Natural Killer Cell–Mediated Innate Sieve Effect on HIV-1: The Impact of KIR/HLA Polymorphism on HIV-1 Subtype-Specific Acquisition in East Africa

Rebecca N. Koehler, Galit Alter, Sodsai Tovanabutra, Elmar Saathoff, Miguel A. Arroyo, Anne M. Walsh, Eric E. Sanders-Buell, Leonard Maboko, Michael Hoelscher, Merlin L. Robb, Nelson L. Michael, Francine E. McCutchan, Jerome H. Kim, Gustavo H. Kijak

Here we explore the association between killer cell immunoglobulin-like receptor (KIR)/HLA and human immunodeficiency virus type 1 (HIV-1) acquisition with different viral subtypes circulating in East Africa. In the prospective Cohort Development (CODE) cohort (Mbeya, Tanzania), carriers of KIR3DS1 and its putative ligand (HLA-A or HLA-B Bw4-80Ile alleles) showed increased HIV-1 acquisition risk (odds ratio [OR] = 3.46; 95% confidence........

Published at:  2013-08-06

Effect of Genital Herpes on Cervicovaginal HIV Shedding in Women Co-Infected with HIV AND HSV-2 in Tanzania

Jim Todd ,Gabriele Riedner,Leonard Maboko,Michael Hoelscher,Helen A. Weiss,Eligius Lyamuya,David Mabey,Mary Rusizoka,Laurent Belec,Richard Hayes

To compare the presence and quantity of cervicovaginal HIV among HIV seropositive women with clinical herpes, subclinical HSV-2 infection and without HSV-2 infection respectively; to evaluate the association between cervicovaginal HIV and HSV shedding; and identify factors associated with quantity of cervicovaginal HIV.

Published at:  2013-03-13

High Seroprevalence for Typhus Group Rickettsiae, Southwestern Tanzania

Tatjana Dill, 1 Gerhard Dobler, 1 Elmar Saathoff, Petra Clowes, Inge Kroidl, Elias Ntinginya, Harun Machibya, Leonard Maboko, Thomas Löscher, Michael Hoelscher, and Norbert Heinrichcorresponding author

Rickettsioses caused by typhus group rickettsiae have been reported in various African regions. We conducted a cross-sectional survey of 1,227 participants from 9 different sites in the Mbeya region, Tanzania; overall seroprevalence of typhus group rickettsiae was 9.3%. Risk factors identified in multivariable analysis included low vegetation density and highway proximity.

Published at:  2013-02-15

Low Specificity of Determine HIV1/2 RDT Using Whole Blood in South West Tanzania

Inge Kroidl ,Petra Clowes ,Wolfram Mwalongo,Lucas Maganga,Leonard Maboko,Arne L. Kroidl,Christof Geldmacher,Harun Machibya,Michael Hoelscher,Elmar Saathoff

To evaluate the diagnostic performance of two rapid detection tests (RDTs) for HIV 1/2 in plasma and in whole blood samples. Methods More than 15,000 study subjects above the age of two years participated in two rounds of a cohort study to determine the prevalence of HIV. HIV testing was performed using the Determine HIV 1/2 test (Abbott) in the first (2006/2007) and the HIV 1/2 STAT-PAK Dipstick .......

Published at:  2012-06-29

Increased and Expedited Case Detection by Xpert MTB/RIF Assay in Childhood Tuberculosis: A Prospective Cohort Study

Andrea Rachow, Petra Clowes, Elmar Saathoff, Bariki Mtafya, Epiphania Michael, Elias N. Ntinginya, Dickens Kowour, Gabriel Rojas-Ponce, Arne Kroidl, Leonard Maboko, Norbert Heinrich, Klaus Reither, Michael Hoelscher

Diagnosis and timely treatment of tuberculosis in children is hampered by the absence of fast and reliable tests, especially in the era of human immunodeficiency virus (HIV). The aim of this study was to evaluate the diagnostic performance of the Xpert MTB/RIF assay (Xpert) in children with suspected tuberculosis in a high tuberculosis/HIV-burden setting.

Published at:  2012-04-03

High Seroprevalence of Rift Valley Fever and Evidence for Endemic Circulation in Mbeya Region, Tanzania, in a Cross-Sectional Study

Norbert Heinrich ,Elmar Saathoff ,Nina Weller,Petra Clowes,Inge Kroidl,Elias Ntinginya,Harun Machibya,Leonard Maboko,Thomas Löscher,Gerhard Dobler,Michael Hoelscher

The Rift Valley fever virus (RVFV) is an arthropod-borne phlebovirus. RVFV mostly causes outbreaks among domestic ruminants with a major economic impact. Human infections are associated with these events, with a fatality rate of 0.5–2%. Since the virus is able to use many mosquito species of temperate climates as vectors, it has a high potential to spread to outside Africa.

Published at:  2012-03-27

Monitoring CD27 Expression to Evaluate Mycobacterium Tuberculosis Activity in HIV-1 Infected Individuals In Vivo

Alexandra Schuetz ,Antelmo Haule,Klaus Reither,Njabulo Ngwenyama,Andrea Rachow,Andreas Meyerhans,Leonard Maboko,Richard A. Koup,Michael Hoelscher,Christof Geldmacher

The level of bacterial activity is only poorly defined during asymptomatic Mycobacterium tuberculosis (MTB) infection. The objective was to study the capacity of a new biomarker, the expression of the T cell maturation marker CD27 on MTB-specific CD4 T cells, to identify active tuberculosis (TB) disease in subjects from a MTB and HIV endemic region. The frequency and CD27 expression of circulating MTB-specific CD4 T cells was determined in 96 study participants after stimulation with purified protein derivative (PPD) using intracellular cytokine staining for IFNgamma (IFNγ). Subjects were then stratified by their TB and HIV status. Within PPD responders, a CD27− phenotype was associated with active TB in HIV− (p = 0.0003) and HIV+ (p = 0.057) subjects, respectively. In addition, loss of CD27 expression preceded development of active TB in one HIV seroconverter. Interestingly, in contrast to HIV− subjects ..........

Published at:  2011-11-07

Scarcity or Absence of Humoral Immune Responses in the Plasma and Cervicovaginal Lavage Fluids of Heavily HIV-1-Exposed But Persistently Seronegative Women

Jiri Mestecky, Peter F. Wright, Lucia Lopalco, Herman F. Staats, Pamela A. Kozlowski, Zina Moldoveanu, Rashada C. Alexander, Rose Kulhavy, Claudia Pastori, Leonard Maboko, Gabriele Riedner, Yuwei Zhu, Terri Wrinn, and Michael Hoelscher

To address an existing controversy concerning the presence of HIV-1-specific antibodies of the IgA isotype in the female genital tract secretions of highly-exposed but persistently seronegative (HEPSN) women, 41 samples of plasma and cervicovaginal lavage (CVL) fluid were distributed to six laboratories for their blinded evaluation using ELISA with 10 different HIV-1 antigens, chemiluminescence-enhanced Western blots (ECL-WB), and virus neutralization. HIV-specific IgG or IgA antibodies in plasma samples from HEPSN women were absent or detectable only at low levels. In CVL, 11/41 samples displayed low levels of reactivity in ELISA against certain antigens. However, only one sample was positive in two of five...........

Published at:  2011-05-04

Defining the human immunodeficiency virus type 1 transmission genetic bottleneck in a region with multiple circulating subtypes and recombinant forms

Andile Nofemela a 1, Gama Bandawe a 1, Ruwayhida Thebus a, Jinny Marais a, Natasha Wood b, Oliver Hoffmann e, Leonard Maboko d, Michael Hoelscher d e, Zenda Woodman c, Carolyn Williamson a

The Mbeya region of Tanzania has a genetically complex HIV epidemic with multiple subtypes and recombinant forms circulating, together with a high frequency of dual infections with more than one subtype. This study aimed to determine whether this impacted the HIV-1 transmission bottleneck. A total of 210 env sequences from 22 participants were generated from recently infected women from Mbeya using the single genome amplification approach. Participants were.......

Published at:  2011-05-04

Publication Archive

  • 2023 (6 publications)
  • 2022 (12 publications)
  • 2021 (5 publications)
  • 2020 (2 publications)
  • 2019 (2 publications)
  • 2018 (7 publications)
  • 2017 (8 publications)
  • 2016 (7 publications)
  • 2015 (7 publications)
  • 2014 (5 publications)
  • 2013 (5 publications)
  • 2012 (3 publications)
  • 2011 (4 publications)
  • 2010 (5 publications)
  • 2009 (5 publications)
  • 2008 (3 publications)
  • 2007 (3 publications)
  • 2006 (2 publications)
  • 2005 (2 publications)
  • 2004 (2 publications)
  • 2001 (1 publications)