Peripheral T lymphocytes from women with breast cancer exhibit abnormal protein expression of several signaling molecules

The significant role of a functional polymorphism in the NF-κB1 gene in breast cancer: evidence from an Iranian cohort

Aims: Breast cancer (BC) is one of the most common cancers among women. The influence of genetic variations on BC risk has been thus far assessed via genome-wide association studies. NF-κB has been recognized as a major player in BC progression. In this study, the association between rs28362491 and BC was evaluated in a population from northeastern Iran. Materials & methods: This study was conducted on 476 patients with BC and 524 healthy controls. The genotyping method used was an amplification-refractory mutation system. Results: The INS/DEL genotype conferred a statistically significant increased risk in patients in comparison with controls. Additionally, in the recessive model, INS/INS + INS/DEL versus DEL/DEL was statistically significant (OR = 0.34; 95% CI: 0.12-0.96; p = 0.042). Conclusion: This study found that rs28362491, as a susceptibility genetic factor, may affect BC risk in the Iranian population.

CD247 expression is associated with differentiation and classification in ovarian cancer

Ovarian cancer (OC) is one of the most common malignant tumors in female reproductive system and most OC cases are diagnosed at an advanced stage with the overall 5-year survival rate below 40%. The function of CD247 enhances T-cell antigen receptor (TCR) signaling cascade and it is necessary for assembling of the TCR/CD3 complex on the surface of T lymphocytes. It is well established that defective CD247 function leads to impaired activation of T cells upon engagement of the TCR.Flow cytometry was used to examine the difference of CD247 T lymphocyte between the OC and ovarian cyst, immunohistochemistry analysis was used to investigate the correlation between CD247 expression and clinicopathologic features of epithelial OC patients.Our study showed that the expression of CD247 in peripheral blood lymphocytes from patients with OC is decreased compared with ovarian cyst patients and the expression of CD247 in tumor infiltrating lymphocytes with cancer tissue is decreased compared with adjacent tissues. We showed that abnormal expression of CD247 was related with differentiation and classification in OC.Our findings suggested that CD247-targeted treatment could be used as a potential therapeutic strategy for OC.

Pathway-focused PCR array profiling of CAL-27 cell with over-expressed ZNF750

Zinc-finger protein 750 (ZNF750) is the potential anti-cancer gene in oral squamous cell carcinoma (OSCC). The present study was to investigate the expression changes of ZNF750 in OSCC tissue and to reveal the induction of altered mRNA expression profiles caused by over-expressed ZNF750 in CAL-27 cell. The expression level of ZNF750 in tissue specimens from OSCC patients was detected by immunohistochemistry. Gene expression profiling was performed using Human Signal Transduction PathwayFinder RT² Profiler™ PCR Array. The expression changes of 84 key genes representing 10 signal transduction pathways in human following over-expressed ZNF750 in CAL-27 cell was examined. The expression of ZNF750 protein was reduced in OSCC tissues. The R² PCR Array analysis revealed that 39 of the 84 examined genes that changed at least a two-fold between control and ZNF750 groups. These genes related to oxidative stress, WNT, JAK/STAT, TGFβ, NF-kappaB (NFκB), p53, Notch, Hedgehog, PPAR and Hypoxia signaling. ZNF750 could inhibit the candidate genes ATF4, SQSTM1, HMOX1, CCND1, TNF-alpha, TNFSF10 and FOSL1 but activate CDKN1A and EMP1. Our studies suggest that ZNF750 can regulate signaling pathways that related to proliferation, cell cycle, inflammation and oxidative stress in CAL-27 cell.

A Tumor Cell-Selective Inhibitor of Mitogen-Activated Protein Kinase Phosphatases Sensitizes Breast Cancer Cells to Lymphokine-Activated Killer Cell Activity

Dual specificity mitogen-activated protein kinase (MAPK) phosphatases [dual specificity phosphatase/MAP kinase phosphatase (DUSP-MKP)] have been hypothesized to maintain cancer cell survival by buffering excessive MAPK signaling caused by upstream activating oncogenic products. A large and diverse body of literature suggests that genetic depletion of DUSP-MKPs can reduce tumorigenicity, suggesting that hyperactivating MAPK signaling by DUSP-MKP inhibitors could be a novel strategy to selectively affect the transformed phenotype. Through in vivo structure-activity relationship studies in transgenic zebrafish we recently identified a hyperactivator of fibroblast growth factor signaling [(E)-2-benzylidene-5-bromo-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI-215)] that is devoid of developmental toxicity and restores defective MAPK activity caused by overexpression of DUSP1 and DUSP6 in mammalian cells. Here, we hypothesized that BCI-215 could selectively affect survival of transformed cells. In MDA-MB-231 human breast cancer cells, BCI-215 inhibited cell motility, caused apoptosis but not primary necrosis, and sensitized cells to lymphokine-activated killer cell activity. Mechanistically, BCI-215 induced rapid and sustained phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK) in the absence of reactive oxygen species, and its toxicity was partially rescued by inhibition of p38 but not JNK or ERK. BCI-215 also hyperactivated MKK4/SEK1, suggesting activation of stress responses. Kinase phosphorylation profiling documented BCI-215 selectively activated MAPKs and their downstream substrates, but not receptor tyrosine kinases, SRC family kinases, AKT, mTOR, or DNA damage pathways. Our findings support the hypothesis that BCI-215 causes selective cancer cell cytotoxicity in part through non-redox-mediated activation of MAPK signaling, and the findings also identify an intersection with immune cell killing that is worthy of further exploration.

