Browsing Faculty of Health Sciences (FHS) by Author "Wachihi, Charles"
Now showing items 1-20 of 30
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Anti-HIV-1 Activity of Elafin Is More Potent than Its Precursor's, Trappin-2, in Genital Epithelial Cells
Drannik, Anna G; Nag, Kakon; Yao, Xiao-Dan; Henrick, Bethany M; Jain, Sumiti; Ball, Blake T; Plummer, Francis A; Wachihi, Charles; Kimani, Joshua; Rosenthal, Kenneth L (Department of Medical Microbiology, 2012)Cervicovaginal lavage fluid (CVL) is a natural source of anti-HIV-1 factors; however, molecular characterization of the anti-HIV-1 activity of CVL remains elusive. In this study, we confirmed that CVLs from HIV-1-resistant ... -
Bacterial vaginosis in HIV-infected women induces reversible alterations in the cervical immune environment
Rebbapragada, Anuradha; Howe, Kathryn; Wachihi, Charles; Pettengell, Christopher; Sunderji, Sherzana; Huibner, Sanja; Ball, T. Blake; Plummer, Francis A.; Jaoko Walter G.; Kaul, Rupert (2008)Bacterial vaginosis (BV) has been associated with increased HIV cervicovaginal shedding. We hypothesized that this might relate to BV-associated increases in mucosal activated CD4+ T cells, which could enhance local HIV ... -
Bacterial vaginosis, HIV serostatus and T-cell subset distribution in a cohort of East African commercial sex workers: retrospective analysis
Schellenberg, John J.; Card, Catherine M.; Ball, T. Blake; Mungai, Jane Njeri; Irungu, Erastus; Kimani, Joshua; Jaoko Walter G.; Wachihi, Charles; Fowke, Keith R.; Plummer, Francis A. (2012)Although bacterial vaginosis is a known correlate of HIV infection, no previous studies have investigated whether women defined as HIV-exposed seronegative (HESN) are less likely to have bacterial vaginosis. Little is known ... -
Blunted IL17/IL22 and pro-inflammatory cytokine responses in the genital tract and blood of HIV Exposed, seronegative female sex workers in Kenya
Chege, Duncan; Chai, Yijie; Huibner, Sanja; Kain, Taylor; Wachihi, Charles; Kimani, Makubo; Barasa, Samson; McKinnon, Lyle R.; Muriuki, Festus K.; Kariri, Anthony; Jaoko Walter G.; Anzala, Omu; Kimani, Joshua; Ball, T. Blake; Plummer, Francis A.; Kaul, Rupert (2012)Identifying the immune correlates of reduced susceptibility to HIV remains a key goal for the HIV vaccine field, and individuals who are HIV-exposed, seronegative (HESN) may offer important clues. Reduced systemic immune ... -
Blunted IL17/IL22 and Pro-Inflammatory Cytokine Responses in the Genital Tract and Blood of HIV-Exposed, Seronegative Female Sex Workers in Kenya
Chege, Duncan; Chai, Yijie; Huibner, Sanja; Kain, Taylor; Wachihi, Charles; Kimani, Makubo; Barasa, Samson; McKinnon, Lyle R; Muriuki, Festus K; Kariri, Anthony; Jaoko, Walter; Anzala, Omu; Kimani, Joshua; Ball, T Blake; Plummer, Francis A; Kaul, Rupert (University of Nairobi, 2012)Identifying the immune correlates of reduced susceptibility to HIV remains a key goal for the HIV vaccine field, and individuals who are HIV-exposed, seronegative (HESN) may offer important clues. Reduced systemic immune ... -
Blunted il17/il22 and pro-inflammatory cytokine responses in the genital tract and blood of HIV-exposed, seronegative female sex workers in Kenya
Chege, Duncan; Chai, Yijie; Huibner, Sanja; Kain, Taylor; Wachihi, Charles; Kimani, Makubo; Barasa, Samson; McKinnon, Lyle R; Muriuki, Festus K; Kariri, Anthony; Jaoko, Walter; Anzala, Omu; Kimani, Joshua; Kaul, Rupert (Univerisyt of Nairobi, 2012-08)Background Identifying the immune correlates of reduced susceptibility to HIV remains a key goal for the HIV vaccine field, and individuals who are HIV-exposed, seronegative (HESN) may offer important clues. Reduced ... -
Clade specific evolution mediated by HLA-B*57/5801 in human immunodeficiency virus type 1 Clade A1 p24
