Principles of Immunotherapy in Melanoma

Advanced/metastatic melanoma is an aggressive cancer with a low survival rate. Traditional cytotoxic chemotherapies do not appreciably extend life and systemic cytokine/chemokine administration produces toxic side effects. By harnessing the surveillance and cytotoxic features of the immune system, immunotherapies can provide a durable response and are proved to improve disease outcomes in patients with advanced/metastatic melanoma and other cancers. Close monitoring is necessary, however, to identify and treat immune system-related adverse events before they become life-threatening. Because metastatic lesions can respond differently to immunotherapies, modified response criteria have been developed to assist physicians in tracking patient response to treatment.

Inhibition of Suv39H1 enhances transgenic IFNα-2b gene expression in Bcap-37 cells

The low expression of exogenous transferred gene limited the application of transgenic animal technology. Suppressor of variegation 3 ∼ 9 homolog 1(SUV39H1) gene plays a prominent role on repressive heterochromatin and transcription. To understand if exogenous transgenic gene expression was affected by SUV39H1 epigenetic modification, in this paper, the effective shRNA fragments targeting SUV39H1 gene were first screened, their roles on expression of exogenous transgenic genes were determined by using Bcap-37 cell line with stable expressing IFNα-2b gene as a model, the preliminary regulation mechanism of SUV39H1 gene was investigated. The results showed that the designed shRNA1/2 fragments of SUV39H1 gene had an obvious inhibition effect on the expression of SUV39H1 gene, reached 53.07 and 31.28%, respectively by qRT-PCR analysis. Compared with the control group, the expression of IFNα-2b gene in transgenic Bcap-37 cells infected with shRNA1 and 2 viruses significantly increased by 96.25 and 121.08%, respectively (p < 0.05). In addition, the expression of DNMT1, HDAC1 and G9a gene in the shRNA infected cells reduced significantly, and the expression of the HAT1 gene increased significantly (p < 0.05). The above results indicated that the expression of exogenous transgenic gene could be promoted by suppressing SUV39H1 gene at the cell level.

Magnetic Relaxation Switching Assay Using IFNα-2b-Conjugated Superparamagnetic Nanoparticles for Anti-Interferon Antibody Detection

Type I interferons, particularly IFNα-2b, play essential roles in eliciting adaptive and innate immune responses, being implicated in the pathogenesis of various diseases, including cancer, and autoimmune and infectious diseases. Therefore, the development of a highly sensitive platform for analysis of either IFNα-2b or anti-IFNα-2b antibodies is of high importance to improve the diagnosis of various pathologies associated with the IFNα-2b disbalance. For evaluation of the anti-IFNα-2b antibody level, we have synthesized superparamagnetic iron oxide nanoparticles (SPIONs) coupled with the recombinant human IFNα-2b protein (SPIONs@IFNα-2b). Employing a magnetic relaxation switching assay (MRSw)-based nanosensor, we detected picomolar concentrations (0.36 pg/mL) of anti-INFα-2b antibodies. The high sensitivity of the real-time antibodies' detection was ensured by the specificity of immune responses and the maintenance of resonance conditions for water spins by choosing a high-frequency filling of short radio-frequency pulses of the generator. The formation of a complex of the SPIONs@IFNα-2b nanoparticles with the anti-INFα-2b antibodies led to a cascade process of the formation of nanoparticle clusters, which was further enhanced by exposure to a strong (7.1 T) homogenous magnetic field. Obtained magnetic conjugates exhibited high negative MR contrast-enhancing properties (as shown by NMR studies) that were also preserved when particles were administered in vivo. Thus, we observed a 1.2-fold decrease of the T2 relaxation time in the liver following administration of magnetic conjugates as compared to the control. In conclusion, the developed MRSw assay based on SPIONs@IFNα-2b nanoparticles represents an alternative immunological probe for the estimation of anti-IFNα-2b antibodies that could be further employed in clinical studies.