Multipotent Stromal Cells in a Tumor Microenvironment

Multipotent mesenchymal stromal cells [also referred to as mesenchymal stem cells (MSCs)] as was previously described, are a heterogeneous subset of stromal cells with regenerative potential. Their present tropism for inflamed sites including tumors lesion may be adverse or therapeutic effects arising from MSC administration; in this context, their potential for producing trophic and immunomodulatory factors raises the question as to whether MSCs promote or interact with a tumor microenvironment. Previous studies show a paradoxical effect regarding MSCs, which seems to depend on isolation and expansion, cells source, dose and both route and timing of administration. The occurrence of neoplastic transformation in ex vivo expanded MSCs after a long-term culture has been reported, however, this event has been subsequently described as uncommon, with an estimated frequency of <10−9. Furthermore, neither ectopic tissue formation nor MSC-originating tumors have ever been reported so far in hundreds of patients treated with MSC therapy. The biosafety of these cells, both in precancerous and cancerous environments, has been little investigated to date. We found in an animal model of oral cancer that locally or systemically administered allogeneic MSCs do not aggravate the progression of precancerous lesions. Moreover, they preclude cancer progression and tumor growth, particularly at papilloma stage

Pro-tumorigenic macrophage infiltration in oral squamous cell carcinoma and possible macrophage-aimed therapeutic interventions

In Oral Squamous Cell Carcinomas (OSCC), as in other solid tumors, stromal cells strongly support the spread and growth of the tumor. Macrophages in tumors (tumor-associated macrophages or “TAMs”), can swing between a pro-inflammatory and anti-tumorigenic (M1-like TAMs) state or an anti‐inflammatory and pro-tumorigenic (M2-like TAMs) profile depending on the tumor microenvironment cues. Numerous clinical and preclinical studies have demonstrated the importance of macrophages in the prognosis of patients with different types of cancer. Here, our aim was to review the role of M2-like TAMs in the prognosis of patients with OSCC and provide a state of the art on strategies for depleting or reprogramming M2-like TAMs as a possible therapeutic solution for OSCC. The Clinical studies reviewed showed that higher density of CD163+ M2-like TAMs associated with worse survival and that CD206+ M2-TAMs are involved in OSCC progression through epidermal growth factor (EGF) secretion, underlining the important role of CD206 as a marker of OSCC progression and as a therapeutic target. Here, we provide the reader with the current tools, in preclinical and clinical stage, for depleting M2-like TAMs, re-educating them towards M1-like TAMs, and exploiting TAMs as drug delivery vectors.Fil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Scodeller, Pablo David. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Tartu; Estoni

Omental adipose tissue is a more suitable source of canine Mesenchymal stem cells

Background: Mesenchymal Stem Cells (MSCs) are a promising therapeutic tool in veterinary medicine. Currently the subcutaneous adipose tissue is the leading source of MSCs in dogs. MSCs derived from distinct fat depots have shown dissimilarities in their accessibility and therapeutic potential. The aims of our work were to determine the suitability of omental adipose tissue as a source of MSCs, according to sampling success, cell yield and paracrine properties of isolated cells, and compared to subcutaneous adipose tissue. Results: While sampling success of omental adipose tissue was 100% (14 collections from14 donors) for subcutaneous adipose tissue it was 71% (10 collections from 14 donors). MSCs could be isolated from both sources. Cell yield was significantly higher for omental than for subcutaneous adipose tissue (38 ± 1 vs. 30 ± 1 CFU-F/g tissue, p < 0.0001). No differences were observed between sources regarding cell proliferation potential (73 ± 1 vs. 74 ± 1 CDPL) and cell senescence (at passage 10, both cultures presented enlarged cells with cytoplasmic vacuoles and cellular debris). Omental- and subcutaneous-derived MSCs expressed at the same level bFGF, PDGF, HGF, VEGF, ANG1 and IL-10. Irrespective of the source, isolated MSCs induced proliferation, migration and vascularization of target cells, and inhibited the activation of T lymphocytes. Conclusion: Compared to subcutaneous adipose tissue, omental adipose tissue is a more suitable source of MSCs in dogs. Since it can be procured from donors with any body condition, its collection procedure is always feasible, its cell yield is high and the MSCs isolated from it have desirable differentiation and paracrine potentials.Fil: Bahamondes, Francisca. Universidad de Chile; Chile. Universidad del Desarrollo; ChileFil: Flores, Estefania. Universidad de Chile; ChileFil: Cattaneo, Gino. Universidad de Chile; ChileFil: Bruna, Flavia Alejandra. Universidad del Desarrollo; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Conget, Paulette. Universidad del Desarrollo; Chil

