[Multicenter evaluation of minimal residual disease monitoring in early induction therapy for treatment of childhood acute lymphoblastic leukemia].

Objective: To evaluate the role of minimal residual disease (MRD) monitoring during early induction therapy for the treatment of childhood acute lymphoblastic leukemia (ALL). Methods: This was a multicenter retrospective cohort study. Clinical data of 1 164 ALL patients first diagnosed between October 2016 and June 2019 was collected from 16 hospitals in South China Children's Leukemia Group. According to MRD assay on day 15 of early induction therapy, they were divided into MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group. According to MRD assay on day 33, they were divided into MRD<0.01% group, MRD 0.01%-<1.00% group and MRD≥1.00% group. Age, onset white blood cell count, central nervous system leukemia (CNSL), molecular genetic characteristics and other data were compared between groups. Kaplan-Meier method was used for survival analysis. Cox regression model was used to analyze prognostic factors. Results: Of the 1 164 enrolled patients, there were 692 males and 472 females. The age of diagnosis was 4.7 (0.5, 17.4) years. The white blood cell count at initial diagnosis was 10.7 (0.4, 1 409.0) ×109/L. Among all patients, 53 cases (4.6%) had CNSL. The follow-up time was 47.6 (0.5, 68.8) months. The 5-year overall survival (OS) and 5-year relapse-free survival (RFS) rates were (93.1±0.8) % and (90.3±1.1) %. On day 15 of early induction therapy, there were 466 cases in the MRD<0.10% group, 523 cases in the MRD 0.10%-<10.00% group and 175 cases in the MRD≥10.00% group. The 5-year OS rates of the MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group were (95.4±1.0) %, (93.3±1.1) %, (85.4±2.9) %, respectively, while the RFS rates were (93.2±1.6) %, (90.8±1.4) %, (78.9±4.3) %, respectively (χ2=16.47, 21.06, both P<0.05). On day 33 of early induction therapy, there were 925 cases in the MRD <0.01% group, 164 cases in the MRD 0.01%-<1.00% group and 59 cases in the MRD≥1.00% group. The 5-year RFS rates in the MRD 0.01%-<1.00% group was lowest among three groups ((91.4±1.2) % vs. (84.5±3.2) % vs. (87.9±5.1) %). The difference between three groups is statistically significant (χ2=9.11, P=0.010). Among ALL patients with MRD≥10.00% on day 15 of induction therapy, there were 80 cases in the MRD <0.01% group on day 33, 45 cases in the MRD 0.01%-<1.00% group on day 33 and 45 cases in the MRD≥1.00% group on day 33. The 5-year RFS rates of three groups were (83.9±6.0)%, (67.1±8.2)%, (83.3±6.9)% respectively (χ2=6.90, P=0.032). Univariate analysis was performed in the MRD≥10.00% group on day 15 and the MRD 0.01%-<1.00% group on day 33.The 5-year RFS rate of children with CNSL was significantly lower than that without CNSL in the MRD≥10.00% group on day 15 ((50.0±20.4)% vs. (80.3±4.4)%,χ2=4.13,P=0.042). Patients with CNSL or MLL gene rearrangement in the MRD 0.01%-<1.00% group on day 33 had significant lower 5-year RFS rate compared to those without CNSL or MLL gene rearrangement ((50.0±25.0)% vs. (85.5±3.1)%,χ2=4.06,P=0.044;(58.3±18.6)% vs. (85.7±3.2)%,χ2=9.44,P=0.002). Multivariate analysis showed that age (OR=0.58, 95%CI 0.35-0.97) and white blood cell count at first diagnosis (OR=0.43, 95%CI 0.27-0.70) were independent risk factors for OS. The MRD level on day 15 (OR=0.55,95%CI 0.31-0.97), ETV6-RUNX1 fusion gene (OR=0.13,95%CI 0.03-0.54), MLL gene rearrangement (OR=2.55,95%CI 1.18-5.53) and white blood cell count at initial diagnosis (OR=0.52,95%CI 0.33-0.81) were independent prognostic factors for RFS. Conclusions: The higher the level of MRD in early induction therapy, the worse the OS. The MRD levels on day 15 is an independent prognostic factor for RFS.The MRD in early induction therapy guided accurate risk stratification and individualized treatment can improve the survival rate of pediatric ALL.

[Risk factors for surgical site infection after emergency abdominal surgery: a multicenter cross-sectional study in China].

