Density Of Tregs Research Articles

Association of intratumoral FoxP3 T-regulatory lymphocytes and perineural invasion in colorectal adenocarcinoma.

51 Background: In colorectal cancer, higher densities of lymphocytes in the tumor microenvironment (TME) have been associated with better clinical outcomes. FoxP3+ regulatory T-cells (Tregs) are a subset of lymphocytes that play an immunosuppressive role in the TME. However, the impact of Tregs in the TME in colon cancer prognosis is more controversial. We evaluated the densities of FoxP3+ Tregs at multiple locations in matched endoscopic biopsies and resection specimens from patients with colonic adenocarcinoma to assess concordance of Treg densities between locations, and the association with prognostic factors. Methods: Patients with banked, matched endoscopic biopsies and surgically resected colon adenocarcinoma specimens from a single institution from 2006-2016 were selected for evaluation. Paraffin embedded tissue samples were cut and stained with FoxP3 immunohistochemical stain. The densities of FoxP3 positive cells were counted within a 1 mm2 area at the center of the tumor and at the invasive margin. The densities of FoxP3 positive lymphocytes were compared between the center and invasive margin, and to prognostic factors. Results: 107 matched endoscopic biopsies and surgical resection specimens were evaluated. A moderate-strong correlation was noted in levels of FoxP3+ cells between endoscopic biopsies and resected specimens at the center of the tumor (r= 0.68) and invasive margin (r=0.69). Higher FoxP3 densities were associated with a decreased rate of perineural invasion (P= 0.040). Levels of Tregs in endoscopic biopsies were correlated with the levels in the larger tumor of resected colon adenocarcinoma specimens. There was a weak correlation between increased density of Tregs and lower anatomic stage (R2 = 0.05). Conclusions: Tregs are a potential biomarker that can be evaluated in neoadjuvant immunomodulatory therapies in clinical trials to assess for response. Moreover, Treg levels are associated with perineural invasion, a predictive factor for decreased response to chemotherapy, underscoring the potential for immunomodulatory therapies in colorectal adenocarcinoma.

The Th17/Treg Cytokine Imbalance in Chronic Obstructive Pulmonary Disease Exacerbation in an Animal Model of Cigarette Smoke Exposure and Lipopolysaccharide Challenge Association

We proposed an experimental model to verify the Th17/Treg cytokine imbalance in COPD exacerbation. Forty C57BL/6 mice were exposed to room air or cigarette smoke (CS) (12 ± 1 cigarettes, twice a day, 30 min/exposure and 5 days/week) and received saline (50 µl) or lipopolysaccharide (LPS) (1 mg/kg in 50 µl of saline) intratracheal instillations. We analyzed the mean linear intercept, epithelial thickness and inflammatory profiles of the bronchoalveolar lavage fluid and lungs. We evaluated macrophages, neutrophils, CD4+ and CD8+ T cells, Treg cells, and IL-10+ and IL-17+ cells, as well as STAT-3, STAT-5, phospho-STAT3 and phospho-STAT5 levels using immunohistochemistry and IL-17, IL-6, IL-10, INF-γ, CXCL1 and CXCL2 levels using ELISA. The study showed that CS exposure and LPS challenge increased the numbers of neutrophils, macrophages, and CD4+ and CD8+ T cells. Simultaneous exposure to CS/LPS intensified this response and lung parenchymal damage. The densities of Tregs and IL-17+ cells and levels of IL-17 and IL-6 were increased in both LPS groups, while IL-10 level was only increased in the Control/LPS group. The increased numbers of STAT-3, phospho-STAT3, STAT-5 and phospho-STAT5+ cells corroborated the increased numbers of IL-17+ and Treg cells. These findings point to simultaneous challenge with CS and LPS exacerbated the inflammatory response and induced diffuse structural changes in the alveolar parenchyma characterized by an increase in Th17 cytokine release. Although the Treg cell differentiation was observed, the lack of IL-10 expression and the decrease in the density of IL-10+ cells observed in the CS/LPS group suggest that a failure to release this cytokine plays a pivotal role in the exacerbated inflammatory response in this proposed model.

