34,271 research outputs found
Role of lactobacilli and lactoferrin in the mucosal cervicovaginal defense
Human lactoferrin is an iron-binding glycoprotein present at high concentrations in breast milk and colostrum. It is produced by many exocrine glands and widely distributed in a variety of body fluids. This protein has antimicrobial, immunomodulatory, antioxidant, and anticancer properties. Two important hLf receptors have been identified: LDL receptor related protein (LRP1), a low specificity receptor, and intelectin-1 (ITLN1), a high specificity receptor. No data are present on the role of hLf on the biliary epithelium. Our aims have been to evaluate the expression of Lf and its receptors in human and murine cholangiocytes and its effect on proliferation. Immunohistochemistry and immunofluorescence (IF) were conducted on human healthy and primary biliary cholangitis (PBC) liver samples as well as on liver samples obtained from normal and bile duct ligated (BDL) mice to evaluate the expression of Lf, LRP1 and ITLN1. Cell proliferation in vitro studies were performed on human cholangiocyte cell lines via 3-(4,5-dimetiltiazol-2-il)-2,5-diphenyltetrazolium assay as well as IF to evaluate proliferating cell nuclear antigen (PCNA) expression. Our results show that mouse and human cholangiocytes express Lf, LRP1 and ITLN1, at higher extent in cholangiocytes from BDL and PBC samples. Furthermore, the in vitro addition of bovine Lf (bLf) has a proliferative effect on human cholangiocyte cell line. The results support a proliferative role of hLf on the biliary epithelium; this pro-proliferative effect of hLf and bLf on cholangiocytes could be particularly relevant in human cholangiopathies such as PBC, characterized by cholangiocyte death and ductopenia
Rectal Microbiome Composition Correlates with Humoral Immunity to HIV-1 in Vaccinated Rhesus Macaques.
The microbiome is an integral and dynamic component of the host and is emerging as a critical determinant of immune responses; however, its influence on vaccine immunogenicity is largely not well understood. Here, we examined the pivotal relationship between the mucosal microbiome and vaccine-induced immune responses by assessing longitudinal changes in vaginal and rectal microbiome profiles after intradermal immunization with a human immunodeficiency virus type 1 (HIV-1) DNA vaccine in adult rhesus macaques that received two prior DNA primes. We report that both vaginal and rectal microbiomes were dominated by Firmicutes but were composed of distinct genera, denoting microbiome specialization across mucosal tissues. Following immunization, the vaginal microbiome was resilient, except for a transient decrease in Streptococcus In contrast, the rectal microbiome was far more responsive to vaccination, exhibiting an increase in the ratio of Firmicutes to Bacteroidetes Within Bacteroidetes, multiple genera were significantly decreased, including Prevotella, Alloprevotella, Bacteroides, Acetobacteroides, Falsiporphyromonas, and Anaerocella. Decreased abundance of Prevotella correlated with induction of gut-homing α4β7 + effector CD4 T cells. Prevotella abundance also negatively correlated with rectal HIV-1 specific IgG levels. While rectal Lactobacillus was unaltered following DNA vaccination, baseline Lactobacillus abundance showed strong associations with higher rectal HIV-1 gp140 IgA induced following a protein boost. Similarly, the abundance of Clostridium in cluster IV was associated with higher rectal HIV-1 gp140 IgG responses. Collectively, these data reveal that the temporal stability of bacterial communities following DNA immunization is site dependent and highlight the importance of host-microbiome interactions in shaping HIV-1 vaccine responses. Our findings have significant implications for microbial manipulation as a strategy to enhance HIV vaccine-induced mucosal immunity.IMPORTANCE There is considerable effort directed toward evaluating HIV-1 vaccine platforms to select the most promising candidates for enhancing mucosal HIV-1 antibody. The most successful thus far, the RV144 trial provided partial protection due to waning HIV-1 antibody titers. In order to develop an effective HIV vaccine, it may therefore be important to understand how biological factors, such as the microbiome, modulate host immune responses. Furthermore, as intestinal microbiota antigens may generate antibodies cross-reactive to the HIV-1 envelope glycoprotein, understanding the relationship between gut microbiota composition and HIV-1 envelope antibody responses after vaccination is important. Here, we demonstrate for the first time in rhesus macaques that the rectal microbiome composition can influence HIV-1 vaccine immunogenicity, and we report temporal changes in the mucosal microbiome profile following HIV-1 vaccination. Our results could inform findings from the HIV Vaccine Trials Network (HVTN) vaccine studies and contribute to an understanding of how the microbiome influences HIV-1 antibody responses
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Acute Infection and Subsequent Subclinical Reactivation of Herpes Simplex Virus 2 after Vaginal Inoculation of Rhesus Macaques.
Herpes simplex virus 2 (HSV-2) is a common sexually transmitted infection with a highly variable clinical course. Many infections quickly become subclinical, with episodes of spontaneous virus reactivation. To study host-HSV-2 interactions, an animal model of subclinical HSV-2 infection is needed. In an effort to develop a relevant model, rhesus macaques (RM) were inoculated intravaginally with two or three HSV-2 strains (186, 333, and/or G) at a total dose of 1 × 107 PFU of HSV-2 per animal. Infectious HSV-2 and HSV-2 DNA were consistently shed in vaginal swabs for the first 7 to 14 days after each inoculation. Proteins associated with wound healing, innate immunity, and inflammation were significantly increased in cervical secretions immediately after HSV-2 inoculation. There was histologic evidence of acute herpesvirus pathology, including acantholysis in the squamous epithelium and ballooning degeneration of and intranuclear inclusion bodies in epithelial cells, with HSV antigen in mucosal epithelial cells and keratinocytes. Further, an intense inflammatory infiltrate was found in the cervix and vulva. Evidence of latent infection and reactivation was demonstrated by the detection of spontaneous HSV-2 shedding post-acute inoculation (102 to 103 DNA copies/swab) in 80% of RM. Further, HSV-2 DNA was detected in ganglia in most necropsied animals. HSV-2-specifc T-cell responses were detected in all animals, although antibodies to HSV-2 were detected in only 30% of the animals. Thus, HSV-2 infection of RM recapitulates many of the key features of subclinical HSV-2 infection in women but seems to be more limited, as virus shedding was undetectable more than 40 days after the last virus inoculation.IMPORTANCE Herpes simplex virus 2 (HSV-2) infects nearly 500 million persons globally, with an estimated 21 million incident cases each year, making it one of the most common sexually transmitted infections (STIs). HSV-2 is associated with increased human immunodeficiency virus type 1 (HIV-1) acquisition, and this risk does not decline with the use of antiherpes drugs. As initial acquisition of both HIV and HSV-2 infections is subclinical, study of the initial molecular interactions of the two agents requires an animal model. We found that HSV-2 can infect RM after vaginal inoculation, establish latency in the nervous system, and spontaneously reactivate; these features mimic some of the key features of HSV-2 infection in women. RM may provide an animal model to develop strategies to prevent HSV-2 acquisition and reactivation
Clearance of human papillomavirus related anal condylomas after oral and endorectal multistrain probiotic supplementation in an HIV positive male: A case report.
Abstract
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Introduction:
Here we present the case of a 56-year-old human immunodeficiency virus (HIV)-infected man with multiple anal condylomas and positivity for human papilloma virus (HPV) 18 on anal brushing. Biopsies of the anal mucosa led to the diagnosis of Bowen's disease and a subsequent pelvic magnetic resonance imaging (MRI) scan evidenced multiple reactive lymphoadenopathies and large intra-anal condylomas. The patient was treated with a complete excision of Bowen's lesion and with a 4 months course of supplementation with a high concentration multistrain probiotic formulation administered orally and by rectal instillation with the purpose to reduce local inflammation and to enhance local mucosal immunity.
