Impact of vaginal microbiome communities on HIV antiretroviral-based pre-exposure prophylaxis (PrEP) drug metabolism

Despite the efficacy of antiretroviral-based pre-exposure prophylactics (PrEP) in men who have sex with men, studies in women have produced widely varying outcomes. Recent evidence demonstrates that vaginal microbial communities are associated with increased HIV acquisition risk and may impact PrEP efficacy. Here, we investigate the mechanisms underlying how vaginal bacteria alter PrEP drug levels and impact HIV infection rates ex vivo. Using cervicovaginal lavages (CVLs) from women with or without bacterial vaginosis (BV), we identified microbial metabolism of PrEP drugs in BV samples through LC-MS/MS analysis of soluble drug levels and metabolite formation in dual T-cell cultures. CVL samples were assessed for microbiome analysis using sequencing of bacterial 16S rRNA genes. We also observed non-Lactobacillus bacteria that are associated with BV may potentially impact PrEP efficacy through increased HIV infection rates in co-cultures containing Lactobacillus or BV bacteria, PrEP drugs, CEM-GFP cells, and HIV-1_LAI virus. Finally, we used these data to develop a novel predictive mathematical simulation modeling system to predict these drug interactions for future trials. These studies demonstrate how dysbiotic vaginal microbiota may impact PrEP drugs and provides evidence linking vaginal bacteria to PrEP efficacy in women.     

Enzymatic synthesis of two ginsenoside Re-beta-xylosides.

Two new beta-xylosyl derivatives of ginsenoside Re, 20(S)-protopanaxatriol 6-O-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-xylopyranosyl-(1 --> 4)]-beta-D-glucopyranosyl-20-O-beta-D-glucopyranoside and 20(S)-protopanaxatriol 6-O-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-xylopyranosyl-(1 --> 6)]-beta-D-glucopyranosyl-20-O-beta-D-glucopyranoside, were respectively synthesized from p-nitrophenyl beta-D-xylopyranoside and phenyl beta-D-xylopyranoside as donors and ginsenoside Re as the acceptor in 25% acetone and acetonitrile by a cellulase preparation from Trichoderma viride and a beta-galactosidase preparation from Aspergillus oryzae. The latter enzyme preparation also catalyzed the hydrolysis of ginsenoside Re to the minor saponin, ginsenoside Rg2.     

5-Hydroxytryptamine-Stimulated Inositol Phospholipid Hydrolysis in the Mouse Cortex Has Pharmacological Characteristics Compatible with Mediation via 5-HT2 Receptors but This Response Does Not Reflect Altered 5-HT2 Function After 5,7-Dihydroxytryptamine Lesioning or Repeated Antidepressant Treatments

5-Hydroxytryptamine (5-HT; 3 x 10(-8)-1 x 10(-5)M) produced a dose-dependent increase in phosphatidylinositol/polyphosphoinositide (PI) turnover in mouse cortical slices, as measured by following production of 3H-labelled inositol phosphates (IPs) in the presence of 10 mM LiCl. Analysis of individual IPs, in slices stimulated for 45 min, indicated substantial increases in inositol monophosphate (IP1; 140%) and inositol bisphosphate (IP2; 95%) contents with smaller increases in inositol trisphosphate (IP3; 51%) and inositol tetrakisphosphate (IP4; 48%) contents. The increase in IP3 level was solely in the 1,3,4-isomer. This response was inhibited by the nonselective 5-HT antagonists methysergide, metergoline, and spiperone. It was also inhibited by the selective 5-HT2 antagonists ketanserin and ritanserin but not by the 5-HT1 antagonists isapirone, (-)-propranolol, or pindolol. 5-HT-stimulated IP formation was also unaltered by atropine, prazosin, and mepyramine. Lesioning brain 5-HT neurones using 5,7-dihydroxytryptamine (5,7-DHT; 50 micrograms i.c.v.) produced a 210% (p less than 0.01) increase in the number of 5-HT2-mediated head-twitches induced by 5-methoxy-N,N-dimethyltryptamine (2 mg/kg). However, 5,7-DHT lesioning had no effect on 5-HT-stimulated PI turnover in these mice. Similarly, an electroconvulsive shock (90 V, 1 s) given five times over a 10-day period caused an 85% (p less than 0.01) increase in head-twitch responses but no change in 5-HT-stimulated PI turnover. Decreasing 5-HT2 function by twice-a-day injection of 5 mg/kg of zimeldine or desipramine (DMI) produced 50% (p less than 0.01) and 56% (p less than 0.01), respectively, reductions in head-twitch behaviour.(ABSTRACT TRUNCATED AT 250 WORDS)     

Developmental changes in the distribution of cecal lectin-binding sites of Balb-c mice.