Objective: Surgical site infection (SSI) is the most common infectious complication after emergency abdominal surgery (EAS). To a large extent, most SSI can be prevented, but there are few relevant studies in China. This study mainly investigated the current situation of SSI occurrence after EAS in China, and further explored risk factors for SSI occurrence. Methods: Multi-center cross-sectional study was conducted. Clinical data of patients undergoing EAS in 33 hospitals across China between May 1, 2019 and June 7, 2019 were prospectively collected, including perioperative data and microbial culture results from infected incisions. The primary outcome was the incidence of SSI after EAS, while the secondary outcomes were postoperative hospital stay, ICU occupancy rate, length of ICU stay, hospitalization cost, and mortality within postoperative 30 days. Univariate and multivariate logistic regression models were used to analyze the risk factors of SSI after EAS. Results: A total of 660 EAS patients aged (47.9±18.3) years were enrolled in this study, including 56.5% of males (373/660). Forty-nine (7.4%) patients developed postoperative SSI. The main pathogen of SSI was Escherichia coli [culture positive rate was 32.7% (16/49)]. As compared to patients without SSI, those with SSI were more likely to be older (median 56 years vs. 46 years, U=19 973.5, P<0.001), male [71.4% (35/49) vs. 56.1% (343/611), χ(2)=4.334, P=0.037] and diabetes [14.3% (7/49) vs. 5.1% (31/611), χ(2)=5.498, P=0.015]; with-lower preoperative hemoglobin (median: 122.0 g/L vs. 143.5 g/L, U=11 471.5, P=0.006) and albumin (median: 35.5 g/L vs. 40.8 g/L, U=9452.0, P<0.001), with higher blood glucose (median: 6.9 mmol/L vs. 6.0 mmol/L, U=17 754.5, P<0.001); with intestinal obstruction [32.7% (16/49) vs. 9.2% (56/611), χ(2)=25.749, P<0.001], with ASA score 3-4 [42.9% (21/49) vs. 13.9% (85/611), χ(2)=25.563, P<0.001] and with high surgical risk [49.0% (24/49) vs. 7.0% (43/611), χ(2)=105.301, P<0.001]. The main operative procedure resulting in SSI was laparotomy [81.6%(40/49) vs. 35.7%(218/611), χ(2)=40.232, P<0.001]. Patients with SSI experienced significantly longer operation time (median: 150 minutes vs. 75 minutes, U=25 183.5, P<0.001). In terms of clinical outcome, higher ICU occupancy rate [51.0% (25/49) vs. 19.5% (119/611), χ(2)=26.461, P<0.001], more hospitalization costs (median: 44 000 yuan vs. 15 000 yuan, U=24 660.0, P<0.001), longer postoperative hospital stay (median: 10 days vs. 5 days, U=23 100.0, P<0.001) and longer ICU occupancy time (median: 0 days vs. 0 days, U=19 541.5, P<0.001) were found in the SSI group. Multivariate logistic regression analysis showed that the elderly (OR=3.253, 95% CI: 1.178-8.985, P=0.023), colorectal surgery (OR=9.156, 95% CI: 3.655-22.937, P<0.001) and longer operation time (OR=15.912, 95% CI:6.858-36.916, P<0.001) were independent risk factors of SSI, while the laparoscopic surgery (OR=0.288, 95% CI: 0.119-0.694, P=0.006) was an independent protective factor for SSI. Conclusions: For patients undergoing EAS, attention should be paid to middle-aged and elderly patients and those of colorectal surgery. Laparoscopic surgery should be adopted when feasible and the operation time should be minimized, so as to reduce the incidence of SSI and to reduce the burden on patients and medical institutions.

Influence of miR-155 on behaviors of depression mice through regulating Wnt/ß-catenin signaling pathway.