Abstract 5736: In silico analysis shows that PTEN loss and AR overexpression are associated with increased CD8+ T-cell and Treg density and earlier disease recurrence in prostate cancer

Abstract PTEN loss occurs in 20-30% prostate cancers (PCa), is associated with worse outcome, and regulates the type I interferon response through the interferon regulatory factor 3 (IRF3). Both PTEN loss and the overexpression of the androgen receptor (AR) promote castrate-resistant PCa leading to a more aggressive disease. To characterize the associations between PTEN loss and AR expression in immune cell infiltration in the tumor microenvironment (TME), we conducted an in silico analysis in two PCa cohorts. RNAseq and gene expression array data were imputed in CIBERSORT to evaluate the relative frequency of 22 immune infiltrating cells in the TME. PTEN was lost in 19.7% (97/491) and 19.8% (26/131) in the TCGA and MSKCC cohorts, respectively. AR was overexpressed in 56% (279/491) and 54% (71/131) of the TCGA and MSKCC cohorts, respectively. Remarkably, AR overexpression was associated with decreased CD8+ T-cells infiltration in both the TCGA (p<0.0001) and MSKCC (p=0.001) cohorts. In addition we found that PTEN loss was associated with increased Treg infiltration in both the TCGA (p=0.002) and MSKCC (p<0.0001) cohorts. PTEN loss was also associated with low plasma cell infiltration in both the TCGA and MSKCC cohorts (p=0.001 and p=0.002, respectively). More detailed analysis of the MSKCC cohort showed that PTEN loss correlated with increased CD8+ T-cell density in the TME (p<0.0001). When we compared the immune cell infiltration profile from the primary and metastatic tumors in the MSKCC cohort, we found an increased infiltration of memory B-cell, Treg, and active dendritic cells (p<0.0001, p=0.005, and p=0.002, respectively) in the metastatic tumors. We then investigated the association between PTEN and AR expression with the most common immunotherapeutic targets. We found that PTEN loss was associated with increased PD-1 expression in MSKCC cohort (p<0.0001) and with reduced PD-L1 expression in the TCGA cohort (p=0.006). Increased AR expression correlated with reduced PD-1 expression in both TCGA and MSKCC cohorts (p<0.0001) and with reduced CTLA-4 expression in TCGA cohort (p=0.009). There was a positive association between PD-1 and CTLA-4 expression with CD8+ T-cell and Treg infiltration in both cohorts. Log-rank analysis showed that PTEN loss and high Treg infiltration predicted earlier disease recurrence in both the TCGA and MSKCC cohorts (p=0.021 and p=0.027, respectively). In addition, combined PTEN loss and increased CD8+ T-cell infiltration promotes earlier disease recurrence in both the TCGA and MSKCC cohorts (p=0.05 and p=0.029, respectively). These findings imply that the immune cell profile in the TME can be influenced by changes in the expression of PTEN and AR, suggesting that novel immunotherapies may promote better responses in castrate-resistant PCa. Citation Format: Thiago Vidotto, Madhuri Koti, Jeremy A. Squire. In silico analysis shows that PTEN loss and AR overexpression are associated with increased CD8+ T-cell and Treg density and earlier disease recurrence in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5736.

