scholarly journals Proline 35 of Human Immunodeficiency Virus Type 1 (HIV-1) Vpr Regulates the Integrity of the N-Terminal Helix and the Incorporation of Vpr into Virus Particles and Supports the Replication of R5-Tropic HIV-1 in Human Lymphoid Tissue Ex Vivo

2007 ◽  
Vol 81 (17) ◽  
pp. 9572-9576 ◽  
Author(s):  
Jörg Votteler ◽  
Nicole Studtrucker ◽  
Stefan Sörgel ◽  
Jan Münch ◽  
Elke Rücker ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Lymphoid Tissue ◽  
Mutational Analysis ◽  
Ex Vivo ◽  
Immunodeficiency Virus ◽  
Human Lymphoid Tissue ◽  
Hiv 1

ABSTRACT Mutational analysis of the four conserved proline residues in human immunodeficiency virus type 1 (HIV-1) Vpr reveals that only Pro-35 is required for efficient replication of R5-tropic, but not of X4-tropic, viruses in human lymphoid tissue (HLT) cultivated ex vivo. While Vpr-mediated apoptosis and G2 cell cycle arrest, as well as the expression and subcellular localization of Vpr, were independent, the capacity for encapsidation of Vpr into budding virions was dependent on Pro-35. 1H nuclear magnetic resonance data suggest that mutation of Pro-35 causes a conformational change in the hydrophobic core of the molecule, whose integrity is required for the encapsidation of Vpr, and thus, Pro-35 supports the replication of R5-tropic HIV-1 in HLT.

scholarly journals Human Immunodeficiency Virus Type 1 Variants Resistant to First- and Second-Version Fusion Inhibitors and Cytopathic in Ex Vivo Human Lymphoid Tissue

2007 ◽  
Vol 81 (12) ◽  
pp. 6563-6572 ◽  
Author(s):  
Raghavan Chinnadurai ◽  
Devi Rajan ◽  
Jan Münch ◽  
Frank Kirchhoff
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Lymphoid Tissue ◽  
Ex Vivo ◽  
Fusion Inhibitors ◽  
Immunodeficiency Virus ◽  
Human Lymphoid Tissue ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) fusion inhibitors blocking viral entry by binding the gp41 heptad repeat 1 (HR1) region offer great promise for antiretroviral therapy, and the first of these inhibitors, T20 (Fuzeon; enfuvirtide), is successfully used in the clinic. It has been reported previously that changes in the 3-amino-acid GIV motif at positions 36 to 38 of gp41 HR1 mediate resistance to T20 but usually not to second-version fusion inhibitors, such as T1249, which target an overlapping but distinct region in HR1 including a conserved hydrophobic pocket (HP). Based on the common lack of cross-resistance and the difficulty of selecting T1249-resistant HIV-1 variants, it has been suggested that the determinants of resistance to first- and second-version fusion inhibitors may be different. To further assess HIV-1 resistance to fusion inhibitors and to analyze where changes in HR1 are tolerated, we randomized 16 codons in the HR1 region, including those making contact with HR2 codons and/or encoding residues in the GIV motif and the HP. We found that changes only at positions 37I, 38V, and 40Q near the N terminus of HR1 were tolerated. The propagation of randomly gp41-mutated HIV-1 variants in the presence of T1249 allowed the effective selection of highly resistant forms, all containing changes in the IV residues. Overall, the extent of T1249 resistance was inversely correlated to viral fitness and cytopathicity. Notably, one HIV-1 mutant showing ∼10-fold-reduced susceptibility to T1249 inhibition replicated with wild type-like kinetics and caused substantial CD4+-T-cell depletion in ex vivo-infected human lymphoid tissue in the presence and absence of an inhibitor. Taken together, our results show that the GIV motif also plays a key role in resistance to second-version fusion inhibitors and suggest that some resistant HIV-1 variants may be pathogenic in vivo.

scholarly journals Vpr and Vpu Are Important for Efficient Human Immunodeficiency Virus Type 1 Replication and CD4+ T-Cell Depletion in Human Lymphoid Tissue Ex Vivo

