Objective:

To investigate the role of human seminal fluid and its fibrils in enhancing mpox virus infection in primary human cells.

Approach:

• Experimental Design: Researchers tested seminal fluid from 6 healthy donors in primary human fibroblasts and keratinocytes, examining the effects of seminal fluid concentrations on mpox virus infection.
• Fibril Analysis: The study focused on two semen-derived amyloid fibrils, SEVI and SEM, assessing their impact on mpox infection across various cell types and viral clades.

Key Findings:

• Seminal fluid increased the number of mpox-positive cells in fibroblasts and keratinocytes.
• At 50% and 10% seminal fluid concentrations, infection rates increased 2.2- to 4.1-fold in fibroblasts and keratinocytes.
• Both SEVI and SEM enhanced mpox infection in a dose-dependent manner.
• SEVI increased infection rates across multiple mpox clades and other viruses like cowpox and camelpox.
• Fibril formation was necessary for the enhancement of infection, as non-fibrillar peptides did not increase infection.

Interpretation:

The study indicates that seminal fluid may enhance viral transmission and infection efficiency.

Limitations:

• The study was limited to cell-based and ex vivo models.
• It did not establish the effect of seminal fluid on person-to-person transmission.
• The complexity of semen and its other components was not fully addressed.

Conclusion:

In vivo studies are needed to further understand the implications of seminal fluid on mpox transmission and infection.

Sources:

• Emerging Microbes & Infections