Immature myeloid-derived suppressor cells: A bridge between inflammation and cancer (Review)

Chronic inflammation is considered to be one of the hallmarks of tumor initiation and progression. Changes occurring in the microenvironment of progressing tumors resemble the process of chronic inflammation, which begins with ischemia followed by interstitial and cellular edema, appearance of immune cells, growth of blood vessels and tissue repair, and development of inflammatory infiltrates. Moreover, long‑term production and accumulation of inflammatory factors lead to local and systemic immunosuppression associated with cancer progression. Of the several mechanisms described to explain this anergy, the accumulation of myeloid cells in the tumor, spleen, and peripheral blood of cancer patients has gained considerable interest. A population of suppressive CD11b+Gr-1+ cells has in fact been designated as myeloid-derived suppressor cells (MDSCs). MDSCs are a unique category of the myeloid lineage, and they induce the prevention of the development of cytotoxic T lymphocytes (CTLs) in vitro, and the induction of antigen-specific CD8+ T-cell tolerance in vivo. Therapeutic approaches directed toward the manipulation of the MDSC population and their function may improve chemoimmune-enhancing therapy for advanced malignancies.

Prognostic value of single nucleotide polymorphisms of candidate genes associated with inflammation in early stage breast cancer

To examine the role of germline genetic variations in inflammatory pathways as modifiers of time to recurrence (TTR) in patients with early stage breast cancer (BC), DNA from 997 early stage BC patients was genotyped for 53 tagging single nucleotide polymorphisms (SNPs) in 12 genes involved in inflammation. SNPs were analyzed separately for Caucasians versus African-Americans and Hispanics. Cox proportional hazards models were used to evaluate the association between SNPs in the inflammatory genes and TTR, adjusted for clinical and pathologic covariates. In univariable analyses of Caucasian women, the homozygous genotype of 12 SNPs, including 6 NFKB1 SNPs, 4 IL4 SNPs, and 2 IL13 SNPs, were significantly associated with a decrease in TTR compared with the heterozygous and/or corresponding homozygous genotype (P < 0.05). The significant NFKB1 and IL4 SNPs were in an area of high linkage disequilibrium (D' > 0.8). After adjusting for stage, age, and treatment, carriage of the homozygous genotypes for NFKB1 rs230532 and IL13rs1800925 were independently associated with a shorter TTR (P = 0.001 and P = 0.034, respectively). In African-American and Hispanic patients, expression of NFKB1 rs3774932, TNFrs1799964, and IL4rs3024543 SNPs were associated with a shorter TTR in univariable model. Only NFKB1 rs3774932 (P = 0.02) and IL4Rrs3024543 (P = 0.03) had independent prognostic value in the multivariable model These data support the existence of host genetic susceptibility as a component in recurrence risk mediated by pro-inflammatory and immune factors, and suggest the potential for drugs which modify immune responses and inflammatory genes to improve prognosis in early stage BC.

Human breast tumor cells express IL-10 and IL-12p40 transcripts and proteins, but do not produce IL-12p70

IL-10 transcripts were expressed in 14/15 primary breast adenocarcinomas and in 5/8 established breast tumor lines. Immunohistochemistry and immunoprecipitation from lysates and supernatants revealed that established breast tumor lines produced IL-10 protein. Immunohistochemistry revealed that IL-10 is localized to tumor cells of primary breast adenocarcinomas and to occasional infiltrating MNC. Established breast tumor cell lines expressed IL-12p40 transcripts (6/8) and protein (4/7) and IL-12p35 transcripts (6/7). Using two sandwich ELISAs, specific, respectively, for IL-12p40 and IL-12p70 proteins, we demonstrated that established breast tumor cell lines produce IL-12p40 monomer/homodimer, but not IL-12p70. Positive staining for IL-12p70 in primary breast adenocarcinomas was found only in MNC infiltrating the tumor while tumor cells were negative. IL-12p40 homodimer/monomer inhibit as antagonists IL-12 or IL-23, although they may also act as agonists and positive regulators. Also, primary breast adenocarcinomas (15/15) and established breast tumor cell lines (6/8) expressed TGF-β1 transcripts. IL-10, IL-12p40 and TGF-β1 may inhibit substantially the anti-tumor immune response.

