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.

scholarly journals Beyond Help: Direct Effector Functions of Human Immunodeficiency Virus Type 1-Specific CD4+ T Cells

2004 ◽  
Vol 78 (16) ◽  
pp. 8844-8851 ◽  
Author(s):  
Philip J. Norris ◽  
Howell F. Moffett ◽  
Otto O. Yang ◽  
Daniel E. Kaufmann ◽  
Margaret J. Clark ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ex Vivo ◽  
Effector Functions ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The immune correlates of protection in human immunodeficiency virus type 1 (HIV-1) infection remain poorly defined, particularly the contribution of CD4+ T cells. Here we explore the effector functions of HIV-1-specific CD4+ T cells. We demonstrate HIV-1 p24-specific CD4+-T-cell cytolytic activity in peripheral blood mononuclear cells directly ex vivo and after enrichment by antigen-specific stimulation. We further show that in a rare long-term nonprogressor, both an HIV-1-specific CD4+-T-cell clone and CD4+ T cells directly ex vivo exert potent suppression of HIV-1 replication. Suppression of viral replication was dependent on cell-cell contact between the effector CD4+ T cells and the target cells. While the antiviral effector activity of CD8+ T cells has been well documented, these results strongly suggest that HIV-1-specific CD4+ T cells are capable of directly contributing to antiviral immunity.

scholarly journals Replicative Fitness of Protease Inhibitor-Resistant Mutants of Human Immunodeficiency Virus Type 1

1999 ◽  
Vol 73 (5) ◽  
pp. 3744-3752 ◽  
Author(s):  
Javier Martinez-Picado ◽  
Anu V. Savara ◽  
Lorraine Sutton ◽  
Richard T. D’Aquila
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Replicative Capacity ◽  
Replicative Fitness ◽  
Immunodeficiency Virus ◽  
Resistant Mutants ◽  
Hiv 1

ABSTRACT The relative replicative fitness of human immunodeficiency virus type 1 (HIV-1) mutants selected by different protease inhibitors (PIs) in vivo was determined. Each mutant was compared to wild type (WT), NL4-3, in the absence of drugs by several methods, including clonal genotyping of cultures infected with two competing viral variants, kinetics of viral antigen production, and viral infectivity/virion particle ratios. A nelfinavir-selected protease D30N substitution substantially decreased replicative capacity relative to WT, while a saquinavir-selected L90M substitution moderately decreased fitness. The D30N mutant virus was also outcompeted by the L90M mutant in the absence of drugs. A major natural polymorphism of the HIV-1 protease, L63P, compensated well for the impairment of fitness caused by L90M but only slightly improved the fitness of D30N. Multiply substituted indinavir-selected mutants M46I/L63P/V82T/I84V and L10R/M46I/L63P/V82T/I84V were just as fit as WT. These results indicate that the mutations which are usually initially selected by nelfinavir and saquinavir, D30N and L90M, respectively, impair fitness. However, additional mutations may improve the replicative capacity of these and other drug-resistant mutants. Hypotheses based on the greater fitness impairment of the nelfinavir-selected D30N mutant are suggested to explain observations that prolonged responses to delayed salvage regimens, including alternate PIs, may be relatively common after nelfinavir failure.

scholarly journals Hemofiltrate CC Chemokine 1[9-74] Causes Effective Internalization of CCR5 and Is a Potent Inhibitor of R5-Tropic Human Immunodeficiency Virus Type 1 Strains in Primary T Cells and Macrophages

