Immunostaining For FOXP3 Research Articles

Association between pathogenic germline mutations in BRCA2 and ATM and tumor-infiltrating lymphocytes in primary prostate cancer.

Pathogenic mutations in homologous recombination (HR) DNA repair genes may be associated with increased tumor mutational burden and numbers of tumor-infiltrating lymphocytes (TIL). Though HR-deficient prostate tumors have been anecdotally associated with improved responses to immunotherapy, it is unclear whether HR mutations or HR deficiency (HRD) scores predict for increased T-cell densities in this cancer. We evaluated 17 primary prostate tumors from patients with pathogenic germline BRCA2 mutations (gBRCA2) and 21 primary prostate tumors from patients with pathogenic germline ATM (gATM) mutations, which were compared to 19 control tumors lacking HR gene mutations, as well as the TCGA prostate cancer cohort. HRD score was estimated by targeted sequencing (gBRCA2 and gATM) or by SNP microarray (TCGA). Tumor-associated T-cell densities were assessed using validated automated digital image analysis of CD8 and FOXP3 immunostaining (gBRCA2 or gATM) or by methylCIBERSORT (TCGA). CD8 + and FOXP3 + T-cell densities were significantly correlated with each other in gBRCA2 and gATM cases. There was no significant difference between CD8 + or FOXP3 + TIL densities in gBRCA2 or gATM cases compared to controls. In the TCGA cohort, HRD score was associated with predicted CD8 + and FOXP3 + TILs. Associations were also seen for HRD score and TIL density among the germline-mutated cases. In contrast to mismatch repair-deficient primary prostate tumors, cancers from germline BRCA2 or ATM mutation carriers do not appear to be associated with elevated TIL density. However, measures of genomic scarring, such as HRD score, may be associated with increased tumor-infiltrating T-cells.

The imbalance of TNF and IL-6 levels and FOXP3 expression at the maternal-fetal interface is involved in adverse pregnancy outcomes in a susceptible murine model of congenital toxoplasmosis

Vertical transmission of Toxoplasma gondii leads to adverse pregnancy outcomes depending on the time at which the infection occurs and the immunological state of the mother. C57BL/6 and BALB/c mice have been described as susceptible and resistant mouse lineages to congenital T. gondii infection, respectively. This study aimed to elucidate the systemic and local cytokine profile of pregnant mice infected with T. gondii and whether the expression of the transcription factor FOXP3, related to T regulatory cells, is associated with the resistance/susceptibility of these lineages of mice in the context of experimental congenital toxoplasmosis. For this purpose, C57BL/6 and BALB/c females were orally infected with the T. gondii ME-49 strain on the day of vaginal plug detection or day 14 of gestation, examined 7 or 5 days later, respectively, as models of early and late pregnancy. Cytokine levels were measured systemically and in the uterus/placenta. Additionally, the uterus/placenta were evaluated macroscopically for resorption rates and histologically for parasite and FOXP3 immunostaining. The FOXP3 protein expression was also evaluated by western blotting assay. It was found that, during early pregnancy, the infection leads to high IFN-γ, TNF and IL-6 levels systemically, with the TNF levels being higher in C57BL/6 mice. At the maternal-fetal interface, the infection induced high levels of IFN-γ in both mouse lineages; however, higher levels were observed in BALB/c, while high TNF and IL-6 levels were found in C57BL/6, but not in BALB/c mice. In contrast, in late gestation, T. gondii interfered less strongly with the cytokine profile. In early pregnancy, a reduction of FOXP3 expression at the maternal-fetal interface of infected mice was also observed, and the reduction was larger in C57BL/6 compared with BALB/c mice. Additionally, the parasite was seldom found in the uterus/placenta. Thus, the worse pregnancy outcomes observed in C57BL/6 mice were associated with higher TNF systemically, and TNF and IL-6 at the maternal-fetal interface, with lower FOXP3 expression.

Clinical Outcomes of Isolated Regional Lymph Node Recurrence in Patients With Malignant Cutaneous Melanoma.