Lipopolysacchride-treated mammary carcinomas secrete proinflammatory chemokines and exhibit reduced growth rates in vivo, but not in vitro

Toll-like receptors (TLR) are pattern recognition receptors that play a pivotal role in the initiation of immune responses. Here we report that the murine mammary carcinoma 4T1 constitutively expressed genes encoding TLR2, 3, 4 and 5. Moreover, treatment of the 4T1 cell line with peptidoglycan (PGN), polyinosinic-polycytidylic acid (Poly(I:C)) or lipopolysaccharide (LPS), agonists for TLR2, 3 or 4 respectively, induced nuclear translocation of NFkappaB and secretion of CCL2, CCL5 and CXCL1 in a dose dependent manner. Although treating the tumor cells with the TLR agonists did not modulate growth or viability of the tumor cells in vitro, 4T1 exhibited a decreased growth rate in vivo following treatment with LPS that was dependent upon the presence of CD8(+) T cells. Analysis of 3 additional murine mammary carcinomas revealed that they also secreted CCL2, CCL5 and CXCL1 in response to TLR agonist treatment, and LPS treated 168 and SM1 tumors exhibited decreased growth rates in vivo, but not in vitro. These data indicated that 4 out of 4 murine mammary carcinomas secreted proinflammatory chemokines following treatment with TLR agonists, and 3 out of 4 of the mammary carcinomas responded to LPS treatment in a manner that decreased tumor growth in vivo.

Signaling defects and functional impairment in T-cells from cervical cancer patients

The ability of T-lymphocytes to recognize antigens and transduce signals to the nucleus successfully is a key component in the initiation and maintenance of an immune response. The present study addressed the expression status of the signal-transducing proteins in relation to the immune impairment in cervical cancer patients. Immune response was measured by evaluating lymphocyte subpopulations CD3(+), CD4(+), and CD8(+), using flowcytometry, natural killer cell activity, using the single-cell cytotoxicity assay, lymphocyte function, using mitogenic response to PHA and T-cell activation following anti-CD3 stimulation, and production of IL-2. Expression of the T-cell signal transduction proteins, TCR-zeta, CD3-epsilon, zap-70, p(56)lck, PKC, NFkappabeta p50, Rel-A, Rel-B, and c-rel, was evaluated by using Western blot assay. A generalized depression of the immune response with respect to the different parameters evaluated was observed. Exogenous interleukin-2 (IL-2) could increase the response in all the controls and in 30% of the patients to different degrees varying from 10% to 90%. Low levels of the signaling molecules (TCR-zeta, CD3-epsilon, zap-70, p(56)lck, and PKC) and impairment in the transduction of NFkappabeta components (p50, Rel-A, Rel-B, and c-rel) to the nuclei were observed in these lymphocytes. Decreased CD4(+)/CD8(+) ratio with an increase in suppressor cells, reduced lymphocyte proliferation, and production of IL-2 suggest a defective immune regulation in cervical cancer. Impairment in the translocation of NFkappabeta p50, Rel-A, and Rel-B to the nucleus and the reduced levels of signal-transducing proteins might be responsible for the decreased production of IL-2 and immune impairment in cervical cancer patients.

TLR4 signaling in effector CD4+ T cells regulates TCR activation and experimental colitis in mice

TLRs sense various microbial products. Their function has been best characterized in DCs and macrophages, where they act as important mediators of innate immunity. TLR4 is also expressed on CD4+ T cells, but its physiological function on these cells remains unknown. Here, we have shown that TLR4 triggering on CD4+ T cells affects their phenotype and their ability to provoke intestinal inflammation. In a model of spontaneous colitis, Il10-/-Tlr4-/- mice displayed accelerated development of disease, with signs of overt colitis as early as 8 weeks of age, when compared with Il10-/- and Il10-/-Tlr9-/- mice, which did not develop colitis by 8 months. Similar results were obtained in a second model of colitis in which transfer of naive Il10-/-Tlr4-/- CD4+ T cells into Rag1-/- recipients sufficient for both IL-10 and TLR4 induced more aggressive colitis than the transfer of naive Il10-/- CD4+ T cells. Mechanistically, LPS stimulation of TLR4-bearing CD4+ T cells inhibited ERK1/2 activation upon subsequent TCR stimulation via the induction of MAPK phosphatase 3 (MKP-3). Our data therefore reveal a tonic inhibitory role for TLR4 signaling on subsequent TCR-dependent CD4+ T cell responses.

Systemic immune effects of adjuvant chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide and/or radiotherapy in breast cancer: a longitudinal study

Immunotherapy is being increasingly utilized for adjuvant treatment for breast cancer (BC). We have previously described immune functions during primary therapy for BC. The present study describes immune recovery patterns during long-term, unmaintained follow-up after completion of adjuvant therapy.A group of patients with primary BC had been treated with adjuvant radio-chemotherapy (RT + CT) 5-fluorouracil, epirubicin and cyclophosphamide (FEC) (n = 21) and another group with radiotherapy (RT) (n = 20) alone. Immunological testing of NK and T-cell functions was performed initially at the end of adjuvant treatment and repeated after 2, 6 and 12 months. NK cell cytotoxicity was significantly higher (P < 0.05) at all time-points in patients than in age-matched controls and did not differ between the two treatments groups during one year observation. In contrast, lower numbers of CD4 T-cells and lower expression of CD28 on T-cells was observed particularly in RT + CT patients and did not normalize during the observation period. The numbers of T(reg) cells (CD4(+)CD25(high)) were low in the RT + CT group during follow-up, as well as expression of TCRxi, Zap70, p56(lck), P59(fyn) and PI3 k in CD4(+) cells. In contrast, expression of intracellular cytokines (IFN-gamma, IL-2, IL-4) in CD4 and CD8 T cells were significantly higher in RT + CT patients than in the RT group and the difference increased during follow-up. In conclusion, NK-cell cytotoxicity increased during unmaintained long-term follow-up whereas CD4 and regulatory T cells as well as signal transduction molecules remained low following adjuvant radio-chemotherapy.