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Conclusion:
An MRI performed at the end of the supplementation period evidenced the clearance of the anal condylomas previously described and no evidence of residual lymphadenopathies. Trials are therefore required to confirm this therapeutic possibility and for a better understanding of the mechanisms by which this specific probiotic formulation interacts with local epithelium when administered by the anal route
A vaccine formulated with the major outer membrane protein can protect C3H/HeN, a highly susceptible strain of mice, from a Chlamydia muridarum genital challenge.
C3H/HeN female mice were vaccinated with native Chlamydia muridarum major outer membrane protein (MOMP), using Montanide+CpG or Alum+CpG as adjuvants. Negative control groups were immunized with ovalbumin (OVA) and the same adjuvants. As positive control, mice were inoculated intranasally with live Chlamydia. Mice were challenged in the ovarian bursa with 10(5) C. muridarum inclusion forming units. Six weeks after the genital challenge the animals were caged with male mice and monitored for pregnancy. Mice vaccinated with MOMP+Montanide+CpG developed high levels of C. muridarum-specific antibodies, with a high IgG2a/IgG1 ratio and neutralizing titres. Animals immunized using Alum+CpG had low antibody levels. Cellular immune responses were significantly higher in mice vaccinated with MOMP and Montanide+CpG, but not with Alum+CpG, when compared with negative controls. Following the genital challenge, only 20% (4/20) of mice vaccinated with MOMP+CpG+Montanide had positive vaginal cultures whereas 100% (9/9) of mice immunized with MOMP+CpG+Alum had positive cultures. Of the positive control animals inoculated with live Chlamydia only 15% (3/20) had positive vaginal cultures. In contrast, 100% (20/20) of mice immunized with OVA+CpG+Montanide, or minimal essential medium, had positive cultures. Following mating, 80% (16/20) of mice vaccinated with MOMP+CpG+Montanide, and 85% (17/20) of animals inoculated intranasally with live C. muridarum carried embryos in both uterine horns. No protection against infertility was observed in mice immunized with MOMP and CpG+Alum or OVA. In conclusion, this is the first time that a subunit vaccine has been shown to elicit a protective immune response in the highly susceptible C3H/HeN strain of mice against an upper genital challenge
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A TRAF3-NIK module differentially regulates DNA vs RNA pathways in innate immune signaling.
Detection of viral genomes by the innate immune system elicits an antiviral gene program mediated by type I interferons (IFNs). While viral RNA and DNA species induce IFN via separate pathways, the mechanisms by which these pathways are differentially modulated are unknown. Here we show that the positive regulator of IFN in the RNA pathway, TRAF3, has an inhibitory function in the DNA pathway. Loss of TRAF3 coincides with increased expression of the alternative NF-κB-inducing molecule, NIK, which interacts with the DNA pathway adaptor, STING, to enhance IFN induction. Cells lacking NIK display defective IFN activation in the DNA pathway due to impaired STING signaling, and NIK-deficient mice are more susceptible to DNA virus infection. Mechanistically, NIK operates independently from alternative NF-κB signaling components and instead requires autophosphorylation and oligomerization to activate STING. Thus a previously undescribed pathway for NIK exists in activating IFN in the DNA pathway
Update on Laboratory Diagnosis and Epidemiology of \u3cem\u3eTrichomonas vaginalis\u3c/em\u3e: You Can Teach an “Old” Dog “New” Trichs
Past viewpoints on Trichomonas vaginalis infection have characterized the associated clinical disease as a “nuisance” condition, with affected demographics largely being older African American females residing in urban centers. The advent of commercial molecular assays specific for T. vaginalis has offered a new outlook on trichomoniasis. Within high-prevalence sexually transmitted infection populations, parasite distribution is not localized to specific population centers, and T. vaginalis prevalence is elevated among both younger and older age groups. Adaptation of these molecular assays can additionally facilitate male screening and subsequent epidemiologic characterization. These findings, combined with associations between T. vaginalis infection and human immunodeficiency virus (HIV) acquisition/transmission and persistent human papillomavirus infection, support consideration of the expansion of T. vaginalis screening efforts in the realms of clinical practice and public health
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Impact of Th1 CD4 Follicular Helper T Cell Skewing on Antibody Responses to an HIV-1 Vaccine in Rhesus Macaques.
