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Updated: Jun 28, 2026
Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry
Published on: June 26, 2019
Proteomic analyses associate cystatin B with restricted HIV-1 replication in placental macrophages
C Luciano-Montalvo1, P Ciborowski, F Duan
1Department of Microbiology and Medical Zoology, University of Puerto Rico, Medical Sciences Campus, Puerto Rico.
Abstract:
Mononuclear phagocytes (MP; monocytes, tissue macrophages, and dendritic cells) are reservoirs, vehicles of dissemination, and targets for persistent HIV infection. However, not all MP population equally support viral growth. Such differential replication is typified by the greater ability of placental macrophages (PM), as compared to blood borne monocyte-derived macrophages (MDM), to restrict viral replication. Since cytosolic protein patterns can differentiate macrophage subtypes, we used a proteomics approach consisting of surface-enhanced laser desorption ionization time-of-flight (SELDI-TOF), tandem mass spectrometry, and Western blots to identify differences between the uninfected and HIV-infected PM and MDM protein profiles linked to viral growth. We performed proteome analysis of PM in the molecular range of 5-20kDa. We found that a SELDI-TOF protein peak with an m/z of 11,100, which was significantly lower in uninfected and HIV-infected PM than in MDM, was identified as cystatin B (CSTB). Studies of siRNA against CSTB treatment in MDM associated its expression with HIV replication. These data demonstrate that the low molecular weight placental macrophage cytosolic proteins are differentially expressed in HIV-infected PM and MDM and identify a potential role for CSTB in HIV replication. This work also serves to elucidate a mechanism by which the placenta protects the fetus from HIV transmission.
Insights
Placental macrophages restrict HIV replication more than blood-derived macrophages. This difference is linked to lower levels of cystatin B (CSTB) in placental cells, suggesting CSTB influences HIV replication and potentially protects the fetus.
Area of Science:
- Immunology
- Virology
- Proteomics
Background:
- Mononuclear phagocytes (MP), including monocytes, macrophages, and dendritic cells, are crucial in HIV infection, serving as reservoirs and vehicles for viral spread.
- Differential susceptibility to HIV replication exists among MP subtypes, with placental macrophages (PM) showing greater restriction compared to blood monocyte-derived macrophages (MDM).
Purpose of the Study:
- To identify differences in protein expression profiles between uninfected and HIV-infected PM and MDM.
- To elucidate the role of specific proteins in the differential restriction of HIV replication by macrophage subtypes.
Main Methods:
- Proteomic analysis using surface-enhanced laser desorption ionization time-of-flight (SELDI-TOF), tandem mass spectrometry, and Western blots.
- Analysis focused on low molecular weight proteins (5-20kDa) in PM.
- siRNA-mediated knockdown of cystatin B (CSTB) in MDM.
Main Results:
- A protein peak at m/z 11,100, identified as cystatin B (CSTB), was significantly lower in both uninfected and HIV-infected PM compared to MDM.
- siRNA studies in MDM indicated that CSTB expression is associated with HIV replication.
Conclusions:
- Low molecular weight cytosolic proteins, specifically CSTB, are differentially expressed in HIV-infected PM and MDM.
- Cystatin B (CSTB) may play a role in regulating HIV replication.
- These findings suggest a potential mechanism by which the placenta protects the fetus from HIV transmission.