Prognostic value of tumor infiltration immune cells in pancreatic cancer

Objective: To investigate the prognostic effect of tumour-infiltrating immune cell, including CD8(+) T cell, regulatory T-cell (Treg) and myeloid-derived suppressor cells (MDSC) on pancreatic patients. Methods: This study retrospectively collected the data of 80 patients who were histologically diagnosed of pancreatic cancer and underwent classical R0 surgical resection at Tianjin Medical University Cancer Institute and Hospital from January 2010 to May 2012. All patients survival were followed up until the cut-off date of January 2015. Clinicopathological features including immunohistochemical staining of FOXP3, CD8 and CD33 were reviewed as indice for evaluating the prognosis of pancreatic patients.The prognostic effect of tumour-infiltrating immune cells were analysed by Kaplan-Meier and Log-rank test. Multiple-factor analysis was conducted with the Cox regression model. The correlation between tumour-infiltrating immune cells and clinicopathological features was analysed by χ(2) test. The C57BL/6 mouse model was used to evaluate the efficacy of Treg and MDSC depletion therapy in vivo. Student's t-test was applied to assess the difference of the tumour volume, Ki-67 positive rate and CD8(+) T-cell infiltration proportion between depletion group and control group. Results: Eventually, 80 patients were included and no patient was lost during the follow-up period. The median follow-up time was 33.2 months (7.4-59.9 months). Patients with high level of tumour-infiltrating CD8(+) T cells had longer overall survival (OS) time ((21.6±11.9)months vs. (13.6±7.4)months, χ(2)=4.647, P = 0.031) than those with low level of tumour-infiltrating CD8(+) T cells. Tumor infiltration FOXP3(+) cells were strongly associated with reduced OS((20.9±8.5)months vs.(13.4±8.8)months, χ(2)=10.528, P=0.001), reduced relapse free survival (RFS) ((15.2±9.0)months vs. (9.5±8.8)months, χ(2)=6.288, P=0.012) and larger tumor size(χ(2)=4.073, r=0.226, P=0.044). The high intratumoural MDSC group showed a significantly shorter OS((23.5±11.8)months vs. (13.8±7.6)months, χ(2)=5.724, P=0.017), RFS((17.9±11.3)months vs. (10.2±7.5)months, χ(2)=7.430, P=0.006) and more advanced N stage (χ(2)=4.714, r=0.243, P=0.030) than the low intratumoural MDSC group. Multivariate Cox analysis revealed that pTNM (P=0.008), tumour-infiltrating Treg density (P=0.009) and intratumoural MDSC density (P=0.034) were independent and negative prognostic factors for OS; pTNM(P=0.003) and tumour-infiltrating MDSC level(P=0.018) were independent and negative factors for RFS. The experiment in vivo revealed that Treg and MDSC depletion therapy significantly decreased tumour volume in the C57BL/6 mouse model of subcutaneous tumours((1 396.3±442.5)mm(3) vs. (3 356.9±533.5)mm(3), t=4.986, P=0.018). Tumour Ki-67 positive rate significantly decreased (23%±5% vs. 55%±10%, t=3.130, P=0.011) in Treg and MDSC depletion group, whereas, the proportion of tumour-infiltrating CD8(+) T cells significantly increased in depletion groups (3.25%±0.69% vs. 0.76%±0.25%, t=3.393, P=0.007). Conclusions: Tumour-infiltrating Treg, MDSC level and pTNM stage are independent prognostic factors for patients with pancreatic cancer. Treg and MDSC depletion therapy can significantly retard tumour growth and increase the level of tumour-infiltrating CD8(+) T-cells in the C57BL/6 mouse model of subcutaneous tumours.

Regulatory T-Cell Distribution within Lung Compartments in COPD

ABSTRACTThe importance of the adaptive immune response, specifically the role of regulatory T (Treg) cells in controlling the obstruction progression in smokers, has been highlighted. To quantify the adaptive immune cells in different lung compartments, we used lung tissues from 21 never-smokers without lung disease, 22 current and/or ex-smokers without lung disease (NOS) and 13 current and/or ex-smokers with chronic obstructive pulmonary disease (COPD) for histological analysis. We observed increased T, B, IL-17 and BAFF+ cells in small and large airways of COPD individuals; however, in the NOS, we only observed increase in T and IL-17+ cells only in small airways. A decrease in the density of Treg+, TGF-β+ and IL-10+ in small and large airways was observed only in COPD individuals. In the lymphoid tissues, Treg, T,B-cells and BAFF+ cells were also increased in COPD; however, changes in Treg inhibitory associated cytokines were not observed in this compartment. Therefore, our results suggest that difference in Treg+ cell distributions in lung compartments and the decrease in TGF-β+ and IL-10+ cells in the airways may lead to the obstruction in smokers.

Pediatric autoimmune hepatitis shows a disproportionate decline of regulatory T cells in the liver and of IL-2 in the blood of patients undergoing therapy.

