collection-isolation-flow-cytometric-analysis-human-endocervical

Collection, Isolation, and Flow Cytometric Analysis of Human Endocervical Samples

Despite the public health importance of mucosal pathogens (including HIV), relatively little is known about mucosal immunity, particularly at the female ...

University of Manitoba

Most studies, to date, on transporter associated with antigen processing (TAP2) polymorphism have been conducted in Caucasians or Asians from industrialized countries. Because of the essential role of this molecule in antigen processing, the implication that polymorphism could be a major factor in human disease and the possible genetic variation at this locus among ethnically diverse populations, we undertook a study to analyze the full extent of TAP2 polymorphism in an indigenous Zimbabwean population (Shona ethnic group). Using single-stranded conformation polymorphism and DNA direct sequencing procedures, we detected the presence of 17 nucleotide sequence variations in the entire coding region of TAP2. Of these variants, 11 are nonconservative substitutions with respect to amino acid composition and are located in a region of the protein that could modulate its function. Six new polymorphic sites were identified in exon 1 (codons 15 Val-->Ala, 53 Leu-->Val), exon 3 (codon 220 Arg-->Arg), exon 4 (codons 257 Thr-->Ile, 313 Arg-->His), and exon10 (codon 609 Ala-->Val). Significant differences were seen in the distribution of the known 374Thr, 565Thr and 651Cys variants between African and non-African populations. These differences may reflect evolutionary pressures generated by environmental factors, such as prevalent pathogens in these geographically distinct regions. Further studies are needed to elucidate the net impact of TAP2 polymorphism on the protein's function and it's role in disease pathogenesis.

New transporter associated with antigen processing (TAP-2) polymorphisms in the Shona people of Zimbabwe.

Because of the essential role of transporter associated with antigen processing (TAP1 or TAP2) molecule in antigen processing, the implication of its polymorphism as a factor involved in human diseases and the possible genetic variation at this locus among ethnically diverse populations, we underwent a study to analyze the full extent of TAP1 polymorphism in an indigenous Zimbabwean population (Shona ethnic group). Using single-stranded conformation polymorphism and DNA direct sequencing procedures, we detected the presence of 11 nucleotide sequence variations in the entire coding region of TAP1. Of these variants, eight are nonconservative substitutions with respect to amino acid composition and are located in a critical part of the protein that could modulate its function. Five new polymorphic sites were identified in exon 1 (codons 7 Pro --> Ser, 17 Gly --> Arg, 141 Val --> Val), exon 6 (codon 419 Gly --> Cys), and exon 7 (codon 487 Arg --> Arg). Significant differences were seen in the distribution of TAP1*0201 and TAP1*0401 alleles, and codon 333 (Ile --> Val) polymorphism among African and non-African populations. Thus, TAP1 polymorphism has evolved differently among populations presumably because of the evolutionary pressures generated by prevalent pathogens in these geographically distinct regions.

Novel TAP1 polymorphisms in indigenous Zimbabweans: their potential implications on TAP function and in human diseases.

Heterosexual transmission of HIV-1 is the major route of infection worldwide. HLA-G molecules are involved in the inhibition of cell-mediated immune responses and could permit or even promote the propagation of infection in the female reproductive tract.

Functionally active HLA-G polymorphisms are associated with the risk of heterosexual HIV-1 infection in African women.

Cyp3A5 activity varies within any given ethnic population, suggesting that genetic variation within the Cyp3A5 gene may be the most important contributor to interindividual and interracial differences in Cyp3A-dependent drug clearance and response. The full extent of Cyp3A5 polymorphism in a white and an indigenous African population was analyzed using DNA direct sequencing procedures. The presence of 10 and 12 single nucleotide polymorphisms was detected in the white and African samples, respectively. Thirteen novel mutations occurring at low frequencies were identified in these populations. Significant differences were observed in the distribution of Cyp3A5*3, Cyp3A5*6, and Cyp3A5*7 alleles among white and African populations. The frequency of Cyp3A5*3 allele in white Canadians (approximately 93%) is higher than in Zimbabweans (77.6%) (p < 0.001). In contrast, Cyp3A5*6 and Cyp3A5*7 alleles are relatively frequent in African subjects (10-22%) but absent in white subjects (p < 0.001). These differences may reflect evolutionary pressures generated by environmental factors in geographically distinct regions. However, the genetic polymorphism of Cyp3A5 alone does not explain the interindividual differences in Cyp3A-mediated metabolism.

