Propionibacterium acnes (P. acnes) is an anaerobic, Gram-positive bacteria encountered in inflammatory acne lesions, particularly in the pilosebaceous follicle. P. acnes triggers a strong immune ...response involving keratinocytes, sebocytes and monocytes, the target cells during acne development. Lipoteicoic acid and peptidoglycan induce the inflammatory reaction, but no P. acnes surface protein interacting with Toll-like receptors has been identified. P. acnes surface proteins have been extracted by lithium stripping and shown to induce CXCL8 production by keratinocytes.
Far-western blotting identified two surface proteins, of 24.5- and 27.5-kDa in size, specifically recognized by TLR2. These proteins were characterized, by LC-MS/MS, as CAMP factor 1 devoid of its signal peptide sequence, as shown by N-terminal sequencing. Purified CAMP factor 1 induces CXCL8 production by activating the CXCL8 gene promoter, triggering the synthesis of CXCL8 mRNA. Antibodies against TLR2 significantly decreased the CXCL8 response. For the 27 P. acnes strains used in this study, CAMP1-TLR2 binding intensity was modulated and appeared to be strong in type IB and II strains, which produced large amounts of CXCL8, whereas most of the type IA1 and IA2 strains presented little or no CAMP1-TLR2 binding and low levels of CXCL8 production. The nucleotide sequence of CAMP factor displays a major polymorphism, defining two distinct genetic groups corresponding to CAMP factor 1 with 14 amino-acid changes from strains phylotyped II with moderate and high levels of CAMP1-TLR2 binding activity, and CAMP factor 1 containing 0, 1 or 2 amino-acid changes from strains phylotyped IA1, IA2, or IB presenting no, weak or moderate CAMP1-TLR2 binding.
Our findings indicate that CAMP factor 1 may contribute to P. acnes virulence, by amplifying the inflammation reaction through direct interaction with TLR2.
•High prevalence of high-risk human papillomavirus infection was found in women attending cervical cancer screening.•Prevalence rates of other sexually transmitted infections were similar to those ...reported previously in West Africa.•Bacterial resistance was found in several strains of Neisseria gonorrhoeae and Mycoplasma genitalium.•Improvement of systematic prevention, screening and treatment is needed in Mali.
To assess the prevalence of sexually transmitted infections (STIs), antimicrobial resistance and cervical lesions among women from Sikasso, Mali.
Women infected with human immunodeficiency virus (HIV) (n=44) and HIV-negative women (n=96) attending cervical cancer screening were included. Screening for human papillomavirus (HPV), Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) was performed using polymerase chain reaction assays, and herpes simplex virus (HSV-1/2) serological status was assessed using enzyme-linked immunosorbent assays. Antibiotic resistance tests were performed for MG- and NG-positive cases.
A high prevalence of high-risk HPV (hrHPV) infection (63%) was found. This was associated with cervical lesions in 7.5% of cases. An unusual distribution was found, with HPV31, HPV56 and HPV52 being the most prevalent. The hrHPV distribution differed by HIV status, with HIV-positive cases having HPV35/31/51-52-56 and HIV-negative cases having HPV31/56/52. The seroprevalence of HSV-2 was 49%, and the prevalence of other STIs was as follows: CT, 4%; MG, 9%; NG, 1%; and TV, 7%. Five of nine MG-positive specimens and the NG strains obtained were resistant to fluoroquinolone.
These results showed high prevalence of hrHPV and fluoroquinolone resistance in several NG and MG strains. Further studies are required to confirm these data in Mali, and to improve prevention, screening and management of cervical cancer and other STIs in women.
We explored the molecular evolution of the spike gene after the administration of anti-spike monoclonal antibodies in patients with mild or moderate forms of COVID-19. Four out of the 13 patients ...acquired a mutation during follow-up; two mutations (G1204E and E406G) appeared as a mixture without clinical impact, while the Q493R mutation emerged in two patients (one receiving bamlanivimab and one receiving bamlanivimab/etesevimab) with fatal outcomes. Careful virological monitoring of patients treated with mAbs should be performed, especially in immunosuppressed patients.