OBJECTIVE: To study the influence of micro ribonucleic acid (miR)-155 on depression-like behaviors of depression mice, and to explore the role of Wnt/b-catenin signaling pathway in behavioral regulation of depression mice. MATERIALS AND METHODS: The mouse model of depression was established via chronic unpredictable mild stress (CUMS). All mice were randomly divided into control group (n=12), model group (n=12), and fluoxetine group (n=12). The expression level of miR-155 in the hippocampus of mice in each group was detected via quantitative Polymerase Chain Reaction (qPCR). The changes in the behaviors of mice in each group were evaluated via behavioral experiments. The apoptosis level in the hippocampus of mice in each group was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Moreover, the content of inflammatory factors in the hippocampus of mice in each group was detected using the enzyme-linked immunosorbent assay (ELISA) kits. The expression levels of Wnt/b-catenin signaling pathway-related proteins in each group were detected via Western blotting. RESULTS: The expression level of miR-155 in the hippocampus was significantly higher in model group than that in control group (p<0.01). Meanwhile, the expression level of miR-155 was significantly lower in fluoxetine group than that in model group (p<0.01). There were no statistically significant differences in the crossing score and rearing score in the open field test among groups (p>0.05). Compared with those in control group, the immobility time in tail suspension test and forced swimming test were significantly increased (p<0.01), while the sucrose preference degree significantly declined (p<0.01) in model group. Fluoxetine could significantly reduce the immobility time in tail suspension test and forced swimming test (p<0.01) and increase the sucrose preference degree (p<0.01) in model group. The number of TUNEL-positive cells in the hippocampus of mice in model group was significantly larger than that in control group (p<0.01). Fluoxetine could effectively reduce the number of TUNEL-positive cells in the hippocampus (p<0.01). Compared with those in control group, the content of tumor necrosis factor-α (TNF-a), interleukin-1b (IL-1b), and IL-6 in the hippocampus was significantly increased (p<0.01), while the content of IL-10 was significantly decreased (p<0.01) in model group. Fluoxetine could effectively reduce the content of TNF-a, IL-1b, and IL-6 (p<0.01) and increase the content of IL-10 (p<0.01). Besides, in model group, the expression levels of dishevelled-1 (DVL-1) and b-catenin in hippocampus remarkably declined (p<0.01), while the expression levels of glycogen synthase kinase-3b (GSK-3b) and adenomatous polyposis coli (APC) were remarkably increased (p<0.01) compared with those in control group. Fluoxetine could effectively lower the expressions of GSK-3b and APC in the hippocampus (p<0.01) and increase the expressions of DVL-1 and b-catenin (p<0.01) in model group. CONCLUSIONS: MiR-155 is involved in regulating the depression-like behaviors of depression mice through promoting the release of inflammatory factors and the apoptosis of hippocampal neurons. Its mechanism may be related to the inhibition of the Wnt/b-catenin signaling pathway.

Specific computed tomography imaging characteristics of congenital mesoblastic nephroma and correlation with ultrasound and pathology.

INTRODUCTION: Congenital mesoblastic nephroma (CMN) is a common solid renal tumor in the neonate. Congenital mesoblastic nephroma can be divided into classic, cellular, and mixed types. The prognosis of CMN is very optimistic. But CMN can easily be misdiagnosed as the other malignant renal tumors by radiology. However, no studies have described the computed tomography (CT) imaging appearance of CNM in detail. The objective of this study is retrospective analyses of the multislice CT characteristics of CMN and their corresponding ultrasound findings and pathology. METHODS: This retrospective study reviewed the enhanced CT images of the CMNs and other renal tumors in children younger than 1 year in the past 10 years from the First Affiliated Hospital of Sun Yat-sen University. Two radiologists had noted the CT imaging characteristics of these images. t-test and Fisher's exact test were used in the comparison of imaging characteristics between the CMNs and other renal tumors. RESULTS AND DISCUSSION: Compared with other malignant renal tumors, the CMNs tend to appear as smaller round masses without clear coverage or clear boundary with the kidney in CT images (P < 0.01). The intratumor pelvis and the double-layer sign are the specific characteristics of CMNs (P < 0.01). The gender, quality of tumor (solid or solid-cystic), character of enhancement (homogeneous or heterogeneous enhancement), peri-renal hemorrhage, or peripheral lymph node enlargement showed no statistical significance (P > 0.05) between CMNs and other renal tumors. The appearances of CMN with classic components in the CT images are relevant to the pathological findings. The intratumor pelvis is caused by the classic components of CMN growing to encapsulate the pelvis. The double-layer sign in CT image correlates with the specific hypoechoic ring in ultrasound, which is caused by the slow blood flow and delay contrast agent filling in the blood sinus located in the peripheral part of the tumor. The differential diagnosis of CMN should include the other solitary renal tumors such as Wilms' tumor, clear-cell sarcoma of the kidney, and rhabdoid tumor of the kidney. CONCLUSION: The unclear coverage and unclear boundary with the kidney, the intratumor pelvis, and double-layer sign after contrast were specific CT imaging characteristics of CMN.

Study of prevalence and influencing factors of depression in tumor patients and the therapeutic effects of fluoxetine.

