Effect of a metalloporphyrin antioxidant (MnTE-2-PyP) on the response of a mouse prostate cancer model to radiation

BACKGROUND

Metalloporphyrin antioxidants can protect tissues against radiation-induced damage. However, for effective use in radiotherapy as normal tissue radioprotectants, they must not protect the cancer. The major objectives were to evaluate the effects of Mn (III) tetrakis (N-ethylpyridinium-2-yl) porphyrin (MnTE-2-PyP) on tumor response to radiation and to explore mechanisms responsible for the observed effects.

MATERIALS AND METHODS

C57BL/6 mice were subcutaneously (s.c.) injected with RM-9 prostate tumor cells on day 0 and grouped according to treatment with MnTE-2-PyP (s.c. 6 mg/kg/day beginning on day 1 for 16 maximum days), 10 Gray (Gy) single fraction radiation on day 7, a combination of both or neither. Subsets per group and non-tumor bearing controls were evaluated for leukocyte populations, red blood cell (RBC) and platelet characteristics and cytokines on day 12; the remaining mice were followed for tumor growth.

RESULTS

Although radiation alone significantly slowed tumor growth and the addition of MnTE-2-PyP resulted in slightly slower tumor progression, the difference between radiation and radiation plus drug was not statistically significant. However, the treatment with drug alone significantly elevated T (helper, Th and cyotoxic, Tc) and natural killer (NK) cells in the spleen, B-cells in the blood and spleen, and the capacity to produce interleukin-2. The addition of the drug to radiation did not ameliorate the depression seen in all the major leukocyte types, but did protect against radiation-induced decreases in RBC counts, hemoglobin and hematocrit. Vascular endothelial growth factor (VEGF) increased in the plasma from both the irradiated groups and a trend for increased transforming growth factor-beta1 (TGF-beta1) was noted with radiation alone.

CONCLUSION

MnTE-2-PyP did not protect RM-9 prostate tumors against radiation damage and was not toxic under the conditions used. The drug-induced enhancement of certain immune parameters suggests that MnTE-2-PyP may be beneficial not only as a normal tissue radioprotectant, but also as a facilitator of antitumor immunity.

In vivo effects of zoledronic acid on peripheral gammadelta T lymphocytes in early breast cancer patients

INTRODUCTION

Amino-bisphosphonates are potent activators of human gammadelta T cells. The aim of our study was to evaluate the immunomodulating properties of a single-dose of zoledronic acid (ZA) on gammadelta T cells in a select group of disease-free breast cancer patients with osteopenia.

MATERIALS AND METHODS

Blood samples were obtained, from 23 patients, before and 7, 28, 56, 90 and 180 days after a single-dose (4 mg) of ZA and analyzed by flow cyometry.

RESULTS

A significant decrease of the different gammadelta T cell subsets was observed: Naïve (CD3+/Vdelta2+/CD45RA+/CD27+) after 180 days (P < 0.01); Central Memory (CD3+/Vdelta2+/CD45RA-CD27+) after 28 (P < 0.05), 90 (P < 0.01) and 180 days (P < 0.01); and Effector Memory (CD3+/Vdelta2+/CD45RA-/CD27-) after 56 (P < 0.01) and 90 (P < 0.05) days. Based on the observed gammadelta T cells kinetics patients could be divided in two groups: "responders" that showed a significant decrease in total numbers of gammadelta T cells and "non-responders" that showed no significant change. However, in vitro phosphoantigen stimulation of patients cells did not show significant differences in terms of IFN-gamma response by Vdelta2 T cells.

CONCLUSION

We describe for the first time a long-lasting activation of effector subsets of gammadelta T cells in disease-free breast cancer patients after a single-dose of ZA. Our results highlight the need to further investigate the clinical significance of the immunomodulating properties of N-BPs.

[Examination of different factors influencing the vascularization of human cutaneous melanoma]

We analyzed the relationship among microvessel density (MVD) and tumor infiltrating cells in cutaneous malignant melanoma. We also studied the effect of hyperforin on tumor- and endothelial cell growth in vitro and in vivo. The density of lymphocyte subpopulations, macrophages, dendritic cells and CD34 + microvessels was determined by immunohistochemistry in primary tumor samples from 52 patients with melanoma thicker than 1 mm. The antiproliferative effect of hyperforin was studied on 16 human- and 7 rat cell lines and on human dermal microvascular endothelial cells (HDMEC). Intratumoral MVD did not show significant association with infiltration for any of these cell types. In the case of peritumoral reactive cell densities analyzed in the whole patient population, significant correlation was found with CD3 + T-cell density. This association was stronger in melanomas >4.0 mm and in visceral metastatic tumors. In these subgroups similar phenomenon was observed for CD8 + cells. We found significant correlation of MVD with CD68 + macrophage density only in the highest thickness category, and weak associations with B-cell and dendritic cell infiltration in visceral metastatic cases. MVD did not vary significantly in tumors categorized according to thickness, location, ulceration or histological type. However, both intratumoral MVD and macrophage infiltration were significantly higher in male patients compared to females. Hyperforin inhibited tumor cell proliferation and induced apoptosis. In vitro, it blocked capillary formation of HDMEC on a complex extracellular matrix. Furthermore, hyperforin reduced proliferation of HDMEC, without displaying toxic effects or inducing apoptosis. In Wistar rats hyperforin inhibited tumor growth and reduced tumor vascularization. Since the net outcome of the enrichment in tumor-infiltrating host cells and in tumor vascularization cannot be easily predicted, further clinicopathological studies are needed on human skin melanoma patients. Hyperforin holds the promise of being an interesting antineoplastic and antiangiogenic agent with low toxicity.