Human Herpesvirus 8 (HHV-8) is associated with three main severe orphan malignancies, Kaposi's sarcoma (KS), multicentric Castleman's disease (MCD), and primary effusion lymphoma (PEL), which present ...few therapeutic options. We identified the antimalarial primaquine diphosphate (PQ) as a promising therapeutic candidate for HHV-8-associated PEL and KS. Indeed, PQ strongly reduced cell viability through caspase-dependent apoptosis, specifically in HHV-8-infected PEL cells. Reactive oxygen species (ROS)- and endoplasmic reticulum (ER) stress-mediated apoptosis signaling pathways were found to be part of the in vitro cytotoxic effect of PQ. Moreover, PQ treatment had a clinically positive effect in a nonobese diabetic (NOD)/SCID xenograft PEL mouse model, showing a reduction in tumor growth and an improvement in survival. Finally, an exploratory proof-of-concept clinical trial in four patients harboring severe KS was conducted, with the main objectives to assess the efficacy, the safety, and the tolerability of PQ, and which demonstrated a positive efficacy on Kaposi's sarcoma-related lesions and lymphedema.
A higher proportion of intermittent viremia (to have a HIV-1 RNA viral load>50 copies/mL not confirmed) was reported in the boosted protease inhibitor monotherapy arm in some studies including MONOI ...trial, and that could have an impact on the replenishment of the HIV-1 DNA reservoirs. The HIV-1 DNA level is an interesting marker which reflects the size of cellular HIV reservoir. Our objectives were to study the impact of 96 weeks of Darunavir/ritonavir monotherapy versus a triple standard combination on the HIV-1 blood reservoir and factors associated with HIV-1 plasma DNA at baseline in MONOI trial sub-study.
This sub-study is focused on 160 patients (79 patients in monotherapy arm and 81 in tritherapy arm) for whom blood cells were available both at baseline and at week 96 (W96). Baseline HIV-1 plasma DNA was associated with CD4 nadir, pre therapeutic HIV-1 RNA viral load and baseline HIV-1 RNA measured by ultrasensitive assay. A similar median delta HIV-DNA was observed between D0 and W96 in both arms; 0.35 log copies/10(6) leucocytes in monotherapy arm versus 0.51 log copies/10(6) leucocytes in tritherapy arm.
Despite a higher proportion of intermittent viremia in monotherapy arm, a similar evolution of cellular HIV-1 DNA level was observed between mono and triple therapy arm.
ClinicalTrials. gov NCT00421551.
Strains responsible for acute hepatitis B infections (AHB) in France have not been characterized. This study was first designed to analyze the molecular epidemiology of AHB and second to describe the ...differences between AHB and chronic hepatitis B (CHB) exacerbations.
This prospective study was based on the French mandatory notification system for AHB. 147 samples corresponding to declared cases were shipped to a central laboratory for classification as AHB or CHB according to the level of anti-HBc IgM and anti-HBc avidity.
Based on biological marker values and file examination, 75 cases (59%) were classified as AHB. Independently of the acute or chronic status, genotype A (57%), D (22%) and E (14%) were the most prevalent and no phylogenetic clustering was observed among HBV sequences (n=68). Precore or basal core-promoter variants were not particularly associated with disease severity but were more prevalent in CHB. No antiviral resistant strains or immune-escape HBsAg was observed. HBV viral loads in AHB or CHB were comparable but with opposite distributions. ALT levels reached 10 times the upper normal value in 94% of AHB but only in 24% of CHB.
After rigorous classification, no major difference at the genetic level was found between HBV strains isolated from AHB and CHB. Absence of potentially deleterious variant detection is reassuring. When based upon HBsAg and anti-HBc IgM determination, AHB notification may falsely include more than 40% CHB, leading to an important risk of bias in national surveillance programs of AHB.
High-risk patients, often immunocompromised and not responding to vaccine, continue to experience severe coronavirus disease 2019 (COVID-19) and death. Monoclonal antibodies (mAbs) were shown to be ...effective to prevent severe COVID-19 for these patients. Nevertheless, concerns about the emergence of resistance mutations were raised.
We conducted a multicentric prospective cohort study, including 264 patients with mild to moderate COVID-19 at high risk for progression to severe COVID-19 and treated early with casirivimab/imdevimab, sotrovimab, or tixagevimab/cilgavimab. We sequenced the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome during follow-up and searched for emerging spike mutations.
Immunocompromised patients have a 6-fold increased risk of developing mutations, which are associated with a prolonged duration of viral clearance but no clinical worsening. Emerging P337S/R/L/H, E340D/K/A/Q/V/G, and K356T/R substitutions in patients treated with sotrovimab are associated with higher viral RNA loads for up to 14 days post-treatment initiation. Tixagevimab/cilgavimab is associated with a 5-fold increased risk of developing mutations. R346K/I/T/S and K444R/N/M substitutions associated with tixagevimab/cilgavimab have been identified in multiple SARS-CoV-2 lineages, including BQ.1 and XBB.
The probability of emerging mutations arising in response to mAbs is significant, emphasizing the crucial need to investigate these mutations thoroughly and assess their impact on patients and the evolutionary trajectory of SARS-CoV-2.