OBJECTIVE: To observe the depression in patients with malignant tumor and influencing factors of the disease, as well as to investigate the effects of fluoxetine on depressive symptoms in cancer patients and the immune function. PATIENTS AND METHODS: 262 patients with malignant tumors, confirmed by pathological and radiological diagnosis as malignant tumor were randomly divided into 2 groups: the control group with chemotherapy; the treatment group with chemotherapy and 20 mg/d fluoxetine for six weeks. Before and after treatment, the scores of QLQ-C30 scale and changes of immune parameters were observed, including the determination of NK and T cell subsets. RESULTS: The prevalence of depression in cancer patients was not related to the tumor location. But gender, age, tumor stage, the income level of satisfaction and chronic cancer pain were related to the occurrence of depression in cancer patients (p < 0.05). In the fluoxetine treatment groups, by QLQ-C30 scores, in quality of life scores including body, function, social and cognitive function, and single symptoms including nausea, vomiting, constipation, diarrhea, and economic difficulties, the differences were not statistically significant. The QLQ-C30 scores of overall quality of life and emotional function were rising in the fluoxetine treatment group. The QLQ-C30 scores of the pain, shortness of breath, fatigue, loss of appetite, insomnia symptoms were decreased, which had a statistical significance (p < 0.05) compared with the control group. To compare with the control group, the scores of HAMD were decreasing in the fluoxetine treatment group, which had a statistical significance (p < 0.05). Before treatment, the NK cells, CD3+, CD4+, CD4+/CD8+ ratios of tumor patients decreased significantly, while CD8+ increased. After 6 weeks of treatment, NK cells, CD3+, CD4+, CD4+/CD8+ ratios increased significantly and CD8+ decreased. CONCLUSIONS: Sex, age, tumor stage, income satisfaction, and cancer pain were relevant factors in patients with tumor-associated depression. If depression can be detected in the early stage, and oral fluoxetine therapy can be conducted, it can improve the depression situation and immune function of patients with malignant tumor.

A phase II trial of dose-dense (biweekly) paclitaxel plus carboplatin as neoadjuvant chemotherapy for operable breast cancer.

The aim of the present study is to investigate the efficacy and safety of dose-dense (biweekly) carboplatin and paclitaxel as a neoadjuvant treatment for operable breast cancer. Patients with previously untreated breast cancer (stages Ic-III) were treated with four cycles of paclitaxel (175 mg/m(2), intravenous drip, D1) and carboplatin (area under the curve of 5, D1). Patients with HER2+ disease simultaneously received trastuzumab (6 mg/kg initial dose with subsequent doses of 4 mg/kg biweekly). The primary endpoint was a pathologically complete response (pCR). Between January 2012 and February 2014, 110 patients were enrolled. The overall pCR rate was 35.45 % (39 of 110). The pCR rates for the different cancer subtypes were as follows: 10.53 % (2 of 19) among the patients with the luminal A subtype, 12.50 % (5 of 40) among the patients with the luminal B (HER2-) subtype, 58.33 % (14 of 24) among the patients with the luminal B (HER2+) subtype, 57.14 % (8 of 14) among the patients with the triple-negative subtype, and 76.92 % (10 of 13) among the patients with the HER2+ subtype. The patients experienced the following toxicity side effects: grade 3/4 neutropenia (N = 27, 24.55 %), grade 3/4 anemia (N = 6, 5.45 %), grade 3/4 thrombocytopenia (N = 2, 1.82 %), grade 3 alanine aminotransferase (ALT) elevation (N = 1, 0.91 %), grade 3 neuropathy (N = 3, 2.73 %), grade 3 pain (N = 2, 1.82 %), and grade 3 fatigue (N = 1, 0.91 %). In total, 19.09 % of the patients experienced treatment delay or discontinuation due to hematological toxicity, and one patient discontinued treatment due to non-hematological toxicity. Neoadjuvant biweekly paclitaxel plus carboplatin is a feasible therapy that achieved high pCR rates in patients with the HER2+, triple-negative, and luminal B (HER2+) cancer subtypes (NCT0205986).

CBAP promotes thymocyte negative selection by facilitating T-cell receptor proximal signaling.

T-cell receptor (TCR)-transduced signaling is critical to thymocyte development at the CD4/CD8 double-positive stage, but the molecules involved in this process are not yet fully characterized. We previously demonstrated that GM-CSF/IL-3/IL-5 receptor common ß-chain-associated protein (CBAP) modulates ZAP70-mediated T-cell migration and adhesion. On the basis of the high expression of CBAP during thymocyte development, we investigated the function of CBAP in thymocyte development using a CBAP knockout mouse. CBAP-deficient mice showed normal early thymocyte development and positive selection. In contrast, several negative selection models (including TCR transgene, superantigen staphylococcal enterotoxin B, and anti-CD3 antibody treatment) revealed an attenuation of TCR-induced thymocyte deletion in CBAP knockout mice. This phenotype correlated with a reduced accumulation of BIM upon TCR crosslinking in CBAP-deficient thymocytes. Loss of CBAP led to reduced TCR-induced phosphorylation of proteins involved in both proximal and distal signaling events, including ZAP70, LAT, PLCγ1, and JNK1/2. Moreover, TCR-induced association of LAT signalosome components was reduced in CBAP-deficient thymocytes. Our data demonstrate that CBAP is a novel component in the TCR signaling pathway and modulates thymocyte apoptosis during negative selection.

