Human Immunodeficiency Virus (HIV) Infection and Use of Illicit Substances Promote Secretion of Semen Exosomes that Enhance Monocyte Adhesion and Induce Actin Reorganization and Chemotactic Migration

Abstract

Semen exosomes (SE) from HIV-uninfected (HIV−) individuals potently inhibit HIV infection in vitro. However, morphological changes in target cells in response to SE have not been characterized or have the effect of HIV infection or the use of illicit substances, specifically psychostimulants, on the function of SE been elucidated. The objective of this study was to evaluate the effect of HIV infection, psychostimulant use, and both together on SE-mediated regulation of monocyte function. SE were isolated from semen of HIV− and HIV-infected (HIV+) antiretroviral therapy (ART)-naive participants who reported either using or not using psychostimulants. The SE samples were thus designated as HIV−Drug−, HIV−Drug+, HIV+Drug−, and HIV+Drug+. U937 monocytes were treated with different SEs and analyzed for changes in transcriptome, morphometrics, actin reorganization, adhesion, and chemotaxis. HIV infection and/or use of psychostimulants had minimal effects on the physical characteristics of SE. However, different SEs had diverse effects on the messenger RNA signature of monocytes and rapidly induced monocyte adhesion and spreading. SE from HIV infected or psychostimulants users but not HIV−Drug− SE, stimulated actin reorganization, leading to the formation of filopodia-like structures and membrane ruffles containing F-actin and vinculin that in some cases were colocalized. All SE stimulated monocyte chemotaxis to HIV secretome and activated the secretion of matrix metalloproteinases, a phenotype exacerbated by HIV infection and psychostimulant use. SE-directed regulation of cellular morphometrics and chemotaxis depended on the donor clinical status because HIV infection and psychostimulant use altered SE function. Although our inclusion criteria specified the use of cocaine, humans are poly-drug and alcohol users and our study participants used psychostimulants, marijuana, opiates, and alcohol. Thus, it is possible that the effects observed in this study may be due to one of these other substances or due to an interaction between different substances.

Electrostatic Surface Properties of Blood and Semen Extracellular Vesicles: Implications of Sialylation and HIV-Induced Changes on EV Internalization

“…To our knowledge, this is the first study to report on HIV-induced alteration in body fluid EV surface charge. Our observation that HIV infection increased the negative surface charge on BEVs and SEVs ( Figure 3 c) is novel, and in line with the notion that HIV reprograms the epigenome and proteome of host cells [ 86 , 87 , 88 , 89 , 90 , 91 ] and EVs [ 51 , 92 ]. The reason for the differences in surface charge between HIV+ and HIV- BEVs and SEVs is unknown.…”

Development of Novel High-Resolution Size-Guided Turbidimetry-Enabled Particle Purification Liquid Chromatography (PPLC): Extracellular Vesicles and Membraneless Condensates in Focus

“…These results showed that multi-bead gSEC separation could be used to separate a variety of biological samples and that each biofluid (at least those tested here) has a unique characteristic absorbance profile. Since seminal plasma exhibit the most complex absorbance profiles and is of particular interest to our group [ 25 , 26 , 27 , 28 , 29 , 30 ], seminal plasma was used as a prototype biofluid for the characterization of the components in the peaks and the development of the analytical algorithms, as well as the compositional and functional studies.…”

“…Transmission electron microscopy analysis of the isolated fractions was conducted as previously described [ 30 ]. Briefly, carbon-coated copper grids were glow-discharged to make the film hydrophilic (Pellco Easiglow, 0.2 mpar, 30 mA, 40 s, negative); then, ten microliters of F1–4 were applied to the grid and allowed to sit for 30 s. After removing the excess samples with filter paper, the grids were washed with distilled deionized water (ddH 2 O) twice, followed by staining with 0.7% uranyl formate solution for 20 s. The grids were allowed to air dry before viewed.…”

“…For our application, we favored the exact Lorenz-Mie solution over the Rayleigh-Gans-Debye approximation for two main reasons: First, the Lorenz-Mie solution applies to wider ranges of sizes, which fits the heterogenic nature of EVs [ 15 , 76 , 77 ], whereas Rayleigh scattering is only applicable in a narrow range of sizes where the particle radii should be significantly smaller than the wavelength of the scattered light [ 78 ]. Second, the exact Lorenz-Mie solution is more favorable than Rayleigh scattering when studying charged particles [ 79 ], which is also the case of EVs that have been reported to be negatively charged [ 30 , 80 , 81 ]. Thus, we applied the Wang et al model [ 40 ], which was developed to calculate the scattering cross-section of concentric vesicles with an arbitrary size, lipid concentration, membrane thickness, or number of layers.…”

Semen exosomes inhibit HIV infection and HIV‐induced proinflammatory cytokine production independent of the activation state of primary lymphocytes

“…Because HIV‐induced immune activation is the result of a robust host response characterized by the upregulation of a vast array of genes that control viral replication and antiviral molecules, it is likely that early in HIV infection, SE may inhibit the production of HIV‐induced molecules that exacerbate immune activation while constitutively promoting a compensatory upregulation in expression of genes promoting antiviral immune response or immune suppressor genes. Therefore, SE may serve as a counterbalance to moderate the immunopathological consequences of sustained immune activation, or to mediate alteration in cellular actin cytoskeleton and morphometrics, as is the case for SE from donors that used psychostimulants and are HIV infected or uninfected . This may be particularly important in regulating the susceptibility of immune cells at the site of infection.…”