Impact of cigarette smoke on T and B cell responsiveness

Although its direct effects cannot be discounted, tobacco's effects on the immune system have been proposed to play a key role in mediating its deleterious health impact. Studies in rats using high levels of smoke exposure have suggested that tobacco smoke exhausts cellular signal transduction cascades, making lymphocytes unresponsive to stimulation. In the present study, we show that purified B or T cells, and total lymphocytes from the lungs, lymph nodes and spleens of smoke-exposed mice fluxed calcium, proliferated, and secreted immunoglobulin or IFN-gamma similarly to control mice when stimulated with ligands including anti-IgM, and anti-CD3. Importantly, we recapitulated these findings in PBMCs from human smokers; cells from long-term smokers and never-smokers proliferated equivalently when stimulated ex vivo. Previous reports of lymphocyte unresponsiveness in rats are inconsistent with these findings, and may reflect a phenomenon observed only at levels of smoke exposure well above those seen in actual human smokers.

Preoperative treatment with a non-steroidal anti-inflammatory drug (NSAID) increases tumor tissue infiltration of seemingly activated immune cells in colorectal cancer

This study evaluates HLA gene expression and tumor infiltration by B-cells, macrophages, dendritic cells, T-helper and cytotoxic T-lymphocytes in response to short-term preoperative treatment with cyclooxygenase inhibitors. Patients with colorectal carcinoma were randomized to receive oral NSAID (indomethacin or celebrex) for three days preoperatively; controls received esomeprazol. Peroperative tumor biopsies and normal colon tissue were analyzed by microarray, quantitative PCR and immunohistochemistry. Efficacy of short-term systemic NSAID treatment was confirmed by measurement of PGE2 production in blood monocytes from healthy volunteers. NSAID treatment upregulated genes at the MHC locus on chromosome 6p21 in tumor tissue, but not in normal colon tissue, from the same patient. 23 of the 100 most upregulated genes belonged to MHC class II. HLA-DM, -DO (peptide loading), HLA-DP, -DQ, -DR (antigen presentation), granzyme B, H, perforin and FCGR3A (CD16) (cytotoxicity) displayed increased expression, as did CD8, a marker of cytotoxic T-lymphocytes, while HLA-A and -C expression were not increased by NSAID treatment. MHC II protein (HLA-DP, -DQ, -DR) levels and infiltration by CD4+ T-helper cells of tumor stroma increased upon NSAID treatment, while CD8+ cytotoxic T-lymphocytes increased in both tumor stroma and epithelium. Molecules associated with immunosuppressive T regulatory cells (FOXP3, IL-10) were significantly decreased in indomethacin-exposed tumors. Standard oral administration of NSAID three days preoperatively was enough to increase tumor infiltration by seemingly activated immune cells. These findings agree with previous information that high prostanoid activities in colorectal cancer increase the risk for reduced disease-specific survival following tumor resection.

Study on effect of yishen capsule in preventing recurrence of chronic glomerulonephritis

OBJECTIVE

To observe the effect of yishen capsule (YSC) on preventing the recurrence of chronic glomerulonephritis (CGN) and to explore its mechanism preliminarily.

METHODS

CGN patients were assigned to the treated group (61 cases) and the control group (48 cases) and all of them were orally administered with 4 mg of Perindopril twice a day, but 3 capsules of YSC, thrice a day, were given additionally to patients in the treated group. The therapeutic course for both groups was 18 months. The recurrence rate of CGN at the 6th, 12th, and 18th month in the two groups was observed and compared, and the changes of 24-h urinary protein quantity and T-lymphocyte subsets before and after treatment were observed as well.

RESULTS

(1) Comparison of recurrence rate between the two groups showed insignificant difference at the 6th month, but it did show significant difference at the 12th and the 18th month, which was significantly decreased in the treated group than in the control group (P<0.05, P<0.01); (2) The 24-h urinary protein quantity at the 18th month decreased significantly in both groups (P<0.05, P<0.01), but in the treated group was more significant (P<0.01); (3) T-lymphocyte subsets showed no obvious change in the control group after treatment (P>0.05), while in the treated group, it showed significant increase in CD3, CD4 and CD4/CD8 (P<0.05 or P<0.01) and significant decrease in CD8 (P<0.05), and also the difference after treatment in T-lymphocyte subsets between the two groups was significant (P<0.05 or P<0.01).