2002 ◽  
Vol 46 (4) ◽  
pp. 982-990 ◽  
Author(s):  
Jan Münch ◽  
Ludger Ständker ◽  
Stefan Pöhlmann ◽  
Frédéric Baribaud ◽  
Armin Papkalla ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Proteolytic Processing ◽  
Cell Surface Expression ◽  
Cc Chemokine ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Proteolytic processing of the abundant plasmatic human CC chemokine 1 (HCC-1) generates a truncated form, HCC-1[9-74], which is a potent agonist of CCR1, CCR3, and CCR5; promotes calcium influx and chemotaxis of T lymphoblasts, monocytes, and eosinophils; and inhibits infection by CCR5-tropic human immunodeficiency virus type 1 (HIV-1) isolates. In the present study we demonstrate that HCC-1[9-74] interacts with the second external loop of CCR5 and inhibits replication of CCR5-tropic HIV-1 strains in both primary T cells and monocyte-derived macrophages. Low concentrations of the chemokine, however, frequently enhanced the replication of CCR5-tropic HIV-1 isolates but not the replication of X4-tropic HIV-1 isolates. Only HCC-1[9-74] and HCC-1[10-74], but not other HCC-1 length variants, displayed potent anti-HIV-1 activities. Fluorescence-activated cell sorter analysis revealed that HCC-1[9-74] caused up to 75% down-regulation of CCR5 cell surface expression, whereas RANTES (regulated on activation, normal T-cell expressed and secreted) achieved a reduction of only about 40%. Studies performed with green fluorescent protein-tagged CCR5 confirmed that both HCC-1[9-74] and RANTES, but not full-length HCC-1, mediated specific internalization of the CCR5 HIV-1 entry cofactor. Our results demonstrate that the interaction with HCC-1[9-74] causes effective intracellular sequestration of CCR5, but they also indicate that the effect of HCC-1[9-74] on viral replication is subject to marked cell donor- and HIV-1 isolate-dependent variations.

scholarly journals Nef Induces Multiple Genes Involved in Cholesterol Synthesis and Uptake in Human Immunodeficiency Virus Type 1-Infected T Cells

2005 ◽  
Vol 79 (15) ◽  
pp. 10053-10058 ◽  
Author(s):  
Angélique B. van ′t Wout ◽  
J. Victor Swain ◽  
Michael Schindler ◽  
Ushnal Rao ◽  
Melissa S. Pathmajeyan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cholesterol Synthesis ◽  
Cholesterol Biosynthesis ◽  
Acetate Incorporation ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Several recent reports indicate that cholesterol might play an important role in human immunodeficiency virus type 1 (HIV-1) replication. We investigated the effects of HIV-1 infection on cholesterol biosynthesis and uptake using microarrays. HIV-1 increased gene expression of cholesterol genes in both transformed T-cell lines and primary CD4+ T cells. Consistent with our microarray data, 14C-labeled mevalonate and acetate incorporation was increased in HIV-1-infected cells. Our data also demonstrate that changes in cholesterol biosynthesis and uptake are only observed in the presence of functional Nef, suggesting that increased cholesterol synthesis may contribute to Nef-mediated enhancement of virion infectivity and viral replication.

scholarly journals Differential Transmission of Human Immunodeficiency Virus Type 1 by Distinct Subsets of Effector Dendritic Cells

2002 ◽  
Vol 76 (15) ◽  
pp. 7812-7821 ◽  
Author(s):  
Rogier W. Sanders ◽  
Esther C. de Jong ◽  
Christopher E. Baldwin ◽  
Joost H. N. Schuitemaker ◽  
Martien L. Kapsenberg ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Dendritic Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Virus Transmission ◽  
Viral Envelope ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Dendritic cells (DC) support human immunodeficiency virus type 1 (HIV-1) transmission by capture of the virus particle in the mucosa and subsequent transport to the draining lymph node, where HIV-1 is presented to CD4+ Th cells. Virus transmission involves a high-affinity interaction between the DC-specific surface molecule DC-SIGN and the viral envelope glycoprotein gp120 and subsequent internalization of the virus, which remains infectious. The mechanism of viral transmission from DC to T cells is currently unknown. Sentinel immature DC (iDC) develop into Th1-promoting effector DC1 or Th2-promoting DC2, depending on the activation signals. We studied the ability of these effector DC subsets to support HIV-1 transmission in vitro. Compared with iDC, virus transmission is greatly upregulated for the DC1 subset, whereas DC2 cells are inactive. Increased transmission by DC1 correlates with increased expression of ICAM-1, and blocking studies confirm that ICAM-1 expression on DC is important for HIV transmission. The ICAM-1-LFA-1 interaction is known to be important for immunological cross talk between DC and T cells, and our results indicate that this cell-cell contact is exploited by HIV-1 for efficient transmission.

