SOCS4 expressed by recombinant HSV protects against cytokine storm in a mouse model

Oncolytic viruses are genetically engineered viruses designed for the treatment of solid tumors, and are often coupled with the antitumor immunity of the host. The challenge of using oncolytic herpes simplex virus (oHSV) as an efficacious oncolytic agent is the potential host tissue damage caused by the production of a range of cytokines following intratumoral oHSV injection. An HSV-suppressor of cytokine signaling 4 (SOCS4) recombinant virus was created to investigate whether it inhibits cytokine storm. Recombinant HSV-SOCS4 and HSV-l(F) were used to infect mice, and levels of several representative cytokines, including monocyte chemoattractant protein-1, interleukin (IL)-1[beta], tumor necrosis factor-[alpha], IL-6 and interferon [gamma], in serum and bronchoalveolar lavage fluid (BALF) of infected mice were determined, and immune cells in BALF and spleen were enumerated. Lung damage, virus titers in the lung, body weight and survival rates of infected mice were also determined and compared between the two groups. The cytokine concentration of HSV-SOCS4-infected mice was significantly decreased compared with that of HSV-l(F)-infected mice in BALF and serum, and a smaller number of cluster of differentiation ([CD)11[b.sup.+] cells of BALF, and [CD8.sup.+][CD62L.sup.+] T cells and [CD4.sup.+][CD62L.sup.+] T cells of the spleen were also identified in HSV-SOCS4-infected mice. HSV-SOCS4-infected mice exhibited slight lung damage, a decrease in body weight loss and a 100% survival rate. The results of the present study indicated that SOCS4 protein may be a useful regulator to inhibit cytokine overproduction, and that HSV-SOCS4 may provide a possible solution to control cytokine storm and its consequences following induction by oncolytic virus treatment.