Circulating tumor cells predict progression-free and overall survival in Chinese patients with metastatic breast cancer, HER2-positive or triple-negative (CBCSG004): a multicenter, double-blind, prospective trial.

BACKGROUND: The aim of this multicenter, double-blind, prospective study was to evaluate the potential utility of circulating tumor cell (CTC) measurements in predicting responses to anticancer therapies, including response to human epidermal growth factor receptor-2 (HER-2)-targeted agents, progression-free survival (PFS), and overall survival (OS) in Chinese women with metastatic breast cancer (MBC). PATIENTS AND METHODS: Three hundred MBC patients planned to complete three CTC blood draws and two imaging studies. RESULTS: A total of 294 of the 300 MBC patients enrolled from six leading Chinese cancer centers were assessable. In multivariate Cox regression analyses, the baseline CTC number remained an independent prognostic factor for PFS [hazard ratio (HR) = 1.93; 95% confidence interval (CI) = 1.39-2.69; P < 0.001) and OS (HR = 3.76; 95% CI = 2.35-6.01; P < 0.001). Similar results were observed for CTC counts at the first follow-up visit for both PFS (P = 0.049) and OS (P < 0.001). CONCLUSIONS: Enumeration of CTCs in Chinese MBC patients provides substantial prognostic information and is an independent factor associated with PFS and OS. Moreover, we demonstrated the prognostic value in the various disease subtypes, including HER-2-positive disease irrespective of therapy.

Prognostic value of a mitochondrial functional score in prostate cancer.

OBJECTIVE: To evaluate the utility of a mitochondrial functional score in predicting the progress of prostate cancer. METHODS: This retrospective study included 72 patients (mean age 70.1 years) with prostate cancer who were treated by radical prostatectomy between October 2006 and March 2007. The epithelioglandular mitochondrial functional scores were assessed according to the Flameng grading. Patients were divided into six groups (groups 1-6) according to their Gleason score (Gleason score 2-7, respectively). The correlation between Gleason score and mitochondrial functional score was examined using Pearson's correlation coefficient. RESULTS: The mean mitochondrial functional score was significantly lower in group 6 compared with group 1. An inverse correlation was found between the Gleason and mitochondrial functional scores. At 1 year, significantly fewer patients in group 1 had died (0/15 patients) than in group 6 (2/10 patients); the deaths were cancer-related. CONCLUSIONS: Mitochondrial dysfunction exists in patients with prostate cancer, particularly in cases with a higher degree of malignancy. The mitochondrial functional score, combined with the Gleason score, is beneficial for predicting the progress of prostate cancer.

Protection against lethal enterovirus 71 infection in newborn mice by passive immunization with subunit VP1 vaccines and inactivated virus.

Enterovirus 71 (EV71), the newest member of Enteroviridae, is notable for its etiological role in epidemics of severe neurological diseases in children. Developing effective vaccines is considered a top choice among all control measures. We compared the inactivated virus vaccine (10 microg protein/mouse) with subunit vaccines--VP1 DNA vaccine (100 microg/mouse) or recombinant VP1 protein (10 microg/mouse)--in its ability to elicit maternal antibody and to provide protection against lethal infection of EV71 in suckling mice. Prior to gestation, all three groups of vaccinated dams possessed similar levels of neutralizing antibody. With a challenge dose of 2300 LD(50) virus/mouse, suckling mice born to dams immunized with inactivated virus showed 80% survival. The subunit vaccines provided protection only at a lower challenge dosage of 230 LD(50) per mouse, with 40% survival for DNA vaccine and 80% survival for VP1 protein. The cytokine profile produced by splenocytes showed a high level of IL-4 in the inactivated virus group, high levels of IFN-gamma and IL-12 in the DNA vaccine group, and high levels of IL-10 and IFN-gamma in the VP1 protein group. Overall, the inactivated virus elicited a much greater magnitude of immune response than the subunit vaccines, including total IgG, all four IgG subtypes, and T-helper-cell responses; these antibodies were shown to be protective against lethal infection when passively transferred to susceptible newborn mice. Our data indicated that inactivated virus is the choice of vaccine preparation capable of fulfilling the demand for effective control, and that VP1 subunit vaccines remain promising vaccine strategies that require further refinement.

