Human papilloma virus (HPV)-induced cervical cancer constitutively expresses viral E6/E7 oncoproteins and is an excellent target for T cell-based immunotherapy. However, not all tumor-infiltrating T cells confer equal benefit to patients, with epithelial T cells being superior to stromal T cells. To assess whether the epithelial T cell biomarker CD103 could specifically discriminate the beneficial antitumor T cells, association of CD103 with clinicopathological variables and outcome was analyzed in the TCGA cervical cancer data set (n = 304) and by immunohistochemistry (IHC) in an independent cohort (n = 460). Localization of CD103+ cells in the tumor was assessed by immunofluorescence. Furthermore, use of CD103 as a response biomarker was assessed in an in vivo E6/E7+ tumor model. Our results show that CD103 gene expression was strongly correlated with cytotoxic T cell markers (e.g. CD8/GZMB/PD1) in the TCGA series. In line with this, CD103+ cells in the IHC series co-expressed CD8 and were preferentially located in cervical tumor epithelium. High CD103+ cell infiltration was strongly associated with an improved prognosis in both series, and appeared to be a better predictor of outcome than CD8. Interestingly, the prognostic benefit of CD103 in both series seemed limited to patients receiving radiotherapy. In a preclinical mouse model, HPV E6/E7-targeted therapeutic vaccination in combination with radiotherapy increased the intratumoral number of CD103+ CD8+ T cells, providing a potential mechanistic basis for our results. In conclusion, CD103 is a promising marker for rapid assessment of tumor-reactive T cell infiltration of cervical cancers and a promising response biomarker for E6/E7-targeted immunotherapy.

Intraepithelial CD8+ tumour-infiltrating T-lymphocytes (TIL) are associated with a prolonged survival in endometrial cancer (EC). By contrast, stromal infiltration of CD8+ TIL does not confer prognostic benefit. A single marker to discriminate these populations would therefore be of interest for rapid assessment of the tumour immune contexture, ex vivo analysis of intraepithelial and stromal T-cells on a functional level and/or adoptive T-cell transfer. Here we determined whether CD103, the αE subunit of the αEβ7integrin, can be used to specifically discriminate the epithelial and stromal CD8+ TIL populations in EC.
CD103+ TIL were quantified in a cohort of 305 EC patients by immunohistochemistry. Localization of CD103+ cells and co-expression of CD103 with CD3, CD8, CD16 and FoxP3 were assessed by immunofluorescence. Further phenotyping of CD103+ cells was performed by flow cytometry on primary endometrial tumour digests.
CD8+CD103+ cells were preferentially located in endometrial tumour epithelium, whereas CD8+CD103- cells were located in stroma. CD103+ lymphocytes were predominantly CD3+CD8+ T-cells and expressed PD1. The presence of a high CD103+ cell infiltration was associated with an improved prognosis in patients with endometrial adenocarcinoma (p = 0.035). Moreover, this beneficial effect was particularly evident in high-risk adenocarcinoma patients (p = 0.031).
Because of the restricted expression on intraepithelial CD8+ T-cells, CD103 may be a suitable biomarker for rapid assessment of immune infiltration of epithelial cancers. Furthermore, this intraepithelial tumour-reactive subset might be an interesting T-cell subset for adoptive T-cell transfer and/or target for checkpoint inhibition therapy.
Copyright © 2016 Elsevier Ltd. All rights reserved.

The expression of the integrin αE (CD103), may enhance the retention of regulatory T cells to peripheral inflammatory sites and possibly contribute to their suppressive potential. The aim of this study was to define the regulatory role of IL-2 and TGF-β1 on the CD103 expression and the optimal in vitro conditions for the induction/expansion of human CD4(+) and CD8(+) Tregs. Cord blood mononuclear cells (CBMC) were stimulated under various culture conditions, including anti-CD3, anti-CD28, IL-2 and TGF-β1. TGF-β1 and IL-2 were both required for optimal expression of CD103. In addition, TGF-β1 and IL-2 synergistically induced CD103 expression on CD8(+) T cells, whereas, only additive induced expression was noted on CD4(+) T cells. Surprisingly, CD103 expression was not dependent upon CD28 costimulation. IL-2 also played a central role in CD103 expression by CD25(hi) Foxp3+ Tregs. IL-2, TGF-β1 and anti-CD3 defined the optimal stimulatory conditions favouring the induction/expansion of both CD4(+) and CD8(+) human Tregs from naive CBMC. Thus, this study provides new insights into the regulatory role of IL-2 upon CD103 expression by human cord blood CD4(+) and CD8(+) T cells. Furthermore, it identifies the in vitro culture conditions driving the differentiation of the novel phenotype CD4(+) and CD8(+) CD103(+) CD25(hi) Foxp3+ Tregs from human CBMC.
© 2012 The Authors. Scandinavian Journal of Immunology © 2012 Blackwell Publishing Ltd.

Most consensus leukemia & lymphoma antibody panels consist of lists of markers based on expert opinions, but they have not been validated. Here we present the validated EuroFlow 8-color antibody panels for immunophenotyping of hematological malignancies. The single-tube screening panels and multi-tube classification panels fit into the EuroFlow diagnostic algorithm with entries defined by clinical and laboratory parameters. The panels were constructed in 2-7 sequential design-evaluation-redesign rounds, using novel Infinicyt software tools for multivariate data analysis. Two groups of markers are combined in each 8-color tube: (i) backbone markers to identify distinct cell populations in a sample, and (ii) markers for characterization of specific cell populations. In multi-tube panels, the backbone markers were optimally placed at the same fluorochrome position in every tube, to provide identical multidimensional localization of the target cell population(s). The characterization markers were positioned according to the diagnostic utility of the combined markers. Each proposed antibody combination was tested against reference databases of normal and malignant cells from healthy subjects and WHO-based disease entities, respectively. The EuroFlow studies resulted in validated and flexible 8-color antibody panels for multidimensional identification and characterization of normal and aberrant cells, optimally suited for immunophenotypic screening and classification of hematological malignancies.

Providing humoral immunity, antibody-secreting plasma cells and their immediate precursors, the plasmablasts, are generated in systemic and mucosal immune reactions. Despite their key role in maintaining immunity and immunopathology, little is known about their homeostasis. Here we show that plasmablasts and plasma cells are always detectable in human blood at low frequency in any unimmunized donor. In this steady state, 80% of plasmablasts and plasma cells express immunoglobulin A (IgA). Expression of a functional mucosal chemokine receptor, C-C motif receptor 10 (CCR10) and the adhesion molecule beta(7) integrin suggests that these cells come from mucosal immune reactions and can return to mucosal tissue. These blood-borne, CCR10(+) plasmablasts also are attracted by CXCL12. Approximately 40% of plasma cells in human bone marrow are IgA(+), nonmigratory, and express beta(7) integrin and CCR10, suggesting a substantial contribution of mucosal plasma cells to bone marrow resident, long-lived plasma cells. Six to 8 days after parenteral tetanus/diphtheria vaccination, intracellular IgG(+) cells appear in blood, both CD62L(+), beta(7) integrin(-), dividing, vaccine-specific, migratory plasmablasts and nondividing, nonmigratory, CD62L(-) plasma cells of different specificities. Systemic vaccination does not impact on peripheral IgA(+) plasmablast numbers, indicating that mucosal and systemic humoral immune responses are regulated independent of each other.