Immunization With the CSF-470 Vaccine Plus BCG and rhGM-CSF Induced in a Cutaneous Melanoma Patient a TCRβ Repertoire Found at Vaccination Site and Tumor Infiltrating Lymphocytes That Persisted in Blood

• Published in: Frontiers in immunology Vol. 10; p. 2213
• Main Authors: Aris, Mariana, Bravo, Alicia Inés, Garcia Alvarez, Heli Magalí, Carri, Ibel, Podaza, Enrique, Blanco, Paula Alejandra, Rotondaro, Cecilia, Bentivegna, Sofia, Nielsen, Morten, Barrio, María Marcela, Mordoh, José
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 18-09-2019
• Subjects: BCG Vaccine - therapeutic use; Cancer Vaccines - therapeutic use; CSF-470 vaccine; cutaneous melanoma; cutaneous metastasis; Granulocyte-Macrophage Colony-Stimulating Factor - therapeutic use; Humans; Immunology; Lymphocytes, Tumor-Infiltrating - drug effects; Lymphocytes, Tumor-Infiltrating - immunology; Male; Melanoma - drug therapy; Melanoma - immunology; Melanoma, Cutaneous Malignant; Middle Aged; Receptors, Antigen, T-Cell, alpha-beta - immunology; Skin Neoplasms - drug therapy; Skin Neoplasms - immunology; TCRβ repertoire; tumor infiltrating lymphocytes; vaccination site; cutaneous melanoma; TCRβ repertoire; cutaneous metastasis; CSF-470 vaccine; tumor infiltrating lymphocytes; vaccination site
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2019.02213

The CSF-470 cellular vaccine plus BCG and rhGM-CSF increased distant metastases-free survival in cutaneous melanoma patients stages IIB-IIC-III relative to medium dose IFN-α2b (CASVAC-0401 study). Patient-045 developed a mature vaccination site (VAC-SITE) and a regional cutaneous metastasis (C-MTS), which were excised during the protocol, remaining disease-free 36 months from vaccination start. CDR3-TCRβ repertoire sequencing in PBMC and tissue samples, along with skin-DTH score and IFN-γ ELISPOT assay, were performed to analyze the T-cell immune response dynamics throughout the immunization protocol. Histopathological analysis of the VAC-SITE revealed a highly-inflamed granulomatous structure encircled by CD11c
nested-clusters, brisk CD8
and scarce FOXP3
, lymphocytes with numerous Langhans multinucleated-giant-cells and macrophages. A large tumor-regression area fulfilled the C-MTS with brisk lymphocyte infiltration, mainly composed of CD8
PD1
T-cells, CD20
B-cells, and scarce FOXP3
cells. Increasing DTH score and IFN-γ ELISPOT assay signal against the CSF-470 vaccine-lysate was evidenced throughout immunization. TCRβ repertoire analysis revealed for the first time the presence of common clonotypes between a VAC-SITE and a C-MTS; most of them persisted in blood by the end of the immunization protocol.
boost with vaccine-lysate revealed the expansion of persistent clones that infiltrated the VAC-SITE and/or the C-MTS; other persistent clones expanded in the patient's blood as well. We propose that expansion of such persistent clonotypes might derive from two different although complementary mechanisms: the proliferation of specific clones as well as the expansion of redundant clones, which increased the number of nucleotide rearrangements per clonotype, suggesting a functional antigenic selection. In this patient, immunization with the CSF-470 vaccine plus BCG and rhGM-CSF induced a T-cell repertoire at the VAC-SITE that was able to infiltrate an emerging C-MTS, which resulted in the expansion of a T-cell repertoire that persisted in blood by the end of the 2-year treatment.