Julie Lajoie

Julie Lajoie
University of Manitoba | UMN · Department of Medical Microbiology and Infectious Diseases

PhD

About

85
Publications
7,998
Reads
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Introduction
The principal focus of my research aims at understanding the mucosal immune system at the female genital tract. We have currently two ongoing project. The first one aims to determine the impact of sex work and the menstrual cycle on the mucosal immune activation. The second one aims to develop a new preventive method against HIV by Inducing T cells Immune Quiescence at the genital tract in sex workers.
Additional affiliations
September 2005 - September 2009
Université de Montréal
Position
  • PhD
Education
April 2010 - August 2013
University of Manitoba
Field of study
  • Mucosal Immunology and Natural resistance to HIV infection
September 2005 - February 2010
Université de Montréal
Field of study
  • Virology and Immunology
January 2001 - May 2003
Université de Montréal
Field of study
  • Microbiologie et Immunologie

Publications

Publications (85)
Article
Full-text available
Despite the public health importance of mucosal pathogens (including HIV), relatively little is known about mucosal immunity, particularly at the female genital tract (FGT). Because heterosexual transmission now represents the dominant mechanism of HIV transmission, and given the continual spread of sexually transmitted infections (STIs), it is cri...
Article
Full-text available
Aging of the immune system, known as immunosenescence, is associated with profound changes in both innate and adaptive immune responses, resulting in increased susceptibility to infection and a decreased ability to respond to vaccination. The purpose of this study was to investigate the effect of age and menopause on the expression of 22 different...
Article
Full-text available
Background: Unprotected intercourse and seminal discharge are powerful activators of the mucosal immune system and are important risk factors for transmission of human immunodeficiency virus (HIV). This study was designed to determine if female sex work is associated with changes in the mucosal immunity. Methods: Cervicovaginal lavage and plasma...
Article
Full-text available
The impact of HIV on the mucosal compartment is now well recognized and contributes to driving immune activation, a characteristic of HIV pathogenesis. The mucosal immune system is greatly affected by HIV from the first days of the infection. A massive depletion of the mucosal CD4+ T cells, over production of chemokines and cytokines and dysregulat...
Article
Full-text available
The predominance of HIV-1 sexual transmission requires a greater understanding of the interaction between HIV-1 and the mucosal immune system. The study of HIV-1-exposed seronegative (HESN) individuals serves as a model to identify the correlates of protection and to aid in microbicide development. A total of 22 cytokines/chemokines were analyzed a...
Article
Full-text available
Depot medroxyprogesterone acetate (DMPA) is an injectable hormonal contraceptive used by millions of women worldwide. However, experimental studies have associated DMPA use with genital epithelial barrier disruption and mucosal influx of human immunodeficiency virus (HIV) target cells. We explored the underlying molecular mechanisms of these findin...
Article
Full-text available
Introduction Acetylsalicylic acid (ASA) is a well-known and safe anti-inflammatory. At low-dose, it is prescribed to prevent secondary cardiovascular events in those with pre-existing conditions and to prevent preeclampsia. Little is known about how low-dose ASA affects the immune response. In this study, we followed women to assess how ASA use mod...
Article
Full-text available
Immunological correlates of natural resistance to HIV have been identified in HIV-exposed seronegative (HESN) individuals and include a low-inflammatory genital mucosal status. The cervicovaginal epithelium has not been studied for such correlates despite constituting an important barrier against sexual HIV transmission. To fill this gap in knowled...
Article
Full-text available
Background Depot Medroxyprogesterone (DMPA) is one of the most widely used contraceptives in Sub-Saharan Africa where HIV incidence is high. We explored the effect of DMPA on the activation of HIV cellular targets and inflammation as a possible mechanism of increased HIV risk with DMPA use. Since sex work is known to affect the immune system, this...
Article
Background: The hormonal contraceptive depot medroxyprogesterone acetate (DMPA) may be associated with an increased risk of acquiring human immunodeficiency virus (HIV). We hypothesize that DMPA use influences the ectocervical tissue architecture and HIV target cell localization. Methods: Quantitative image analysis workflows were developed to a...
Article
Full-text available
The hormonal contraceptive medroxyprogesterone acetate (MPA) is associated with increased risk of human immunodeficiency virus (HIV), via incompletely understood mechanisms. Increased diversity in the vaginal microbiota modulates genital inflammation and is associated with increased HIV-1 acquisition. However, the effect of MPA on diversity of the...
Article
Full-text available
Introduction Human papillomaviruses (HPVs) are responsible for one-third of all cancers caused by infections. Most HPV studies focus on chronic infections and cancers, and we know little about the early stages of the infection. Our main objective is to better understand the course and natural history of cervical HPV infections in healthy, unvaccin...
Article
Full-text available