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 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 Human Immunodeficiency Virus Type 1 Evades T-Helper Responses by Exploiting Antibodies That Suppress Antigen Processing

2004 ◽  
Vol 78 (14) ◽  
pp. 7645-7652 ◽  
Author(s):  
Peter C. Chien ◽  
Sandra Cohen ◽  
Michael Tuen ◽  
James Arthos ◽  
Pei-de Chen ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Antigen Processing ◽  
T Helper ◽  
Peptide Epitopes ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT T-helper responses are important for controlling chronic viral infections, yet T-helper responses specific to human immunodeficiency virus type 1 (HIV-1), particularly to envelope glycoproteins, are lacking in the vast majority of HIV-infected individuals. It was previously shown that the presence of antibodies to the CD4-binding domain (CD4bd) of HIV-1 glycoprotein 120 (gp120) prevents T-helper responses to gp120, but their suppressive mechanisms were undefined (C. E. Hioe et al., J. Virol. 75:10950-10957, 2001). The present study demonstrates that gp120, when complexed to anti-CD4bd antibodies, becomes more resistant to proteolysis by lysosomal enzymes from antigen-presenting cells such that peptide epitopes are not released and presented efficiently by major histocompatibility complex class II molecules to gp120-specific CD4 T cells. Antibodies to other gp120 regions do not confer this effect. Thus, HIV may evade anti-viral T-helper responses by inducing and exploiting antibodies that conceal the virus envelope antigens from T cells.

scholarly journals Role of Cell Surface Glycosaminoglycans of Human T Cells in Human Immunodeficiency Virus Type-1 (HIV-1) Infection

1996 ◽  
Vol 40 (11) ◽  
pp. 827-835 ◽  
Author(s):  
Yukako Ohshiro ◽  
Tsutomu Murakami ◽  
Kazuhiro Matsuda ◽  
Kiyoshi Nishioka ◽  
Keiichi Yoshida ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Human T Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

scholarly journals LFA-1 Is a Key Determinant for Preferential Infection of Memory CD4+ T Cells by Human Immunodeficiency Virus Type 1

2005 ◽  
Vol 79 (21) ◽  
pp. 13714-13724 ◽  
Author(s):  
Mélanie R. Tardif ◽  
Michel J. Tremblay
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cell Subset ◽  
T Cell Subsets ◽  
Virus Infectivity ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Memory CD4+ T cells are considered a stable latent reservoir for human immunodeficiency virus type 1 (HIV-1) and a barrier to eradication of this retroviral infection in patients under therapy. It has been shown that memory CD4+ T cells are preferentially infected with HIV-1, but the exact mechanism(s) responsible for this higher susceptibility remains obscure. Previous findings indicate that incorporation of host-derived intercellular adhesion molecule 1 (ICAM-1) in HIV-1 increases virus infectivity. To measure the putative involvement of virus-anchored ICAM-1 in the preferential infection of memory cells by HIV-1, quiescent and activated naive and memory T-cell subsets were exposed to isogenic virions either lacking or bearing ICAM-1. Memory CD4+ T cells were found to be more susceptible than naive CD4+ T cells to infection with ICAM-1-bearing virions, as exemplified by a more important virus replication, an increase in integrated viral DNA copies, and a more efficient entry process. Interactions between virus-associated host ICAM-1 and cell surface LFA-1 under a cluster formation seem to be responsible for the preferential HIV-1 infection of the memory cell subset. Altogether, these data shed light on a potential mechanism by which HIV-1 preferentially targets long-lived memory CD4+ T cells.

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