Influência do biofármaco DNA-hsp65 na lesão pulmonar induzida por bleomicina

Abstract

Objective: To evaluate the effects of immunization with a DNA-hsp65 vaccine in an experimental model of pulmonary fibrosis. Methods: A total of 120 male C57BL/6 mice were distributed into four groups: SS, injected with saline (placebo) and then receiving intratracheal (IT) instillation of saline; SB, injected with saline (placebo) and then receiving IT instillation of bleomycin; PB, treated with plasmid only, without bacterial genome, and then receiving IT instillation of bleomycin; and BB, treated with the vaccine and then receiving IT instillation of bleomycin. Bleomycin was instilled 15 days after the last immunization, and the animals were killed six weeks thereafter. The left and right lungs were removed, the former for morphological analysis and the latter for hydroxyproline measurements. Results: The proportion of deaths within the first 48 h after the IT instillation (deaths attributed to the surgical procedure) was higher in the SB group than in the SS group (57.7% vs. 11.1%). The mean area of pulmonary interstitial septa was greater in the SB and PB groups (53.1 ± 8.6% and 53.6 ± 9.3%, respectively) than in the SS and BB groups (32.9 ± 2.7% and 34.3 ± 6.1%, respectively). The mean area of interstitial septa stained by picrosirius was greater in the SB, PB and BB groups than in the SS group (8.2 ± 4.9%, 7.2 ± 4.2% and 6.6 ± 4.1%, respectively, vs. 2.0 ± 1.4%). The total hydroxyproline content in the lung was significantly lower in the SS group (104.9 ± 20.9 pg/lung) than in the other groups (SB: 160.4 ± 47.8 pg/lung; PB: 170.0 ± 72.0 pg/lung; and BB: 162.5 ± 39.7 pg/lung). Conclusions: Immunization with the DNA-hsp65 vaccine reduced the deposition of noncollagen matrix in a model of bleomycin-induced lung lesion.Keywords: Pulmonary fibrosis; Bleomycin; Collagen. ResumoObjetivo: Avaliar a influência do biofármaco DNA-hsp65 em um modelo de distúrbio fibrosante pulmonar experimental. Métodos: Foram estudados 120 camundongos machos C57BL/6, divididos em quatro grupos: grupo SS, animais tratados com salina (placebo) e injetados com salina intratraqueal (IT); grupo SB, tratados com salina (placebo) e injetados com bleomicina IT; grupo PB, tratados com plasmídeo, sem gene bacteriano, e injetados com bleomicina IT; e grupo BB, tratados com DNA-hsp65 e injetados com bleomicina IT. A bleomicina foi injetada 15 dias após a última imunização, e os animais sacrificados seis semanas após o uso da droga IT. O pulmão esquerdo retirado foi utilizado para análise morfológica, e o pulmão direito para dosagens de hidroxiprolina. Resultados: A proporção de camundongos que apresentaram morte não-programada depois de 48 h da injeção IT foi maior no grupo SB em comparação ao grupo SS (57,7% vs. 11,1%). A área percentual média de interstício septal foi maior nos grupos SB e PB (53,1 ± 8,6% e 53,6 ± 9,3%, respectivamente) em comparação aos grupos SS e BB (32,9 ± 2,7% e 34,3 ± 6,1%, respectivamente). Os grupos SB, PB e BB mostraram aumentos nos valores médios da área de interstício septal corada por picrosirius em compara...

Immunotherapeutic Activities of a DNA Plasmid Carrying the Mycobacterial hsp65 Gene (DNAhsp65)

“…The results of immunogenicity and therapeutic efficacy in experimental models of TB in cell culture and in animals showed that the preventive and therapeutic activities of DNAhsp65 are associated with a series of factors related to the activation of the innate and adaptive immune systems. The results of immunogenicity and efficacy tests demonstrated that the vaccine activates DCs, macrophages, and B lymphocytes; activates CD4, CD8, and γδT cells; controls the activation of lymphocytes of the Th1, Th17, and Treg patterns; guides a Th1 immune response profile, with high IFN-γ signaling; produces cytokines and activation molecules needed to control the growth of bacilli; and activates fibrosis control and resolution of the granulomatous process (20,85). Due to the great immunotherapeutic potential of DNAhsp65 for TB, we are starting a clinical study to test the safety, maximum tolerated dose, immunogenicity, and preliminary efficacy of this product as a therapeutic adjunct for the treatment of patients with MDR-TB (DNAhsp65 + drugs).…”

“…Some monoclonal antibody treatments are currently available that target profibrotic cytokines or activate Th1 cells as a novel immunopharmacological intervention (84). In this context, treatment with DNAhsp65 in an experimental model of pulmonary fibrosis reduced the deposition of noncollagenous matrix (85), and when associated with anti-TB drugs, it was more efficient in reducing tissue damage, resulting in reduced fibrosis during synergistic immunochemotherapy in experimental TB (20). Taken together, these data indicate that treatment with DNAhsp65 was effective in reducing tissue damage caused by excessive ECM deposition.…”

Hyaluronidase recruits mesenchymal-like cells to the lung and ameliorates fibrosis

“…Specimens were processed, embedded in paraffin and cut into for to six lm sections and stained with haematoxylin and eosin (H&E). For evaluation of collagen fibres in the pulmonary parenchyma, the slides were stained with Picro Sirius [41]. The surface density of collagen fibres in the lung was determined by optical density by image analysis.…”