Deciphering the Role of Mucosal Immune Responses and the Cervicovaginal Microbiome in Resistance to HIV Infection in HIV-Exposed Seronegative (HESN) Women.

The female genital tract (FGT) is an important site of human immunodeficiency virus (HIV) infection. Discerning the nature of HIV-specific local immune responses is crucial for identifying correlates of protection in HIV-exposed seronegative (HESN) individuals. The present study involved a comprehensive analysis of soluble immune mediators, secretory immunoglobulins (sIg), natural killer (NK) cells, CXCR5+ CD8+ T cells, T follicular helper (Tfh) cells, and T regulatory cells (Tregs) in the vaginal mucosa as well as the nature and composition of the cervicovaginal microbiome in HESN women. We found significantly elevated antiviral cytokines, soluble immunoglobulins, and increased frequencies of activated NK cells, CXCR5+ CD8+ T cells, and Tfh cells in HESN females compared to HIV-unexposed healthy (UH) women. Analysis of the genital microbiome of HESN women revealed a greater bacterial diversity and increased abundance of Gardnerella spp. in the mucosa. The findings suggest that the female genital tract of HESN females represents a microenvironment equipped with innate immune factors, antiviral mediators, and critical T cell subsets that protect against HIV infection. IMPORTANCE The vast majority of human immunodeficiency virus (HIV) infections across the world occur via the sexual route. The genital tract mucosa is thus the primary site of HIV replication, and discerning the nature of HIV-specific immune responses in this compartment is crucial. The role of the innate immune system at the mucosal level in exposed seronegative individuals and other HIV controllers remains largely unexplored. This understanding can provide valuable insights to improve vaccine design. We investigated mucosal T follicular helper (Tfh) cells, CXCR5+ CD8+ T cells, natural killer (NK) cells subsets, soluble immune markers, and microbiome diversity in HIV-exposed seronegative (HESN) women. We found a significantly higher level of mucosal CXCR5+ CD8+ T cells, CD4+ Tfh cells, activated NK cell subsets, and antiviral immune cell mediators in HESN women. We also found a higher abundance of Gardnerella spp., microbiome dysbiosis, and decreased levels of inflammatory markers to be associated with reduced susceptibility to HIV infection. Our findings indicate that increased distribution of mucosal NK cells, CXCR5+ CD8+ T cells, Tfh cells, and soluble markers in HIV controllers with a highly diverse cervicovaginal microbiome could contribute effectively to protection against HIV infection. Overall, our findings imply that future vaccine design should emphasize inducing these highly functional cell types at the mucosal sites.

Circulating human papillomavirus DNA detection in Barrett's dysplasia and esophageal adenocarcinoma.

There is evidence to suggest that human papillomaviruses (HPV) are associated with Barrett's dysplasia and esophageal adenocarcinoma. In other HPV-linked cancers such as cervical and oropharyngeal cancer, circulating HPV DNA is a potential biomarker to assist in tumor diagnosis and management. This study aimed to determine whether circulating HPV DNA was detectable in patients with Barrett's dysplasia and esophageal adenocarcinoma, and if so, whether there is any correlation with esophageal tissue HPV status. Plasma from 138 patients representing esophageal adenocarcinoma (N = 41), Barrett's dysplasia (N = 48) and hospital controls (N = 49) were analyzed for the presence of circulating HPV DNA using droplet-digital PCR targeting the E7 gene of HPV types 16 and 18. Circulating HPV DNA was detected in 11/138 (8.0%) study subjects including 1/49 (2.0%) hospital controls, 4/48 (8.3%) Barrett's dysplasia patients, and 6/41 (14.6%) esophageal adenocarcinoma patients. Detection of circulating HPV DNA was higher in patients with HPV-positive esophageal tissue (6/35, 17.1%) compared to those with HPV-negative specimens (5/103; 4.9%) (OR = 4.06; 95% CI 1.15-14.25; P = 0.020). The highest rates of detection occurred in esophageal adenocarcinoma patients, particularly those with invasive tumors that had breached the esophageal submucosa, had regional lymph node involvement or metastatic disease. Circulating HPV DNA was detectable in a subset of Barrett's dysplasia and esophageal adenocarcinoma patients. Detection was associated with tissue HPV positivity and possibly disease severity.

Transforming human papillomavirus infection and the esophageal transformation zone: prime time for total excision/ablative therapy?

