Medical Immunology Commons^™

Global Neuroaids Roundtable, Jeymohan Joseph, Cristian L. Achim, Michael J. Boivin, Bruce J. Brew, David B. Clifford, Deborah A. Colosi, Ronald J. Ellis, Robert K. Heaton, Amadou Gallo-Diop, Igor Grant, Georgette D. Kanmogne, Mahendra Kumar, Scott Letendre, Thomas D. Marcotte, Avindra Nath, Carlos A. Pardo, Robert H. Paul, Lynn Pulliam, Kevin Robertson, Walter Royal Iii, Ned Sacktor, Pasiri Sithinamsuwan, Davey M. Smith, Victor Valcour, Brian Wigdahl, Charles Wood

Nebraska Center for Virology: Faculty Publications

In May 2012, the Division of AIDS Research at the National Institute of Mental Health (NIMH) organized the “Global NeuroAIDS Roundtable” in conjunction with the 11th International Symposium on Neurovirology and the 2012 Conference on HIV in the Nervous System. The meeting was held in New York, NY, USA and brought together NIMH-funded investigators who are currently working on projects related to the neurological complications of AIDS (NeuroAIDS) in Africa, Asia, Eastern Europe, and Latin America in order to provide an opportunity to share their recent findings and discuss the challenges encountered within each country. The major goals of the …

Two Coiled-Coil Domains Of Chlamydia Trachomatis Inca Affect Membrane Fusion Events During Infection., Erik Ronzone, Fabienne Paumet

Department of Microbiology and Immunology Faculty Papers

Chlamydia trachomatis replicates in a parasitophorous membrane-bound compartment called an inclusion. The inclusions corrupt host vesicle trafficking networks to avoid the degradative endolysosomal pathway but promote fusion with each other in order to sustain higher bacterial loads in a process known as homotypic fusion. The Chlamydia protein IncA (Inclusion protein A) appears to play central roles in both these processes as it participates to homotypic fusion and inhibits endocytic SNARE-mediated membrane fusion. How IncA selectively inhibits or activates membrane fusion remains poorly understood. In this study, we analyzed the spatial and molecular determinants of IncA's fusogenic and inhibitory functions. Using …

Toward A Network Model Of Mhc Class Ii-Restricted Antigen Processing., Michael A Miller, Asha Purnima V Ganesan, Laurence C. Eisenlohr

Department of Microbiology and Immunology Faculty Papers

The standard model of Major Histocompatibility Complex class II (MHCII)-restricted antigen processing depicts a straightforward, linear pathway: internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4(+) T cells (TCD4+). Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while …

Analysis Of Autophagy And Inflammasome Regulation In Neuronal Cells And Monocytes Infected With Chlamydia Pneumoniae: Implications For Alzheimer’S Disease, Brian J. Balin, Christine J. Hammond, Juliana Zoga, Ahmad B. Cader, Annette K. Slutter, Jonathan M. Anzman, Ian Kohler, Susan T. Hingley, Denah M. Appelt

Scholarly Posters

Objectives: Our laboratory has been studying the role of infection with the obligate intracellular bacterium Chlamydia pneumoniae in sporadic late-onset Alzheimer disease (LOAD). This infection may be a trigger for the pathology observed in LOAD as a function of initiating changes in gene regulation following entry of the organism into the brain. As such, we are analyzing how this infection can promote changes in autophagy and inflammasome gene regulation as both have been shown to be altered in LOAD. Methods: Human SKNMC neuronal cells and THP1 monocytes were infected in vitro for 24-72 hrs with a laboratory strain of Chlamydia …

The Prevalence Of Smoking And The Knowledge Of Smoking Hazards And Smoking Cessation Strategies Among Hiv Positive Patients In Johannesburg, South Africa, Peter Waweru, R. Anderson, H. Steel, Wdf. Venter, D. Murdoch, C. Feldman

Internal Medicine, East Africa

Background: While the detrimental effects of smoking among HIV positive patients have been well documented, there is a paucity of data regarding cigarette smoking prevalence among these patients in South Africa.

Objectives: To establish the frequency, demographics, and knowledge of harmful effects and of smoking cessation strategies among HIV-positive patients in Johannesburg, South Africa.

Methods: A prospective cross-sectional survey, using a structured questionnaire interview, of HIV-positive patients attending the HIV Clinic at the Charlotte Maxeke Johannesburg Academic Hospital between 1 July 2011 and 31 October 2011.

Results: Of 207 HIV positive patients attending an ARV roll-out clinic, 31 (15%) were …

The Effect Of Exogenous Leptin On Dendritic Cell Migration And Interactions With T Cells, Amanda L. Gonzales

Open Access Theses & Dissertations

Obesity is a complex, chronic disease that has reached epidemic proportions in the United States and shows no indication of receding. It is a state of chronic low-grade inflammation that is initiated by morphological changes in large accumulations of adipose tissue. Leptin is a pleiotropic hormone secreted by adipose tissue, presenting a possible link between obesity and inflammation. In this study, we assessed the effect of leptin on bone marrow-derived (BM) dendritic cells (DC) (BM-DC) function, antigen presenting cells vital for the activation of naí¯ve T cells. Previous data produced in our laboratory established that the addition of leptin to …

Is Starting Antiretroviral Therapy (Art) In Hiv Positive Adults With Cd4 Cell Count Of <300 Cells/Μl Within Four Weeks Of Initiating New Tuberculosis (Tb) Therapy More Effective In Reducing Mortality Rates Than Starting Art Four Weeks Or Later After Initiating New Tb Therapy?, Janna Erlien

PCOM Physician Assistant Studies Student Scholarship

OBJECTIVE: The objective of this selective EBM review is to determine whether or not starting antiretroviral therapy (ART) in HIV positive adults with CD4 cell count of /µl within four weeks of initiating new tuberculosis therapy more effective in reducing mortality rates than starting ART four weeks or later after initiating new tuberculosis therapy.

STUDY DESIGN: Systematic review of three English language primary studies published in the New England Journal of Medicine in 2011.

DATA SOURCES: Three open label, randomized, controlled trials published in 2011, comparing the timing of ART for HIV+ adults with confirmed or suspected new TB …

Investigating The Role For Il-21 In Rabies Virus Vaccine-Induced Immunity., Corin L Dorfmeier, Evgeni P Tzvetkov, Anthony Gatt, James P Mcgettigan

Department of Microbiology and Immunology Faculty Papers

Over two-thirds of the world's population lives in regions where rabies is endemic, resulting in over 15 million people receiving multi-dose post-exposure prophylaxis (PEP) and over 55,000 deaths per year globally. A major goal in rabies virus (RABV) research is to develop a single-dose PEP that would simplify vaccination protocols, reduce costs associated with RABV prevention, and save lives. Protection against RABV infections requires virus neutralizing antibodies; however, factors influencing the development of protective RABV-specific B cell responses remain to be elucidated. Here we used a mouse model of IL-21 receptor-deficiency (IL-21R-/-) to characterize the role for IL-21 in RABV …

Comparison Of Heterologous Prime-Boost Strategies Against Human Immunodeficiency Virus Type 1 Gag Using Negative Stranded Rna Viruses., Tessa M Lawrence, Celestine N Wanjalla, Emily A Gomme, Christoph Wirblich, Anthony Gatt, Elena Carnero, Adolfo García-Sastre, Douglas S Lyles, James P Mcgettigan, Matthias J Schnell

Department of Microbiology and Immunology Faculty Papers

This study analyzed a heterologous prime-boost vaccine approach against HIV-1 using three different antigenically unrelated negative-stranded viruses (NSV) expressing HIV-1 Gag as vaccine vectors: rabies virus (RABV), vesicular stomatitis virus (VSV) and Newcastle disease virus (NDV). We hypothesized that this approach would result in more robust cellular immune responses than those achieved with the use of any of the vaccines alone in a homologous prime-boost regimen. To this end, we primed BALB/c mice with each of the NSV-based vectors. Primed mice were rested for thirty-five days after which we administered a second immunization with the same or heterologous NSV-Gag viruses. …

Towards Defining The Chloroviruses: A Genomic Journey Through A Genus Of Large Dna Viruses, Adrien Jeanniard, David D. Dunigan, James Gurnon, Irina V. Agarkova, Ming Kang, Jason Vitek, Garry Duncan, O William Mcclung, Megan Larsen, Jean-Michel Claverie, James L. Van Etten, Guillaume Blanc

Nebraska Center for Virology: Faculty Publications

Background: Giant viruses in the genus Chlorovirus (family Phycodnaviridae) infect eukaryotic green microalgae. The prototype member of the genus, Paramecium bursaria chlorella virus 1, was sequenced more than 15 years ago, and to date there are only 6 fully sequenced chloroviruses in public databases. Presented here are the draft genome sequences of 35 additional chloroviruses (287 – 348 Kb/319 – 381 predicted protein encoding genes) collected across the globe; they infect one of three different green algal species. These new data allowed us to analyze the genomic landscape of 41 chloroviruses, which revealed some remarkable features about these viruses. …

Evaluation Of Higher Plant Virus Resistance Genes In The Green Alga, Chlorella Variabilis Nc64a, During The Early Phase Of Infection With Paramecium Bursaria Chlorella Virus-1, Janet M. Rowe, David D. Dunigan, Guillaume Blanc, James R. Gurnon, Yuannan Xia, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

With growing industrial interest in algae plus their critical roles in aquatic systems, the need to understand the effects of algal pathogens is increasing. We examined a model algal host–virus system, Chlorella variabilis NC64A and virus, PBCV-1. C. variabilis encodes 375 homologs to genes involved in RNA silencing and in response to virus infection in higher plants. Illumina RNA-Seq data showed that 325 of these homologs were expressed in healthy and early PBCV-1 infected (≤60 min) cells. For each of the RNA silencing genes to which homologs were found, mRNA transcripts were detected in healthy and infected cells. C. variabilis …

A Twin-Cysteine Motif In The V2 Region Of Gp120 Is Associated With Siv Envelope Trimer Stabilization, Christopher Bohl, Dane Bowder, Jesse Thompson, Levon Abrahamyan, Sandra Gonzalez-Ramirez, Youdong Mao, Joseph Sodroski, Charles Wood, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

The V1 and V2 variable regions of the primate immunodeficiency viruses contribute to the trimer association domain of the gp120 exterior envelope glycoprotein. A pair of V2 cysteine residues at 183 and 191 (‘‘twin cysteines’’) is present in several simian immunodeficiency viruses, human immunodeficiency virus type 2 (HIV-2) and some SIV_cpz lineages, but not in HIV-1. To examine the role of this potentially disulfide-bonded twin-cysteine motif, the cysteine residues in the SIVmac239 envelope glycoproteins were individually and pairwise substituted by alanine residues. All of the twin-cysteine mutants exhibited decreases in gp120 association with the Env trimer, membrane-fusing activity, and …

Hiv-1 Env C2-V4 Diversification In A Slow-Progressor Infant Reveals A Flat But Rugged Fitness Landscape, S. Abigail Smith, Charles Wood, John T. West

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type-1 (HIV-1) fitness has been associated with virus entry, a process mediated by the envelope glycoprotein (Env). We previously described Env genetic diversification in a Zambian, subtype C infected, slow-progressor child (1157i) in parallel with an evolving neutralizing antibody response. Because of the role the Variable-3 loop (V3) plays in transmission, cell tropism, neutralization sensitivity, and fitness, longitudinally isolated 1157i C2-V4 alleles were cloned into HIV-1_NL4-3-eGFP and -DsRed2 infectious molecular clones. The fluorescent reporters allowed for dual-infection competitions between all patient-derived C2-V4 chimeras to quantify the effect of V3 diversification and selection on fitness. ‘Winners’ …

‘‘Megavirales’’, A Proposed New Order For Eukaryotic Nucleocytoplasmic Large Dna Viruses, Philippe Colson, Xavier De Lamballerie, Natalya Yutin, Sassan Asgari, Yves Bigot, Dennis K. Bideshi, Xiao-Wen Cheng, Brian A. Federici, James L. Van Etten, Eugene V. Koonin, Bernard La Scola, Didier Raoult

Nebraska Center for Virology: Faculty Publications

The nucleocytoplasmic large DNA viruses (NCLDVs) comprise a monophyletic group of viruses that infect animals and diverse unicellular eukaryotes. The NCLDV group includes the families Poxviridae, Asfarviridae, Iridoviridae, Ascoviridae, Phycodnaviridae, Mimiviridae and the proposed family ‘‘Marseilleviridae’’. The family Mimiviridae includes the largest known viruses, with genomes in excess of one megabase, whereas the genome size in the other NCLDV families varies from 100 to 400 kilobase pairs. Most of the NCLDVs replicate in the cytoplasm of infected cells, within so-called virus factories. The NCLDVs share a common ancient origin, as demonstrated by evolutionary reconstructions that trace approximately 50 genes encoding …

Recent Advances On The Use Of Structural Biology For The Design Of Novel Envelope Immunogens Of Hiv-1, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

Many efforts have been made in the worldwide quest for a prophylactic HIV vaccine to end the AIDS pandemic, but none has yet succeeded. The lessons learned have repeatedly informed us that the traditional or conventional approaches directly using the pathogens or subunits will not be sufficient for an effective HIV/AIDS vaccine. Recent advances in structure-based technology have shown some promise in the quest for a better immunogen in HIV vaccine development. According to the basic binding structural relationship of an antigen and an antibody, structure-based antigen design could bring some hope for the development of an effective vaccine against …

The Highly Conserved Layer-3 Component Of The Hiv-1 Gp120 Inner Domain Is Critical For Cd4-Required Conformational Transitions, Anik Désormeaux, Mathieu Coutu, Halima Medjahed, Beatriz Pacheco, Alon Herschhorn, Christopher Gu, Shi-Hua Xiang, Youdong Mao, Joseph Sodroski, Andrés Finzi

Nebraska Center for Virology: Faculty Publications

The trimeric envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) mediates virus entry into host cells. CD4 engagement with the gp120 exterior envelope glycoprotein subunit represents the first step during HIV-1 entry. CD4-induced conformational changes in the gp120 inner domain involve three potentially flexible topological layers (layers 1, 2, and 3). Structural rearrangements between layer 1 and layer 2 have been shown to facilitate the transition of the envelope glycoprotein trimer from the unliganded to the CD4-bound state and to stabilize gp120-CD4 interaction. However, our understanding of CD4-induced conformational changes in the gp120 inner domain remains incomplete. Here, …

Analysis Of Primary Resistance Mutations To Hiv-1 Entry Inhibitors In Therapy Naive Subtype C Hiv-1 Infected Mother– Infant Pairs From Zambia, Hongyan Guo, Chang Liu, Bin Liu, Charles Wood, Xiaohong Kong

Nebraska Center for Virology: Faculty Publications

Background—Small molecular CCR5 inhibitors represent a new class of drugs for treating HIV-1 infection. The evaluation of the primary resistance mutations associated with entry inhibitors during HIV-1 perinatal transmission is required because they may have a profound impact on the clinical management in MTCT.

Objectives—To evaluate the primary resistance mutations to maraviroc and vicriviroc during perinatal transmission and analyze the sensitivity of Env derived from mother–infant pairs to maraviroc.

Study design—Nine MIPs infected by subtype C HIV-1 were recruited to analyze the prevalence and transmission of primary resistance mutations to maraviroc and vicriviroc. Moreover, Env derived from six MIPs were …

Early Childhood Infection Of Kaposi’S Sarcoma-Associated Herpesvirus In Zambian Households: A Molecular Analysis, Landon Olp, Danielle M. Shea, Maxine K. White, Clement Gondwe, Chipepo Kankasa, Charles Wood

Nebraska Center for Virology: Faculty Publications

Sub-Saharan Africa is endemic for Kaposi’s sarcoma-associated herpesvirus (KSHV) and there is a high rate of early childhood infection; however, the transmission sources are not well characterized. We examined household members as potential KSHV transmission sources to young children in the KSHV-endemic country of Zambia. To this end, we enrolled and followed Zambian households with at least one KSHV-seropositive child and collected longitudinal buccal swab samples. KSHV burden was evaluated and K1 sequences from the children were determined and analyzed for differences to K1 sequences from household members. The K1 sequences were also analyzed for evolution over time. We generated …

Multiple Regulatory Mechanisms Control B-1 B Cell Activation, Vishal Sindhava, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B-1 cells constitute a unique subset of B cells identified in several species including mice and humans. B-1 cells are further subdivided into B-1a and B-1b subsets as the former but not the later express CD5.The B-1a subset contributes to innate type of immune responses while the B-1b B cell subset contributes to adaptive responses. B-1 cell responses to B cell receptor (BCR) as well as Toll-like receptor (TLR) ligation are tightly regulated due to the cross-reactivity of antigen specific receptors on B-1 cells to self-antigens. B-1 cells are elevated in several autoimmune diseases. CD5 plays a major role in …

Molecular Characterization Of A Tetraspanin From The Human Liver Fluke, Opisthorchis Viverrini, Supawadee Piratae, Smarn Tesana, Malcolm K. Jones, Paul J. Brindley, Alex Loukas, Erica Lovas, Veerachai Eursitthichai, Banchob Sripa, Sirikanda Thanasuwan, Thewarach Laha

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Background

The human liver fluke, Opisthorchis viverrini, is designated as a group 1 carcinogen, and is the major risk factor for cholangiocarcinoma in endemic countries throughout Southeast Asia. Proteins in the excretory-secretory products and tegumental surface membranes of the fluke have been proposed to play pivotal roles in parasite survival in the host, and subsequent pathogenesis. These macromolecules are therefore valid targets for the development of vaccines and new drugs to control the infection. Tetraspanins (TSP) are prominent components of the tegument of blood flukes where they are essential for tegument formation, are directly exposed to the immune system, …