Background & AimsThe autoimmune hepatitis (AIH) is a chronic hepatitis driven by the adaptive immunity that affects all age groups. A functional and numerical regulatory T cell (Treg) defect has been reported in pediatric AIH (pAIH), while an intrahepatic increase in adult AIH (aAIH) patients has been detected in current research findings.MethodsTherefore, we quantified the intrahepatic numbers of Treg, T and B cells, as well as serum cytokine levels before and during therapy in pAIH.ResultsWe found a disproportional intrahepatic enrichment of Tregs in untreated pAIH compared to pediatric non-alcoholic fatty liver disease. The increase of Treg/total T cells was even more pronounced than in aAIH due to fewer infiltrating T and B cells. Portal densities of Treg, as well as total T and B cells, declined significantly during therapy. However, portal Treg densities decreased disproportionately, leading to even decreasing ratios of Treg to T and B cells during therapy. Out of 28 serum cytokines IL-2 showed the strongest (10fold) decrease under therapy. This decline of IL-2 was associated with decreasing intrahepatic Treg numbers under therapy. None of the baseline T and B cell infiltration parameters were associated with the subsequent treatment response in pAIH.ConclusionsIntrahepatic Tregs are rather enriched in untreated pAIH. The disproportional decrease of Tregs during therapy may be caused by a decrease of IL-2 levels. New therapies should, therefore, aim in strengthening intrahepatic immune regulation.

Neoadjuvant randomized trial of degarelix (Deg) ± cyclophosphamide/GVAX (Cy/GVAX) in men with high-risk prostate cancer (PCa) undergoing radical prostatectomy (RP).

5077 Background: GVAX-Prostate is a GM-CSF–secreting allogeneic cellular vaccine, whose immunogenicity may be enhanced by androgen ablation as well as low-dose Cy. We conducted a neoadjuvant immunologic study comparing Deg vs. Cy/GVAX→Deg. Methods: Men with high-risk PCa (T1c–3b N0 M0, Gleason 7–10) were randomized 1:1 to Deg(240 mg SQ) vs. Cy(200 mg/m2 IV)/GVAX(2.5×108 PC3 cells, 1.6×108 LNCaP cells) given 2 wk before Deg; all pts then had RP 2 wk after Deg. CD8+ T cell and Treg densities in the primary tumor were quantified by IHC (cells/mm2). Clinical endpoints were time-to-PSA-relapse, time-to-next-therapy, and time-to-metastasis. The study was powered (α = 0.05, β = 0.18) to show a 2-fold increase in mean CD8+ density with Cy/GVAX→Deg (Arm B) vs. Deg (Arm A). Results: 28 men were enrolled (Arm A = 15, Arm B = 13). A concurrent control group (N = 20) who did not receive neoadjuvant therapy provided untreated RP tumor samples. Baseline variables were balanced across study arms: 64% had Gleason ≥8, 56% were pT3b, 18% were pN1. There were nonsignificant increases in CD8+ and Treg densities in Arm B vs. A, and statistically significant increases in CD8+ and Treg densities in both arms (A, B) compared to group C (TABLE). CD8+ and Treg densities were strongly correlated. Outcomes were numerically better in Arm B vs A with respect to time-to-PSA-relapse (HR 0.42, 95%CI 0.13–1.38, P= 0.15) and time-to-next-therapy (HR 0.43, 95%CI 0.13–1.39, P= 0.16), although not statistically significant. Conclusions: Intratumoral immune infiltrates were marginally augmented by Cy/GVAX→Deg vs. Deg alone, while CD8+ and Treg densities were significantly greater in both study arms vs. control, supporting the immunogenic effects of androgen ablation. CD8+ / Treg ratios were remarkably consistent across groups. Clinical trial information: NCT01696877. [Table: see text]

The microenvironment in primary cutaneous melanoma with associated spontaneous tumor regression: evaluation for T-regulatory cells and the presence of an immunosuppressive microenvironment.