The administration of multipotent stromal cells at precancerous stage precludes tumor growth and epithelial dedifferentiation of oral squamous cell carcinoma

Multipotent stromal cells (MSCs) are envisioned as a powerful therapeutic tool. As they home into tumors, secrete trophic and vasculogenic factors, and suppress immune response their role in carcinogenesis is a matter of controversy. Worldwide oral squamous cell carcinoma (OSCC) is the fifth most common epithelial cancer. Our aim was to determine whether MSC administration at precancerous stage modifies the natural progression of OSCC. OSCC was induced in Syrian hamsters by topical application of DMBA in the buccal pouch. At papilloma stage, the vehicle or 3 × 106 allogenic bone marrow-derived MSCs were locally administered. Four weeks later, the lesions were studied according to: volume, stratification (histology), proliferation (Ki-67), apoptosis (Caspase 3 cleaved), vasculature (ASMA), inflammation (Leukocyte infiltrate), differentiation (CK1 and CK4) and gene expression profile (mRNA). Tumors found in individuals that received MSCs were smaller than those presented in the vehicle group (87 ± 80 versus 54 ± 62 mm3, p < 0.05). The rate of proliferation was two times lower and the apoptosis was 2.5 times higher in lesions treated with MSCs than in untreated ones. While the laters presented dedifferentiated cells, the former maintained differentiated cells (cytokeratin and gene expression profile similar to normal tissue). Thus, MSC administration at papilloma stage precludes tumor growth and epithelial dedifferentiation of OSCC.Fil: Bruna, Flavia Alejandra. Universidad del Desarrollo; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Arango Rodríguez, Martha. Universidad del Desarrollo; ChileFil: Plaza, Anita. Universidad del Desarrollo; ChileFil: Espinoza, Iris. Universidad del Desarrollo; ChileFil: Conget, Paulette. Universidad del Desarrollo; Chil

High Intake of Maternal Milk Prevents the Development of Mammary Cancer in Pups Maintaining Elevated Ingestion of Saturated Fat

Environmental factors in early life have a strong implication on the development of diseases in adult life. Nutritional changes during perinatal life can modify the susceptibility to develop breast carcinoma. In this report, we studied the influence of a diet high in saturated fat in the development of breast cancer, in rats that maintained a differential milk intake during their lactation period. We also analysed the possible mechanisms involved in tumor development. We compared mammary carcinogenesis in Sprague-Dawley adult rats, grown-up in litters of 3 (L3) or 8 (L8) pups per mother during lactation to induce a differential consumption of maternal milk. After weaning all pups were fed with a diet high in saturated fat “HF” (40% of energy from lipids) until adulthood. At 55 days of age, the animals were treated with a single dose of dimethylbenzanthracene to study tumor latency, incidence and progression. Histological and immunohistochemical studies were performed. We observed that animals that maintained high milk intake (L3) had lower mammary cancer incidence than animals that maintained lower milk consumption (L8; P <0.05) when exposed to a HF diet. Tumor latency and rate of tumor growth did not show variations between the groups. However, the mitotic index (P< 0.05) and the expression of CD1 were significantly lower, in tumors of L3 respect to L8 (P <0.01). Animals with greater consumption of breast milk develop tumors that proliferate less and tend to have a more pronounced apoptotic process, although when maintaining a high consumption of saturated fat. These results may explain, in part, the lower incidence observed in this group of animals. Our work reflects the importance of lactation during postnatal life in the prevention of breast cancer, despite other nutritional factors that may act as promoters of tumor development throughout life, such as the consumption of saturated fat.Fil: Santiano, Flavia Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Sasso, Corina Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Zyla, Leila Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Campo Verde Arbocco, Fiorella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Pistone Creydt, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: López Fontana, Constanza Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Caron, Ruben Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentin

Effects of thyroxine on apoptosis and proliferation of mammary tumors

Hypothyroidism is a protective factor against breast cancer but long-term exposure or overdoses of thyroid replacement therapy with thyroxine (T4) may increase breast cancer risk. Objective: to study, in vivo and in vitro, the effects of T4 on the proliferation and apoptosis of mammary tumors of hypo- and euthyroid rats, and the possible mechanisms involved in these effects. Material and Methods: Female Sprague-Dawley rats were treated with a single dose of dimethylbenzathracene (15 mg/rat) at 55 days of age and were divided into three groups: hypothyroidism (HypoT; 0.01% 6-N-propyl-2-thiouracil -PTU- in drinking water, n = 20), hypothyroidism treated with T4 (HypoT + T4; 0.01% PTU in drinking water and 0.25 mg/kg/day T4 via sc; n = 20) and EUT (untreated control, n = 20). At sacrifice, tumor explants from HypoT and EUT rats were obtained and treated either with 10−10 M T4 in DMEM/F12 without phenol red with 1% Charcoalized Fetal Bovine Serum or DMEM/F12 only for 15 min to evaluate intracellular signaling pathways associated with T4, and 24 h to evaluate changes in the expression of hormone receptors and proteins related to apoptosis and proliferation by immunohistochemistry and Western Blot. Results: In vivo, hypothyroidism retards mammary carcinogenesis but its treatment with T4 reverted the protective effects. In vitro, the proliferative and anti-apoptosis mechanisms of T4 were different regarding the thyroid status. In EUT tumors, the main signaling pathway involved was the cross-talk with other receptors, such as ERα, PgR, and HER2. In HypoT tumors, the non-genomic signaling pathway of T4 was the chief mechanism involved since αvβ3 integrin, HER2, β-catenin and, downstream, PI3K/AKT and ERK signaling pathways were activated. Conclusion: T4 can regulate mammary carcinogenesis by mainly activating its non-genomic signaling pathway and by interacting with other hormone or growth factor pathways endorsing that overdoses of thyroid replacement therapy with T4 can increase the risk of breast cancer.Fil: Zyla, Leila Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Cano, Rocio Yasmin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Gomez, Silvina Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Escudero, Alexa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Rey Echalecu, Lara Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Santiano, Flavia Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Pistone Creydt, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Caron, Ruben Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: López Fontana, Constanza Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentin

Human renal adipose tissue from normal and tumor kidney: ITS influence on renal cell carcinoma

Tumor cells can interact with neighboring adipose tissue. We evaluated components present in human adipose explants from normal (hRAN) and kidney cancer (hRAT) tissue, and we evaluated the effects of conditioned media (CMs) from hRAN and hRAT on proliferation, adhesion and migration of tumor and non- tumor human renal epithelial cell lines. In addition, we evaluated the expression of AdipoR1, ObR, CD44, vimentin, pERK and pPI3K on cell lines incubated with CMs. hRAN were obtained from healthy operated donors, and hRAT from patients who underwent a nephrectomy. hRAT showed increased levels of versican, leptin and ObR; and decreased levels of perilipin, adiponectin and AdipoR1, compared to hRAN. Cell lines showed a significant decrease in cell adhesion and increase in cell migration after incubation with hRAT-CMs vs. hRAN- or control-CMs. Surprisingly, HK-2, 786- O and ACHN cells showed a significant decrease in cell migration after incubation with hRAN-CMs vs. control-CMs. No difference in proliferation of cell lines was found after 24 or 48 h of treatment with CMs. AdipoR1 in ACHN and Caki-1 cells decreased significantly after incubation with hRAT-CMs vs. hRAN-CMs and control-CMs. ObR and CD44 increased in tumor line cells, and vimentin increased in non-tumor cells, after incubation with hRAT-CMs vs. hRAN-CMs and control-CMs. We observed an increase in the expression of pERK and pPI3K in HK-2, 786-O and ACHN, incubated with hRAT- CMs. In conclusion, results showed that adipose microenvironment can regulate thebehavior of tumor and non tumor human renal epithelial cells.Fil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad del Desarrollo; Chile. Universidad Nacional de Cuyo. Facultad de Odontologia; ArgentinaFil: Romeo, Leonardo Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Hospital Español de Mendoza; ArgentinaFil: Campo Verde Arbocco, Fiorella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Contador, David. Universidad del Desarrollo; ChileFil: Gomez, Silvina Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Santiano, Flavia Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Sasso, Corina Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Zyla, Leila Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: López Fontana, Constanza Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Calvo, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Caron, Ruben Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Pistone Creydt, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentin

Chemical composition, antioxidant, antimicrobial and antiproliferative activity of Laureliopsis philippiana essential oil of Chile, study in vitro and in silico

Chilean Laureliopsis philippiana has been used in traditional medicine by the Mapuche and their ancestors. To evaluate its pharmacological activity, Laureliopsis philippiana leaf essential oil extract (LP_EO) was chemically and biologically characterized in the present study. In vitro antioxidant potential was analyzed, and antitumor activity was evaluated in non-tumor and tumor cell culture lines. Caenorhabditis elegans was used as a model for evaluating toxicity, and the chemical composition of the essential oil was analyzed using gas chromatography–mass spectrometry. The oil contains six major monoterpenes: eucalyptol (27.7 %), linalool (27.6 %), isozaphrol (19.5 %), isohomogenol (12.6 %), α-terpineol (7.7 %), and eudesmol (4.8 %). Based on quantum mechanical calculations, isosafrole and isohomogenol conferred in vitro antioxidant and antimicrobial activity to LP_EO. In addition, LP_EO showed antimicrobial activity against clinical Helicobacter pylori isolates (MIC 64 and MBC > 128 μg·mL−1), Staphylococcus aureus (MIC 32 and MBC > 64 μg·mL−1), Escherichia coli (MIC 8 and MBC 16 μg·mL−1) and Candida albicans (MIC 64 and > 128 μg·mL−1). LP_EO could selectively inhibit the proliferation of epithelial tumor cell lines but showed low toxicity against Caenorhabditis elegans (0.39 to 1.56 μg·mL−1). Therefore, LP_EO may be used as a source of bioactive compounds in novel pharmacological treatments for veterinary and human application, cosmetics, or sanitation.Fil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Diego Portales; ChileFil: Fernández, Katia. Universidad Diego Portales; ChileFil: Urrejola, Felipe. Universidad Diego Portales; ChileFil: Touma, Jorge. Universidad Diego Portales; ChileFil: Navarro, Myriam. Universidad Diego Portales; ChileFil: Sepúlveda, Betsabet. Universidad de Chile; ChileFil: Larrazabal Fuentes, María. Universidad de Antofagasta (uantof);Fil: Paredes, Adrián. Universidad de Antofagasta (uantof);Fil: Neira, Iván. Universidad de Antofagasta (uantof);Fil: Ferrando, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Osorio, José Manuel. Universidad Andrés Bello; Chile. Universidad Diego Portales; ChileFil: Yáñez, Osvaldo. Universidad de Las Américas.; Ecuador. Center of New Drugs for Hypertension; ChileFil: Bravo, Jessica. Universidad Diego Portales; Chil

The essential oil from Drimys winteri possess activity: Antioxidant, theoretical chemistry reactivity, antimicrobial, antiproliferative and chemical composition

The Mapuche and their ancestors have used D. winteri in traditional medicine. In the present study, the essential oil extract of D. winteri leaves (DW_EO) were characterized chemically and biologically to evaluate its pharmacological activity. In vitro antioxidant activity was assayed, and antitumor activity was evaluated in non-tumor and tumor-cell culture lines. Caenorhabditis elegans was used as a model to evaluate toxicity, and the chemical composition of the essential oil was analyzed by gas chromatography-mass spectrometry. The chemical oil composition was characterized principally of five major terpenes: 4 sesquiterpenes γ-Eudesmol (39.7%), β-Caryophyllene (33.7%), Elemol (25.9%), α-Eudesmol (0.3%) and 1 diterpene Kaunene (0.4%). By quantum calculations, it was determined that all oils have the ability to capture and yield electrons, which is consistent with the moderate antioxidant activity of DW_EO detected in vitro. Furthermore, by molecular docking is estimated that these oils can bind to proteins involved in the production of oxygen radicals. Of these proteins, CYP2C9 could bind energetically, reaching binding energy between −6.8 and −9.2 kCal/mol for the 5 terpenes studied, highlighting among these β-Caryophyllen and γ-Eudesmol. DW_EO has effect against H. pylori (MIC 32 μg/ml), S. aureus (MIC 8 μg/ml), E. coli (MIC 32 μg/ml) and C. albicans (MIC 64 μg/ml), β-Caryophyllen and γ -Eudesmol (MIC 64 μg/ml) and could selectively inhibit the proliferation of epithelial tumor cell lines but showed low against C. elegans (0.39–1.56 μg mL−1). Therefore, DW_EO may be used as a source of bioactive compounds in novel pharmacological treatments for medical application, agronomics, sanitation, and food.Fil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Diego Portales; ChileFil: Fernández, Katia. Universidad Diego Portales; ChileFil: Urrejola, Felipe. Universidad Diego Portales; ChileFil: Touma, Jorge. Universidad Diego Portales; ChileFil: Navarro, Myriam. Universidad Diego Portales; ChileFil: Sepúlveda, Betsabet. Universidad de Chile; ChileFil: Larrazabal Fuentes, María. Universidad de Antofagasta (uantof);Fil: Paredes, Adrián. Universidad de Antofagasta (uantof);Fil: Neira, Iván. Universidad de Antofagasta (uantof);Fil: Ferrando, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Osorio, José Manuel. Universidad Diego Portales; Chile. Universidad Andrés Bello; ChileFil: Yañez, Osvaldo. Universidad de Las Américas.; Ecuador. Center of New Drugs for Hypertension; ChileFil: Bravo, Jessica. Universidad Diego Portales; Chil