2004 ◽  
Vol 78 (22) ◽  
pp. 12689-12693 ◽  
Author(s):  
Elke Rücker ◽  
Jean-Charles Grivel ◽  
Jan Münch ◽  
Frank Kirchhoff ◽  
Leonid Margolis
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Lymphoid Tissue ◽  
Ex Vivo ◽  
Immunodeficiency Virus ◽  
Human Lymphoid Tissue ◽  
Hiv 1

ABSTRACT The relevance of the accessory vpr, vpu, and nef genes for human immunodeficiency virus type 1 (HIV-1) replication in human lymphoid tissue (HLT), the major site of viral replication in vivo, is largely unknown. Here, we show that an individual deletion of nef, vpr, or vpu significantly decreases HIV-1 replication and prevents CD4+ T-cell depletion in ex vivo HLT. However, only combined defects in all three accessory genes entirely disrupt the replicative capacity of HIV-1. Our results demonstrate that nef, vpr, and vpu are all essential for efficient viral spread in HLT, suggesting an important role in AIDS pathogenesis.

scholarly journals CD4 Down-Modulation by Human Immunodeficiency Virus Type 1 Nef Correlates with the Efficiency of Viral Replication and with CD4+ T-Cell Depletion in Human Lymphoid Tissue Ex Vivo

2001 ◽  
Vol 75 (21) ◽  
pp. 10113-10117 ◽  
Author(s):  
Svetlana Glushakova ◽  
Jan Münch ◽  
Silke Carl ◽  
Thomas C. Greenough ◽  
John L. Sullivan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Lymphoid Tissue ◽  
Ex Vivo ◽  
Immunodeficiency Virus ◽  
Human Lymphoid Tissue ◽  
Hiv 1

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) Nef protein is an important virulence factor. Nef has several functions, including down-modulation of CD4 and class I major histocompatibility complex cell surface expression, enhancement of virion infectivity, and stimulation of viral replication in peripheral blood mononuclear cells. Nef also increases HIV-1 replication in human lymphoid tissue (HLT) ex vivo. We analyzed recombinant and primarynef alleles with highly divergent activity in different in vitro assays to clarify which of these Nef activities are functionally linked. Our results demonstrate that Nef activity in CD4 down-regulation correlates significantly with the efficiency of HIV-1 replication and with the severity of CD4+ T-cell depletion in HLT. In conclusion, HIV-1 Nef variants with increased activity in CD4 down-modulation would cause severe depletion of CD4+ T cells in lymphoid tissues and accelerate AIDS progression.

scholarly journals Human Immunodeficiency Virus Type 1 (HIV-1) Non-B Subtypes Are Similar to HIV-1 Subtype B in that Coreceptor Specificity Is a Determinant of Cytopathicity in Human Lymphoid Tissue Infected Ex Vivo

2001 ◽  
Vol 75 (21) ◽  
pp. 10520-10522 ◽  
Author(s):  
Nina Malkevich ◽  
Chad Womack ◽  
Punita Pandya ◽  
Jean-Charles Grivel ◽  
Anthony S. Fauci ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Lymphocytes ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Lymphoid Tissue ◽  
Ex Vivo ◽  
Immunodeficiency Virus ◽  
Human Lymphoid Tissue ◽  
Hiv 1

ABSTRACT We sought to determine the relationship between virus-mediated CD4+ T-lymphocyte cytopathicity and viral coreceptor preference among various human immunodeficiency virus type 1 (HIV-1) subtypes in an ex vivo-infected human lymphoid tissue model. Our data show that all R5 HIV-1 infections resulted in mild depletion of CD4+ T lymphocytes, whereas all X4 HIV-1 infections caused severe depletion of CD4+ T lymphocytes regardless of their subtype origin. Thus, at least for the viruses within subtypes A, B, C, and E that were tested, coreceptor specificity is a critical factor that determines the ability of HIV-1 to deplete CD4+ T cells in human lymphoid tissue infected ex vivo.

scholarly journals Cytopathicity of Human Immunodeficiency Virus Type 1 Primary Isolates Depends on Coreceptor Usage and Not Patient Disease Status