Docosahexaenoic acid induces apoptosis in lung cancer cells by increasing MKP-1 and down-regulating p-ERK1/2 and p-p38 expression

Different agents able to modulate apoptosis have been shown to modify the expression of the MAP-kinase-phosphatase-1 (MKP-1). The expression of this phosphatase has been considered a potential positive prognostic factor in lung cancer, and smoke was shown to reduce the levels of MKP-1 in ferret lung. Our aim was to assess whether the n-3 polyunsaturated fatty acid docosahexaenoic acid (DHA), known to inhibit the growth of several cancer cells mainly inducing apoptosis, may exert pro-apoptotic effect in lung cancer cells by modifying MKP-1 expression. We observed that DHA increased MKP-1 protein and mRNA expression and induced apoptosis in different lung cancer cell lines (mink Mv1Lu adenocarcinoma cells, human A549 adenocarcinoma and human BEN squamous carcinoma cells). We inhibited the pro-apoptotic effect of DHA by treating the cells with the phosphatase inhibitor Na(3)VO(4) or by silencing the MKP-1 gene with the specific siRNA. This finding demonstrated that the induction of apoptosis by DHA involved a phosphatase activity, specifically that of MKP-1. DHA reduced also the levels of the phosphorylated MAP-kinases, especially ERK1/2 and p38. Such an effect was not observed when the MKP-1 gene was silenced. Altogether, the data provide evidence that the DHA-induced overexpression of MKP-1 and the resulting decrease of MAP-kinase phosphorylation by DHA may underlie the pro-apoptotic effect of this fatty acid in lung cancer cells. Moreover, they support the hypothesis that DHA may exert chemopreventive action in lung cancer.

NK-cell and T-cell functions in patients with breast cancer: effects of surgery and adjuvant chemo- and radiotherapy

Breast cancer is globally the most common malignancy in women. Her2-targeted monoclonal antibodies are established treatment modalities, and vaccines are in late-stage clinical testing in patients with breast cancer and known to promote tumour-killing through mechanisms like antibody-dependent cellular cytotoxicity. It is therefore increasingly important to study immunological consequences of conventional treatment strategies. In this study, functional tests and four-colour flow cytometry were used to detect natural killer (NK)-cell functions and receptors as well as T-cell signal transduction molecules and intracellular cytokines in preoperative breast cancer patients, and patients who had received adjuvant radiotherapy or adjuvant combined chemo-radiotherapy as well as in age-matched healthy controls. The absolute number of NK cells, the density of NK receptors as well as in vitro quantitation of functional NK cytotoxicity were significantly higher in preoperative patients than the post-treatments group and controls. A similar pattern was seen with regard to T-cell signalling molecules, and preoperative patients produced significantly higher amounts of cytokines in NK and T cells compared to other groups. The results indicate that functions of NK and T cells are well preserved before surgery but decrease following adjuvant therapy, which may speak in favour of early rather than late use of immunotherapeutic agents such as trastuzumab that may depend on intact immune effector functions.

Mitogen-Activated Protein Kinase Phosphatase-1 Is a Mediator of Breast Cancer Chemoresistance

The mitogen-activated protein kinase (MAPK) phosphatase (MKP)-1 is overexpressed in a large proportion of breast cancers, and in some systems interferes with chemotherapy-mediated proapoptotic signaling through c-Jun-NH2-terminal kinase (JNK). We therefore sought to examine whether MKP-1 is a mediator of breast cancer chemoresistance using A1N4-myc human mammary epithelial cells, and BT-474 and MDA-MB-231 breast carcinoma cells. Transient or stable overexpression of MKP-1 reduced caspase activation and DNA fragmentation while enhancing viability in the face of treatment with alkylating agents (mechlorethamine), anthracylines (doxorubicin), and microtubule inhibitors (paclitaxel). This overexpression was associated with suppression of JNK activation, and JNK blockade alone induced similar effects. In contrast, reduction of MKP-1 levels using a small interfering RNA, or its targeted inactivation, enhanced sensitivity to these drugs, and this was associated with increased JNK activity. Pharmacologic reduction of MKP-1 by pretreatment with a novel p38 MAPK inhibitor, SD-282, suppressed MKP-1 activation by mechlorethamine, enhanced active JNK levels, and increased alkylating agent–mediated apoptosis. Combination treatment with doxorubicin and mechlorethamine had similar effects, and the enhanced efficacy of this regimen was abolished by forced overexpression of MKP-1. These results suggest that the clinical efficacy of combinations of alkylating agents and anthracyclines are due to the ability of the latter to target MKP-1. Moreover, they support the hypothesis that MKP-1 is a significant mediator of breast cancer chemoresistance, and provide a rationale for development and translation of other agents targeting MKP-1 into the clinical arena to overcome resistance and induce chemosensitization. [Cancer Res 2007;67(9):4459–66]