Regional lymph node recurrence (RLNR) is the most common pattern of recurrence within 2 years from the diagnosis of patients with non-metastatic malignant cutaneous melanoma. However, isolated RLNR without distant metastasis has been rarely studied. Forty patients with isolated RLNR as a first recurrence were analyzed retrospectively. The clinical outcomes and prognostic impact of clinicopathologic parameters were analyzed. Immunostaining for FOXP3, VEGF, pAKT, and pS6 was also performed. The median disease-free interval from first diagnosis to isolated RLNR and post-recurrence recurrence-free survival (pRFS) were 12 months and 7.2 months, respectively. Distant failure was the most common pattern of failure after isolated RLNR (67.5%). The number of initially harvested lymph nodes (LN) >7 and LN ratio >22.2% at the time of recurrence were prognosticators for pRFS in multivariate analysis. None of the tested biomarkers were significantly related to prognosis. The 5-year post-recurrence overall survival rate was 84.9%. Most patients with isolated RLNR will experience a second failure within months, especially distantly. The number of initially harvested LNs and LN ratio at the time of recurrence could predict pRFS.

Abstract 5678: Developing a preclinical immunotherapy platform using syngeneic mouse models of human melanoma

Abstract Melanoma is an aggressive and lethal disease with no efficacious therapies for a broad subset of late stage patients. Current immunotherapies, including immune checkpoint blockade (ICB), may prolong survival in certain patients, but generate responses in less than 40% of the treated cohort. This demands a better understanding of molecular mechanisms underlying the lack of response and acquired resistance to ICB. However, functional studies are limited in patients, and current preclinical studies are handicapped by the absence of appropriate mouse models that recapitulate the pathological and immunological diversity of human melanomas. Here we develop four syngeneic melanoma mouse models with human-relevant genetic modifications and carcinogenic agents, which we hypothesize will mirror the spectrum of responses to ICB and offer a platform for future mechanistic studies in melanoma. The models are: 1) neonatal ultraviolet radiation (UV)-induced melanoma in a HGF-transgenic mouse, in which melanocyte localization at the epidermal-dermal junction mimics human distribution (HU); 2) 7,12-Dimethylbenz(a)anthracene (DMBA)-induced melanoma in a HGF-tg and Cdk4R24C mouse (HC4D); 3) UV-induced melanoma in a BrafCA/+; HGF-tg; Cdkn2aflox/+; Tyr-CreERT2-t mouse (BHCU); and 4) UV-induced melanoma in a BrafCA/+; Ptenflox/+; Cdkn2aflox/+; Tyr-CreERT2-tg mouse (BPCU). Exome sequencing of the four models reveals a high correlation with mutational subtypes previously described in human melanoma. BPCU and BHCU represent different Braf mutant patient populations and HU and HC4D represent triple wildtype melanoma (non-BRAF, -NRAS, -NF1). The four mouse models demonstrate distinct responses to ICB with anti-CTLA-4 treatment. While HU and HC4D melanomas show high or partial sensitivity to anti-CTLA-4, respectively, BPCU and BHCU do not respond to treatment. In vivo vaccination assays demonstrate that the anti-CTLA-4 response in our models is linked to increased tumor immunogenicity. However, the number of non-synonymous mutations and antigen presentation functionality do not correlate with ICB efficacy. Tumor infiltration by T cells was assessed by CD3 and FoxP3 immunostaining and gene expression analysis. Although clear differential gene expression profiles are noted among the four models and in those tumors responding to the treatment, we unexpectedly found that “hot” melanomas (e.g., showing upregulation of inflammatory pathways and high T-cell infiltration) do not necessarily predict ICB efficacy. These results suggest that additional mechanisms could help determine the response or intrinsic resistance to anti-CTLA-4 and open new avenues for future research and treatment. Overall, our study offers four genetically and phenotypically distinct mouse models representing diverse human melanoma subtypes as powerful tools for the mechanistic study of the response to immunotherapies in melanoma. Citation Format: Corinne Rauck, Eva Perez-Guijarro, Zoe W. Ohler, Rajaa El E. Meskini, Howard Yang, Suman Vodnala, Cari Graff-Cherry, Sung Chin, Anyen Fon, Helen Michael, Maxwell Lee, Terry Van Dyke, Shyam Sharan, Glenn Merlino, Chi-Ping Day. Developing a preclinical immunotherapy platform using syngeneic mouse models of human melanoma [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 5678.