Spontaneous tumor regression, regression in the absence of therapeutic intervention, can be identified histologically in over 25% of primary cutaneous melanomas at initial diagnosis. A unique subset of T lymphocytes found in areas of regression can be histologically distinguished from tumor-infiltrating T lymphocytes (TIL) found in areas of tumor progression. We call this unique subset of T lymphocytes regression-associated T lymphocytes (RATs). The aim of this study is to determine the phenotype of lymphocytes and the density of specific cell types linked to immunosuppression in areas of tumor progression compared with areas of tumor regression. These specific cell types include T-regulatory cells (Tregs) and S100A9 cells. A total of 14 primary cutaneous melanomas with areas of progression and regression were used. Immunohistochemistry staining was used to identify CD4 cells, CD8 cells, Tregs, and S100A9 cells. Two independent observers manually counted three high-powered ×40 fields. There was no predominance of CD4 or CD8 T lymphocytes in either RATs or TIL. We identified a lower density of Tregs in RATs compared with TIL when using the FOXP3/CD4 Treg marker (P=0.04) and a marginal difference when using our second, confirmatory Treg marker, FOXP3/CD25 (P=0.11). We observed a lower density of S100A9 cells in RATs compared with TIL (P=0.002). There was an observable difference in the tumor microenvironments of RATs and TIL, with RATs having a significantly lower density of Tregs and S100A9 cells. We deduce that the absence of immunosuppression in areas of regression allows for a more robust immune response and thus effective eradication of tumor cells.

Higher densities of Foxp3+ regulatory T cells are associated with better prognosis in triple-negative breast cancer

The role of Forkhead Box Protein 3 (Foxp3) expressing regulatory T cells (Tregs) in breast cancer remains unclear. We examined the abundance and localisation of total T cells, B cells and Tregs within samples from triple-negative breast cancers (TNBCs) and asked whether these parameters were associated with clinicopathological features of the cancer or clinical outcomes. Samples from TNBCs diagnosed between 2003 and 2010 in Singapore were divided into "high" and "low" intra-tumoural or stromal groups, based on whether they had higher or lower than median densities of specific tumour-infiltrating lymphocyte populations (CD3+ total T cells, Foxp3+CD3+ Tregs, or CD20+ B cells) in the intra-tumoural space or stroma. Of the 164 samples, patients bearing tumours with high Tregs within their intra-tumoural, but not stromal, areas experienced significantly longer overall and disease-free survival compared to individuals with low Treg densities. These "high intra-tumoural Treg" tumours were also characterised by relatively higher frequencies of CD8+ T cells and CD20+ B cells, and expressed significantly higher levels of some genes associated with inflammation, immune cell functions and trafficking, altogether consistent with a more "immune-activated" tumour microenvironment, in contrast to tumours bearing lower densities of Tregs. In summary, the combination of high densities of intra-tumoural Tregs, CD8+ T cells and CD20+ B cells represents a favourable prognostic panel in TNBCs. These data also indicate new avenues for further investigation on the interaction between immune cell types within the tumour microenvironment and highlight the potential of Treg density and localisation within tumours to affect clinical outcome.

Tumour-infiltrating regulatory T cell density before neoadjuvant chemoradiotherapy for rectal cancer does not predict treatment response.

Neoadjuvant (preoperative) chemoradiotherapy (CRT) decreases the risk of rectal cancer recurrence and reduces tumour volume prior to surgery. However, response to CRT varies considerably between individuals and factors associated with response are poorly understood. Foxp3+ regulatory T cells (Tregs) inhibit anti-tumour immunity and may limit any response to chemotherapy and radiotherapy. We have previously reported that a low density of Tregs in the tumour stroma following neoadjuvant CRT for rectal cancer is associated with improved tumour regression. Here we have examined the association between Treg density in pre-treatment diagnostic biopsy specimens and treatment response, in this same patient cohort. We aimed to determine whether pre-treatment tumour-infiltrating Treg density predicts subsequent response to neoadjuvant CRT. Foxp3+, CD8+ and CD3+ cell densities in biopsy samples from 106 patients were assessed by standard immunohistochemistry (IHC) and evaluated for their association with tumour regression grade and survival. We found no association between the density of any T cell subset pre-treatment and clinical outcome, indicating that tumour-infiltrating Treg density does not predict response to neoadjuvant CRT in rectal cancer. Taken together with the findings of the previous study, these data suggest that in the context of neoadjuvant CRT for rectal cancer, the impact of chemotherapy and/or radiotherapy on anti-tumour immunity may be more important than the state of the pre-existing local immune response.

In Situ Detection of Regulatory T Cells in Human Genital Herpes Simplex Virus Type 2 (HSV-2) Reactivation and Their Influence on Spontaneous HSV-2 Reactivation.