High-risk human papillomavirus (hr-HPV) infection is causal for almost all cervical malignancy (both squamous and adenocarcinoma), 90% of anal neoplasia, 70% of penile tumors, and 25% of head and neck cancers. The shared immunogenetics of cervical and esophageal malignancy suggests that HPV infection could well be a common denominator in the etiology of both cancers. In this regard, we have demonstrated that transcriptionally active hr-HPV (genotypes 16 and 18) is strongly associated with Barrett's dysplasia and esophageal adenocarcinoma. Increasing hr-HPV viral load and integration status has been linked with greater disease severity along the Barrett metaplasia-dysplasia-adenocarcinoma sequence as has been demonstrated in cervical intraepithelial neoplasia and cancer. HPV infections in both the cervix and esophagus are both focal, i.e., present in greater quantities at the squamocolumnar junction (SCJ). HPV affinity is to junctional tissue, as basal cells are particularly accessible at the squamocolumnar transformation zone and especially susceptible to this viral infection. We have postulated that progressive acid damage to the esophagus increases the likelihood of mucosal breaks enabling the virus to enter the basal layer of the transformation zone. The SCJ is the transformation zone of the esophagus and is strikingly similar to the transition zone (ectoendocervical SCJ) of the uterine cervix where almost all high-grade cervical lesions and cancers arise including 80% of adenocarcinomas. These transition zone cells exhibit features of squamous epithelium as well as glandular cells, which have been described in both Barrett's esophagus and cervical mucosa. Barrett's esophagus (BE) is derived from a discrete population of embryonic cells residing at the SCJ. There is loss of SCJ immune-phenotype following excision without regeneration at other junctional sites. Prevention of cervical cancer in up to 80-95% of patients with screen-detected CIN is dependent on the excision/ablation of the entire transformation zone. The persistence of hr-HPV 16/18 following eradication of CIN is a significant risk factor for recurrence. Similarly, we have demonstrated that persistent hr-HPV infection 16/18 and p53 overexpression are associated with treatment failure after endoscopic ablation of BD/EAC. Thus, we believe that excision/ablation of the SCJ in patients with BD/intramucosal EAC should be performed to reduce the potential malignant risk. We propose to test this hypothesis by a multicenter randomized controlled trial whereby patients (both HPV positive and those which are virus negative) will be allocated into two arms: complete excision of the SCJ via endoscopic mucosal resection (EMR) in addition to radiofrequency ablation (RFA) ± EMR of BD/intramucosal EAC (experimental arm) versus current standard of care (RFA ± EMR) of said lesions. Treatment efficacy in both groups will be evaluated by comparing disease elimination, regression/progression, and recurrence (if any). All patients would be entered into an intensive endoscopic surveillance protocol (biannually) for at least 2 years with lesional/neosquamous biopsies to compare the recurrence rate of both dysplasia/neoplasia in both arms. Viral (HPV DNA/p16INK4A/E6/E7 mRNA) and host biomarkers (e.g., p53) will be analyzed both at baseline and posttreatment intervals. A positive study would initiate development of tools best suited for SCJ destruction.

Cytomegalovirus (CMV) in gastrointestinal mucosal biopsies: should a pathologist perform CMV immunohistochemistry if the clinician requests it?

Cytomegalovirus (CMV) causes clinically significant gastrointestinal (GI) injury. CMV inclusions can be identified on routine hematoxylin and eosin (H&E) stain, but immunohistochemistry (IHC) is also available for identifying CMV in tissue. The advent of accountable care organization models of care bring into question whether it is cost-effective for immunohistochemistry to be performed upfront at the request of clinicians and whether the quality of viral detection is compromised when the diagnosis of CMV is predicated on histologic review. In this study, a retrospective review of GI biopsies with CMV evaluations was performed. There were 449 cases with clinical requests to rule out CMV and 238 CMV analyses initiated by the pathologist without a clinical request. Among the cases that included a clinician's request, 37 had CMV detected. Immunostaining was performed on 26 cases, while a diagnosis based on readily identifiable viral inclusions on H&E-stained slides was made in 11. Among pathologist-initiated work-ups, 15 were CMV+, 3 of which had inclusions identified by H&E only. Among 38 CMV cases for which IHC had been performed, 27 had overt viral inclusions obvious on H&E. Seventy-two cases revealed uninflamed GI mucosa, and although a clinical concern about CMV infection was present, a CMV IHC work-up was not initially performed; all were negative for CMV by IHC and H&E. Clinical suspicion for CMV has a high yield for CMV detection, but "upfront" testing is likely unnecessary. Careful histopathologic review by a pathologist remains critical in the efficient and cost-effective detection of CMV.