Hormetic Response to Low-Dose Radiation: Focus on the Immune System and Its Clinical Implications

Abstract

The interrelationship between ionizing radiation and the immune system is complex, multifactorial, and dependent on radiation dose/quality and immune cell type. High-dose radiation usually results in immune suppression. On the contrary, low-dose radiation (LDR) modulates a variety of immune responses that have exhibited the properties of immune hormesis. Although the underlying molecular mechanism is not fully understood yet, LDR has been used clinically for the treatment of autoimmune diseases and malignant tumors. These advancements in preclinical and clinical studies suggest that LDR-mediated immune modulation is a well-orchestrated phenomenon with clinical potential. We summarize recent developments in the understanding of LDR-mediated immune modulation, with an emphasis on its potential clinical applications.

Hybrids of Iron-Filled Multiwall Carbon Nanotubes and Anticancer Agents as Potential Magnetic Drug Delivery Systems: In Vitro Studies against Human Melanoma, Colon Carcinoma, and Colon Adenocarcinoma

“…A similar phenomenon called hormesis is frequently found in the radiosensitivity or radioresistance assays where low doses of ionizing radiation are more toxic than higher ones, because of cancer cells adaptation to the toxic conditions at higher doses of IR [60]. Also, for starshaped copolymers as nanocarriers of bioactive compounds tested on MCF-7 and MCF-7 doxorubicin-resistant cell lines, bimodal activities were observed: cytotoxicity decreased with the increasing concentrations [61].…”

Turning natural adaptations to oncogenic factors into an ally in the war against cancer

“…Yet, under this scenario, at the mechanistic level, beneficial effects of toxins in low concentrations can be the result of compensatory biological processes following an initial disruption in homeostasis ("homeostatic overcompensation," Calabrese & Baldwin, 2002). At the cellular level, this overcompensation phenomenon includes processes associated with receptor/signaling mechanisms (Calabrese, 2013), DNA damage repair (Schöllnberger, Stewart, Mitchel, & Hofmann, 2004), immunefunction enhancement (Cui et al, 2017), and alteration of gene expression (Sokolov & Neumann, 2015). As epigenetic mechanisms have also been described for hormetic effects (Vaiserman, 2011), a link to environmental matching theory can be made (Kaiser, 2003).…”

Hormesis and immunity: A review

“…In general, high-dose irradiation causes the suppression of immunity and low-dose irradiation stimulates immunity [11,12]. This is a typical case of hormesis and it can be used clinically in the radiation treatment of numerous diseases [11].…”

“…In general, high-dose irradiation causes the suppression of immunity and low-dose irradiation stimulates immunity [11,12]. This is a typical case of hormesis and it can be used clinically in the radiation treatment of numerous diseases [11]. The low-dose irradiation enhances the proliferation of immune cells as well as the interactions of innate and adaptive immune systems [13,14].…”