Santana Jhonne Pedro Pedott, Marcato Priscyla Daniely, Massaro Tais Nader Chrysostomo, Godoy Naiane Lima, Anibal Fernanda de Freitas, Borra Ricardo Carneiro
Department of Genetics and Evolution, Federal University of Sao Carlos, São Carlos, Brazil.
GNanoBio, School of Pharmaceutical Science of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Lab Anim Res. 2022 May 5;38(1):11. doi: 10.1186/s42826-022-00122-7.
Activating the immune system for therapeutic benefit has long been a goal in immunology, especially in cancer treatment, but the low immunogenicity of antitumor vaccines remains a limiting factor in the fight against malignant neoplasms. The increase in the immunogenicity of weak antigens using biodegradable polymers, such as chitosan, has been observed in the field of cancer immunotherapy. However, the effects of the vaccine using a combination of tumor cells and a thermoreversible delivery system based on chitosan in bladder cancer models, mainly using the intravesical route to stimulate the antitumor immune response, are unknown. We propose to evaluate the efficacy of a polymeric gel matrix (TPG) formed by poloxamer 407 and chitosan, associated with MB49 cells, as an intravesical antitumor vaccine using a C57BL/6 murine model of bladder urothelial carcinoma. The effectiveness of immunization was analyzed with the formation of three experimental groups: Control, TPG and TPG + MB49. In the vaccination phase, the TPG + MB49 group underwent a traumatic injury to the bladder wall with immediate intravesical instillation of the vaccine compound containing MB49 cells embedded in TPG. The TPG group was subjected to the same procedures using the compound containing the gel diluted in medium, and the control group using only the medium. After 21 days, the animals were challenged with tumor induction.
In vitro tests showed loss of viability and inability to proliferate after exposure to TPG. In vivo tests showed that animals previously immunized with TPG + MB49 had higher cumulative survival, as well as significantly lower bladder weight and size in contrast to the other two groups that did not show a statistically different tumor evolution. In addition, the splenocytes of these animals also showed a higher rate of antitumor cytotoxicity in relation to the TPG and control groups.
We can conclude that MB49 cells embedded in a polymeric thermoreversible gel matrix with chitosan used in the form of an intravesical vaccine are able to stimulate the immune response and affect the development of the bladder tumor in an orthotopic and syngeneic C57BL/6 murine model.
激活免疫系统以获得治疗益处长期以来一直是免疫学的目标，尤其是在癌症治疗中，但抗肿瘤疫苗的低免疫原性仍然是对抗恶性肿瘤的一个限制因素。在癌症免疫治疗领域，已观察到使用可生物降解聚合物（如壳聚糖）可提高弱抗原的免疫原性。然而，在膀胱癌模型中，使用基于壳聚糖的肿瘤细胞与热可逆递送系统组合的疫苗效果尚不清楚，该疫苗主要通过膀胱内途径刺激抗肿瘤免疫反应。我们建议使用膀胱尿路上皮癌的C57BL/6小鼠模型，评估泊洛沙姆407和壳聚糖形成的聚合物凝胶基质（TPG）与MB49细胞联合作为膀胱内抗肿瘤疫苗的疗效。通过形成三个实验组来分析免疫效果：对照组、TPG组和TPG + MB49组。在接种阶段，TPG + MB49组对膀胱壁进行创伤性损伤，并立即膀胱内灌注含有包埋在TPG中的MB49细胞的疫苗复合物。TPG组使用含在培养基中稀释的凝胶的复合物进行相同操作，对照组仅使用培养基。21天后，对动物进行肿瘤诱导攻击。
体外试验显示，暴露于TPG后细胞活力丧失且无法增殖。体内试验表明，与其他两组未显示出统计学上不同肿瘤进展的组相比，先前用TPG + MB49免疫的动物具有更高的累积生存率，以及显著更低的膀胱重量和大小。此外，这些动物的脾细胞相对于TPG组和对照组也显示出更高的抗肿瘤细胞毒性率。
我们可以得出结论，以膀胱内疫苗形式使用的、包埋在含壳聚糖的聚合物热可逆凝胶基质中的MB49细胞能够刺激免疫反应，并影响原位同基因C57BL/6小鼠模型中膀胱肿瘤的发展。