MAPK phosphatases--regulating the immune response

Mitogen-activated protein kinase (MAPK) phosphatases (MKPs) are protein phosphatases that dephosphorylate both the phosphothreonine and phosphotyrosine residues on activated MAPKs. Removal of the phosphates renders MAPKs inactive, effectively halting their cellular function. In recent years, evidence has emerged that, similar to MAPKs, MKPs are pivotal in the regulation of immune responses. By deactivating MAPKs, MKPs can modulate both innate and adaptive immunity. A number of immunomodulatory agents have been found to influence the expression of MKP1 in particular, highlighting the central role of this phosphatase in immune regulation. This Review discusses the properties, function and regulation of MKPs during immune responses.

Tumor-associated macrophages and CD3-zeta expression of tumor-infiltrating lymphocytes in human esophageal squamous-cell carcinoma

The clinical significance of tumor-associated macrophages (TAMs) and CD3-zeta chain expression of tumor-infiltrating lymphocytes (TILs), and their correlation in human esophageal squamous cell carcinoma (SCC) are not very clear. Serial histological slides from 137 esophageal SCC patients who had undergone tumor resection were immunohistochemically studied with anti-CD68, anti-CD3-zeta and anti-CD3-epsilon antibodies. TAMs infiltration (expressed as macrophage index, M(phi)I) and CD3-zeta expression (judged by Z/E = CD3-zeta+ cells/CD3-epsilon+ cells ratio) in different tissue compartments were observed. We found that the total tumor tissue region had significantly higher macrophage density and lower CD3-zeta expression (mean +/- SD: M(phi)I(normal): 225.3 +/- 85.9; Z/E(total): 0.52 +/- 0.25; n = 137) relative to adjacent histologically normal esophageal squamous epithelium (M(phi)I(normal): 60.5 +/- 31.7, P < 0.001; Z/E(normal): 0.79 +/- 0.35, P = 0.001; n = 70). Significantly higher M(phi)I(stroma) (P = 0.006) and lower Z/E(total) (P = 0.016) were detected in patients with lymph node metastasis than in those without. Patients with high M(phi)I(total) and M(phi)I(cancer) but low Z/E(total) had poorer surgical outcomes. Univariate analysis of M(phi)I(total) and multivariate analysis of M(phi)I(total) with specific clinico-pathological parameters demonstrated M(phi)I(total) to be an independent prognostic factor for survival in esophageal SCC patients (Cox proportional hazard model, P = 0.029 and P = 0.031, respectively).

Immunobiology of the sentinel lymph node and its potential role for antitumour immunity

The sentinel lymph node (SLN) is thought to be an important lymphoid organ for protecting against metastasis and is thought to play a crucial part in provoking antitumour immunity. Because SLN biopsy is undertaken for various types of cancers, such as malignant melanoma and breast cancer, SLN mapping has become a standard procedure, thereby eliminating unnecessary lymph-node resection in patients who do not have affected nodes. The immune surveillance activities of the SLN in melanoma and breast cancer are thought to be suppressed, whereas in cancers of gastrointestinal-tract, the presence of T cells in the SLN has not been shown to suppress the host's immune function. Furthermore, cell death after primary systemic chemotherapy for solid tumours can provoke an antigen-specific immunity in the tumour, which affects tumour response to treatment and, therefore, survival in patients. This review discusses the immunobiology of the SLN and potential strategies for activation of antitumour immunity by primary systemic chemotherapy and other modalities, in terms of tumour-size reduction and survival benefit.

TCR zeta down-regulation under chronic inflammation is mediated by myeloid suppressor cells differentially distributed between various lymphatic organs

T cell AgR zeta chain down-regulation associated with T cell dysfunction has been described in cancer, infectious, and autoimmune diseases. We have previously shown that chronic inflammation is mandatory for the induction of an immunosuppressive environment leading to this phenomenon. To identify the key immunosuppressive components, we used an in vivo mouse model exhibiting chronic inflammation-induced immunosuppression. Herein, we demonstrate that: 1) under chronic inflammation secondary lymphatic organs display various immunological milieus; zeta chain down-regulation and T cell dysfunction are induced in the spleen, peripheral blood, and bone marrow, but not in lymph nodes, correlating with elevated levels of Gr1(+)Mac-1(+) myeloid suppressor cells (MSC); 2) MSC are responsible for the induction of such an immunosuppression under both normal and inflammatory conditions; and 3) normal T cells administered into mice exhibiting an immunosuppressive environment down-regulate their zeta expression. Such an environment is anticipated to limit the success of immunotherapeutic strategies based on vaccination and T cell transfer, which are currently under investigation for immunotherapy of cancer.