Herpes simplex virus type 2 (HSV-2) reactivation is accompanied by a sustained influx of CD4(+) and CD8(+) T cells that persist in genital tissue for extended periods. While CD4(+) T cells have long been recognized as being present in herpetic ulcerations, their role in subclinical reactivation and persistence is less well known, especially the role of CD4(+) regulatory T cells (Tregs). We characterized the Treg (CD4(+)Foxp3(+)) population during human HSV-2 reactivation in situ in sequential genital skin biopsy specimens obtained from HSV-2-seropositive subjects at the time of lesion onset up to 8 weeks after healing. High numbers of Tregs infiltrated to the site of viral reactivation and persisted in proximity to conventional CD4(+) T cells (Tconvs) and CD8(+) T cells. Treg density peaked during the lesion stage of the reactivation. The number of Tregs from all time points (lesion, healed, 2 weeks after healing, 4 weeks after healing, and 8 weeks after healing) was significantly higher than in control biopsy specimens from unaffected skin. There was a direct correlation between HSV-2 titer and Treg density. The association of a high Treg to Tconv ratio with high viral shedding suggests that the balance between regulatory and effector T cells influences human HSV-2 disease.

032 Suppressor of cytokine signaling 2 directs early tumor-immune escape of skin cancer

032 Suppressor of cytokine signaling 2 directs early tumor-immune escape of skin cancer

A study of Foxp3+ regulatory T-cell in lesional skin of mycosis fungoides in comparison with some histological mimickers

Introduction Regulatory T-cells (Tregs) are essential to balance between proinflammatory and anti-inflammatory responses by protecting against autoimmune reactions. They have different roles in skin tumors, including cutaneous T-cell lymphomas. Foxp3 (forkhead box P3) is thought to be a reliable marker for Tregs. Contradictory results were reported in the literature when the density of Tregs in the skin of mycosis fungoides (MF, a type of cutaneous T-cell lymphoma) was compared with some pathologically mimicking inflammatory dermatoses. Patients and methods This is a comparative cross-sectional study of lesional skin biopsies from 36 cases of MF versus those from 36 cases of histopathological mimickers, including 10 cases of psoriasis, 10 cases of spongiotic dermatitis, and 16 cases of lichenoid dermatoses (10 with pityriasis lichenoides chronica and six with discoid lupus erythematosus). We compared the densities of Foxp3+ Tregs in relation to CD4+ cells in the epidermis and dermis of these groups using Foxp3 and CD4 monoclonal antibodies. Results The MF group showed a lower statistically significant difference as regards epidermal and dermal Foxp3/CD4+ ratios compared with the histologic mimicker group. Conclusion MF lesions showed a significantly lower density of CD4+ Foxp3+ Tregs compared with its histological mimickers, which might be attributed to their limited proliferation at the expense of malignant T-lymphocytes.

FOXP3+ T regulatory lymphocytes in primary melanoma are associated with BRAF mutation but not with response to BRAF inhibitor

Tumour infiltrating lymphocytes in primary melanoma have been found to correlate with patient outcomes. A subpopulation of tumour infiltrating lymphocytes expresses the transcription factor forkhead box protein 3 (FOXP3). These are known as FOXP3+ T-regulatory cells (Tregs) and are thought to play an immune suppressive role in tumourigenesis. In most tumours, including melanoma, a high density of intratumoural FOXP3+ Tregs has been associated with poor prognosis. It is not known whether these cells also influence the response to BRAF inhibition therapy in metastatic melanoma. In the present study we retrospectively investigated the density of FOXP3+ Tregs in primary melanomas, with known subsequent metastasis, in relation to various clinicopathological parameters including BRAF and NRAS mutation status, and response to BRAF inhibitor therapy. The intratumoural density of FOXP3+ Tregs was two-fold higher in melanomas with mutant BRAF compared to those with wild type BRAF status (p = 0.03). In patients treated with BRAF kinase inhibitors FOXP3+ Treg density in the primary tumour was not predictive of treatment response (p = 0.38).

Changes in Foxp3-Positive Regulatory T Cell Number in the Intestine of Dogs With Idiopathic Inflammatory Bowel Disease and Intestinal Lymphoma.