CONCLUSION

YSC has marked effects in reducing the recurrence of CGN and in decreasing urinary protein, and its mechanism might be related with its function in regulating the ratio of T-lymphocyte subsets to enhance the immunity of patients.

Aflatoxin-related immune dysfunction in health and in human immunodeficiency virus disease

Both aflatoxin and the human immunodeficiency virus (HIV) cause immune suppression and millions of HIV-infected people in developing countries are chronically exposed to aflatoxin in their diets. We investigated the possible interaction of aflatoxin and HIV on immune suppression by comparing immune parameters in 116 HIV positive and 80 aged-matched HIV negative Ghanaians with high (> or =0.91 pmol/mg albumin) and low (<0.91 pmol/mg albumin) aflatoxin B1 albumin adduct (AF-ALB) levels. AF-ALB levels and HIV viral load were measured in plasma and the percentages of leukocyte immunophenotypes and cytokine expression were determined using flow cytometry. The cross-sectional comparisons found that (1) among both HIV positive and negative participants, high AF-ALB was associated with lower perforin expression on CD8+ T-cells (P = .012); (2) HIV positive participants with high AF-ALB had significantly lower percentages of CD4+ T regulatory cells (Tregs; P = .009) and naive CD4+ T cells (P = .029) compared to HIV positive participants with low AF-ALB; and (3) HIV positive participants with high AF-ALB had a significantly reduced percentage of B-cells (P = .03) compared to those with low AF-ALB. High AF-ALB appeared to accentuate some HIV associated changes in T-cell phenotypes and in B-cells in HIV positive participants.

Effects of cyanocobalamin on immunity in patients with pernicious anemia

OBJECTIVE

The aim of the study was to evaluate the role of vitamin B(12) in patients with pernicious anemia.

MATERIALS AND METHODS

This study was conducted prospectively at the Turgut Ozal Medical Center, Department of Hematology, between April and November 2002. Absolute numbers and ratio of the surface antigens of T and B lymphocyte subgroups, CD4/CD8 ratio were calculated in order to evaluate changes in leukocyte and lymphocyte numbers; natural killer (NK) cell count, serum C3, C4, and levels of immunoglobulins G, A, and M were also measured to evaluate vitamin B(12) effect on immunity. Values obtained before treatment with cyanocobalamin were compared with those found during peak reticulocyte count.

RESULTS

In vitamin B(12)-deficient patients, absolute numbers of CD4+ and especially CD8+ lymphocytes were found to be decreased; CD4/CD8 ratio increased, and NK cell activity was depressed. After cyanocobalamin treatment, absolute numbers and percentage of lymphocyte subgroups were elevated. Increased CD4/CD8 ratio and depressed NK cell activity were restored and levels of C3, C4, and immunoglobulins were elevated.

CONCLUSION

These findings suggest that vitamin B(12) has important immunomodulatory effects on cellular immunity, and abnormalities in the immune system in pernicious anemia are restored by vitamin B(12) replacement therapy.

Immunomodulatory effects of dietary potassium perfluorooctane sulfonate (PFOS) exposure in adult Sprague-Dawley rats

Perfluorooctanesulfonate (PFOS) is a stable and environmentally persistent metabolic or degradation product of perfluorooctanyl compounds that were manufactured for a variety of industrial and consumer applications. PFOS itself was sold for use as a surfactant. The structurally related contaminants perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and N-ethyl perfluorooctane sulfonamide (N-EtPFOSA) were shown to suppress immune responses in laboratory rodents. Relatively low doses of PFOS were found to be immunosuppressive in mice. To assess effects of PFOS on the rat immune system at doses known to alter hepatic function, changes in the morphology and function of immune tissues and cells were measured in adult rats exposed to PFOS in their diet for 28 d at levels ranging from 2 to 100 mg PFOS/kg diet (corresponding to approximately 0.14 to 7.58 mg/kg body weight [bw]/d) and compared to those receiving control diet. Body weight reductions were significant in male and female rats exposed to 50 and 100 mg PFOS/kg diet. Liver/body weight was significantly increased in females exposed to 2 mg PFOS/kg diet and in males exposed to 20 mg PFOS/kg diet. Female rats exposed to 100 mg PFOS/kg diet exhibited a significant increase in spleen weight relative to body weight; these changes lacked a histologic correlate and were not observed in males. While thymus weights relative to body weights were not affected, numbers of apoptotic lymphocytes rose in thymus with increasing dietary PFOS. There was a significant dose-related increase in total peripheral blood lymphocyte numbers in female but not male rats. In both genders the percentages of cells within lymphocyte subclasses were altered. There was a significant trend toward increasing T and T-helper (Th) cells and decreasing B cells with higher PFOS dose. Serum total immunoglobulin (Ig) G1 levels were significantly reduced in males exposed to 2 and 20 mg PFOS/kg diet. The ability of male and female rats to mount delayed-type hypersensitivity (DTH) responses to the T-cell-dependent antigen keyhole limpet hemocyanin (KLH) was not altered by PFOS. There was a significant trend toward elevated KLH-specific IgG in serum from male rats exposed to increasing levels of PFOS in diet. Splenic T- and B-cell proliferation in response to ex vivo mitogen exposure was unaffected by exposure to dietary PFOS. In conclusion, changes in immune parameters in rat did not manifest as functional alterations in response to immune challenge with KLH and may be secondary to hepatic-mediated effects of PFOS in this model.