McKinnon, Lyle R.; Capina, Rupert; Peters, Harold; Mendoza, Mark; Kimani, Joshua; Wachihi, Charles; Kariri, Anthony; Kimani, Makobu; Richmond, Meika; Kiazyk, Sandy Koesters; Fowke, Keith R.; Jaoko Walter G; Luo, Ma; Ball, T. Blake; Plummer, Francis A. (2009)HLA-B*57-mediated selection pressure leads to a typical escape pathway in human immunodeficiency virus type 1 (HIV-1) CD8 epitopes such as TW10. Whether this T242N pathway is shared by all clades remains unknown. We ... -
A common HLA-DP genotype is associated with resistance to hiv-1 infection in Kenyan sex workers
Hardie, Rae-Anne; Knight, Erin; Bruneau, Brigitte; Semeniuk, Christina; Gill, Kulvinder; Nagelkerke, Nico; Kimani, Joshua; Wachihi, Charles; Ngugi, Elizabeth; Luo, Ma; Plummer, Francis A (Univerisyt of Nairobi, 2008-10)HLA-DP antigens present peptides to CD4+ T cells and play an important role in parasitic infections and autoimmune diseases, yet their influence on HIV-1 susceptibility has not been well studied. Here, we report several ... -
Does antiretroviral therapy initiation increase sexual risk taking in Kenyan female sex workers? A retrospective case–control study
Mawji, Elysha; McKinnon, Lyle; Wachihi, Charles; Chege, Duncan; Thottingal, Paul; Kariri, Anthony; Plummer, Francis; Ball, Blake T; Jaoko Walter G.; Ngugi, Elizabeth N; Kimani, Joshua; Gelmon, Lawrence; Nagelkerke, Nico; Kaul, Rupert (Department of Community HealthDepartment of Medical Microbiology, 2012)Although antiretroviral therapy (ART) prolongs life and reduces infectiousness, in some contexts, it has been associated with increased sexual risk taking. Design Retrospective case–control study. Setting ... -
Effect of Baseline HIV Disease Parameters on CD4+ T Cell Recovery After Antiretroviral Therapy Initiation in Kenyan Women
McKinnon, Lyle R; Kimani, Makobu; Wachihi, Charles; Nagelkerke, Nico J; Muriuki, Festus K; Kariri, Anthony; Lester, Richard T; Gelmon, Lawrence; Ball, Blake T; Plummer, Francis A; Kaul, Rupert; Kimani, Joshua (Department of Medical Microbiology, 2010)Background Antiretroviral therapy (ART) for HIV infection reconstitutes the immune system and improves survival. However, the rate and extent of CD4+ T cell recovery varies widely. We assessed the impact of several ... -
Elevated elafin/trappin-2 in the female genital tract is associated with protection against HIV acquisition
Iqbal, Shehzad M.; Ball, Terry B.; Levinson, Pauline; Maranan, Lillian; Jaoko Godfrey W.; Wachihi, Charles; Pak, Brian J.; Podust, Vladimir N.; Broliden, Kristina; Hirbod, Taha; Kaul, Rupert; Plummer, FA (2009)Globally, heterosexual intercourse is the primary route of HIV-1 (HIV) transmission. It follows that mechanisms that protect against HIV infection are likely operative at the genital mucosa. In HIV-resistant Kenyan sex ... -
Epitope Cross-Reactivity Frequently Differs between Central and Effector Memory HIV-Specific CD8 T Cells1
McKinnon, Lyle R.; Ball, T. Blake; Wachihi, Charles; McLaren, Paul J.; Waruk, Jillian L. M.; Mao, Xiaojuan; Ramdahin, Sue; Anzala, A. Omu; Kamene, Jane; Luo, Ma; Fowke, Keith R.; Plummer, Francis A. (2007)HIV diversity may limit the breadth of vaccine coverage due to epitope sequence differences between strains. Although amino acid substitutions within CD8 T cell HIV epitopes can result in complete or partial abrogation ... -
Epitope cross-reactivity frequently differs between central and effector memory HIV-specific CD8+ t cells1
McKinnon, Lyle R; Ball, T Blake; Wachihi, Charles; McLaren, Paul J; Waruk, Jillian LM; Mao, Xiaojuan; Ramdahin, Sue; Anzala, A Omu; Kamene, Jane; Luo, Ma; Fowke, Keith R; Plummer, Francis A (Univerisyt of Nairobi, 2007-03)HIV diversity may limit the breadth of vaccine coverage due to epitope sequence differences between strains. Although amino acid substitutions within CD8+ T cell HIV epitopes can result in complete or partial abrogation ... -
Epitope Mapping of HIV-Specific CD8+ T cells in a Cohort Dominated by Clade A1 Infection
McKinnon, Lyle R; Mao, Xiaojuan; Kimani, Joshua; Wachihi, Charles; Semeniuk, Christina; Mendoza, Mark; Liang, Binhua; Luo, Ma; Fowke, Keith R; Plummer, Francis A; Ball, Blake T (Department of Medical Microbiology, 2009)Background CD8+ T cell responses are often detected at large magnitudes in HIV-infected subjects, and eliciting these responses is the central aim of many HIV-1 vaccine strategies. Population differences in CD8+ T cell ... -
Evaluation of a quantitative real-time PCR assay to measure HIV-specific mucosal CD8+ T Cell responses in the cervix
Chege, Duncan; Chai, Yijie; Huibner, Sanja; McKinnon, Lyle; Wachihi, Charles; Kimani, Makubo; Jaoko Walter G.; Kimani, Joshua; Ball, T. Blake; Plummer, Francis A.; Kaul, Rupert; Rebbapragada, Anuradha (2010)Several candidate HIV vaccines aim to induce virus-specific cellular immunity particularly in the genital tract, typically the initial site of HIV acquisition. However, standardized and sensitive methods for evaluating ... -
Evaluation of a quantitative real-time PCR assay to measure HIV-specific mucosal CD8+ T cell responses in the cervix
Chege, Duncan; Chai, Yijie; Huibner, Sanja; McKinnon, Lyle; Wachihi, Charles; Kimani, Makubo; Jaoko, Walter; Kimani, Joshua; Ball, T Blake; Plummer, Francis A; Kaul, Rupert; Rebbapragada, Anuradha (Univerisyt of Nairobi, 2010-10)Several candidate HIV vaccines aim to induce virus-specific cellular immunity particularly in the genital tract, typically the initial site of HIV acquisition. However, standardized and sensitive methods for evaluating ... -
For protection from HIV-1 infection, more might not be better: a systematic analysis of HIV Gag epitopes of two alleles associated with different outcomes of HIV-1 infection
Luo, Ma; Daniuk, Christina A; Diallo, Tamsir O; Capina, Rupert E; Kimani, Joshua; Wachihi, Charles; Kimani, Makubo; Bielawny, Thomas; Peterson, Trevor; Mendoza, Mark GR; Kiazyk, Sandra; Ball, T Blake; Plummer, Francis A (Univerisyt of Nairobi, 2011)A subset of women in the Pumwani Sexworker cohort, established in 1985 in Nairobi, Kenya, remains uninfected despite repeated high-risk exposure(HESN) through active sex work. This HESN phenotype is associated with several ... -
A Genetic Polymorphism of FREM1 Is Associated with Resistance against HIV Infection in the Pumwani Sex Worker Cohort
Luo, Ma; Sainsbury, James; Tuff, Jeffrey; Lacap, Philip A; Yuan, Xin-Yong; Hirbod, Taha; Kimani, Joshua; Wachihi, Charles; Ramdahin, Sue; Bielawny, Thomas; Embree, Joanne; Broliden, Kristina; Ball, Blake T; Plummer, Francis A (Department of Medical Microbiology, 2012)A subgroup of women enrolled in the Pumwani sex worker cohort remain seronegative and PCR negative for human immunodeficiency virus type 1 despite repeated exposure through high-risk sex work. Studies have shown that ... -
High Prevalence of Genetically Similar HIV-1 Recombinants among Infected Sex Workers in Nairobi, Kenya
Land, Allison M; Luo, Ma; Pilon, Richard; Sandstrom, Paul; Embree, Joanne; Wachihi, Charles; Kimani, Joshua; Plummer, Francis A; Ball, T Blake (University of Nairobi, 2008)HIV-1, a highly diverse infectious agent, shows the greatest sequence diversity in highly exposed individuals, including greater levels of recombination. HIV-1 diversity in Nairobi, Kenya was examined in 240 individuals, ... -
HIV-1 Clade D Is Associated with Increased Rates of CD4 Decline in a Kenyan Cohort
McKinnon, Lyle R; Nagelkerke, Nico J; Kaul, Rupert; Shaw, Souradet Y; Capina, Rupert; Luo, Ma; Kariri, Anthony; Apidi, Winnie; Kimani, Makobu; Wachihi, Charles; Jaoko, Walter; Anzala, A Omu; Kimani, Joshua; Ball, T Blake; Plummer, Francis A (University of Nairobi, 2012)HIV-1 is grouped phylogenetically into clades, which may impact rates of HIV-1 disease progression. Clade D infection in particular has been shown to be more pathogenic. Here we confirm in a Nairobi-based prospective female ...