Mechanisms of herpes simplex virus latency and reactivation / 浙江大学学报·医学版

Herpes simplex virus (HSV), including HSV-1 and HSV-2, is an important pathogen that can cause many diseases. Usually these diseases are recurrent and incurable. After lytic infection on the surface of peripheral mucosa, HSV can enter sensory neurons and establish latent infection during which viral replication ceases. Moreover, latent virus can re-enter the replication cycle by reactivation and return to peripheral tissues to start recurrent infection. This ability to escape host immune surveillance during latent infection and to spread during reactivation is a viral survival strategy and the fundamental reason why no drug can completely eradicate the virus at present. Although there are many studies on latency and reactivation of HSV, and much progress has been made, many specific mechanisms of the process remain obscure or even controversial due to the complexity of this process and the limitations of research models. This paper reviews the major results of research on HSV latency and reactivation, and discusses future research directions in this field.

Immunoregulatory effects of 1,25(OH)2D3 on Der p stimulating the expression of TLR4 and IL-4 in P815 mast cells / 中华微生物学和免疫学杂志

Objective To investigate the effects of Dermatophagoides pteronyssinus ( Der p) on the expression of TLR4 and IL-4 in P815 mast cells and to further analyze the immunoregulatory effects of 1,25-(OH)2D3 on Der p treated P815 mast cells.Methods Different concentrations of Der p and 1,25-( OH) 2 D3 were used alone or in combination to stimulate P815 mast cells.The supernatants of the stimulated cell culture were analyzed by enzyme-linked immunosorbent assay ( ELISA) for the detection of IL-4.The stimulated cells were collected and analyzed by real-time PCR and Western blot assays for the detection of TLR4atmRNAandproteinlevels,respectively.Results (1)TLR4expressionwasdetectedinP815 cells.The expression of TLR4 was enhanced in P815 cells treated with various concentrations of Der p.A significant dose-dependent up-regulation of TLR4 was observed in P815 cells after incubation with Der p for 36 h.(2) Der p promoted the release of IL-4 in P815 cells (P0.05).(4) 10-8 mol/L of 1,25(OH)2D3 promoted the Der p-induced expression of TLR4 in P815 cells (P<0.01).However, 1,25(OH)2D3 inhibited the release of IL-4 in a dose-dependent manner(P<0.05orP<0.01).Conclusion (1)Derpcouldpromotetheinflammationandallergicreac-tion through up-regulating TLR4 and IL-4 in mast cells.(2) The possible mechanism for the inhibitory of 1, 25(OH)2D3 on Der p-induced immune responses was due to the suppression of Th2-type immune responses through inhibiting the synthesis and secretion of IL-4 in mast cells.