[Effects of low dose mifepristone on population and subsets of natural killer cells in human endometrium during receptive phase]

OBJECTIVE

To investigate the immunologic mechanism of low dose mifepristone as an anti-implantation contraceptive drug.

METHODS

Endometrial biopsies were obtained from fourteen normally cycling women during the receptive phase. Each endometrial tissue, divided into three equal parts, was assigned to three groups: control group, 65 nmol/L mifepristone group (group A) and 200 nmol/L mifepristone group (group B). Endometrial explants were cultured in vitro. The numbers of natural killer cells and the percentages of CD3- CD56+ CD16- subset and CD3- CD56+ CD16+ subset were analysed by immunohistochemistry and flow cytometry.

RESULTS

(1) The mean number of CD56+ NK cells in group A (148 +/- 11) and group B (150 +/- 12) were significantly higher when compared to the control group (121 +/- 7, P < 0.05). There was no significant difference between the two mifepristone-treated groups (P > 0.05). (2) The percentage of CD3- CD56+ Nk cells in group A (44 +/- 5)% and in group B (48 +/- 4)% were significantly higher when compared to the control group (35 +/- 3)% (P < 0.05), there was no significantly difference between the two mifepristone-treated groups (P > 0.05); The percentage of CD3- CD56+ CD16- subset in group A (42 +/- 5)% and in group B (45 +/- 5)% were significantly higher when compared to the control group (33 +/- 3)%, (P < 0.05), there was no significantly difference between the two mifepristone-treated groups (P > 0.05); the percentages of CD3- CD56+ CD16+ subset in three groups [(2.70 +/- 0.24)% (3.26 +/- 0.37)% and (2.33 +/- 0.29)%] were not significantly different (P > 0.05).

CONCLUSION

Low dose mifepristones increase the number of CD56+ NK cells and the percentage of CD3- CD56+ CD16- NK subset, which might result in the disturbance of human endometrial immuno-microenvironment during receptive phase and lead to implantation failure.

Sphingosine-1-Phosphate Analogue FTY720 Causes Lymphocyte Redistribution and Hypercholesterolemia in ApoE-Deficient Mice

Objective— Resident immune cells are a hallmark of atherosclerotic lesions. The sphingolipid analogue drug FTY720 mediates retrafficking of immune cells and inhibits their homing to inflammatory sites. We have evaluated the effect of FTY720 on atherogenesis and lipid metabolism.

Methods and Results— ApoE −/− mice on a normal laboratory diet received oral FTY720 for 12 weeks, which led to a 2.4-fold increase in serum cholesterol (largely VLDL fraction) and a 1.8-fold increase in hepatic HMGCoA reductase mRNA. FTY720 increased plasma sphingosine-1-phosphate and induced marked peripheral blood lymphopenia. A discoordinate modulation of B, T and monocyte cell numbers was found in peripheral lymphoid organs. Overall depletion of T cells was accompanied by a relative (2-fold) increase in regulatory T cell content paralleled by a similar increase in effector memory T cells (CD4+CD44hiCD62lo) as absolute numbers of both subpopulations remained essentially unchanged. Lymphocyte function was unaltered as indicated by anti-OxLDL antibodies and T cell proliferation. There were no changes in atherosclerotic lesions in early and established atherosclerosis.

Conclusions— FTY720 mediated peripheral lymphocyte depletion and retrafficking without altering function and overall balance of pro- and antiatherogenic lymphocyte populations. A net decrease in lymphocyte numbers occurred concomitantly with a more proatherogenic hypercholesterolemia resulting in unaltered atherogenesis.

[Cellular immune response to 3 anesthetic techniques for simple abdominal hysterectomy]

BACKGROUND AND OBJECTIVE

The effect of surgery and anesthesia on the immune response may have a significant effect on perioperative tumor surveillance. The aim of this study was to characterize the cellular immune response of patients undergoing simple abdominal hysterectomy under 3 types of anesthesia.

PATIENTS AND METHODS

ASA 1-2 patients undergoing simple abdominal hysterectomy were enrolled prospectively after they gave informed consent; the patients were randomized to 3 groups of 20 each to receive balanced anesthesia (group A), remifentanil-based anesthesia and analgesia (group B), or combined general-epidural anesthesia (group C). Postoperative analgesia was provided in accordance with group assignment. Four and 24 hours after surgery, 20 mL of blood was drawn from each patient for analysis of leukocyte populations and lymphocyte subpopulations. Statistics were calculated with the SPSS software package, version 12.0.

RESULTS

All groups had elevated neutrophil counts after surgery; the lowest levels were in group C (P<.05). Patients in all 3 groups developed lymphopenia, which was still evident 24 hours after surgery (P<.05). CD3 cell counts at 4 hours were lowest in patients who had received combined anesthesia (group C), CD19 cell counts were highest in group A, and CD16 cell counts were lowest in group C; this last difference was maintained at 24 hours (P<.05 for all these comparisons).

CONCLUSION

Combined general-epidural anesthesia seems to lower the counts of natural killer cells that are involved in tumor surveillance and destruction.

Prostaglandins, leukotrienes and PAF selectively modulate lymphocyte subset and eosinophil infiltration into the airways in a murine model of asthma

The effects of inhibitors of prostaglandins synthesis, indomethacin and nimesulide, or of receptor antagonists of cysteinyl-leukotrienes, MK571 or of platelet activating factor (PAF), WEB2170, were studied on the infiltration of lymphocytes (Tgammadelta, NKT, CD4, CD8 and B cells) and eosinophils into the bronchoalveolar lavage fluid (BALF) in two mouse strains (C57Bl/6 and BALB/c) as well as on bronchial hyperreactivity and mucus production. It was found that indomethacin and nimesulide strongly reduced the number of all cell types analyzed in both mouse strains. MK571 did not affect Tgammadelta or CD4 lymphocytes but reduced the other populations. WEB2170 reduced all lymphocyte subpopulations in both mouse strains. Moreover, the relative numbers of the lymphocyte subsets in the airways and their response to PAF antagonist were strain-dependent. The intensity of bronchoconstriction and mucus production did not correlate with BALF cell types or numbers. The cysteinyl-leukotriene receptor antagonist inhibited eosinophil infiltration and bronchial hyperreactivity, without affecting the Tgammadelta cell subset. Since Tgammadelta cells play a major role in mucosa protection and resolution of lung inflammation, this would represent an additional benefit of cysteinyl-leukotrienes antagonism in asthma.

Overcoming drug resistance induced by P-glycoprotein on lymphocytes in patients with refractory rheumatoid arthritis

OBJECTIVE

P-glycoprotein (P-gp), a member of the ATP-binding cassette transporter family, causes drug resistance by exclusion of intracellular drugs. Here, we elucidate the clinical relevance of P-gp expression on lymphocytes to drug resistance in patients with rheumatoid arthritis (RA).

METHODS

P-gp expression on lymphocytes from 20 normal volunteers and 100 RA patients was analysed by flow cytometry. Drug exclusion analysis of lymphocytes was conducted by radioisotope-labelled dexamethasone.

RESULTS

P-gp was overexpressed on RA lymphocytes compared with normal lymphocytes. P-gp expression levels were higher in partial responders with a Disease Activity Score (DAS) 28-3 of >5.1 despite taking at least two disease-modifying antirheumatic drugs (DMARDs) or one DMARD and corticosteroids for at least 2 years. P-gp expression levels correlated with DAS28-3. Intracellular dexamethasone levels (IDLs) in RA lymphocytes decreased according to P-gp expression. Tacrolimus, a P-gp inhibitor, restored IDLs in RA lymphocytes. P-gp overexpression in patients with highly active RA was suppressed by methotrexate but enhanced by corticosteroids. Furthermore, infliximab (3 mg/kg) resulted in improvement of RA disease activity, reduction of P-gp and recovery of IDLs.

CONCLUSIONS

P-gp overexpression on lymphocytes might cause efflux of corticosteroids and DMARDs, P-gp substrates, from lymphocytes, resulting in drug resistance in patients with highly active RA. P-gp inhibition/reduction could overcome such drug resistance. Measurement of P-gp expression on lymphocytes could be a potentially useful marker for assessing drug resistance in RA, and may be suitable for selecting infliximab or DMARDs including tacrolimus for RA treatment.

The CD16−/CD56brightSubset of NK Cells Is Resistant to Oxidant-Induced Cell Death

Phagocyte-derived reactive oxygen species ("oxygen radicals") have been ascribed a suppressive role in immunoregulation by inducing dysfunction and apoptotic cell death in lymphocytes. Earlier studies show that human NK cells are exceptionally sensitive to oxygen radical-induced apoptosis and functional inhibition. Two subsets of human CD56(+) NK cells have been identified: the highly cytotoxic CD56(dim) cells which constitute >90% of NK cells in peripheral blood, and the less cytotoxic but efficiently cytokine-producing CD56(bright) cells. In this study, we demonstrate that the CD56(bright) subset of NK cells, in contrast to CD56(dim) cells, remains viable and functionally intact after exposure to phagocyte-derived or exogenously added oxygen radicals. The resistance of CD56(bright) cells to oxidative stress was accompanied by a high capacity of neutralizing exogenous hydrogen peroxide, and by a high cell-surface expression of antioxidative thiols. Our results imply that CD56(bright) NK cells are endowed with an efficient antioxidative defense system that protects them from oxygen radical-induced inactivation.

Delayed reconstitution of CD4+ iNKT cells after effective HIV type 1 therapy

CD1d-restricted natural killer T (iNKT) cells are increasingly recognized as key immunoregulatory cells linking innate and adaptive immunity. These fall into functionally distinct CD4+ versus CD4- subsets that are believed to steer cellular immunity toward tolerigenic/atopic versus proinflammatory phenotypes, respectively. Preferential depletion of the CD4+ subset has been observed in HIV-1 infection, but the repletion of these cells after antiretroviral therapy has not been examined in detail. T lymphocytes, CD8+ lymphocyte activation, viremia, and iNKT cell subsets in peripheral blood were compared between 18 HIV-1-uninfected (Control) and 18 seropositive (SP) men initially not on suppressive antiretroviral therapy. Compared to the Control group, the SP group demonstrated reduction of CD4+ and lesser reduction of CD4- iNKT cells at baseline. After initiation of suppressive antiretroviral treatment, the SP CD4+ iNKT cell levels remained unchanged after a year and increased by 2 years, while CD4+ iNKT cells showed a gradual increase notable after the first year. Over the first year of treatment, there was a significant correlation between changes in total CD4+ T lymphocyte and changes in CD4+ iNKT cell levels, and a significant inverse correlation between changes in CD8+ T lymphocyte activation and changes in CD4- iNKT cell levels. These results confirm preferential depletion of tolerigenic/atopic CD4+ iNKT cells by HIV-1, and suggest that disproportionate persistence of proinflammatory CD4- iNKT cells could contribute to the inappropriate immune activation believed to cause immunodeficiency in HIV-1 infection.

Expansion of CD56Bright natural killer cells in the peripheral blood of multiple sclerosis patients treated with interferon-beta

We studied how interferon-beta (IFN-beta) treatment of relapsing-remitting multiple sclerosis (MS) affects subgroups of natural killer cells (NK cells). Following IFN-beta treatment, there was an expansion of CD56(Bright) NK-cells in the peripheral blood of MS patients, while at the same time the proportion of CD56(Dim) cells was diminished. In a control group, the proportion of CD56(Bright) NK-cells was significantly higher in secondary lymphoid tissues compared to the peripheral blood of the same individual. Our findings confirm that CD56(Bright) NK-cells preferably locate within the secondary lymphoid tissues, where they may interact with T cells and thereby contribute to the control of the disease activity in MS.

Effects of the administration of high-dose interleukin-2 on immunoregulatory cell subsets in patients with advanced melanoma and renal cell cancer

PURPOSE

High-dose recombinant human interleukin-2 (IL-2) therapy is of clinical benefit in a subset of patients with advanced melanoma and renal cell cancer. Although IL-2 is well known as a T-cell growth factor, its potential in vivo effects on human immunoregulatory cell subsets are largely unexplored.

EXPERIMENTAL DESIGN

Here, we studied the effects of high-dose IL-2 therapy on circulating dendritic cell subsets (DC), CD1d-reactive invariant natural killer T cells (iNKT), and CD4(+)CD25(+) regulatory-type T cells.

RESULTS

The frequency of both circulating myeloid DC1 and plasmacytoid DC decreased during high-dose IL-2 treatment. Of these, only a significant fraction of myeloid DC expressed CD1d. Although the proportion of Th1-type CD4(-) iNKT increased, similarly to DC subsets, the total frequency of iNKT decreased during high-dose IL-2 treatment. In contrast, the frequency of CD4(+)CD25(+) T cells, including CD4(+)Foxp3(+) T cells, which have been reported to suppress antitumor immune responses, increased during high-dose IL-2 therapy. However, there was little, if any, change of expression of GITR, CD30, or CTLA-4 on CD4(+)CD25(+) T cells in response to IL-2. Functionally, patient CD25(+) T cells at their peak level (immediately after the first cycle of high-dose IL-2) were less suppressive than healthy donor CD25(+) T cells and mostly failed to Th2 polarize iNKT.

CONCLUSIONS

Our data show that there are reciprocal quantitative and qualitative alterations of immunoregulatory cell subsets with opposing functions during treatment with high-dose IL-2, some of which may compromise the establishment of effective antitumor immune responses.

Alefacept (anti-CD2) causes a selective reduction in circulating effector memory T cells (Tem) and relative preservation of central memory T cells (Tcm) in psoriasis

BACKGROUND

Alefacept (anti-CD2) biological therapy selectively targets effector memory T cells (Tem) in psoriasis vulgaris, a model Type 1 autoimmune disease.

METHODS

Circulating leukocytes were phenotyped in patients receiving alefacept for moderate to severe psoriasis.

RESULTS

In all patients, this treatment caused a preferential decrease in effector memory T cells (CCR7- CD45RA-) (mean 63% reduction) for both CD4+ and CD8+ Tem, while central memory T cells (Tcm) (CCR7+CD45RA-) were less affected, and naïve T cells (CCR7+CD45RA+) were relatively spared. Circulating CD8+ effector T cells and Type 1 T cells (IFN-gamma-producing) were also significantly reduced.

CONCLUSION

Alefacept causes a selective reduction in circulating effector memory T cells (Tem) and relative preservation of central memory T cells (Tcm) in psoriasis.

The correlation between the percent of CD3- CD56+ cells and NK precursor function

The number and function of human natural killer (NK) cells are generally assessed to monitor the baseline of immune function, the effect of treatment, the progress of malignancy or metastases and diseases. NK cells recognise and kill target cells in the absence of prior sensitisation and are able to defend the host from infection or prevent the progression of a disease. Human NK cells express CD16 and CD56 which are (massively) being used as a major hallmark for the NK cell. The purpose of this study was to identify the unique subsets of peripheral blood mononuclear cells (PBMC) (%CD3-CD56+ cells) by flow cytometry and to determine whether there is any correlation with functionally mature progeny of (NKp) precursor after five days of culture. The correlation was analysed using samples obtained from 120 Caucasian patients. 20-30ml of whole blood was collected in sterile tube containing preservative free sodium heparin and a similar sample was obtained after five days. Maturation of NKp required the continuous presence of recombinant interleukin 2 (rIL-2), or interleukin 15 (rIL-15) and functional maturity of NK cells was determined by their ability to lyse target cells from the K562 cell line. The NK precursor frequency was measured by limiting dilution analysis (LDA), which The NKpf assay was set up with a range of cell dilutions from 40,000 to 625 per 100ml/well in 96 well culture plates. At the end of the culture period the K562 cell line labelled with Europium (Eu-K562) was added and Eu release measured in culture supernatants using time-resolved fluorometry. The PBMC were set up in parallel cultures under various conditions . On day five cells were collected from culture plates and adjusted to 1x10 cells/ml and then mixed. The mixture was incubated and anti CD3 and anti CD56 were added. NK cells were enumerated in 120 patients by double staining with a combination of anti-CD3- and anti-CD56+. The results of these Immunophenotyping studies by flow cytometry showed no correlation between the NKpf (natural killer precursor frequency) and the percent of CD3-CD56+ cells expressed after five days confirming that CD56 was inadequate as a unique marker for functional NK cells.

Dextran sulfate sodium-induced colitis generates a transient thymic involution--impact on thymocyte subsets

One of the most widely used animal models for inflammatory bowel disease (IBD) is the dextran sulfate sodium (DSS)-induced colitis. We have previously reported that 5 days administration of DSS in C57Bl/6J mice induces a colonic inflammation that progresses into chronicity after DSS removal, whereas in BALB/cJ mice the inflammation resolves within 4 weeks post-DSS. Here we show that both thymic size and thymocyte numbers dramatically decreased in the acute phase of inflammation in C57Bl/6 mice, 7 days after DSS withdrawal. Mature, CD4(+) and CD8(+) single positive (SP) CD69(lo) CD62L(hi) thymocytes were enriched in these mice, accompanied by a major decrease in the number of immature double positive (DP) thymocytes. However, the different maturation stages within the DP thymocyte subset were unchanged between healthy and inflamed C57Bl/6J mice. Interestingly, as the inflammation progressed into the chronic phase, the thymus recovered and 2 weeks after the acute inflammatory phase all the thymic parameters investigated in this study were restored to normal. In contrast, BALB/cJ mice only develop mild thymic alterations. Nevertheless, we found that within the double negative (DN) thymocytes an increased frequency and also total numbers of CD44(+) CD25(-) (DN1) cells correlated with the severity of colitis, and that the frequency of CD44(-) CD25(-) (DN4) thymocytes decreased proportionally in the acute phase in BALB/cJ mice. Our observations suggest that the thymic effects are intimately connected to the intestinal inflammatory response in colitis regardless of the inflammatory stimuli.