Intratumoral FOXP3+ Regulatory T Cells in Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma in Egypt and worldwide. Gene expression profiling classifies DLBCL into: germinal center B cell-like (GCB) and non germinal center B cell-like (non-GCB) DLBCL. Hans' algorithm has high concordance with gene expression profiling results. Regulatory T cells (Tregs) represent important modulators for the interaction between lymphoma cells and host microenvironment. FOXP3 is a popular single marker for Tregs. There is little information about the possible role of Tregs in high-grade lymphoma such as DLBCL. This study aims to assess the prognostic impact of FOXP3+ Tregs in DLBCL. The study was carried out on 70 archival cases (61 de novo DLBCL and 9 reactive follicular hyperplasia cases). DLBCL cases were classified into GCB and non-GCB groups using Hans' algorithm. All studied cases are subjected to FOXP3 immunostaining. Density of FOXP3+ Tregs was higher in reactive cases compared with DLBCL (P=0.000). In DLBCL cases, FOXP3 expression was associated with free spleen (P=0.02), early stage (P=0.05), centroblastic variant (P=0.003), and absence of necrosis (P=0.05). In germinal cases, density of FOXP3 was significantly higher in cases with good PS (P=0.02), very good and good revised international prognostic index (P=0.002), and low-risk age-adjusted international prognostic index >60 (P=0.01). Non germinal DLBCL cases with negative FOXP3 were significantly associated with splenic involvement (P=0.005). DLBCL cases with high FOXP3 have longer survival (P=0.03). T cells in the background of DLBCL may play a role in modulation of tumor progression. Their presence is associated with favorable prognostic parameters in DLBCL.

B cell activating factor and T-helper 17 cells: possible synergistic culprits in the pathogenesis of Alopecia Areata

The role of T-helper 17 cells (Th17) and regulatory T-cells (Tregs) in the pathogenesis of alopecia areata (AA) has not been clearly elucidated. B cell activating factor (BAFF) being a regulator of T cell activation could be involved in this pathologic process as well. The current study evaluated the expression of IL-17, IL-22, Foxp3 and BAFF in tissue and sera of AA patients. Forty AA patients and 40 age and sex matched healthy controls were included. Tissue and serum levels of IL-17, IL-22, BAFF as well as serum level of Foxp3 were measured by enzyme-linked immunosorbent assay (ELISA). Immunohistochemical staining was used for assessment of tissue level of Foxp3. Tissue and serum levels of IL-17, tissue levels of IL-22 and BAFF were significantly higher in patients. Serum levels of IL-22, Foxp3 and BAFF were non-significantly higher in patients. Foxp3 immunostaining showed negativity in tissue of patients and controls. A significant positive correlation was found between both tissue levels of IL-17 and BAFF (r = 0.474, P = 0.035) and tissue level of IL-22 and disease duration (r = 0.766, P < 0.001) in AA patients. Th17 cells and BAFF are synergistically involved in the pathogenesis of AA. BAFF represents a promising therapeutic target for such a challenging disease. Defective Tregs number and/or function in AA warrants further studies.

Immunohistochemical analysis of FoxP3+ regulatory T cells in lower lip squamous cell carcinomas.

The aim of this study was to determine the number of FoxP3+ regulatory T (Treg) cells in the microenvironment of lower lip squamous cell carcinomas (LLSCCs) and to correlate the findings with clinicopathological parameters (tumor size/extent, regional lymph node metastasis, clinical stage, and histopathological grade of malignancy). Fifty cases of LLSCC were selected. Lymphocytes exhibiting nuclear immunostaining for FoxP3 were quantified in 10 microscopic fields at the deep invasive front of LLSCCs. The results were analyzed statistically using the nonparametric Mann-Whitney test and Fisher's exact test. FoxP3+ lymphocytes were observed in all cases studied. The number of these cells tended to be higher in smaller tumors, tumors without regional lymph node metastasis, and tumors in early clinical stages, but the difference was not statistically significant (p > 0.05). Low-grade tumors contained a larger number of FoxP3+ lymphocytes than high-grade tumors (p = 0.019). Tumors with an intense inflammatory infiltrate exhibited a larger number of Treg cells (p = 0.035). On the other hand, the number of FoxP3+ lymphocytes was smaller in tumors arranged in small cell clusters (p = 0.003). No significant differences in the number of FoxP3+ lymphocytes were observed according to the degree of keratinization (p = 0.525) or nuclear pleomorphism (p = 0.343). The results suggest the participation of Treg cells in immune and inflammatory responses in the microenvironment of LLSCCs. These cells may play a more important role in early stages rather than in advanced stages of lip carcinogenesis.

