Lrp1 is essential for lethal Rift Valley fever hepatic disease in mice

Rift Valley fever virus (RVFV) is an emerging arbovirus found in Africa. While RVFV is pantropic and infects many cells and tissues, viral replication and necrosis within the liver play a critical role in mediating severe disease. The low-density lipoprotein receptor-related protein 1 (Lrp1) is a recently identified host factor for cellular entry and infection by RVFV. The biological significance of Lrp1, including its role in hepatic disease in vivo, however, remains to be determined. Because Lrp1 has a high expression level in hepatocytes, we developed a mouse model in which Lrp1 is specifically deleted in hepatocytes to test how the absence of liver Lrp1 expression affects RVF pathogenesis. Mice lacking Lrp1 expression in hepatocytes showed minimal RVFV replication in the liver, longer time to death, and altered clinical signs toward neurological disease. In contrast, RVFV infection levels in other tissues showed no difference between the two genotypes. Therefore, Lrp1 is essential for RVF hepatic disease in mice

Role of Il-21 in CD8 T cell response against E.cuniculi infection

Microsporidia are a group of obligate intracellular opportunistic parasites that induce a wide-range of pathology in immunocompromised individuals, including HIV-AIDS patients, organ transplant recipients, cancer patients and the elderly. Among the many species of microsporidia, at least eight can infect humans, but the pathogen is often underdiagnosed due to its small size and the need to be identified by specialized staining techniques. Encephalitozoon cuniculi is a microsporidia with one of the widest host ranges among mammals and has the ability to disseminate into multiple tissues. Due to the fact that it can be cultured in the laboratory, a majority of experimental studies have been conducted with E.cuniculi. In a mouse model of E.cuniculi infection, robust CD8 T cell response manifested by strong polyfunctional characteristics (both IFNg and cytolytic activity) is critical for host protection. Interestingly, the parasite does not induce a high inflammatory environment, and the CD8 T cell response elicited after oral/natural infection is independent of IL-2 and primarily driven by IL-21. Although importance of IL-21 is associated with B cell responses, this cytokine has also been reported to play a critical role in maintaining a robust CD8 T cell memory. We observed that in the absence of IL-21 signaling (IL-21R KO), effector CD8 T cell response to E.cuniculi infection was reduced both in terms of number and polyfunctionality. T follicular helper cells (TFH) are considered to be the major source of IL-21 and this CD4 T cell subset is critical for the formation of germinal centers, which is dependent on signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) expression. SAP knock out animals were used to study the role of this CD4 T cell subset in programing of effector CD8 T cell response against E.cuniculi. Intracellular staining analysis showed that TFH (ICOShiPD1hi CD4 T cells) are the main producers of IL-21 during early infection. As compared to wild type animals, SAP-/- mice exhibited lower IL-21 production at day 5-post infection. Interestingly, although the knock out mice exhibited increased short-lived effector CD8 T cell response (SLEC; KLRG1+CD127-) in terms of numbers, their polyfunctionality (IFNg production and significantly impaired cytotoxicity) was reduced. Moreover, activation status of SAP deficient SLECs (based on CD43 staining), in comparison to cells from wild type mice was also decreased. These findings strongly suggest that early IL-21 production by TFH may be critical for optimal effector CD8 T cell immunity against E.cuniculi infection

Cross comparison of AmpFire HPV genotyping assay and Roche human papillomavirus (HPV) linear array for HPV genotyping of anal swab samples.

Although anal cancers represent just 0.5% of all new cancer cases in U.S., rates have increased markedly, with highest rates in HIV-infected MSM. American Cancer Society estimates there will be ~9,090 new cases and ~1,420 deaths in 2021. We compared Roche Linear Array HPV Genotyping (Roche) and AmpFire HPV Genotyping (AmpFire) assays for concordance and agreement to detect 15 HR-HPV types from 151 anal specimens. Within run precision of AmpFire was assessed on 50 anal specimens. Specimens with Roche Combo-positive and HPV33, HPV35 and/or HPV58-positive results were further tested using HPV52-specific TaqMan assay. AmpFire generated valid results on 149/151 (98.7%) specimens; 135/149 (90.6%) and 134/149 (89.9%) had detectable HR-HPV DNA by AmpFire or Roche, respectively. Overall concordance was 89.8% (2007/2235, κ=0.65). HPV16 showed highest overall concordance at 93.3% (139/149, κ=0.84). HPV68 had lowest overall concordance at 77.2% (115/149, κ=0.28). Kappa values were interpreted as being moderate or good for all other HR-HPV types. Within run precision generated 744/750 concordant results; R(2) value=0.97 (p<0.0001) (Mantel Test). In conclusion, AmpFire and Roche demonstrated good inter-assay agreement for detecting most HR-HPV types from anal samples, with AmpFire detecting a broader range of HPV68 subtypes and detecting HPV52 without the need for confirmatory testing

Demonstrating a Statistically Significant Association Between Anal High-Grade Squamous Intraepithelial Lesion and Positive OncoE6 Anal Test in Men Who Have Sex With Men and are Living With HIV

OBJECTIVES: The aim of the study is to determine whether a positive OncoE6 Anal Test result has statistically significant higher odds of being associated with high-grade squamous intraepithelial lesion (HSIL) and to calculate sensitivity and specificity of this test for predicting HSIL in adult men who have sex with men and are living with HIV (MSMLWH). MATERIALS AND METHODS: Men living with HIV 18 years or older having ≥atypical squamous cells of undetermined significance-grade anal cytology results were eligible to enroll in this cross-sectional study. Anal samples were collected just before the high-resolution anoscopy procedure. OncoE6 Anal Test results were compared with histology, the reference standard. Sensitivity, specificity, and odds ratio were calculated using HSIL as the threshold. RESULTS: Two hundred seventy-seven consented MSMLWH were enrolled between June 2017 and January 2022. Of these, 219 (79.1%) had biopsies obtained and histology performed; 81 of 219 participants (37%) had 1 or more biopsies with HSIL results while the remaining 138 of 219 (63%) had only low-grade squamous intraepithelial lesion or were negative for dysplasia. Anal samples from 7 participants (8.6%, 7/81) with HSIL and 3 (2.2%, 3/138) with low-grade squamous intraepithelial lesion had positive OncoE6 Anal Test results. Odds of having HSIL were 4.26 times higher among participants testing positive for HPV16/HPV18 E6 oncoprotein(s) (OR = 4.26, 95% CI = 1.07-16.95, p = .04). The OncoE6 Anal Test demonstrated excellent specificity, 97.83% (93.78-99.55), but poor sensitivity, 8.64% (3.55-17.0). CONCLUSIONS: In this highest-risk population for anal cancer, one could combine the OncoE6 Anal Test, having excellent specificity, with the anal Pap test, having higher sensitivity. Patients found having both an abnormal anal Pap and positive OncoE6 Anal Test result could be triaged for rapid scheduling of their high-resolution anoscopy

A summary of the fifth annual Virology Education HIV Microbiome workshop.

In October of 2019, researchers and community members from around the world met at the NIH for the fifth annual International Workshop on Microbiome in HIV. New research was presented on the role of the microbiome on chronic inflammation and vaccine design, interactions of genetics, environment, sexual practice and HIV infection with the microbiome and the development and clinical trials of microbiome-based therapeutic approaches intended to decrease the probability of HIV acquisition/transmission or ameliorate sequelae of HIV. The keynote address by Dr. Jacques Ravel focused on his work on the vaginal microbiome and efforts to improve the analysis and resolution of microbiome data