Depot medroxyprogesterone acetate (DMPA) is the most common hormonal contraceptive used by women in sub-Saharan Africa, however, it has been epidemiologically associated with HIV infections. To assess whether DMPA has an effect on the number and activation of HIV target cells, this study assessed the levels and phenotype of blood- and mucosal-deriv...
Preprint
Full-text available
The hormonal contraceptive Medroxyprogesterone Acetate (MPA) is associated with increased risk of Human Immunodeficiency Virus (HIV), via incompletely understood mechanisms. Increased diversity in the vaginal microbiota modulates genital inflammation and is associated with increased HIV-1 acquisition. However, the effect of MPA on diversity of the...
Article
Full-text available
Events related to HCMV infection drive accumulation of functionally enhanced CD57posNKG2Cpos adapted NK cells. We investigated NK cell adaptation to HCMV along a proposed continuum progressing from acute activation through maturation and memory formation towards functional exhaustion. Acute exposure to conditioned medium collected 24 h after HCMV i...
Article
Full-text available
Background: Inflammation and immune activation are key factors in sexual transmission of human immunodeficiency virus (HIV). We sought to define the impact of hormonal cycling on the mucosal immune environment and HIV risk in sex workers with a natural menstrual cycle. Methods: We compared soluble mucosal immune factors and cervical mononuclear...
Data
Figure S1. Proteome changes in cervicovaginal lavage fluid of women in the HCQ and ASA treatment arms.
Data
Table S1. Protein differently expressed at the genital tract after hydroxychloroquine treatment. Table S2. Pathway affected by hydroxychloroquine treatment. Table S3. Protein differently expressed at the genital tract after acetylsalicylic acid treatment. Table S4. Pathway affected by acetylsalicylic acid treatment.
Article
Full-text available
Introduction At its basic level, HIV infection requires a replication‐competent virus and a susceptible target cell. Elevated levels of vaginal inflammation has been associated with the increased risk of HIV infection as it brings highly activated HIV target cells (CCR5+CD4+ T cells; CCR5+CD4+CD161+ Th17 T cells) to the female genital tract (FGT) w...
Article
Evidence suggests that women who are naturally resistant to HIV infection exhibit low baseline immune activation at the female genital tract (FGT). This "immune quiescent" state is associated with lower expression of T-cell activation markers, reduced levels of gene transcription and pro-inflammatory cytokine or chemokine production involved in HIV...
Article
Full-text available
CD161 identifies a subset of circulating Th17 cells that are depleted in the blood and gut of HIV-infected individuals. In the female reproductive tract (FRT), the pattern of CD161 expression on CD4⁺ cells remains unknown. Here, we characterized CD161 expression in the FRT of Kenyan female sex workers (FSW). Compared to the blood, CD161⁺CD4⁺ T cell...
Article
Full-text available
Objective To compare the vaginal microbiota of women engaged in high-risk sexual behaviour (sex work) with women who are not engaged in high-risk sexual behaviour. Diverse vaginal microbiota, low in Lactobacillus species, like those in bacterial vaginosis (BV), are associated with increased prevalence of sexually transmitted infections (STIs) and h...
Data
Principle coordinate analysis demonstrates CSTs and sub-clusters. PCoA plot demonstrate the beta-diversity of the vaginal microbiota of Non-Sex Workers (NSW, N = 19), and Female Sex Workers (FSW, N = 48). The vaginal microbiota clustered by Community State Type (CST) which included 3 sub-clusters within CSTIV. Clusters are coloured by CST. Sub-clus...
Data
Chao1 Richness Estimates. Table containing Chao1 Richness rarefactions and iterations. (XLSX)
Data
Representative 16S sequences by OTU. List of representative 16S sequences, listed by OTU. len: length. tot-seq: total number of sequences. (PDF)
Data
Observed species. Table containing observed species rarefactions and iterations. (XLSX)
Data
Multiple sequence alignment BVAB1. Clustal Omega was employed to align two Bacterial Vaginosis Associated Bacteria 1 (BVAB1) sequences found in the literature to OTU5 from our dataset. There was 100% consensus between our sequence and the two previously reported (AY724739.1 and AY959097.1). (PDF)
Data
Metadata, relative abundance table, and OTU table. Data table containing sample metadata, list of top 5 bacterial genera identified by 16S sequencing of vaginal microbiota, bacterial morphotypes visualized during Nugent Scoring, and 16S sequencing results (relative abundance table at genus level, OTU table). BV: bacterial vaginosis, CST: community...
Data
16S sequences per sample. List of the number of 16S reads per sample obtained by Illumina sequencing. (XLSX)
Data
Shannon Diversity Index. Table containing Shannon Diversity rarefactions and iterations. (XLSX)
Article
Full-text available
For over three decades, HIV infection has had a tremendous impact on the lives of individuals and public health. Microbicides and vaccines studies have shown that immune activation at the genital tract is a risk factor for HIV infection. Furthermore, lower level of immune activation, or what we call immune quiescence, has been associated with a low...
Article
Full-text available
Problem: Cervical biopsies offer a unique opportunity for studying local immune response. To investigate hormonally induced immune fluctuations in cervical tissues of Kenyan female sex workers, we improved biopsy sampling protocol safety. Here, we report on steps taken to minimize exposure to HIV following two cervical biopsies. Methods of study:...