2001 ◽  
Vol 75 (18) ◽  
pp. 8842-8847 ◽  
Author(s):  
Jason F. Kreisberg ◽  
David Kwa ◽  
Birgit Schramm ◽  
Verena Trautner ◽  
Ruth Connor ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Lymphoid Tissue ◽  
Disease Status ◽  
Immunodeficiency Virus ◽  
Human Lymphoid Tissue ◽  
Hiv 1

ABSTRACT It has been hypothesized that human immunodeficiency virus type 1 (HIV-1) evolves toward increased cytopathicity in conjunction with disease progression in infected patients. A viral property known to evolve in some but not all patients is coreceptor utilization, and it has been shown that a switch in coreceptor utilization is sufficient for the development of increased cytopathicity. To test the hypothesis that the evolution of other viral properties also contributes to accelerating cytopathicity in vivo, we used human lymphoid tissue explants to assay the cytopathicity of a panel of primary HIV-1 isolates derived from various stages of disease characterized by the presence or absence of changes in coreceptor preference. We found no evidence of coreceptor-independent increases in cytopathicity in isolates obtained either before coreceptor preference changes or from patients who progressed to AIDS despite an absence of coreceptor evolution. Instead, the cytopathicity of all HIV-1 isolates was determined solely by their coreceptor utilization. These results argue that HIV-1 does not evolve toward increased cytopathicity independently of changes in coreceptor utilization.

scholarly journals CD4+ T-Lymphocyte Depletion in Human Lymphoid Tissue Ex Vivo Is Not Induced by Noninfectious Human Immunodeficiency Virus Type 1 Virions

1998 ◽  
Vol 72 (11) ◽  
pp. 9345-9347 ◽  
Author(s):  
A. W. Sylwester ◽  
J.-C. Grivel ◽  
W. Fitzgerald ◽  
J. L. Rossio ◽  
J. D. Lifson ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ex Vivo ◽  
Productive Infection ◽  
Lymphoid Tissues ◽  
Immunodeficiency Virus ◽  
Human Lymphoid Tissue ◽  
Hiv 1

ABSTRACT We tested infectious human immunodeficiency virus type 1 (HIV-1), noninfectious but conformationally authentic inactivated whole HIV-1 virions, and purified gp120 for the ability to induce depletion of CD4+ T cells in human lymphoid tissues ex vivo. Infectious CXCR4-tropic HIV-1, but not matched inactivated virions or gp120, mediated CD4+ T-cell depletion, consistent with mechanisms requiring productive infection.

scholarly journals CCR5- and CXCR4-Tropic Subtype C Human Immunodeficiency Virus Type 1 Isolates Have a Lower Level of Pathogenic Fitness than Other Dominant Group M Subtypes: Implications for the Epidemic

2009 ◽  
Vol 83 (11) ◽  
pp. 5592-5605 ◽  
Author(s):  
Awet Abraha ◽  
Immaculate L. Nankya ◽  
Richard Gibson ◽  
Korey Demers ◽  
Denis M. Tebit ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ex Vivo ◽  
Sub Saharan Africa ◽  
Subtype C ◽  
Immunodeficiency Virus ◽  
Subtype A ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) subtype C is the dominant subtype globally, due largely to the incidence of subtype C infections in sub-Saharan Africa and east Asia. We compared the relative replicative fitness (ex vivo) of the major (M) group of HIV-1 subtypes A, B, C, D, and CRF01_AE and group O isolates. To estimate pathogenic fitness, pairwise competitions were performed between CCR5-tropic (R5) or CXCR4-tropic (X4) virus isolates in peripheral blood mononuclear cells (PBMC). A general fitness order was observed among 33 HIV-1 isolates; subtype B and D HIV-1 isolates were slightly more fit than the subtype A and dramatically more fit than the 12 subtype C isolates. All group M isolates were more fit (ex vivo) than the group O isolates. To estimate ex vivo transmission fitness, a subset of primary HIV-1 isolates were examined in primary human explants from penile, cervical, and rectal tissues. Only R5 isolates and no X4 HIV-1 isolates could replicate in these tissues, whereas the spread to PM1 cells was dependent on active replication and passive virus transfer. In tissue competition experiments, subtype C isolates could compete with and, in some cases, even win over subtype A and D isolates. However, when the migratory cells from infected tissues were mixed with a susceptible cell line, the subtype C isolates were outcompeted by other subtypes, as observed in experiments with PBMC. These findings suggest that subtype C HIV-1 isolates might have equal transmission fitness but reduced pathogenic fitness relative to other group M HIV-1 isolates.

