title: CD4+FOXP3+T regulatory cells decrease and CD3+CD8+T cells recruitment in TILs from melanoma metastases after electrochemotherapy.
abstract: Electrochemotherapy (ECT) represents an effective local treatment for skin unresectable melanoma metastases with high overall objective response rate. ECT is based on the combination of anti-neoplastic drugs administration and cancer cells electroporation. Whether ECT can also activate the immune system is a matter of debate, however a significant recruitment of dendritic cells in melanoma treated metastases has been described. Herein we investigated immediate and late effects of ECT treatment on T cell subsets in ECT-treated lesions by fluorescent immunohistochemistry. Biopsies from melanoma patients (n = 10) were taken before ECT (t0), at d1 and d14 from treatment. At t0, CD3+CD4+T cells were the most represented T cells, well detected in the perilesional dermis, particularly at tumour margin, while CD3+CD8+T cells were less represented. CD4+FOXP3+T regulatory (Treg) cells were present in the perilesional dermis and within the lesion. ECT induced a significant decrease of CD4+FOXP3+Treg cells percentage in the perilesional dermis, observed at d1 and at d14 (p < 0.001). CD3+CD8+T cells frequency significantly increased at d14 from treatment in the perilesional dermis (p < 0.001). Furthermore calreticulin translocation to the plasma membrane, a hallmark of immunogenic cell death, was observed in metastatic cells after ECT. The data reported here confirm that ECT induces a local response, with a lymphoid infiltrate characterized by CD4+FOXP3+Treg cells decrease and CD3+CD8+T cells recruitment in the treated lesions. These results might contribute to design novel combinational therapeutic approaches with ECT and immunotherapy in order to generate a systemic long-lasting anti-melanoma immunity.
authors.affiliation: Plastic and Reconstructive Surgery Unit - Regional Melanoma Referral Center - Tuscan Tumour Institute (ITT), Santa Maria Annunziata Hospital, Via Antella, 58-50012, Bagno a Ripoli, Florence, Italy. paola.digennaro@unifi.it.
authors.forename: P
authors.identifier: 0000-0002-5019-2405
authors.initials: P
authors.lastname: Di Gennaro
authors.affiliation: Plastic and Reconstructive Surgery Unit - Regional Melanoma Referral Center - Tuscan Tumour Institute (ITT), Santa Maria Annunziata Hospital, Via Antella, 58-50012, Bagno a Ripoli, Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Gerlini
authors.affiliation: Department of Anatomic Pathology - Dermatopathology Section, Santa Maria Annunziata Hospital, Florence, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Urso
authors.affiliation: Plastic and Reconstructive Surgery Unit - Regional Melanoma Referral Center - Tuscan Tumour Institute (ITT), Santa Maria Annunziata Hospital, Via Antella, 58-50012, Bagno a Ripoli, Florence, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Sestini
authors.affiliation: Plastic and Reconstructive Surgery Unit - Regional Melanoma Referral Center - Tuscan Tumour Institute (ITT), Santa Maria Annunziata Hospital, Via Antella, 58-50012, Bagno a Ripoli, Florence, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Brandani
authors.affiliation: Department of Surgery and Translational Medicine, Dermatology Section, University of Florence, Florence, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Pimpinelli
authors.affiliation: Plastic and Reconstructive Surgery Unit - Regional Melanoma Referral Center - Tuscan Tumour Institute (ITT), Santa Maria Annunziata Hospital, Via Antella, 58-50012, Bagno a Ripoli, Florence, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Borgognoni
mesh_terms: D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003131:Combined Modality Therapy; D053672:Electrochemotherapy; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology; D006801:Humans; D008297:Male; D008545:Melanoma / Q000276:immunology / Q000473:pathology / Q000556:secondary / Q000628:therapy*; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000473:pathology
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors
keywords: Electrochemotherapy; ICD; Immunotherapy; Melanoma; TILs; Treg cells