Functional impairment of regulatory T cell in multiple low dose streptozotocin induced murine diabetes (P3099)

Abstract Despite intense research on the role of the regulatory T cells (Treg) , the kinetics of regulatory T cells in the early development of T1D is still not clear. We have examined the proportions of CD4+CD25+Foxp3+ regulatory T (Treg) cells and CD4+ T helper (Th) cells at close intervals in the multiple low dose streptozotocin (MLDSTZ) murine diabetes model using flow cytometry, PCR and immunostaining. The Foxp3 mRNA levels were elevated in the spleen, pancreas and PDLNs of MLDSTZ treated mice. Foxp3 immunostaining in pancreas and spleen suggested that the infiltration of Treg cells increased in pancreas and spleen of MLDSTZ treated mice. The proportions of CD4+CD25+FoxP3+ Treg cells increased in MLDSTZ treated mice from day 7 in pancreatic draining lymph nodes (PDLNs) and day 21 in spleen. The proportions of CD4+ Th cells in MLDSTZ treated mice decreased on day 7 but increase from day 10, at which time the numbers of Tregs increased suggesting that the increase in Tregs fail to control the ongoing immune insult. Impaired mRNA expression levels of IL-35 and IL-10 in PDLNs and spleen of MLDSTZ suggest a functional impairment of the Tregs. Elevated IL-17 mRNA level in spleen of MLDSTZ mice on day 21 further provide evidence of a functional defect in the Tregs. In conclusion Tregs are upregulated in the development of MLDSTZ. However, the upregulation does not protect from hyperglycemia possibly because of a functional deficiency in the Treg population in MLDSTZ treated mice.

Clinical significance of the ratio between FOXP3 positive regulatory T cell and interleukin‐17 secreting cell in renal allograft biopsies with acute T‐cell‐mediated rejection

The aim of this study is to investigate the clinical significance of the ratio between interleukin-17 (IL-17) secreting cell and FOXP3-positive regulatory T cell (FOXP3(+) Treg) infiltration in renal allograft tissues with acute T-cell-mediated rejection (ATCMR). Fifty-six patients with biopsy-proven ATCMR were included. Infiltration of FOXP3(+) Treg and IL-17-secreting cells was evaluated with immunostaining for FOXP3 or IL-17 on the biopsy specimens, and the patients were divided into the FOXP3 high group (Log FOXP3/IL-17 > 0·45) or the IL-17 high group (Log FOXP3/IL-17 < 0·45). We compared the allograft function, severity of tissue injury, and clinical outcome between the two groups. In the IL-17 high group, allograft function was significantly decreased compared with the FOXP3 high group (P < 0·05). The severity of interstitial and tubular injury in the IL-17 high group was higher than the FOXP3 high group (P < 0·05). The proportions of steroid-resistant rejection, incomplete recovery and recurrent ATCMR were higher in the IL-17 high group than in the FOXP3 high group (all indicators, P < 0·05). The IL-17 high group showed lower 1-year (54% versus 90%, P < 0·05) and 5-year (38% versus 85%, P < 0·05) allograft survival rates compared with the FOXP3 high group. Multivariate analysis revealed that the FOXP3/IL-17 ratio was a significant predictor for allograft outcome. The FOXP3/IL-17 ratio is a useful indicator for representing the severity of tissue injury, allograft dysfunction and for predicting the clinical outcome of ATCMR.

Foxp3 expression in patients with non-small cell lung cancer.

e18059 Background: Lung cancer is rarely cured by the current therapeutic approaches. Although numerous studies have implicated Foxp3 positive T regulatory cells in cancer pathogenesis, the role of Foxp3 in lung cancer pathogenesis remains unknown. Methods: We determined Foxp3 expression, using immunohistochemistry in 44 NSCLC tissue specimens, 20 samples from adjacent non neoplastic lung parenchyma and 5 normal lung tissue specimens. Immunohistochemical reactivity was graded on a scale of 0–3 according to intensity of staining and percentage of immunopositive cells. Foxp3 expression in cancer cells was categorized in three groups (high vs median vs low) using as a cut-off point the 33rd and 66th percentile. The total score for each slide was the sum of the intensity and distribution (between 0 and 6). Statistical analysis was performed with SPSS 17.0. Results: Nuclear Foxp3 immunostaining was detected in al tissues assessed. Foxp3 expression levels were higher in neoplastic cells than in adjacent non neoplastic tissue and normal lung parenchyma. Moreover, Foxp3 expression in tumor cells correlated with lymphocytic Foxp3-immunopositivity and the presence of lymph node metastasis. Furthermore, Foxp3 lymphocytic expression was negatively associated with the age of the patients. Conclusions: Foxp3 is overexpressed in NSCLC cells and tumor infiltrating lymphocytes. Moreover, tumor Foxp3 expression correlates with lymph node metastasis while lymphocytic Foxp3 levels may be age-related.