Preferential cell death of CD8+ effector memory (CCR7-CD45RA-) T cells by hydrogen peroxide-induced oxidative stress

T cells are used in many cell-based cancer treatments. However, oxidative stress that is induced during various chronic inflammatory conditions, such as cancer, can impair the immune system and have detrimental effects on T cell function. In this study, we have investigated the sensitivity of different human T cell subsets to H(2)O(2)-induced oxidative stress. We showed that central memory (CD45RA(-)CCR7(+)) and effector memory (CD45RA(-)CCR7(-)) T cells are more sensitive to H(2)O(2) as compared with naive (CD45RA(+)CCR7(+)) T cells. Furthermore, the study showed that CD8(+) effector memory T cells are more sensitive to low levels of H(2)O(2) (5 microM) compared with other types of T cells investigated. H(2)O(2)-exposed CD45RO(+) T cells showed mitochondrial depolarization prior to caspase 3 activity. Moreover, the pan-caspase inhibitor z-Val-Ala-Asp(OMe)-fluoromethylketone rescued cells from death. These experiments suggest that H(2)O(2)-induced cell death of CD45RO(+) T cells acts via the mitochondrial pathway and that caspase involvement is needed. This study suggests that oxidative stress in cancer patients can be disadvantageous for T cell-based adoptive cell transfer therapies, since effector memory T cells are the primary phenotype of the cells administered.

Polarized development of memory cell-like IFN-gamma-producing cells in the absence of TCR zeta-chain

TCR/CD3 complex-mediated signals play critical roles in regulating CD4(+) Th cell differentiation. In this report, we have examined the in vivo role of a key TCR/CD3 complex molecule zeta-chain in regulating the differentiation of Th cells. We have studied T cells from zeta-chain-deficient mice (zetaKO mice), zeta-chain-bearing mice (zeta(+) mice), and from zetaKO mice expressing a FcRgamma chain transgene (FcRgammaTG, zetaKO mice). Our results demonstrated that, compared with those of control mice, CD4(+) T cells and not CD8(+) T cells from zetaKO mice were polarized into IFN-gamma-producing cells. Some of these IFN-gamma-producing cells could also secrete IL-10. Interestingly, zetaKO mouse T cells produced IFN-gamma even after they were cultured in a Th2 condition. Our studies to determine the molecular mechanisms underlying the polarized IFN-gamma production revealed that the expression level of STAT4 and T-bet were up-regulated in freshly isolated T cells from zetaKO mice. Further studies showed that noncultured zetaKO mice CD4(+) T cells and thymocytes bore a unique memory cell-like CD44(high), CD62L(low/neg) phenotype. Altogether, these results suggest that, in the absence of the zeta-chain, CD4(+) T cells develop as polarized IFN-gamma-producing cells that bear a memory cell-like phenotype. The zeta-chain-bearing T cells may produce a large amount of IFN-gamma only after they are cultured in a condition favoring Th1 cell differentiation. This study may provide important implications for the down-regulation of zeta-chain in T cells of patients bearing a variety of tumors, chronic inflammatory and infectious diseases.

Evaluation of glucocorticoid sensitivity in 697 pre-B acute lymphoblastic leukemia cells after overexpression or silencing of MAP kinase phosphatase-1

PURPOSE

To determine the effect of modulating MAP kinase phosphatase-1 (MKP-1) expression levels on cell death induced by glucocorticoid (GC) or hydroxyurea (HU) treatment in the human pre-B acute lymphoblastic leukemia cell line 697.

METHODS

Stable MKP-1 overexpressing transformants of the 697 pre-B acute lymphoblastic leukemia cell line were created and tested for sensitivity to the GC triamcinolone acetonide (TA) and HU, and compared to a control 697 cell line containing normal MKP-1 expression levels. Small interfering RNAs (siRNAs) were designed to inhibit MKP-1 expression and evaluated for their effect on GC-mediated cell death.

RESULTS

MKP-1 overexpression caused a phenotype of partial resistance to HU-induced apoptosis but not to GC-induced apoptosis. Electroporation of siRNAs effectively silenced MKP-1 expression, and increased sensitivity to TA by 9.6+/-1.9%.

CONCLUSIONS

Because MKP-1 protects certain tumor cells from chemotherapy-induced apoptosis, its inhibition is being considered as a possible strategy for combination cancer therapy. However, this study suggests that while MKP-1 inhibition may improve the efficacy of DNA damaging agents, it may have only limited utility in combination with glucocorticoids.

CD28 expression in sentinel node biopsies from breast cancer patients in comparison with CD3-zeta chain expression

Background

Immunosuppression is documented in several malignant diseases, including breast cancer. Subsequently, future therapeutic concepts might include immunological approaches. However, detailed knowledge about tumor immunogenicity and host immunoreactivity, and how to assess these adequately, is still limited. We studied CD28 and CD3-ζ expression in sentinel node biopsies (SNB) from breast cancer patients to analyze tumor-related changes in T cell activity.