IL-15 promotes survival but not effector function differentiation of CD8+ TCRalphabeta+ intestinal intraepithelial lymphocytes.

CD8 single-positive cells, including CD8alphaalpha+ and CD8alphabeta+ subsets, constitute the majority of TCRalphabeta+ intestinal intraepithelial lymphocytes (alphabeta iIEL) in mice. CD8+ alphabeta iIEL show significantly weaker responses to TCR stimulation in the presence of exogenous IL-2 than do CD8+ T cells of the central immune system. IL-15 is a T cell growth factor likely expressed in the intestine mucosa. To understand the role of IL-15 in CD8+ alphabeta iIEL biology, we compared the effects of exogenous IL-15 and IL-2 on the survival and primary responses of the two CD8+ alphabeta iIEL subsets in vitro. In contrast to the death of approximately 60% of both CD8alphaalpha+ and CD8alphabeta+ iIEL cultured in IL-2 with or without TCR stimulation, IL-15 promoted survival of the CD8alphaalpha+ subset in the presence of TCR stimulation and promoted survival of both subsets in the absence of TCR stimulation. The higher proliferation level of TCR stimulated CD8alphaalpha+ alphabeta iIEL cultured in IL-15 compared with those cultured in IL-2 is likely due to IL-15's prosurvival effects. In addition, unlike exogenous IL-2, exogenous IL-15 did not support the effector functions of either iIEL subsets, including IFN-gamma production, IL-4-induced Th2 cytokine production, and anti-TCR mAb-redirected cytotoxicity. These findings demonstrate that IL-15 and IL-2 are functionally distinct and suggest that IL-15 plays a unique role in the maintenance of the CD8+ alphabeta iIEL pool in the absence of Ag stimulation and in the survival and expansion of CD8alphaalpha+ alphabeta iIEL upon Ag stimulation.

Modulation of cytokine responses of murine CD8+ alphabeta intestinal intraepithelial lymphocytes by IL-4 and IL-12.

The immune responses of the intestine mucosa feature the noninflammatory type, such as IgA production and oral tolerance. Th2 type cytokines have been implicated in the induction of these noninflammatory responses. In the present study, cytokine responses of CD8+ and CD4+ TCRalphabeta+ intestinal intraepithelial lymphocyte (alphabeta iIEL) subsets to TCR stimulation under the influence of IL-12, IL-4, or CD28 costimulation were examined. IL-12 enhanced production of IL-10 and IFN-gamma by the CD8alphabeta+ alphabeta iIEL significantly but only marginally affected the CD8alphaalpha+ subset, whereas IL-4 induced IL-4, IL-5, and IL-10 production and augmented TGF-beta production by both subsets. CD28 costimulation induced production of Th2 cytokines by CD4+ iIEL in the absence of exogenous IL-4. Unlike lymph node CD4+ cells, the CD28 costimulation-induced Th2 differentiation of CD4+ iIEL was not inhibited by IFN-gamma. These results demonstrate active cytokine production by CD4+, CD8alphabeta+, as well as CD8alphaalpha+ alphabeta iIEL. The Th2- skewed cytokine profile of CD8alphaalpha+ alphabeta iIEL and the IFN-gamma-resistance of Th2 differentiation of the CD4+ alphabeta iIEL suggest that both iIEL subsets contribute to the induction of noninflammatory mucosal immune responses.

Differential effects of IL-2 and IL-15 on the death and survival of activated TCR gamma delta+ intestinal intraepithelial lymphocytes.

TCR gamma delta+ cells are enriched in the intestine mucosa and constitute approximately half of the intestinal intraepithelial lymphocytes (iIEL) in mice. They are likely activated by self and foreign Ags in situ, but little is known about how the activated gamma delta iIEL are regulated. In the iIEL compartment, IL-2 is produced by activated TCR alpha beta+ iIEL, and IL-15 message is detected in iIEL and in the epithelial cells. We found surface expression of IL-2 as well as IL-15Rs on activated gamma delta iIEL, and examined the effects of IL-2 and IL-15 on the survival and death of gamma delta iIEL during secondary stimulation through TCR. We found that both cytokines supported growth of the restimulated gamma delta iIEL, but exerted different effects on their survival. A significant higher number of live cells were recovered from the gamma delta iIEL cultures restimulated in IL-15 than in IL-2. Quantitation of apoptotic cells showed more cell death in the IL-2 group than in the IL-15 group. The cell death was associated with restimulation through TCR and was not caused by insufficient growth factor, thus representing activation-induced cell death. Western blot analyses found no difference in the levels of Bcl-2 and Bax proteins between the two groups. However, the level of Bcl-xL protein diminished with time in the IL-2 group whereas the level was sustained in the IL-15 group, which may contribute to the pro-survival effect of IL-15. These results demonstrated that the survival of activated gamma delta iIEL is differentially regulated by IL-2 and IL-15.

