8 results on '"Lyle R. McKinnon"'
Search Results
2. High prevalence of vaccine‐preventable anal human papillomavirus infections is associated with <scp>HIV</scp> infection among gay, bisexual, and men who have sex with men in Nairobi, Kenya
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Myo Minn Oo, Samantha Moore, Suzanne Gibbons, Wendy Adhiambo, Peter Muthoga, Naomi Siele, Maureen Akolo, Henok Gebrebrhan, Aida Sivro, Blake T. Ball, Robert R. Lorway, Alberto Severini, Joshua Kimani, and Lyle R. McKinnon
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Cancer Research ,Oncology ,Radiology, Nuclear Medicine and imaging - Published
- 2023
3. An updated review on the effects of depot medroxyprogesterone acetate on the mucosal biology of the female genital tract
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Lyle R. McKinnon, Christina Farr Zuend, Adam Burgener, Hossaena Ayele, Michelle Perner, and Kenzie Birse
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0301 basic medicine ,Female circumcision ,medicine.drug_class ,Immunology ,Review: Clinical Reproductive Immunology ,Physiology ,chemokines ,Medroxyprogesterone Acetate ,Review Article ,Biology ,03 medical and health sciences ,immune cells ,0302 clinical medicine ,Immune system ,Contraceptive Agents, Female ,medicine ,Humans ,Immunology and Allergy ,Medroxyprogesterone acetate ,Sex organ ,Mucous Membrane ,030219 obstetrics & reproductive medicine ,Microbiota ,Mortality rate ,vaginal microbiome ,Obstetrics and Gynecology ,Genitalia, Female ,cytokines ,3. Good health ,depot medroxyprogesterone acetate ,DMPA ,030104 developmental biology ,Reproductive Medicine ,vaginal epithelium ,Delayed-Action Preparations ,Vagina ,Vaginal microbiome ,Female ,Observational study ,Progestin ,medicine.drug - Abstract
Background Access to safe, effective, and affordable contraception is important for women’s health and essential to mitigate maternal and fetal mortality rates. The progestin‐based contraceptive depot medroxyprogesterone acetate (DMPA) is a popular contraceptive choice with a low failure rate and convenient administration schedule. Aim In this review, we compiled observational data from human cohorts that examine how DMPA influences the mucosal biology of the female genital tract (FGT) that are essential in maintaining vaginal health, including resident immune cells, pro‐inflammatory cytokines, epithelial barrier function, and the vaginal microbiome Materials and Methods This review focused on the recent published literature published in 2019 and 2020. Results Recent longitudinal studies show that DMPA use associates with an immunosuppressive phenotype, increase in CD4+CCR5+ T cells, and alterations to growth factors. In agreement with previous meta‐analyses, DMPA use is associated with minimal effects of the composition of the vaginal microbiome. Cross‐sectional studies associate a more pro‐inflammatory relationship with DMPA, but these studies are confounded by inherent weaknesses of cross‐sectional studies, including differences in study group sizes, behaviors, and other variables that may affect genital inflammation. Discussion & Conclusion These recent results indicate that the interactions between DMPA and the vaginal mucosa are complex emphasizing the need for comprehensive longitudinal studies that take into consideration the measurement of multiple biological parameters.
- Published
- 2021
4. Genital and systemic immune effects of the injectable, contraceptive norethisterone enanthate (NET‐EN), in South African women
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Samkelisiwe Ngcobo, Sinaye Ngcapu, Natasha Samsunder, Jo-Ann S. Passmore, John H. Adamson, Lyle R. McKinnon, Mthobisi M Zondi, Lenine J. P. Liebenberg, Alasdair Leslie, Amanda Mabhula, Salim S. Abdool Karim, Quarraisha Abdool Karim, Nobuhle Nokubonga Mchunu, Katya Govender, Aida Sivro, and Refilwe P Molatlhegi
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Adult ,0301 basic medicine ,Adolescent ,medicine.medical_treatment ,Immunology ,Physiology ,South Africa ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Tandem Mass Spectrometry ,Contraceptive Agents, Female ,Humans ,Immunology and Allergy ,Medicine ,Sex organ ,030219 obstetrics & reproductive medicine ,business.industry ,Growth factor ,Confounding ,Obstetrics and Gynecology ,030104 developmental biology ,Cytokine ,Reproductive Medicine ,chemistry ,Vagina ,Cytokines ,Immunohistochemistry ,Female ,Tumor necrosis factor alpha ,Norethisterone enanthate ,Norethindrone ,business ,Chromatography, Liquid ,Hormone - Abstract