Although regulatory T cells (Tregs) play an integral role in immunologic tolerance and the maintenance of intestinal homeostasis, their involvement in canine gastrointestinal diseases, including idiopathic inflammatory bowel disease (IBD) and intestinal lymphoma, remains unclear. Here we show altered numbers of forkhead box P3 (Foxp3)-positive Tregs in the intestine of dogs with IBD and intestinal lymphoma. IBD was diagnosed in 48 dogs; small cell intestinal lymphoma was diagnosed in 46 dogs; large cell intestinal lymphoma was diagnosed in 30 dogs; and 25 healthy beagles were used as normal controls. Foxp3-positive Tregs in the duodenal mucosa were examined by immunohistochemistry and immunofluorescence. Duodenal expression of interleukin-10 mRNA was quantified by real-time reverse transcription polymerase chain reaction. The number of Foxp3-positive lamina propria cells and the expression of interleukin-10 mRNA were significantly lower in dogs with IBD than in healthy dogs and dogs with intestinal lymphoma. The number of Foxp3-positive intraepithelial cells was higher in dogs with small cell intestinal lymphoma. Some large cell intestinal lymphoma cases had high numbers of Foxp3-positive cells, but the increase was not statistically significant. Double-labeling immunofluorescence showed that CD3-positive granzyme B-negative helper T cells expressed Foxp3. In small cell intestinal lymphoma cases, the overall survival of dogs with a high Treg density was significantly worse than that of dogs with a normal Treg density. These results suggest that a change in the number of Foxp3-positive Tregs contributes to the pathogenesis of canine IBD and intestinal lymphoma by disrupting mucosal tolerance and suppressing antitumor immunity, respectively.

Quantification of tumor infiltrating Foxp3+ regulatory T cells enables the identification of high-risk patients for developing synchronous cancers over upper aerodigestive tract

Patients with squamous cell carcinomas (SCC) of upper aerodigestive tract, either over head and neck (HNSCC) or esophagus (ESCC), frequently developed synchronous multiple cancers, leading to worse prognosis. This study validated whether suppression of host cancer immunosurveillance mediated by regulatory T cells (Treg) may predispose to the development of synchronous cancers. Tumor tissues of 200 patients (100 ESCC only, 50 HNSCC only, and 50 synchronous SCCs) were quantitatively accessed for the tumor infiltrating Treg by immunohistochemistry. The density of Treg was also correlated to the level of Treg-associated inhibitory cytokines (IL-10, IL-35 and TGF-β1), and chemokine (CCL22). The density of tumor infiltrating Treg in the index tumor (i.e. the first malignancy diagnosed) of synchronous SCC group was higher than those of HNSCC or ESCC only (p<0.05). Selecting the optimal cut-off value of Treg density as 34.6 cells/mm(2) by ROC curve, an increased Treg density of the index tumor can be an independent factor for developing synchronous SCCs (OR: 6.13; 95% CI: 2.84-13.26). The Treg density was positively correlated with serum IL-10 level and the degree of CCL22-positive cells infiltration in tumor. Furthermore, the serum inhibitory cytokine IL-10 level was higher in synchronous SCC than in non-synchronous ones (p<0.001), that indicated the cellular immunosuppression in patients with synchronous cancers. A more severe defect in cellular immunity may predispose to multifocal tumor. The Treg cell number in SCC may serve as a novel predictive biomarker for the risk of synchronous cancer development to initiate a proper surveillance program.

Cutting edge: epigenetic regulation of Foxp3 defines a stable population of CD4+ regulatory T cells in tumors from mice and humans.

CD4(+) regulatory T cells (Tregs) are critical for maintaining self-tolerance and function to prevent autoimmune disease. High densities of intratumoral Tregs are generally associated with poor patient prognosis, a correlation attributed to their broad immune-suppressive features. Two major populations of Tregs have been defined, thymically derived natural Tregs (nTregs) and peripherally induced Tregs (iTregs). However, the relative contribution of nTregs versus iTregs to the intratumoral Treg compartment remains controversial. Demarcating the proportion of nTregs versus iTregs has important implications in the design of therapeutic strategies to overcome their antagonistic effects on antitumor immune responses. We used epigenetic, phenotypic, and functional parameters to evaluate the composition of nTregs versus iTregs isolated from mouse tumor models and primary human tumors. Our findings failed to find evidence for extensive intratumoral iTreg induction. Rather, we identified a population of Foxp3-stable nTregs in tumors from mice and humans.