Crystal-induced neutrophil activation VI. Involvment of FcgammaRIIIB (CD16) and CD11b in response to inflammatory microcrystals.

The inflammatory reaction associated with the deposition of monosodium urate (MSU) crystals in synovial spaces is known to be due to interactions with polymorphonuclear neutrophils mediated by presently unidentified surface structures. In this study, we have observed that antibodies directed against CD16 (VIFcRIII) and CD11b (VIM12) selectively and potently inhibit the activation of neutrophils by MSU crystals. The responses affected include the stimulation of tyrosine phosphorylation, activation of the tyrosine kinase syk, tyrosine phosphorylation of the proto-oncogene Cbl, mobilization of calcium, and stimulation of the activity of phospholipase D and of the production of superoxide anions. Tyrosine phosphorylation responses to MSU crystals develop during the Me2SO4-induced differentiation of HL-60 cells in parallel with the surface expression of CD16. These data strongly support the hypothesis that inflammatory microcrystals interact opportunistically with CD16 initially, and that the signal transduction pathways activated thereby depend on CD11b. An examination of the relevance of the hypothesis that an uncontrolled activation of CD16/CD11b may play a role in inflammatory reactions associated with a dysregulation of neutrophil function (other than crystal arthropathies) appears warranted on the basis of the present results.

Activated alpha beta-CD8+, but not alpha alpha-CD8+, TCR-alpha beta+ murine intestinal intraepithelial lymphocytes can mediate perforin-based cytotoxicity, whereas both subsets are active in Fas-based cytotoxicity.

CD8 single-positive (CD8+) T cells in murine intestinal intraepithelial lymphocytes (iIEL) consist of alpha alpha-CD8+ and alpha beta-CD8+ subpopulations. Cytotoxicity represents an important function of peripheral CD8+ T cells, so we examined perforin-granzymebased and Fas-based cytotoxicity of activated CD8+ TCR-alpha beta+ iIEL subsets. We found that allospecific CTL activity was induced from alpha beta-CD8+ iIEL but not from alpha alpha-CD8+ iIEL even when allospecific TCR were present on the iIEL, as demonstrated by using 2C TCR transgenic mice. On the other hand, both CD8+ iIEL subsets proliferated upon allostimulation with a lower responder frequency than CD8+ LN cells. The alpha alpha-CD8+ TCR-alpha beta+ iIEL appeared to lose their ability to perform perforin-based killing after activation through TCR because fresh cells lysed P815 cells coated with anti-TCR beta-chain (TCR-beta) mAb, whereas cells activated by plate-bound anti-TCR mAb did not. Of interest, both activated CD8+ TCR-alpha beta+ iIEL subsets, but not fresh cells, were able to mediate Fas-based killing when triggered with PMA and CA2+ ionophore.

Regulation of stimulated integrin surface expression in human neutrophils by tyrosine phosphorylation.

The control of the adhesive properties of human neutrophils is an essential element of their defense function. One level at which this control is exerted involves the upregulation of the surface expression of beta 2-integrins. In this study, we have examined the potential involvement of tyrosine phosphorylation in the latter process. Two inhibitors of tyrosine kinases with differing modes of action, erbstatin and herbimycin A, were found to inhibit the expression of CD11b and CD18 stimulated by chemotactic factors (fMet-Leu-Phe or leukotriene B4) or growth factors (tumor necrosis factor alpha). This inhibition was not shared by an inactive analog of erbstatin or by the protein kinase C inhibitor Ro 31-8330. Erbstatin also inhibited the unveiling of activation-specific neoepitopes detected by antibody CBRM1/5. Pretreatment of neutrophils (but not of endothelial cells) with erbstatin inhibited the stimulation of neutrophils' adherence to endothelial cells induced by fMet-Leu-Phe. Augmentation of tyrosine phosphorylation by inhibiting tyrosine phosphatases using hydroperoxyvanadate led to an increased surface expression of CD11b and CD18 and enhanced the adhesion of neutrophils to endothelial cells. Finally, the leumedin NPC 15669, which had previously been shown to inhibit stimulated CD11b expression and neutrophil adherence to endothelial cells and to exhibit anti-inflammatory properties in various in vivo models of inflammation, inhibited the stimulation of tyrosine, phosphorylation induced by fMet-Leu-Phe. Taken together, these data establish a strong correlation between tyrosine phosphorylation and integrin upregulation in stimulated human neutrophils.

