Sternberg cells produce the chemokine TARC that could lead to the specific attraction of a Th2 T-cell subset.

CONCLUSION

RS cells have several mechanisms that may allow it to escape an effective immune response. The relative contributions of each of these and other potential mechanisms are not yet known.

Natural Killer Cell Depletion Fails to Influence Initial CD4 T Cell Commitment In Vivo in Exogenous Antigen-Stimulated Cytokine and Antibody Responses

The role played by NK- and NK1.1-expressing T cells in CD4 T cell activation and induction of immune responses in vivo is controversial. These effector cells of the innate immune response are hypothesized to play a pivotal role in shaping initial T cell activation, with some groups reporting that classical NK cells are required for optimal Th1-like T cell activation, and others supporting a role for NK1.1+ αβ T cells in Th2 generation. Here, we examine the impact of in vivo NK cell depletion on the development of exogenous Ag-specific cytokine and Ab responses using a murine model of human immediate hypersensitivity. OVA-specific immune responses were induced in 1) C57Bl/6 bg/bg and bg/+ mice, 2) BALB/c mice pretreated with anti-asialoGM1 or control Ab, and 3) C57Bl/6 mice depleted of NK1.1-expressing cells by in vivo administration of anti-NK1.1 mAb PK136. Depletion efficacy was assessed by functional assays and flow cytometric analysis. Each of these approaches indicated that depletion of NK cells and NK1.1+CD4+ T cells fails to alter the Th1:Th2 balance of Ag-driven cytokine synthesis, as indicated by OVA-stimulated cytokine synthesis in primary bulk culture. Similarly, the kinetics and intensity of effector responses such as OVA-specific IgG2a and IgE synthesis were neither increased nor decreased in any of the three models examined. The results argue that NK cells and peripheral NK1.1+ T cells do not play an essential role in shaping the induction of Ag-specific immune responses to soluble exogenous Ags, the most common class of inhalant allergen.