Abdominal γ-Radiation Induces an Accumulation of Function-Impaired Regulatory T Cells in the Small Intestine

To assess the frequency and the functional characteristics of one major component of immune tolerance, the CD4(+)FoxP3(+) regulatory T cells (Tregs) in a mouse model of abdominal irradiation. Mice were exposed to a single abdominal dose of γ-radiation (10 Gy). We evaluated small intestine Treg infiltration by Foxp3 immunostaining and the functional suppressive activity of Tregs isolated from mesenteric lymph nodes. Foxp3 immunostaining showed that radiation induced a long-term infiltration of the intestine by Tregs (levels 5.5 times greater than in controls). Co-culture of Tregs from mesenteric lymph nodes with CD4(+) effector cells showed that the Tregs had lost their suppressive function. This loss was associated with a significant decrease in the levels of Foxp3, TGF-β, and CTLA-4 mRNA, all required for optimal Treg function. At Day 90 after irradiation, Tregs regained their suppressive activity as forkhead box P3 (Foxp3), transforming growth factor beta (TGF-β), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) expression returned to normal. Analysis of the secretory function of mesenteric lymph node Tregs, activated in vitro with anti-CD3/anti-CD28 Abs, showed that this dysfunction was independent of a defect in interleukin-10 secretion. Radiation caused a long-term accumulation of function-impaired Foxp3(+)CD4(+) Tregs in the intestine. Our study provides new insights into how radiation affects the immune tolerance in peripheral tissues.

A potential role for indoleamine 2,3-dioxygenase (IDO) in Rhodococcus equi infection

Rhodococcus equi is a facultative intracellular bacterial pathogen of foals and immunocompromised humans that infects and proliferates within host macrophages and dendritic cells (DC). Indoleamine 2,3-dioxygenase (IDO), the initial enzyme in the tryptophan catabolism pathway, is upregulated in R. equi infected equine monocyte-derived DC and alveolar macrophages. Tryptophan requirement of R. equi for extracellular and intracellular growth was assessed. Growth of R. equi in minimal media did not require tryptophan and pharmacologic inhibition of IDO had no effect on intracellular proliferation of R. equi in equine alveolar macrophages. To investigate an immune-regulatory role for INDO in R. equi infection, IDO −/− (B6.129- Indotm1Alm/J) ( n = 22) and strain matched control (C57BL/6J) ( n = 20) mice were infected with R. equi by intraperitoneal injection, for 3 and 6 days. There was no difference in bacterial counts in liver or spleen between the two groups. Histological sections of liver and spleen were assigned inflammation scores and RT-PCR for interferon-gamma (IFNγ), tumor necrosis factor-alpha (TNFα), IL-4, IL-6, IL-10, IL-12, IL-23, forkhead box P3 (FoxP3), and transforming growth factor-beta (TGFβ) was performed on liver and spleen. Liver tissue of IDO −/− had higher inflammation scores at 6 days post-infection (PI) ( P = 0.05) and had decreased expression of TGFβ at 3 days PI ( P = 0.01), and FOXP3 at 3 days ( P = 0.02) and 6 days ( P = 0.03) compared to control mice. Immunostaining for FOXP3 showed lower numbers of FOXP3+ regulatory T cells in liver of IDO −/− mice 6 days PI. Prolonged inflammation in the liver tissue of IDO −/− mice corresponded with lower expression of FOXP3 and TGFβ in that tissue, and also with lower numbers of FOXP3+ regulatory T cells. We conclude that IDO expression by activated macrophages and DC plays a role in dampening the inflammatory response to R. equi infection in mice.