Method

25 women underwent surgery for primary breast cancer, including SNB. Frozen sections from 21 sentinel nodes could be analyzed with a double-staining technique. CD28 expression was studied in CD4+ and CD8+ T-lymphocyte subsets and compared with CD3-ζ expression in three specified nodal regions.

Results

The degree of CD28 expression varied between the different lymph node areas. The lowest degree of CD28 expression was observed in CD4+ T-lymphocytes in the paracortex and germinal centers. Here, a good agreement with CD3-ζ expression was found. A higher CD28 expression was noted in CD4+ T-cells in the primary follicles, where concordance with CD3-ζ expression was weaker. The CD8+ T-lymphocyte subset displayed generally a higher degree of CD28 expression than the CD4+ subset.

Conclusion

Sentinel lymph nodes from breast cancer patients displayed local immunosuppression of varying extent. In the areas with the lowest degree of CD28 expression an accordingly low CD3-ζ expression was found. The SNB might prove an important diagnostic tool for the evaluation of interactions between tumor and the host immune system, helping to select patients who might benefit from adjuvant immunotherapy.

TCR zeta-chain downregulation: curtailing an excessive inflammatory immune response

The T-cell receptor (TCR) functions in both antigen recognition and signal transduction, which are crucial initial steps of antigen-specific immune responses. TCR integrity is vital for the induction of optimal and efficient immune responses, including the routine elimination of invading pathogens and the elimination of modified cells and molecules. Of the TCR subunits, the zeta-chain has a key role in receptor assembly, expression and signalling. Downregulation of TCR zeta-chain expression and impairment of T-cell function have been shown for T cells isolated from hosts with various chronic pathologies, including cancer, and autoimmune and infectious diseases. This review summarizes studies of the various pathologies that show this phenomenon and provides new insights into the mechanism responsible for downregulation of zeta-chain expression, its relevance and its clinical implications.

Helicobacter pylori arginase inhibits T cell proliferation and reduces the expression of the TCR zeta-chain (CD3zeta)

Helicobacter pylori infects approximately half the human population. The outcomes of the infection range from gastritis to gastric cancer and appear to be associated with the immunity to H. pylori. Patients developing nonatrophic gastritis present a Th1 response without developing protective immunity, suggesting that this bacterium may have mechanisms to evade the immune response of the host. Several H. pylori proteins can impair macrophage and T cell function in vitro through mechanisms that are poorly understood. We tested the effect of H. pylori extracts and live H. pylori on Jurkat cells and freshly isolated human normal T lymphocytes to identify possible mechanisms by which the bacteria might impair T cell function. Jurkat cells or activated T lymphocytes cultured with an H. pylori sonicate had a reduced proliferation that was not caused by T cell apoptosis or impairment in the early T cell signaling events. Instead, both the H. pylori sonicate and live H. pylori induced a decreased expression of the CD3zeta-chain of the TCR. Coculture of live H. pylori with T cells demonstrated that the wild-type strain, but not the arginase mutant rocF(-), depleted L-arginine and caused a decrease in CD3zeta expression. Furthermore, arginase inhibitors reversed these events. These results suggest that H. pylori arginase is not only important for urea production, but may also impair T cell function during infection.

Sustained exposure to bacterial antigen induces interferon-γ-dependent T cell receptor ζ down-regulation and impaired T cell function

T cell antigen receptor zeta chain down-regulation and impaired in vitro T cell function have been described in cancer and autoimmune and infectious diseases. However, the immunological basis for this phenomenon is unknown. Sustained exposure to antigen and chronic systemic inflammation, factors shared by the various pathologies, might account for this phenomenon. We developed an in vivo experimental system that mimics these conditions and show that sustained exposure of mice to bacterial antigens was sufficient to induce T cell antigen receptor zeta chain down-regulation and impair T cell function, provided an interferon-gamma-dependent T helper type 1 immune response developed. This indicates zeta chain down-regulation could be a physiological response that attenuates an exacerbated immune response. However, it can act as a 'double-edged sword', impairing immune responses to chronic diseases.

Down-regulation of the CD3-zeta chain in sentinel node biopsies from breast cancer patients

BACKGROUND

In several neoplastic diseases, immunosuppression has been shown to correlate with disease stage, progression, and outcome. As the prognosis for metastatic breast cancer is still pessimistic, additional strategies are being sought to improve survival. Local immunosuppression in sentinel node biopsies from 24 evaluable breast cancer patients was studied as a possible way of selecting patients for immunotherapy.

METHOD

Sentinel node biopsy was performed in 24 out of 25 women operated on for primary breast cancer (one was not evaluable). Specimens were snap-frozen and double-stained for the zeta-chain of the T-cell receptor. The degree of down-regulation of the zeta-chain was evaluated in three different lymph-node areas: primary follicles, secondary follicles, and paracortex.

RESULTS

Down-regulation of varying degrees was noted in all 24 sentinel node biopsies. A high degree of down-regulation (more than 50% of T-cells not expressing zeta-chain) was seen in the primary follicles in six patients (25%), in the secondary follicles in 13 patients (72%), and in the paracortex in 19 patients (79%).

