Prolonged high-intensity exercise induces fluctuating immune responses to herpes simplex virus infection via glucocorticoids

Single-cell RNA sequencing reveals the diversity of the immunological landscape response to genital herpes

Genital herpes (GH) is a common sexually transmitted disease, which is primarily caused by herpes simplex virus type 2 (HSV-2), and continues to be a global health concern. Although our understanding of the alterations in immune cell populations and immunomodulation in GH patients is still limited, it is evident that systemic intrinsic immunity, innate immunity, and adaptive immunity play crucial roles during HSV-2 infection and GH reactivation. To investigate the mechanisms underlying HSV-2 infection and recurrence, single-cell RNA sequencing (scRNA-seq) was performed on immune cells isolated from the peripheral blood of both healthy individuals and patients with recurrent GH. Furthermore, the systemic immune response in patients with recurrent GH showed activation of classical monocytes, CD4+ T cells, natural killer cells (NK cells), and plasmacytoid dendritic cells (pDCs), especially of genes associated with the Toll-like receptor signaling pathway and T cell activation. Circulating immune cells in GH patients show higher expression of genes associated with inflammation and antiviral responses both in the scRNA-Seq data set and in independent quantitative real-time polymerase chain reaction (qRT-PCR) analysis and ELISA experiments. This study demonstrated that localized genital herpes, resulting from HSV reactivation, may influence the functionality of circulating immune cells, suggesting a potential avenue for future research into the role of systemic immunity during HSV infection and recurrence.

Herpes simplex virus-induced murine dry skin model through sweating disturbance

BACKGROUND

Given that ocular glands become infected secondarily to herpes simplex virus 1 (HSV-1) keratitis, resulting in the loss of tear production, sweat glands may also be susceptible to HSV-1 infection, resulting in sweating disturbance, which is observed frequently in atopic dermatitis. However, due to the lack of sweat glands on the hairy skin of mice, the role of sweating in the maintenance of skin hydration has not been elucidated.

OBJECTIVE

To determine the relationship between HSV-1 infection of sweat glands and sweating disturbance-induced dry skin.

METHODS

By using the impression mold technique, we examined the sweating response together with the detection of HSV-1 DNA in the sweat glands of footpads, the only area with sweat glands in mice, after local cutaneous HSV-1 inoculation of immunocompetent mice.

RESULTS

The sweating response and skin surface hydration were significantly decreased at 7-14 days post-infection. Sweating disturbance and dry skin was markedly enhanced when HSV-1 inoculation was followed by hyperthermic stress. Both resolved spontaneously and became resistant to a second HSV-1 inoculation, associated with increased anti-HSV-IgG antibodies. HSV-1 DNA was detected in sweat glands and dorsal root ganglia. The sweating response remained decreased after subcutaneous injection with pilocarpine, correlating histologically with marked dilatation of sweat gland lumens. These findings indicate that sweating disturbance is unlikely to be the outcome of nerve damage by HSV-1 infection.

CONCLUSION

Sweating disturbance could be due to HSV-induced dysfunction of sweat glands. We developed a sweating disturbance-induced dry skin mouse model by infection with HSV-1.

Glucocorticoid circadian rhythms in immune function

Adrenal glucocorticoid (GC) hormones are important regulators of energy metabolism, brain functions, and the immune system. Their release follows robust diurnal rhythms and GCs themselves serve as entrainment signals for circadian clocks in various tissues. In the clinics, synthetic GC analogues are widely used as immunosuppressive drugs. GC inhibitory effects on the immune system are well documented and include suppression of cytokines and increased immune cell death. However, the circadian dynamics of GC action are often neglected. Synthetic GC medications fail to mimic complex GC natural rhythms. Several recent publications have shown that endogenous GCs and their daily concentration rhythms prepare the immune system to face anticipated environmental threats. That includes migration patterns that direct specific cell population to organs and tissues best exemplified by the rhythmic expression of chemoattractants and their receptors. On the other hand, chronotherapeutic approaches may benefit the treatment of immunological diseases such as asthma. In this review, we summarise our current knowledge on the circadian regulation of GCs, their role in innate and adaptive immune functions and the implications for the clinics.