Ovarian cancer tumor infiltrating T-regulatory (T reg) cells are associated with a metastatic phenotype

Objective The objective of this study was to examine the clinicopathologic correlates of T-regulatory (T reg) cell infiltration in serous ovarian cancers and to define gene signatures associated with high T regs. Methods Tumor infiltrating T reg and cytotoxic T-cells (CTLs) were quantitated in 232 primary serous ovarian cancers by immunostaining for FOXP3 and CD8. Expression microarray analysis was performed in a subset of 48 advanced cancers with the highest and lowest numbers of infiltrating T regs and a genomic signature was developed using binary regression. ANOVA analysis was performed to assess the most differentially expressed genes and these genes were further assessed using Ingenuity Pathway Analysis (IPA) software. Results High T reg infiltration in ovarian cancers was associated with high grade ( p < 0.0001), advanced stage ( p = 0.004) and suboptimal debulking ( p < 0.04), but not with survival. In contrast, high tumor infiltrating CD8 CTL infiltration was associated with favorable survival (median survival 48.7 vs. 34.6 months, p = 0.01). A microarray-based genomic signature for high tumor-infiltrating T reg cells had a 77% predictive accuracy using leave-one-out cross-validation. ANOVA of microarray data revealed the antigen presentation pathway as the most differentially expressed canonical pathway ( p < 0.00001) between cancers with high and low T reg cells. Conclusions These data suggest that there may be an association between increased T reg cell infiltration in ovarian cancers and advanced stage. Increased T reg infiltration is characterized by a genomic signature enriched with several immunologic pathway genes. Therapeutic strategies that reduce tumor infiltrating T reg cells are under investigation and may prove useful in ovarian cancers with high numbers of these cells.

The “atheroprotective” mediators apolipoproteinA-I and Foxp3 are over-abundant in unstable carotid plaques

Inflammation is important in plaque vulnerability but the role of atheroprotective mediators in unstable plaques is not defined. The apolipoproteinA-I (apoA-I) component of HDL, and CD4+/CD25+ regulatory T cells (with their major transcription factor, Foxp3), have been implicated in the suppression of vascular inflammation. Our aim was to characterise the presence of these novel "protective" markers (apoA-I and Foxp3) in carotid plaques from symptomatic and asymptomatic subjects. Plaques from 57 patients (25 symptomatic, 32 asymptomatic) were stained immunohistochemically for macrophages (CD68), T cells (CD3), monocyte chemotactic protein-1 (MCP-1), matrix metalloproteinase-2 (MMP-2), myeloperoxidase (MPO), apoA-I and Foxp3. Twelve randomly selected plaques (6 asymptomatic, 6 symptomatic) were immunostained for interleukin-10 (IL-10) and interleukin-17 (IL-17). Staining was quantified using Image-Pro Plus software. Significantly greater areas of positive immunostaining for CD68, CD3, MCP-1, MMP-2, IL-17 and MPO were found in plaques from symptomatic patients compared with asymptomatic patients (p<0.05 for all). Furthermore, significantly greater areas of positive immunostaining for apoA-I, Foxp3 and IL-10 were found in symptomatic versus asymptomatic plaques (p<0.05 for all). The presence of apoA-I was correlated significantly and co-localised with CD3, CD68, MCP-1, MMP-2 and MPO immunostaining (R=0.70, 0.63, 0.52, 0.55 and 0.79, respectively; p<0.01 for all). Foxp3 immunostaining also correlated significantly with CD3 (R=0.42), CD68 (R=0.47), MCP-1 (R=0.55) and MMP-2 (R=0.44) immunostaining (p<0.05 for all). ApoA-I and Foxp3 are over-abundant in plaques from symptomatic subjects and co-localise with key inflammatory mediators. These data suggest ineffective/insufficient protection against atherosclerosis-mediated inflammation by these "atheroprotective" moieties.

Presence of FoxP3+ Regulatory T Cells Predicts Outcome of Subclinical Rejection of Renal Allografts

Subclinical rejection (SCR) of renal allografts refers to histologic patterns of acute rejection despite stable renal function. The clinical approach to SCR is controversial; it would be helpful to identify biomarkers that could determine whether the identified cellular infiltrates were detrimental. For investigation of whether the presence of FoxP3+ regulatory T cells (Treg) could help determine the functional importance of tubulointerstitial infiltrates observed in 6-mo protocol biopsies, 37 cases of SCR were evaluated. The presence of FoxP3+ Treg discriminated harmless from injurious infiltrates, evidenced by independently predicting better graft function 2 and 3 yr after transplantation. Furthermore, the FoxP3+ Treg/CD3+ T cell ratio positively correlated with graft function at 2 yr after transplantation, suggesting that an increasing proportion of Treg within the global T cell infiltrate may facilitate renal engraftment; therefore, immunostaining for FoxP3+ Treg in patients with SCR on protocol biopsies may ultimately be useful to identify patients who may require alterations in their immunosuppressive regimens.