CONCLUSION

Local down-regulation of an immune function parameter was seen in sentinel node biopsies from breast cancer patients. In addition to possible prognostic implications, the sentinel node might be an appropriate location for detecting early-stage immunological down-regulation, which might open a possibility of selecting patients who could benefit from immunotherapy.

Immunologic monitoring of cancer vaccine therapy: results of a workshop sponsored by the Society for Biological Therapy

The Society for Biological Therapy held a Workshop last fall devoted to immune monitoring for cancer immunotherapy trials. Participants included members of the academic and pharmaceutical communities as well as the National Cancer Institute and the Food and Drug Administration. Discussion focused on the relative merits and appropriate use of various immune monitoring tools. Six breakout groups dealt with assays of T-cell function, serologic and proliferation assays to assess B cell and T helper cell activity, and enzyme-linked immunospot assay, tetramer, cytokine flow cytometry, and reverse transcription polymerase chain reaction assays of T-cell immunity. General conclusions included: (1) future vaccine studies should be designed to determine whether T-cell dysfunction (tumor-specific and nonspecific) correlated with clinical outcome; (2) tetramer-based assays yield quantitative but not functional data (3) enzyme-linked immunospot assays have the lowest limit of detection (4) cytokine flow cytometry have a higher limit of detection than enzyme-linked immunospot assay, but offer the advantages of speed and the ability to identify subsets of reactive cells; (5) antibody tests are simple and accurate and should be incorporated to a greater extent in monitoring plans; (6) proliferation assays are imprecise and should not be emphasized in future studies; (7) the reverse transcription polymerase chain reaction assay is a promising research approach that is not ready for widespread application; and (8)there is a critical need to validate these assays as surrogates for vaccine potency and clinical effect. Current data and opinion support the use of a functional assay like the enzyme-linked immunospot assay or cytokine flow cytometry in combination with a quantitative assay like tetramers for immune monitoring. At present, assays appear to be most useful as measures of vaccine potency. Careful immune monitoring in association with larger scale clinical trials ultimately may enable the correlation of monitoring results with clinical benefit.

Aberrant nuclear expression of AP-1 and NFkappaB in lymphocytes of women stressed by the experience of breast biopsy

We have investigated the expression of AP-1 and NFkappaB in peripheral blood lymphocytes of women scheduled for breast biopsy. Samples were collected when women were informed of the need for biopsy (prebiopsy, T1, 5-7 days prior to the actual biopsy) and 7-10 days after they learned the result of their biopsy (postbiopsy, T2). At the time of blood collection, psychological stress was evaluated using Speilberger's State Trait Anxiety Inventory (STAI) and the Profile of Mood States (POMS). Women scheduled to undergo breast biopsy reported significant increases in anxiety (STAI) and mood disturbance (POMS). Gel shift mobility assays showed that mitogen stimulated peripheral blood lymphocytes of these women were less capable of the nuclear expression of AP-1 or NFkappaB at T1. Similar assessments, 7-10 days after the women learned of the results of their breast biopsy, showed these same women to have a marked reduction in anxiety and mood disturbance and an increased nuclear translocation of AP-1 and NFkappaB. These results show a significant decrease in nuclear AP-1 and NFkappaB expression during the period of emotional distress prior to biopsy with a return of nuclear transcription activity to normal levels when distress was relieved. Several studies have correlated increased psychological stress with decreased immune function. The results of this study suggest that psychological stress may mediate immunosuppression by altering the expression of the transcription factors, AP-1 and NFkappaB.

Differential Loss of T Cell Signaling Molecules in Metastatic Melanoma Patients’ T Lymphocyte Subsets Expressing Distinct TCR Variable Regions

In this study we tested the hypothesis that loss of T cell signaling molecules in metastatic melanoma patients’ T cells may affect differently T cell subsets characterized by distinct TCR variable regions. By a two-color immunofluorescence technique, expression of ζ-chain, lck, and ZAP-70 was evaluated in CD3+ T cells and in three representative T cell subsets expressing TCRAV2, TCRBV2, or TCRBV18. Partial loss of lck and ZAP-70 was found in CD3+ T cells from PBL of most melanoma patients, but not of healthy donors. The extent of ζ-chain, lck, and ZAP-70 loss depended on the TCRV region expressed by the T cells, and this association was maintained or increased during progression of disease. Coculture of patients’ or donors’ T cell with melanoma cells, or with their supernatants, but not with normal fibroblasts or their supernatants, down-modulated expression of ζ-chain, lck, and ZAP-70 in a TCRV region-dependent way. Immunodepletion of soluble HLA class I molecules present in tumor supernatants, but not of soluble ICAM-1, blocked the suppressive effect on T cell signaling molecule expression. T cell activation with mAbs to a single TCRV region and to CD28 led to significant and TCRV region-specific re-induction of ζ-chain expression. These findings indicate that extent of TCR signaling molecules loss in T lymphocytes from metastatic melanoma patients depends on the TCRV region and suggest that tumor-derived HLA class I molecules may contribute to induce such alterations.