Article
Full-text available
Background: Unprotected sexual intercourse exposes the female genital tract (FGT) to semen-derived antigens, which leads to a proinflammatory response. Studies have shown that this postcoital inflammatory response can lead to recruitment of activated T cells to the FGT, thereby increasing risk of HIV infection. Objective: The purpose of this study...
Conference Paper
Full-text available
Chronic human immunodeficiency virus type 1 (HIV-1) infection induces severe immune alterations, including hyperactivation, exhaustion and apoptosis. In fact, viral control has been associated with low frequencies of these processes. Here, we evaluated the expression of activation and inhibitory molecules (CD69, LAG-3, PD-1 and TIM-3) on NK cells s...
Article
Background Sexual transmission of HIV is actually fairly inefficient and when it does occur usually a single virus is responsible for establishing the infection. Since activated HIV target cells (CD4+CCR5+) are known to be 1000x more susceptible to HIV infection than quiescent cells, one of the known risk factors for HIV acquisition is elevated bas...
Article
Full-text available
Chronic HIV-1 infection induces severe immune alterations, including hyperactivation, exhaustion and apoptosis. In fact, viral control has been associated with low frequencies of these processes. Here, we evaluated the expression of activation and inhibitory molecules on NK and CD4+ T-cells in individuals exhibiting viral control: a cohort of HIV-1...
Article
ProblemThe expression of inhibitory markers such as LAG-3 and PD-1 on T lymphocytes regulates immune function. Their expression at the genital mucosa is poorly understood, but regulation of immune activation at the female genital tract likely controls susceptibility to sexually transmitted infections.Method of studyCervical mononuclear cells were p...
Conference Paper
Full-text available
Background / Purpose: Activated T cells are ideal targets for HIV infection and low levels of immune activation contribute to protect HIV Exposed Seronegative (HESN) female sex workers from Nairobi, Kenya, against HIV acquisition. Sex work may impact the regulation of immune activation at the female genital tract and therefore influence susceptib...
Article
HIV controllers demonstrate a natural ability to control HIV replication in the absence of antiretroviral therapy. We performed a comprehensive evaluation of inflammation and T-cell activation in a demographically unique cohort of HIV controllers and noncontrollers. Plasma concentrations of 22 cytokines and chemokines were evaluated using a multipl...
Article
Not all individuals exposed to HIV-1 become infected, and evidence from HIV-1 highly exposed seronegative women (HIV-1-resistant) suggests that mucosal factors in the female genital tract, the first site of contact for the virus, are playing a role. To better understand factors mediating protection from HIV-1, we performed a large clinical study us...
Data
sHLA-G genital levels according to the presence or absence of vaginosis in HIV-1-uninfected CSWs, HIV-1-infected CSWs, and HIV-1- uninfected non-CSW control subjects. (DOC)
Data
Chemokine genital levels according to the presence or absence of bacterial vaginosis in HIV-1-uninfected CSWs, HIV-1-infected CSWs, and HIV-1- uninfected non-CSW women. (DOC)
Data
Spearman's correlations between soluble HLA-G and cytokine genital levels in HIV-1-uninfected CSWs, HIV-1-infected CSWs, and HIV-1-uninfected non-CSW women. (DOC)
Data
Spearman's correlations between soluble HLA-G and chemokine genital levels in HIV-1-uninfected CSWs, HIV-1-infected CSWs, and HIV-1- uninfected non-CSW women. (DOC)
Data
Cytokine genital levels according to the presence or absence of bacterial vaginosis in HIV-1-uninfected CSWs, HIV-1-infected CSWs, and HIV-1- uninfected non-CSW women. (DOC)
Article
Full-text available
Most HIV infections are transmitted across mucosal epithelium. Understanding the role of innate and specific mucosal immunity in susceptibility or protection against HIV infection, as well as the effect of HIV infection on mucosal immunity, are of fundamental importance. HLA-G is a powerful modulator of the immune response. The aim of this study wa...
Article
Understanding the genital mucosal immunity and the factors involved in linking innate to adaptive immunity is crucial for the design of efficient preventive strategies against human immunodeficiency virus (HIV)-1. Levels of both genital mucosal and blood chemokines were compared between 58 HIV-1-uninfected and 50 HIV-1-infected female commercial se...
Article
Human leukocyte antigen (HLA)-G is a powerful modulator of the immune response. The aim of this study was to investigate whether soluble HLA-G (sHLA-G) expression is associated with human immunodeficiency virus type 1 (HIV-1) infection. HIV-1-infected female commercial sex workers (CSWs) had significantly lower levels of plasma sHLA-G compared with...
Article
Human leukocyte antigen-G is an important suppressor of the immune response, and HIV can modulate its expression. Longitudinal monitoring of soluble human leukocyte antigen-G plasma levels in patients with primary HIV infection undergoing different rates of disease progression showed that levels were elevated in the early phases of infection and re...
Article
We identified six novel human leukocyte antigen-G alleles with synonymous mutations in Caucasian and/or African populations.
Article
We identified five novel human leukocyte antigen-G alleles with protein-modifying mutations in Caucasian and/or African populations.