FOXP3+ Tregs: heterogeneous phenotypes and conflicting impacts on survival outcomes in patients with colorectal cancer.

The tumor microenvironment composites a mixture of immune lymphoid cells, myeloid cells, stromal cells with complex cytokines, as well as numerous lymphovascular vessels. Colorectal cancer (CRC) is a common malignancy and one of the leading causes of tumor-related death in the United States and worldwide. The immune status in the tumor microenvironment contributes to the survival of a patient with CRC. Regulatory T cells (Tregs) are considered a key factor in immune escape and immunotherapy failure among cancer patients. The transcription factor forkhead box P3 (FOXP3) is a crucial intracellular marker and also a key developmental and functional factor for CD4+CD25+ Tregs. Tregs are correlated with survival in various human neoplasms, and elevated proportions of Tregs are usually associated with unfavorable clinical outcomes. However, the role of Tregs in CRC remains controversial. High densities of tumor-infiltrating Tregs in CRC patients are reported to be correlated with worse or better outcomes. And Tregs may not be predictive of prognosis after resection of the primary tumor. The exact explanations for these discordant results remain unclear. The heterogeneous instincts of cell phenotype, gene expression, and functional activities of Tregs may partly contribute this contrasting result. Furthermore, the lack of a robust marker for identifying Tregs or due to the different techniques applied is also account. The Treg-specific demethylated region (TSDR) was recently reported to be a specific epigenetic marker for natural Tregs (nTregs), which can stably express FOXP3. The FOXP3-TSDR demethylation assay may be an promising technique for CRC-related nTregs studies.

Cellular immune environment in endometrial polyps

To investigate the immune environment of endometrial polyps (EPs). Prospective case-control study. Teaching hospital and university research laboratory. Reproductive-age women undergoing hysteroscopy dilation and curettage for benign indications. Samples were collected from women with (n = 23) and without (n = 40) EPs. Endometrial samples were immunohistochemically stained with antibodies against mast cells (MCs) and regulatory T cells (Tregs). Tryptase+, chymase+, and c-Kit+ MCs and Foxp3+ Tregs were quantified in EPs and polyp-adjacent, polyp-distant, and control endometrium. Densities of all MC types were highly significantly increased in EPs compared with adjacent, distant, and control endometrium. Chymase+ and c-Kit+ MCs were increased in density in adjacent compared with control endometrium. c-Kit+ MCs were also increased in distant compared with control endometrium. Foxp3+ Treg density was increased in EPs compared with distant and control endometrium and decreased in distant compared with control endometrium. This study provides novel insights into localized disturbances in the cellular immune environment within EPs consistent with EPs being inflammatory lesions associated with MC overactivity. Tregs are likely to be recruited to EPs in an attempt to suppress the inflammatory process due to the greatly increased presence of MCs. These immunologic disturbances are likely to be involved in the causation of abnormal bleeding and infertility in premenopausal women with EPs, and their role in the pathophysiology requires further research.

Expression and prognostic value of regulatory T cells and M2 macrophages in diffuse large B-cell lymphoma tissues

To explore the prognostic value of regulatory T cells (Tregs) and M2 macrophages in diffuse large B-cell lymphoma (DLBCL) tissues. The expression of CD163 and Foxp3 was detected by immunohistochemistry in 92 cases of DLBCL, and it was statistically analyzed whether their expressions correlate with clinical data and prognosis in patients with DLBCL. The density of M2 macrophage and regulatory T cells in DLBCL tumor tissues was significantly higher than that in the adjacent tissues (P = 0.02, P = 0.04). The expression of M2 macrophages was significantly positively correlated with regulatory T cells expression (r = 2.012, P < 0.05). High density of M2 or Tregs had a relationship with extranodal involvement (P < 0.05). Cox regression analysis showed that the expressions of CD163 and Foxp3 were independent prognostic factors of DLBCL (P < 0.05). Combined detection of the expression of CD163 and Foxp3 proteins and then evaluation of the amount of M2 macrophages and Tregs can be used to more closely predict the prognosis for DLBCL patients.