CYP3A5 genetic polymorphisms in different ethnic populations.

Human leukocyte antigen (HLA)-E and HLA-G molecules act as powerful modulators of the innate immune response. The present study shows that the HLA-E(G) genetic variant (the HLA-E*0103 allele) alone is significantly (P = .001) associated with a 4.0-fold decreased risk of human immunodeficiency virus 1 (HIV-1) infection in Zimbabwean women. Furthermore, women carrying the combination of the protective HLA-E(G) homozygote and HLA-G*0105N heterozygote genotypes had a 12.5-fold decreased risk of HIV-1 infection (P = .03), compared with women carrying neither genotype. These associations remained significant after adjustment was made for other significant sociodemographic risk factors for HIV prevalence in this population. In conclusion, HLA-E and HLA-G polymorphisms can independently and synergistically influence susceptibility to heterosexual acquisition of HIV-1.

Genetic variants in nonclassical major histocompatibility complex class I human leukocyte antigen (HLA)-E and HLA-G molecules are associated with susceptibility to heterosexual acquisition of HIV-1.

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 remained high throughout follow-up in rapid progressors who responded to antiretroviral therapy but were restored to normal levels in the chronic phase of infection in both untreated normal progressors and long-term nonprogressors.

Persistence of high levels of blood soluble human leukocyte antigen-G is associated with rapid progression of HIV infection.

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.

Chemokine expression patterns in the systemic and genital tract compartments are associated with HIV-1 infection in women from Benin.

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 those in both the HIV-1-uninfected CSW and the non-CSW groups. The presence of HLA-G*010101, HLA-G*010404 alleles, and the 3'-untranslated region (3'UTR) genetic variant at position 3,952 were all significantly associated with lower plasma sHLA-G levels in the HIV-1-infected CSWs, whereas the HLA-G 3'UTR 14-bp sequence insertion was also associated with lower plasma sHLA-G levels in the overall population. When adjustment was made for all significant variables, the reduced expression of sHLA-G in the plasma remained significantly associated with HIV-1 infection and the HLA-G 3'UTR 14-bp insertion homozygote genotype. This study demonstrates that low levels of plasma sHLA-G are associated with HIV-1 infection.

Blood soluble human leukocyte antigen G levels are associated with human immunodeficiency virus type 1 infection in Beninese commercial sex workers.

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 was to investigate whether soluble HLA-G (sHLA-G) expression in the female genital tract is associated with HIV-1 infection.

High level of soluble HLA-G in the female genital tract of Beninese commercial sex workers is associated with HIV-1 infection.

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.

HIV controllers are distinguished by chemokine expression profile and HIV-specific T-cell proliferative potential.

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.

Association of sex work with reduced activation of the mucosal immune system.

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 cytokines/chemokines in both plasma and cervical lavage samples from female sex-worker cohort from Nairobi, Kenya (age range 20-65).

Age and menopause affect the expression of specific cytokines/chemokines in plasma and cervical lavage samples from female sex workers in Nairobi, Kenya.

Julie Lajoie

Department of Medical Microbiology

University of Manitoba

Collection, Isolation, and Flow Cytometric Analysis of Human Endocervical Samples

Julie Lajoie

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Medical Microbiology

University of Manitoba

Collection, Isolation, and Flow Cytometric Analysis of Human Endocervical Samples

Department of Medical Microbiology