The existence of lectin-binding sites was investigated in the cecum of Balb-c mice at seven developmental stages ranging from 18 days post conception (p.c.) to 8 weeks after birth. Nine horseradish-peroxidase-conjugated lectins (concanavalin A, Triticum vulgaris, Dolichus biflorus, Helix pomatia, Arachis hypogaea, Glycine maximus, Lotus tetragonolobus, Ulex europaeus, Limulus polyphemus) were applied to 5- to 7-microns thin paraffin sections of Bouin-fixed tissue. After DAB staining the sections were evaluated by light microscopy. It was shown that each lectin exhibits a unique developmental pattern. The adult binding patterns were established at the age of 3-4 weeks with only minor changes occurring thereafter. Considerable differences in binding patterns occurred not only between lectins of different groups but also between lectins with the same nominal monosaccharide specificity.     

Infectivity of Cryptosporidium parvum oocysts following cryopreservation.

This study was undertaken to investigate the cryopreservation of Cryptosporidium parvum oocysts. Oocysts purified from mouse feces were suspended in distilled water, 10% glycerin, and 2.5% potassium dichromate. They were stored at -20 C and -80 C for 2, 7, and 30 days, respectively. In addition to the purified oocysts, the feces of C. parvum-infected mice were preserved under the same conditions described above. Purified and fecal oocysts were thawed at 4 C, and their viability was assessed by a nucleic acid stain, excystation test, tissue culture infectivity test, and infectivity to immunosuppressed adult mice. Oocysts purified from fecal material prior to cryopreservation lost most of their viability and all of their infectivity for tissue culture and mice. However, when oocysts were cryopreserved in feces, between 11.7 and 34.0% were judged to be viable and retained their infectivity for mice when stored at -20 C (but not -80 C) for 2, 7, and 30 days. Clearly, fecal material provides a cryoprotective environment for C. parvum oocysts stored at -20 C for at least 30 days.     

Long-term effect of retrobulbar hematomas on the vision of cynomolgus monkeys.

Using the monkey model previously developed, we investigated the long-term effects of retrobulbar hematoma-induced retinal ischemia on functional vision and retinal histology. In this experimental model, ischemic periods of up to 120 minutes did not cause permanent visual deficits, as measured by flashed evoked visual potentials. Similarly, retinal histology showed no evidence of ischemic injury. From this we conclude that blindness after blepharoplasty is not due to retrobulbar hematomas alone and that additional predisposing factors are involved. The most likely additional factor is preexisting occult vascular ocular pathology.     

SECRETORY VESICLE FORMATION IN GLANDULAR TRICHOMES OF CANNABIS SATIVA (CANNABACEAE)

Formation of secretory vesicles in the noncellular secretory cavity of glandular trichomes of Cannabis saliva L. was examined by transmission electron microscopy. Two patterns of vesicle formation occurred during gland morphogenesis. 1) During initial phases of cavity formation small hyaline areas arose in the wall near the plasma membrane of the disc cell. Hyaline areas of elongated shape and different sizes were distributed throughout the wall and adjacent to the secretory cavity. Hyaline areas increased in size, some possibly fusing with others. These hyaline areas, possessing a membrane, moved into the cavity where they formed vesicles. As membraned vesicles they developed a more or less round shape and their contents became electron-dense. 2) During development of the secretory cavity and when abundant secretions were present in the disc cells, these secretions passed through the wall to accumulate as membraned vesicles of different sizes in the cavity. As secretions emerged from the wall, a membrane of wall origin delimited the secretory material from cavity contents. Vesicles released from the wall migrated in the secretory cavity and contacted the sheath where their contents permeated into the subcuticular wall as large or diffused quantities of secretions. In the subcuticular wall these secretions migrated to the wall–cuticle interface where they contributed to structural thickening of the cuticle. This study demonstrates that the secretory process in glands of Cannabis involves not only secretion of materials from the disc cell, but that the disc cell somehow packages these secretions into membraned vesicles outside the cell wall prior to deposition into the secretory cavity for subsequent structural development of the sheath.