Generating durable humoral immunity through vaccination depends upon effective interactions of follicular helper T (Tfh) cells with germinal center (GC) B cells. Th1 polarization of Tfh cells is an important process shaping the success of Tfh-GC B cell interactions by influencing costimulatory and cytokine-dependent Tfh help to B cells. However, the question remains as to whether adjuvant-dependent modulation of Tfh cells enhances HIV-1 vaccine-induced antienvelope (anti-Env) antibody responses. We investigated whether an HIV-1 vaccine platform designed to increase the number of Th1-polarized Tfh cells enhances the magnitude and quality of anti-Env antibodies. Utilizing a novel interferon-induced protein 10 (IP-10)-adjuvanted HIV-1 DNA prime followed by a monophosphoryl lipid A and QS-21 (MPLA+QS-21)-adjuvanted Env protein boost (DIP-10 PALFQ) in macaques, we observed higher anti-Env serum IgG titers with greater cross-clade reactivity, specificity for V1V2, and effector functions than in macaques primed with DNA lacking IP-10 and boosted with MPLA-plus-alum-adjuvanted Env protein (DPALFA) The DIP-10 PALFQ vaccine regimen elicited higher anti-Env IgG1 and lower IgG4 antibody levels in serum, showing for the first time that adjuvants can dramatically impact the IgG subclass profile in macaques. The DIP-10 PALFQ regimen also increased vaginal and rectal IgA antibodies to a greater extent. Within lymph nodes, we observed augmented GC B cell responses and the promotion of Th1 gene expression profiles in GC Tfh cells. The frequency of GC Tfh cells correlated with both the magnitude and avidity of anti-Env serum IgG. Together, these data suggest that adjuvant-induced stimulation of Th1-Tfh cells is an effective strategy for enhancing the magnitude and quality of anti-Env antibody responses.IMPORTANCE The results of the RV144 trial demonstrated that vaccination could prevent HIV transmission in humans and that longevity of anti-Env antibodies may be key to this protection. Efforts to improve upon the prime-boost vaccine regimen used in RV144 have indicated that booster immunizations can increase serum anti-Env antibody titers but only transiently. Poor antibody durability hampers efforts to develop an effective HIV-1 vaccine. This study was designed to identify the specific elements involved in the immunological mechanism necessary to produce robust HIV-1-specific antibodies in rhesus macaques. By clearly defining immune-mediated pathways that improve the magnitude and functionality of the anti-HIV-1 antibody response, we will have the foundation necessary for the rational development of an HIV-1 vaccine
Vaccines in Current Culture: The HPV Vaccine Controversy
The use of vaccinations has drastically decreased mortality and morbidity rates related to infectious disease and has become an intrinsic part of modern health care. However, the fear of risks related to vaccines has been partially responsible for the decisions of many parents to delay or avoid vaccinating their children. The human papilloma virus (HPV) vaccine specifically is one of the most controversial vaccines in current culture due to reports of new onset or exacerbation of autoimmune diseases, infertility, and even death following its administration. This review synthesizes information regarding the relevance and safety of the HPV vaccine, as well as its efficacy in preventing cervical cancer and precancerous lesions. There appears to be a need for thorough education regarding concepts of immunity, infection, and vaccine function for those hesitant about receiving vaccines. Particularly regarding the HPV vaccine, practitioners should be familiar with common reasons for vaccine refusal and be prepared to respond with accurate information
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