Tyrosine phosphorylation in activated human neutrophils. Comparison of the effects of different classes of agonists and identification of the signaling pathways involved.

The tyrosine phosphorylation responses initiated in human neutrophils by soluble and particulate agonists were characterized. Chemotactic factors, hematopoietic growth factors, and inflammatory microcrystals stimulated in a time- and concentration-dependent manner the tyrosine phosphorylation of distinct patterns of substrates: pp120, pp85, pp70, and pp60 in the case of chemotactic factors; pp155, pp130, pp120, pp85, pp60, and pp40 in the case of granulocyte macrophage-CSF; and pp130, pp120, pp70, and pp60 in the case of monosodium urate (MSU) crystals. Several of the single bands on one-dimensional blots (including pp40, pp70, and pp120) could be resolved into multiple spots on two-dimensional gels. The responses of several other chemotactic factors resembled those of FMLP. Cytokineplasts retained the capacity to respond to FMLP, granulocyte-macrophage-CSF, or MSU crystals with a stimulation of tyrosine phosphorylation, and contained the major substrates detected in intact neutrophils. Several unrelated tyrosine kinase inhibitors (herbimycin A, genistein, and erbstatin) strongly diminished the tyrosine phosphorylation response to chemotactic factors. Pertussis toxin abrogated the tyrosine phosphorylation response to FMLP, whereas protein kinase C (Ro 21-8220, chelerithryn) inhibitors were without effect. Chelation of intracellular calcium attenuated the tyrosine phosphorylation response to FMLP. These results indicate that G proteins play a crucial role in the coupling of chemotactic factor receptors to tyrosine phosphorylation and that this coupling occurs in parallel to that of phospholipase C. These results also underline the complexity of the transduction pathways implicated in the initiation of tyrosine phosphorylation.

Granulocyte-macrophage colony-stimulating factor primes phospholipase D activity in human neutrophils in vitro: role of calcium, G-proteins and tyrosine kinases.

The addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) to human peripheral blood neutrophils primes phospholipase D (PLD) to subsequent stimulation by N-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol myristate acetate (PMA). The present investigation was directed at the elucidation of the pathway(s) involved in the regulation of the activity of PLD in untreated as well as in GM-CSF-primed neutrophils. Pretreatment with pertussis toxin (PT) totally inhibited fMLP-induced activation of PLD in control or GM-CSF-treated cells. PT did not affect the activation of PLD by PMA but inhibited the priming effect of GM-CSF. Activation of PLD by fMLP was dose-dependently inhibited by erbstatin, an inhibitor of tyrosine kinases. Furthermore, pre-incubation with GM-CSF accelerated the tyrosine phosphorylation response to fMLP (as analysed by protein immunoblot with antiphosphotyrosine antibodies). In PMA-stimulated neutrophils, erbstatin antagonized the priming effect of GM-CSF on PLD without affecting the direct effects of the phorbol ester. Buffering cytoplasmic calcium with the chelator BAPTA inhibited fMLP-induced activation of PLD as monitored by the formation of phosphatidylethanol. The stimulation of PLD by PMA was partially attenuated in BAPTA-loaded cells while the priming effect of GM-CSF was abolished. Thus, priming of human neutrophil PLD by GM-CSF may be mediated by G-proteins, by increases in the levels of cytosolic free calcium, and by stimulation of protein kinase C and/or tyrosine kinase(s).

Expression of the Mls-1a superantigen results in an increased frequency of V beta 14+ T cells.

Minor lymphocyte-stimulating (Mls) Ag are alloantigens that stimulate T cells expressing specific V beta regions. Recent studies have established that Mls Ag are examples of endogenous superantigens encoded by the products of endogenous mouse mammary tumor virus (MLV) genomes. In a mouse strain that expresses a given mammary tumor virus (Mls) Ag, reactive T cells expressing the corresponding V beta region are profoundly deficient, due at least in part to clonal deletion of the cells during their development. Expression of Mls and other endogenous superantigens, therefore, results in profound alterations in the ultimate repertoire of T cells in an animal. A role for endogenous superantigens in positive selection of T cells has not been previously established. Here we present evidence that expression of Mls-1a leads to a specific increase in the abundance of V beta 14+ T cells. Genetic studies indicate linkage of the effect to the Mls-1a gene. Neonatal tolerance studies argue against the possibility that the increase is due solely to the deletion of Mls-reactive V beta 14- T cells. The results are consistent with the Mls-1a product playing a role in the positive selection of V beta 14+ T cells.