Purified human anti-Tn and anti-T antibodies specifically recognize carcinoma tissues

Described in several epithelial cancer cells, Tn- (GalNAcα1-O-Ser/Thr) and T- (Galβ3GalNAcα1-O-Ser/Thr) antigens are examples of tumor-associated antigens. Increased expression of Tn- and T-antigens is associated with tumor invasion and metastasis, and patients with high concentration of anti-Tn and anti-T antibodies have a more benign evolution of pathology. Asialofetuin (ASF) and ovine submaxillary mucin (OSM) are two glycoproteins that expose T- and Tn-antigen, respectively. In this work, using ASF or OSM we affinity-purified anti-T and anti-Tn antibodies from normal human plasma and tested their ability to specifically recognize tumor human tissues. Whereas purified anti-T antibodies (purity degree increase of 127-fold, and 22% recovery) were mainly IgG, for purified anti-Tn antibodies (purity degree enhancement of 125-fold, and 26% yield) the IgM fraction was predominant over the IgG one. IgG2 subclass was significantly enriched in both purified antibody samples. Purified antibodies did not bind normal human tissue (0/42), although recognized malignant tissues from different origin such as colon carcinoma (11/77 by anti-Tn; 7/79 by anti-T), breast carcinoma (10/23 by anti-Tn; 7/23 by anti-T), and kidney carcinoma (45/51 by anti-Tn; 42/51 by anti-T). Our results suggest that purified human anti-Tn and anti-T antibodies have a potential as anti-tumor therapeutic agents; restoring their levels in human sera could positively affect the evolution of patients with epithelial tumor pathologies.Fil: Zlocowski, Natacha. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Grupe, Verónica Maria. Fundación Para El Progreso de la Medicina; ArgentinaFil: Garay, Yohana Camila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Nores, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Lardone, Ricardo Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Irazoqui, Fernando Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentin

High IRF8 expression correlates with CD8 T cell infiltration and is a predictive biomarker of therapy response in ER-negative breast cancer

Characterization of breast cancer (BC) through the determination of conventional markers such as ER, PR, HER2 and Ki67 has been useful as a predictive and therapeutic tool. Also, assessment of tumor-infiltrating lymphocytes has been proposed as an important prognostic aspect to be considered in certain BC subtypes. However, there is still a need to identify additional biomarkers that could add precision indistinguishing therapeutic response of individual patients. To this end, we focused in the expression of Interferon regulatory factor 8 (IRF8) in BC cells. IRF8 is a transcription factor which plays a well determined role in myeloid cells and that seems to have multiple antitumoral roles: it has tumor suppressor functions; it acts down stream IFN/STAT1, required for the success of some therapeutic regimes and its expression in neoplastic cells seems to depend on a cross talk between the immune contexture and the tumor cells.The goal of the present study was to examine the relationship between IRF8 with the therapeutic response and the immune contexture in BC, since its clinical significance in this type of cancer has not been thoroughly addressed. We identified the relationship between IRF8 expression and the clinical outcome of BCpatients and validated IRF8 as predictive biomarker by using public databases and then performed in silico analysis. To correlate the expression of IRF8 with the immune infiltrate in BC samples we performed quantitative multiplex immuno histochemistry. IRF8 expression can precisely predict the complete pathological response to monoclonal antibody therapy or to select combinations of chemotherapy such as FAC (Fluorouracil, Adriamycin and Cytoxan) in ER negative BC subtypes. Analysis of immune cell infiltration indicates there is a strong correlation between activated and effector CD8 + T cell infiltration and tumoral IRF8 expression. Conclusions Wepropose IRF8 expression as a potent biomarker not only for prognosis, but also forpredicting therapy response in ER negative BC phenotypes. Its expression inneoplastic cells also correlates with CD8 + T cell activation and infiltration. Therefore, our results justify new efforts towards understanding mechanisms regulating IRF8 expression and how they can be therapeutically manipulated.Fil: Gatti, Gerardo Alberto. Fundación Para El Progreso de la Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Betts, Courtney. Oregon Health & Science University; Estados UnidosFil: Rocha, Darío Gastón. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Nicola, Maribel. Fundación Para El Progreso de la Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Grupe, Verónica Maria. Fundación Para El Progreso de la Medicina; ArgentinaFil: Ditada, Cecilia. Fundación Para El Progreso de la Medicina; ArgentinaFil: Núñez, Nicolás G.. Institute Of Experimental Immunology; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Roselli, Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Araya, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Dutto, Jeremias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Boffelli, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Fernández, Elmer. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas. Universidad Católica de Córdoba. Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas; ArgentinaFil: Coussens, Lisa M.. Knight Cancer Institute; Estados UnidosFil: Maccioni, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin