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Updated: Jun 4, 2026
Phosphopeptide Analysis of Rodent Epididymal Spermatozoa
Published on: December 30, 2014
HIV-1 enhancing effect of prostatic acid phosphatase peptides is reduced in human seminal plasma
Julie A Martellini1, Amy L Cole, Pavel Svoboda
1Department of Molecular Biology & Microbiology, Biomolecular Science Center, Burnett School of Biomedical Sciences at the University of Central Florida College of Medicine, Orlando, Florida, United States of America.
Abstract:
We recently reported that HIV-1 infection can be inhibited by innate antimicrobial components of human seminal plasma (SP). Conversely, naturally occurring peptidic fragments from the SP-derived prostatic acid phosphatase (PAP) have been reported to form amyloid fibrils called "SEVI" and enhance HIV-1 infection in vitro. In order to understand the biological consequence of this proviral effect, we extended these studies in the presence of human SP. PAP-derived peptides were agitated to form SEVI and incubated in the presence or absence of SP. While PAP-derived peptides and SEVI alone were proviral, the presence of 1% SP ablated their proviral activity in several different anti-HIV-1 assays. The anti-HIV-1 activity of SP was concentration dependent and was reduced following filtration. Supraphysiological concentrations of PAP peptides and SEVI incubated with diluted SP were degraded within hours, with SP exhibiting proteolytic activity at dilutions as high as 1:200. Sub-physiological concentrations of two prominent proteases of SP, prostate-specific antigen (PSA) and matriptase, could degrade physiological and supraphysiological concentrations of PAP peptides and SEVI. While human SP is a complex biological fluid, containing both antiviral and proviral factors, our results suggest that PAP peptides and SEVI may be subject to naturally occurring proteolytic components capable of reducing their proviral activity.
Insights
Human seminal plasma (SP) contains factors that inhibit HIV-1. While certain SP peptides (SEVI) can enhance infection, SP
Area of Science:
- Virology
- Biochemistry
Background:
- Human seminal plasma (SP) possesses innate antimicrobial properties.
- Naturally occurring peptidic fragments from prostatic acid phosphatase (PAP) form amyloid fibrils (SEVI), which can enhance HIV-1 infection in vitro.
Purpose of the Study:
- To investigate the biological consequence of SEVI's proviral effect in the presence of human SP.
- To determine if SP can counteract the proviral activity of PAP-derived peptides and SEVI.
Main Methods:
- PAP-derived peptides were agitated to form SEVI and incubated with or without human SP.
- Anti-HIV-1 assays were performed to assess proviral activity.
- SP's concentration-dependent activity and proteolytic degradation of SEVI were analyzed.
- The role of specific SP proteases (PSA, matriptase) in degrading PAP peptides and SEVI was examined.
Main Results:
- Human SP (1% concentration) significantly inhibited the proviral activity of PAP peptides and SEVI in anti-HIV-1 assays.
- SP's anti-HIV-1 activity was concentration-dependent and reduced by filtration.
- SP demonstrated proteolytic activity, degrading PAP peptides and SEVI within hours, even at high dilutions (1:200).
- Prostate-specific antigen (PSA) and matriptase in SP could degrade both PAP peptides and SEVI.
Conclusions:
- Human seminal plasma contains both antiviral and proviral factors regarding HIV-1.
- Proteolytic components within human SP, including PSA and matriptase, can degrade PAP peptides and SEVI.
- These naturally occurring proteases may reduce the proviral activity of SEVI in vivo.