scholarly journals Baculovirus-Derived Human Immunodeficiency Virus Type 1 Virus-Like Particles Activate Dendritic Cells and Induce Ex Vivo T-Cell Responses

2006 ◽  
Vol 80 (18) ◽  
pp. 9134-9143 ◽  
Author(s):  
L. Buonaguro ◽  
M. L. Tornesello ◽  
M. Tagliamonte ◽  
R. C. Gallo ◽  
L. X. Wang ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Dendritic Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ex Vivo ◽  
Secondary Response ◽  
Virus Like Particles ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We have recently developed a candidate human immunodeficiency virus type 1 (HIV-1) vaccine model based on HIV-1 Pr55 gag virus-like particles (HIV-VLPs), produced in a baculovirus expression system and presenting a gp120 molecule from a Ugandan HIV-1 isolate of clade A (HIV-VLPAs). The HIV-VLPAs show the induction in BALB/c mice of systemic and mucosal neutralizing antibodies as well as cytotoxic T lymphocytes, by intraperitoneal as well as intranasal administration. In the present article, the effects of the baculovirus-expressed HIV-VLPs on human immature monocyte-derived dendritic cells (MDDCs) have been evaluated. The HIV-VLPs efficiently induce maturation and activation of MDDCs and are incorporated into MDDCs preferentially via an actin-dependent macropinocytosis and endocytosis. The HIV-VLP-activated MDDCs show enhanced Th1- and Th2-specific cytokine production, and the effects of HIV-VLPs on MDDCs are not mediated through Toll-like receptors 2 and 4 (TLR2 and -4) signaling. Finally, HIV-VLP-loaded MDDCs are able to induce a primary and secondary response in autologous human CD4+ T cells in an ex vivo immunization assay. Our results on the interaction and processing of baculovirus HIV-VLPs by MDDCs give an insight into the mechanisms underlying the immune response induced by HIV-VLPAs in vivo.

scholarly journals Biological Signature Characteristics of Primary Isolates from Human Immunodeficiency Virus Type 1 Group O in Ex Vivo Human Tonsil Histocultures

2009 ◽  
Vol 83 (20) ◽  
pp. 10494-10503 ◽  
Author(s):  
Silvia Geuenich ◽  
Lars Kaderali ◽  
Ina Allespach ◽  
Serkan Sertel ◽  
Oliver T. Keppler
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ex Vivo ◽  
Replicative Capacity ◽  
Replicative Fitness ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) group M viruses have achieved a global distribution, while HIV-1 group O viruses are endemic only in particular regions of Africa. Here, we evaluated biological characteristics of group O and group M viruses in ex vivo models of HIV-1 infection. The replicative capacity and ability to induce CD4 T-cell depletion of eight group O and seven group M primary isolates were monitored in cultures of human peripheral blood mononuclear cells and tonsil explants. Comparative and longitudinal infection studies revealed HIV-1 group-specific activity patterns: CCR5-using (R5) viruses from group M varied considerably in their replicative capacity but showed similar levels of cytopathicity. In contrast, R5 isolates from group O were relatively uniform in their replicative fitness but displayed a high and unprecedented variability in their potential to deplete CD4 T cells. Two R5 group O isolates were identified that cause massive depletion of CD4 T cells, to an extent comparable to CXCR4-using viruses and not documented for any R5 isolate from group M. Intergroup comparisons found a five- to eightfold lower replicative fitness of isolates from group O than for isolates from group M yet a similar overall intrinsic pathogenicity in tonsil cultures. This study establishes biological ex vivo characteristics of HIV-1 group O primary isolates. The current findings challenge the belief that a grossly reduced replicative fitness or inherently impaired cytopathicity of viruses from this group underlies their low global prevalence.

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