PROBLEM Injectable hormonal contraceptives (IHC) have been associated with altered mucosal and systemic milieu which might increase HIV risk, but most studies have focused on DMPA and not NET-EN, despite the growing popularity and lower HIV risk associated with the latter in observational studies. METHOD OF STUDY We used high-performance liquid chromatography in combination with tandem triple quadrupole mass spectrometry (HPLC-LC-MS/MS) to measure steroid hormones in plasma samples of CAPRISA004 study participants. Concentrations of 48 cytokines were measured in the cervicovaginal lavage (CVL) and plasma, and their expression was compared between participants with detectable NET-EN (n = 201) versus non-detectable IHC (n = 90). Each log10 cytokine concentration was tested as an outcome in linear-mixed models, with NET-EN detection as the main explanatory variable. Multivariable models were adjusted for potential confounders. RESULTS In bivariate analysis, detectable NET-EN was associated with reduced cervicovaginal M-CSF (P = 0.008), GM-CSF (P = 0.025) and G-CSF (P = 0.039), and elevated levels MIF (P = 0.008), IL-18 (P = 0.011), RANTES (P = 0.005) and IL-1Rα (P
- Published
- 2021
5. Mechanisms of sexually transmitted infection‐induced inflammation in women: implications for<scp>HIV</scp>risk
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Quarraisha Abdool Karim, Salim S. Abdool Karim, Lyle R. McKinnon, Cheryl Baxter, and Ruth S. Mwatelah
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adaptive immune responses ,Sexually Transmitted Diseases ,Human immunodeficiency virus (HIV) ,HIV Infections ,Inflammation ,medicine.disease_cause ,Asymptomatic ,immunology ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,medicine ,Humans ,030212 general & internal medicine ,Vaginitis ,sexually transmitted infections ,Reproductive health ,030505 public health ,Infection induced ,business.industry ,Public Health, Environmental and Occupational Health ,HIV ,virus diseases ,Vaginosis, Bacterial ,medicine.disease ,Acquired immune system ,3. Good health ,mucosal immune responses ,Infectious Diseases ,Immunology ,Commentary ,Female ,women ,medicine.symptom ,Bacterial vaginosis ,0305 other medical science ,business ,bacterial vaginosis - Abstract
Introduction Globally, sexually transmitted infections (STI) affect >300 million people annually, and are a major cause of sexual and reproductive health complications in women. In this commentary, we describe how STIs interact with the immune and non‐immune cells, both within and below the cervicovaginal mucosal barrier, to cause inflammation, which in turn has been associated with increased HIV acquisition risk. Discussion STIs have a major impact on the female genital mucosa, which is an important biological and physical barrier that forms the first line of defence against invading microorganisms such as HIV. Pattern recognition of STI pathogens, by receptors expressed either on the cell surface or inside the cell, typically triggers inflammation at the mucosal barrier. The types of mucosal responses vary by STI, and can be asymptomatic or culminate in the formation of discharge, ulcers and/or warts. While the aim of this response is to clear the invading microbes, in many cases these responses are either evaded or cause pathology that impairs barrier integrity and increases HIV access to target cells in the sub‐mucosa. In addition, innate responses to STIs can result in an increased number of immune cells, including those that are the primary targets of HIV, and may contribute to the association between STIs and increased susceptibility to HIV acquisition. Many of these cells are mediators of adaptive immunity, including tissue‐resident cells that may also display innate‐like functions. Bacterial vaginosis (BV) is another common cause of inflammation, and evidence for multiple interactions between BV, STIs and HIV suggest that susceptibility to these conditions should be considered in concert. Conclusions STIs and other microbes can induce inflammation in the genital tract, perturbing the normal robust function of the mucosal barrier against HIV. While the impact of STIs on the mucosal immune system and HIV acquisition is often under‐appreciated, understanding their interactions of the infections with the immune responses play an important role in improving treatment and reducing the risk of HIV acquisition. The frequent sub‐clinical inflammation associated with STIs underscores the need for better STI diagnostics to reverse the immunological consequences of infection.