Identification of Immunodominant Antigens From a First-Generation Vaccine Against Cutaneous Leishmaniasis

Leishmaniasis is a neglected tropical disease (NTD) caused by parasites belonging to the Leishmania genus for which there is no vaccine available for human use. Thus, the aims of this study are to evaluate the immunoprotective effect of a first-generation vaccine against L. amazonensis and to identify its immunodominant antigens. BALB/c mice were inoculated with phosphate buffer sodium (PBS), total L. amazonensis antigens (TLAs), or TLA with Poly (I:C) and Montanide ISA 763. The humoral and cellular immune response was evaluated before infection. IgG, IgG1, and IgG2a were measured on serum, and IFN-γ, IL-4, and IL-10 cytokines as well as cell proliferation were measured on a splenocyte culture from vaccinated mice. Immunized mice were challenged with 104 infective parasites of L. amazonensis on the footpad. After infection, the protection provided by the vaccine was analyzed by measuring lesion size, splenic index, and parasite load on the footpad and spleen. To identify immunodominant antigens, total proteins of L. amazonensis were separated on 2D electrophoresis gel and transferred to a membrane that was incubated with serum from immunoprotected mice. The antigens recognized by the serum were analyzed through a mass spectrometric assay (LC-MS/MS-IT-TOF) to identify their protein sequence, which was subjected to bioinformatic analysis. The first-generation vaccine induced higher levels of antibodies, cytokines, and cell proliferation than the controls after the second dose. Mice vaccinated with TLA + Poly (I:C) + Montanide ISA 763 showed less footpad swelling, a lower splenic index, and a lower parasite load than the control groups (PBS and TLA). Four immunodominant proteins were identified by mass spectrometry: cytosolic tryparedoxin peroxidase, an uncharacterized protein, a kinetoplast-associated protein-like protein, and a putative heat-shock protein DNAJ. The identified proteins showed high levels of conserved sequence among species belonging to the Leishmania genus and the Trypanosomatidae family. These proteins also proved to be phylogenetically divergent to human and canine proteins. TLA + Poly (I:C) + Montanide ISA 763 could be used as a first-generation vaccine against leishmaniasis. The four proteins identified from the whole-protein vaccine could be good antigen candidates to develop a new-generation vaccine against leishmaniasis.Fil: Germano, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Mackern Oberti, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Vitório, Jessica Gardone. Universidade Federal de Minas Gerais; BrasilFil: Duarte, Mariana Costa. Universidade Federal de Minas Gerais; BrasilFil: Pimenta, Daniel Carvalho. Governo do Estado de Sao Paulo. Secretaria da Saude. Instituto Butantan; BrasilFil: Sanchez Sanchez, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Histologia y Embriologia de Mendoza Dr. Mario H. Burgos. Grupo Vinculado de Investigacion y Desarrollo Biotecnologico Aplicado Al Diagnostico Al Ihem | Universidad Nacional de Cuyo. Facultad de Ciencias Medicas. Instituto de Histologia y Embriologia de Mendoza Dr. Mario H. Burgos. Grupo Vinculado de Investigacion y Desarrollo Biotecnologico Aplicado Al Diagnostico Al Ihem.; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Fernandes, Ana Paula. Universidade Federal de Minas Gerais; BrasilFil: Cargnelutti, Diego Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentin