scholarly journals Human Immunodeficiency Virus Type 1 Infection Increases the In Vivo Capacity of Peripheral Monocytes To Cross the Blood-Brain Barrier into the Brain and the In Vivo Sensitivity of the Blood-Brain Barrier to Disruption by Lipopolysaccharide

2008 ◽  
Vol 82 (15) ◽  
pp. 7591-7600 ◽  
Author(s):  
Hongwei Wang ◽  
Jinglin Sun ◽  
Harris Goldstein

ABSTRACT Human immunodeficiency virus type 1 (HIV-1), introduced into the brain by HIV-1-infected monocytes which migrate across the blood-brain barrier (BBB), infects resident macrophages and microglia and initiates a process that causes HIV-1-associated neurocognitive disorders. The mechanism by which HIV-1 infection circumvents the BBB-restricted passage of systemic leukocytes into the brain and disrupts the integrity of the BBB is not known. Circulating lipopolysaccharide (LPS), which can compromise the integrity of the BBB, is significantly increased in HIV-1-infected individuals. We hypothesized that HIV-1 infection increases monocyte capacity to migrate across the BBB, which is further facilitated by a compromise of BBB integrity mediated by the increased systemic LPS levels present in HIV-1-infected individuals. To investigate this possibility, we examined the in vivo BBB migration of monocytes derived from our novel mouse model, JR-CSF/EYFP mice, which are transgenic for both a long terminal repeat-regulated full-length infectious HIV-1 provirus and ROSA-26-regulated enhanced yellow fluorescent protein. We demonstrated that JR-CSF/EYFP mouse monocytes displayed an increased capacity to enter the brain by crossing either an intact BBB or a BBB whose integrity was partially compromised by systemic LPS. We also demonstrated that the JR-CSF mouse BBB was more susceptible to disruption by systemic LPS than the control wild-type mouse BBB. These results demonstrated that HIV-1 infection increased the ability of monocytes to enter the brain and increased the sensitivity of the BBB to disruption by systemic LPS, which is elevated in HIV-1-infected individuals. These mice represent a new in vivo system for studying the mechanism by which HIV-1-infected monocytes migrate into the brain.

Blood ◽  
1992 ◽  
Vol 80 (8) ◽  
pp. 2128-2135 ◽  
Author(s):  
MP Busch ◽  
TH Lee ◽  
J Heitman

Abstract Various immunologic stimuli and heterologous viral regulatory elements have been shown to increase susceptibility to, and replication of, human immunodeficiency virus type 1 (HIV-1) in lymphocytes and monocytes in vitro. Transfusion of allogeneic blood components from heterologous donors constitutes a profound immunologic stimulus to the recipient, in addition to being a potential route of transmission of lymphotropic viral infections. To investigate the hypothesis that transfusions, and particularly those containing leukocytes, activate HIV-1 replication in infected recipient cells, we cocultured peripheral blood mononuclear cells (PBMC) from three anti-HIV-1-positive individuals with allogeneic donor PBMC, as well as partially purified populations of donor lymphocytes, monocytes, granulocytes, platelets, and red blood cells (RBC) and allogeneic cell-free plasma. Allogeneic PBMC induced a dose-related activation of HIV-1 expression in in vivo infected cells, followed by dissemination of HIV-1 to previously uninfected patient cells. Activation of HIV-1 replication was observed with donor lymphocytes, monocytes, and granulocytes, whereas no effect was seen with leukocyte-depleted RBC, platelets, or plasma (ie, therapeutic blood constituents). Allogeneic donor PBMC were also shown to upregulate HIV-1 expression in a “latently” infected cell line, and to increase susceptibility of heterologous donor PBMC to acute HIV-1 infection. Studies should be performed to evaluate whether transfusions of leukocyte-containing blood components accelerate HIV-1 dissemination and disease progression in vivo. If so, HIV-1-infected patients should be transfused as infrequently as possible and leukocyte-depleted (filtered) blood components should be used to avoid this complication.


2000 ◽  
Vol 74 (15) ◽  
pp. 7039-7047 ◽  
Author(s):  
Louis M. Mansky ◽  
Sandra Preveral ◽  
Luc Selig ◽  
Richard Benarous ◽  
Serge Benichou

ABSTRACT The Vpr protein of human immunodeficiency virus type 1 (HIV-1) influences the in vivo mutation rate of the virus. Since Vpr interacts with a cellular protein implicated in the DNA repair process, uracil DNA glycosylase (UNG), we have explored the contribution of this interaction to the mutation rate of HIV-1. Single-amino-acid variants of Vpr were characterized for their differential UNG-binding properties and used to trans complement vpr null mutant HIV-1. A striking correlation was established between the abilities of Vpr to interact with UNG and to influence the HIV-1 mutation rate. We demonstrate that Vpr incorporation into virus particles is required to influence the in vivo mutation rate and to mediate virion packaging of the nuclear form of UNG. The recruitment of UNG into virions indicates a mechanism for how Vpr can influence reverse transcription accuracy. Our data suggest that distinct mechanisms evolved in primate and nonprimate lentiviruses to reconcile uracil misincorporation into lentiviral DNA.


2003 ◽  
Vol 84 (10) ◽  
pp. 2715-2722 ◽  
Author(s):  
Gkikas Magiorkinis ◽  
Dimitrios Paraskevis ◽  
Anne-Mieke Vandamme ◽  
Emmanouil Magiorkinis ◽  
Vana Sypsa ◽  
...  

Recombination plays a pivotal role in the evolutionary process of many different virus species, including retroviruses. Analysis of all human immunodeficiency virus type 1 (HIV-1) intersubtype recombinants revealed that they are more complex than described initially. Recombination frequency is higher within certain genomic regions, such as partial reverse transcriptase (RT), vif/vpr, the first exons of tat/rev, vpu and gp41. A direct correlation was observed between recombination frequency and sequence similarity across the HIV-1 genome, indicating that sufficient sequence similarity is required upstream of the recombination breakpoint. This finding suggests that recombination in vivo may occur preferentially during reverse transcription through the strand displacement-assimilation model rather than the copy-choice model.


2009 ◽  
Vol 83 (19) ◽  
pp. 9875-9889 ◽  
Author(s):  
Elodie Beaumont ◽  
Daniela Vendrame ◽  
Bernard Verrier ◽  
Emmanuelle Roch ◽  
François Biron ◽  
...  

ABSTRACT Lentiviruses, including human immunodeficiency virus type 1 (HIV-1), typically encode envelope glycoproteins (Env) with long cytoplasmic tails (CTs). The strong conservation of CT length in primary isolates of HIV-1 suggests that this factor plays a key role in viral replication and persistence in infected patients. However, we report here the emergence and dominance of a primary HIV-1 variant carrying a natural 20-amino-acid truncation of the CT in vivo. We demonstrated that this truncation was deleterious for viral replication in cell culture. We then identified a compensatory amino acid substitution in the matrix protein that reversed the negative effects of CT truncation. The loss or rescue of infectivity depended on the level of Env incorporation into virus particles. Interestingly, we found that a virus mutant with defective Env incorporation was able to spread by cell-to-cell transfer. The effects on viral infectivity of compensation between the CT and the matrix protein have been suggested by in vitro studies based on T-cell laboratory-adapted virus mutants, but we provide here the first demonstration of the natural occurrence of similar mechanisms in an infected patient. Our findings provide insight into the potential of HIV-1 to evolve in vivo and its ability to overcome major structural alterations.


2003 ◽  
Vol 77 (5) ◽  
pp. 3119-3130 ◽  
Author(s):  
Ming Dong ◽  
Peng Fei Zhang ◽  
Franziska Grieder ◽  
James Lee ◽  
Govindaraj Krishnamurthy ◽  
...  

ABSTRACT We have studied the induction of neutralizing antibodies by in vivo expression of the human immunodeficiency virus type 1 (HIV-1) envelope by using a Venezuelan equine encephalitis virus (VEE) replicon system with mice and rabbits. The HIV-1 envelope, clone R2, has broad sensitivity to cross-reactive neutralization and was obtained from a donor with broadly cross-reactive, primary virus-neutralizing antibodies (donor of reference serum, HIV-1-neutralizing serum 2 [HNS2]). It was expressed as gp160, as secreted gp140, and as gp160ΔCT with the cytoplasmic tail deleted. gp140 was expressed in vitro at a high level and was predominantly uncleaved oligomer. gp160ΔCT was released by cells in the form of membrane-bound vesicles. gp160ΔCT induced stronger neutralizing responses than the other forms. Use of a helper plasmid for replicon particle packaging, in which the VEE envelope gene comprised a wild-type rather than a host range-adapted sequence, also enhanced immunogenicity. Neutralizing activity fractionated with immunoglobulin G. This activity was cross-reactive among a panel of five nonhomologous primary clade B strains and a Chinese clade C strain and minimally reactive against a Chinese clade E (circulating recombinant form 1) strain. The comparative neutralization of these strains by immune mouse sera was similar to the relative neutralizing effects of HNS2, and responses induced in rabbits were similar to those induced in mice. Together, these results demonstrate that neutralizing antibody responses can be induced in mice within 2 to 3 months that are similar in potency and cross-reactivity to those found in the chronically infected, long-term nonprogressive donor of HNS2. These findings support the expectation that induction of highly cross-reactive HIV-1 primary virus-neutralizing activity by vaccination may be realized.


2009 ◽  
Vol 83 (8) ◽  
pp. 3617-3625 ◽  
Author(s):  
Xiaoying Shen ◽  
Robert J. Parks ◽  
David C. Montefiori ◽  
Jennifer L. Kirchherr ◽  
Brandon F. Keele ◽  
...  

ABSTRACT The broadly neutralizing human monoclonal antibodies (MAbs) 2F5 and 4E10, both targeting the highly conserved human immunodeficiency virus type 1 (HIV-1) envelope membrane proximal external region (MPER), are among the MAbs with the broadest heterologous neutralizing activity and are of considerable interest for HIV-1 vaccine development. We have identified serum antibodies from an HIV-infected subject that both were broadly neutralizing and specifically targeted MPER epitopes that overlap the 2F5 epitope. These MPER-specific antibodies were made 15 to 20 months following transmission and concomitantly with the development of autoantibodies. Our findings suggest that multiple events (i.e., genetic predisposition and HIV-1 immune dysregulation) may be required for induction of broadly reactive gp41 MPER antibodies in natural infection.


2003 ◽  
Vol 84 (3) ◽  
pp. 603-606 ◽  
Author(s):  
Lars H. Lund ◽  
Britta Wahren ◽  
Mariano A. Garcia-Blanco

Human immunodeficiency virus type 1 (HIV-1) Tat and human Cyclin T1 form a complex and together recognize the viral TAR RNA element with specificity. Using HIV-1/equine infectious anaemia virus TAR chimeras, we show that in addition to the well-characterized interaction with the bulge, Tat recognizes the distal stem and the loop of TAR. These data support previously proposed, but unproven, molecular models.


2001 ◽  
Vol 75 (8) ◽  
pp. 3916-3924 ◽  
Author(s):  
Karen M. Duus ◽  
Eric D. Miller ◽  
Jonathan A. Smith ◽  
Grigoriy I. Kovalev ◽  
Lishan Su

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) is frequently attenuated after long-term culture in vitro. The attenuation process probably involves mutations of functions required for replication and pathogenicity in vivo. Analysis of attenuated HIV-1 for replication and pathogenicity in vivo will help to define these functions. In this study, we examined the pathogenicity of an attenuated HIV-1 isolate in a laboratory worker accidentally exposed to a laboratory-adapted HIV-1 isolate. Using heterochimeric SCID-hu Thy/Liv mice as an in vivo model, we previously defined HIV-1 env determinants (HXB/LW) that reverted to replicate in vivo (L. Su, H. Kaneshima, M. L. Bonyhadi, R. Lee, J. Auten, A. Wolf, B. Du, L. Rabin, B. H. Hahn, E. Terwilliger, and J. M. McCune, Virology 227:46–52, 1997). Here we further demonstrate that HIV-1 replication in vivo can be separated from its pathogenic activity, in that the HXB/LW virus replicated to high levels in SCID-hu Thy/Liv mice, with no significant thymocyte depletion. Restoration of the nef gene in the recombinant HXB/LW genome restored its pathogenic activity, with no significant effect on HIV-1 replication in the thymus. Our results suggest that in vitro-attenuated HIV-1 lacks determinants for pathogenicity as well as for replication in vivo. Our data indicate that (i) the replication defect can be recovered in vivo by mutations in the envgene, without an associated pathogenic phenotype, and (ii)nef can function in the HXB/LW clone as a pathogenic factor that does not enhance HIV-1 replication in the thymus. Furthermore, the HXB/LW virus may be used to study mechanisms of HIV-1nef-mediated pathogenesis in vivo.


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