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- 2019
6. HIV‐specific CD8 + T‐cell proliferation is prospectively associated with delayed disease progression
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Charles Wachihi, Lyle R. McKinnon, Nico J. D. Nagelkerke, Francis A. Plummer, Terry B. Ball, Rupert Kaul, Joshua Kimani, and Keith R. Fowke
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Adult ,Male ,Enzyme-Linked Immunospot Assay ,Immunology ,HIV Infections ,CD8-Positive T-Lymphocytes ,Biology ,Lymphocyte Activation ,Disease-Free Survival ,Interferon-gamma ,03 medical and health sciences ,0302 clinical medicine ,Acquired immunodeficiency syndrome (AIDS) ,medicine ,Humans ,Immunology and Allergy ,Cytotoxic T cell ,Prospective Studies ,030212 general & internal medicine ,HIV vaccine ,Prospective cohort study ,Cells, Cultured ,Cell Proliferation ,030304 developmental biology ,0303 health sciences ,Proportional hazards model ,ELISPOT ,env Gene Products, Human Immunodeficiency Virus ,HIV ,Cell Biology ,medicine.disease ,CD4 Lymphocyte Count ,3. Good health ,Disease Progression ,Female ,Viral load ,CD8 ,Follow-Up Studies - Abstract
Human immunodeficiency virus (HIV)-specific CD8(+) T-cell proliferation is consistently correlated with enhanced host HIV immune control, but whether proliferative responses are a cause or consequence of immune protection is unclear. We measured Env-specific CD8(+) T-cell proliferation and interferon (IFN)-γ secretion in HIV-infected participants with CD4 counts >200, who then completed 121 person-years of prospective follow-up to monitor HIV disease progression. In all, 13 of 31 participants (42%) reached end point during longitudinal follow-up. Strong Env-specific CD8(+) T-cell proliferation (>10% of CD8(+) T cells) was observed in 14/31 participants at baseline, and this was associated with a longer time to HIV disease progression end point, stratified baseline CD4 count (P=0.016). No associations were observed for IFN-γ ELISPOT responses and progression (P>0.2). Strong proliferation remained significant in multivariate Cox regression analyses (P=0.044) as an independent predictor of delayed HIV disease progression, along with baseline CD4 count (P=0.04). Duration of HIV infection was associated with more rapid progression in univariate, but not multivariate, analysis (P=0.112). Age and baseline viral load were not predictive of progression. HIV-specific CD8(+) T-cell proliferation was a correlate of protective immunity in this prospective study; such responses may be important for HIV vaccine protection.
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- 2011
7. Biological Factors that May Contribute to Regional and Racial Disparities in HIV Prevalence
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Wangari Tharao, Omu Anzala, Robert S. Remis, Craig R. Cohen, Joshua Kimani, Tae J. Yi, Lyle R. McKinnon, Rupert Kaul, and Duncan Chege
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medicine.medical_specialty ,Sexual transmission ,business.industry ,media_common.quotation_subject ,Immunology ,Prevalence ,Ethnic group ,Obstetrics and Gynecology ,Hiv prevalence ,Blame ,Race (biology) ,Reproductive Medicine ,Environmental health ,Epidemiology ,Pandemic ,medicine ,Immunology and Allergy ,business ,media_common - Abstract
Despite tremendous regional and subregional disparities in HIV prevalence around the world, epidemiology consistently demonstrates that black communities have been disproportionately affected by the pandemic. There are many reasons for this, and a narrow focus on socio-behavioural causes may be seen as laying blame on affected communities or individuals. HIV sexual transmission is very inefficient, and a number of biological factors are critical in determining whether an unprotected sexual exposure to HIV results in productive infection. This review will focus on ways in which biology, rather than behaviour, may contribute to regional and racial differences in HIV epidemic spread. Specific areas of focus are viral factors, host genetics, and the impact of co-infections and host immunology. Considering biological causes for these racial disparities may help to destigmatize the issue and lead to new and more effective strategies for prevention.
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- 2011
8. Identification of a novel HLA-DQA1 null allele, DQA1*0403N, from an East African woman
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Craig R. Cohen, Robert C. Brunham, Ma Luo, Lyle R. McKinnon, Francis A. Plummer, M.J. Narayansingh, and S. Pan
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Adult ,musculoskeletal diseases ,endocrine system diseases ,Molecular Sequence Data ,Immunology ,Population ,Fixed allele ,Biology ,Biochemistry ,HLA-DQ alpha-Chains ,HLA-DQ Antigens ,Genetics ,Humans ,Immunology and Allergy ,Allele ,skin and connective tissue diseases ,education ,Allele frequency ,education.field_of_study ,Base Sequence ,nutritional and metabolic diseases ,General Medicine ,C957T ,Kenya ,Null allele ,Molecular biology ,Stop codon ,Minor allele frequency ,Codon, Nonsense ,Female ,Sequence Alignment - Abstract
We report a novel DQA1 allele (DQA1*0403N) identified during sequence-based HLA-DQA1 typing of a Kenyan population. The new allele is identical to DQA1*0401 at exon 2 except for a single-nucleotide substitution at codon 53, changing it from lysine to a stop codon (CAA-->TAA). The substitution at codon 53 was confirmed by sequencing two separate polymerase chain reaction products and by sequencing multiple clones obtained following TOPO-TA cloning. The resulting stop codon at position of codon 53 in exon 2 is predicted to produce a non-functional DQA1 alpha-chain. The new allele has been named by the WHO nomenclature committee as DQA1*0403N. This is the first report of a null allele detected in the DQA1 gene.
- Published
- 2004
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