Immunologic effects of perinatal exposure to dioxins, PCBs and organochlorine pesticides in Japanese infants

Effects of perinatal exposure to dioxins, PCBs and organochlorine pesticides on lymphocyte subsets were investigated in the peripheral blood from 101 Japanese infants with approximately 10 months of age. Perinatal exposure to these organochlorine compounds were estimated by their contamination levels in the breast milk of the mothers. Lymphocyte subsets such as CD16+, HLA-DR+, CD4+, CD4+8+, CD8+, CD3+ and CD20+ cells in peripheral venous blood were assessed in a subgroup of 92 infants. Greater exposures to HCE, chlordane and dioxins were significantly associated with the increase in the percentages of CD8+ and CD3+ T lymphocytes and CD4+/CD8+ T cell ratios, respectively. In addition, higher HCH exposure was also associated with a decrease in the percentage of HLA-DR+ T lymphocytes. Furthermore effects of dioxins, DDT and PCBs on the percentage of CD16+ T lymphocyte were more pronounced by the combined exposure of dioxins and PCBs or by the combined exposure of DDT and PCBs. Effects of HCE on the percentages of CD8+ T lymphocyte were also more pronounced by the combined exposure of HCE and chlordane. In conclusion, our study suggests that greater exposures to dioxins, PCBs and organochlorine pesticides determined in this study (except dieldrin) influence the immune system of Japanese infant, although the clinical significance of these changes is uncertain.

Effect of PUVA, narrow-band UVB and cyclosporin on inflammatory cells of the psoriatic plaque

BACKGROUND

Because antigen presenting is necessary for T-cell activation, antigen-presenting cells should be involved in the pathogenesis of psoriasis. In this study, our purpose was to evaluate and compare effects of PUVA, cyclosporine A and narrow-band UVB on dendritic cells and activated lymphocytes in the psoriatic lesions.

METHODS

Forty-five volunteered patients (15 patients in each treatment group as PUVA, cyclosporin A and narrow-band UVB) were enrolled in this study. Lesional skin biopsies were taken from each patient before and after treatments. Fresh frozen biopsies were studied for the expressions of CD1a, CD68, CD86, CD4, CD8 and HLA-DR proteins by immunohistochemistry.

RESULTS

There was no correlation between severity of the lesions and expressions of the antigens. Only PUVA significantly decreased CD1a+ epidermal Langerhans cells' (LCs) counts. Treatment modalities decreased expression of costimulator CD86, and most of them decrease antigen-presenting capacity of skin by decreasing HLA class-II expression.

CONCLUSIONS

All treatment modalities equally reduce lymphocytes, macrophages and dendritic cells. PUVA is the only treatment that decreases epidermal LCs. All treatments effectively diminish expression of CD86 and inhibit this step of inflammation.

Investigation of post-weaning changes in immunological parameters in male rats

Normal post-weaning changes in immunological parameters were investigated in male Crl:CD(SD) rats (n=7) for matching of ages with children (referential data). The animals received a single intravenous administration of keyhole limpet hemocyanin (KLH) 3mg/kg on day 1 and were euthanized on day 7 at 5, 7, 9, and 11 weeks of age. Furthermore, to investigate age-dependent differences in susceptibility to cyclophosphamide immunotoxicity, the animals were given oral cyclophosphamide 5mg/kgday from days 1 to 8 and intravenous KLH on day 3, and were euthanized on day 9 at the above ages. As a result, the post-weaning development pattern of a continuous increase until 9 weeks of age, followed by a mild decrease at 11 weeks of age, was commonly observed in white blood cell counts and all of its differential counts in peripheral blood, spleen weight, and total cell, CD3+, CD4+, CD8+ and CD45RA+ cell counts in the spleen. This pattern is similar to the development pattern of peripheral blood cell counts in infants, which mostly peaks at 6-12 months of age. Cyclophosphamide decreased almost all of peripheral blood cell counts and lymphocyte subset counts in the thymus and spleen at all ages, to similar degrees. However, decreases in serum anti-KLH IgM and IgG levels were greatest at 9 weeks of age. In conclusion, 9 (immunization at 8) weeks of age in rats was shown to be the most susceptible timing for cyclophosphamide immunotoxicity, likely corresponding to 6-12 months of age in infants.

Oral pharmacokinetic and pharmacodynamic effects of FTY720 in cats

The aim of the study was to determine pharmacokinetic and pharmacodynamic profiles of FTY720 in cats and identify any toxic side effects. Six adult cats were used for the experimental study. Single oral dosages were tested at 0.05, 0.3 and 1.0 mg/kg. Whole blood drug concentration, total white blood cell and differential counts were monitored. Flow cytometry evaluated the effects on lymphocyte subsets. A toxicity study consisted of cats receiving a dose of 0.15 mg/kg daily for 30 days. Daily observation, physical examination and bloodwork were evaluated to assess for toxicity. All single doses resulted in > or =80% reduction in circulating lymphocytes within 12 h after administration, with the duration of lymphopenia being dose dependent. CD4+ and CD5+ T cells were specifically depleted. Peripheral neutrophils declined by approximately 70% at all dosages tested. No other toxic side effects were observed. Results of this study suggest that FTY720 is effective at inducing a peripheral lymphopenia in cats without any toxic side effects. Currently, cats appear to be the only species in which FTY720 induces a neutropenia. This study provides the foundation for future clinical transplantation trials using FTY720 in cats. By using combination therapy of FTY720 and low dose cyclosporine, the incidence of serious side effects may be reduced while still preventing allograft rejection.