scholarly journals The Heptad Repeat 2 Domain Is a Major Determinant for Enhanced Human Immunodeficiency Virus Type 1 (HIV-1) Fusion and Pathogenicity of a Highly Pathogenic HIV-1 Env

2009 ◽  
Vol 83 (22) ◽  
pp. 11715-11725 ◽  
Author(s):  
Vijay Sivaraman ◽  
Liguo Zhang ◽  
Eric G. Meissner ◽  
Jerry L. Jeffrey ◽  
Lishan Su
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Cd4 T Cell ◽  
Heptad Repeat ◽  
Fusion Activity ◽  
Highly Pathogenic ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-mediated depletion of CD4+ lymphocytes in an infected individual is the hallmark of progression to AIDS. However, the mechanism for this depletion remains unclear. To identify mechanisms of HIV-1-mediated CD4 T-cell death, two similar viral isolates obtained from a rapid progressor patient with significantly different pathogenic phenotypes were studied. One isolate (R3A) demonstrates enhanced pathogenesis in both in vivo models and relevant ex vivo lymphoid organ model systems compared to another isolate, R3B. The pathogenic determinants were previously mapped to the V5-gp41 envelope region, correlating functionally with enhanced fusion activity and elevated CXCR4 binding affinity. To further elucidate specific differences between R3A and R3B within the V5-gp41 domains that enhance CD4 depletion, R3A-R3B chimeras to study the V5-gp41 region were developed. Our data demonstrate that six residues in the ectodomain of R3A provide the major determinant for both enhanced Env-cell fusion and pathogenicity. Furthermore, three amino acid differences in the heptad repeat 2 (HR-2) domain of R3A determined its fusion activity and significantly elevated its pathogenic activity. The chimeric viruses with enhanced fusion activity, but not elevated CXCR4 affinity, correlated with high pathogenicity in the thymus organ. We conclude that the functional domain of a highly pathogenic HIV-1 Env is determined by mutations in the HR-2 region that contribute to enhanced fusion and CD4 T-cell depletion.

scholarly journals Entry and Transcription as Key Determinants of Differences in CD4 T-Cell Permissiveness to Human Immunodeficiency Virus Type 1 Infection

2004 ◽  
Vol 78 (19) ◽  
pp. 10747-10754 ◽  
Author(s):  
Angela Ciuffi ◽  
Gabriela Bleiber ◽  
Miguel Muñoz ◽  
Raquel Martinez ◽  
Corinne Loeuillet ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Virus Production ◽  
Cd4 T Cell ◽  
Total Variance ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Isolated primary human cells from different donors vary in their permissiveness—the ability of cells to be infected and sustain the replication of human immunodeficiency virus type 1 (HIV-1). We used replicating HIV-1 and single-cycle lentivirus vectors in a population approach to identify polymorphic steps during viral replication. We found that phytohemagglutinin-stimulated CD4+ CD45RO+ CD57− T cells from healthy blood donors (n = 128) exhibited a 5.2-log-unit range in virus production. For 20 selected donors representing the spectrum of CD4 T-cell permissiveness, we could attribute up to 42% of the total variance in virus production to entry factors and 48% to postentry steps. Efficacy at key intracellular steps of the replicative cycle (reverse transcription, integration, transcription and splicing, translation, and budding and release) varied from 0.71 to 1.45 log units among donors. However, interindividual differences in transcription efficiency alone accounted for 64 to 83% of the total variance in virus production that was attributable to postentry factors. While vesicular stomatitis virus G protein-mediated fusion was more efficacious than CCR5/CD4 entry, the latter resulted in greater transcriptional activity per proviral copy. The phenotype of provirus transcription was stable over time, indicating that it represents a genetic trait.

scholarly journals Levels of Soluble CD40 Ligand (CD154) in Serum Are Increased in Human Immunodeficiency Virus Type 1-Infected Patients and Correlate with CD4+ T-Cell Counts

2002 ◽  
Vol 9 (3) ◽  
pp. 558-561 ◽  
Author(s):  
Nikolaos V. Sipsas ◽  
Petros P. Sfikakis ◽  
Athanasios Kontos ◽  
Theodore Kordossis
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Load ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Cd40 Ligand ◽  
Cd4 T Cell ◽  
Cell Counts ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT CD40 ligand (CD40L or CD154) is a costimulatory molecule expressed mainly on activated CD4+ T cells. Concentrations of the soluble form of CD40L (sCD40L) in serum were determined for a cohort of 77 human immunodeficiency virus type 1 (HIV-1)-infected patients before and after initiation of highly active antiretroviral treatment (HAART) by a quantitative enzyme-linked immunosorbent assay. Circulating sCD40L levels were higher by twofold in untreated patients than in healthy controls (means ± standard deviations [SD]: 1.41 ± 1.48 versus 0.69 ± 0.59 ng/ml; P < 0.001). HIV-1-infected patients classified as CD4 T-cell category 1 had significantly higher sCD40L levels than patients classified as CD4 categories 2 and 3 (mean ± SD: 2.08 ± 1.46 ng/ml versus 1.57 ± 1.58 [category 2] and 0.94 ± 1.25 ng/ml [category 3]; P = 0.046), while no correlation with clinical categories A, B, and C was found. Individual serum sCD40L levels correlated with CD4+ T-cell counts (P = 0.039) but not with viral load, gamma globulin levels, or acute-inflammatory-response markers. After 8 to 12 months of HAART, a further threefold increase of serum sCD40L levels, which paralleled the increase of CD4+ T-cell counts, was observed. These novel findings suggest that sCD40L measurement in HIV-1-infected patients could serve as a new surrogate marker useful in the assessment of treatment efficacy, especially in settings where well-equipped laboratories and funding required for CD4+ T-cell count and viral load measurements are not available.

Once-daily Doravirine in Human Immunodeficiency Virus Type 1–Infected, Antiretroviral-naive Adults: An Integrated Efficacy Analysis

2019 ◽  
Vol 70 (7) ◽  
pp. 1344-1352 ◽  
Author(s):  
Chloe Orkin ◽  
Jean-Michel Molina ◽  
Johan Lombaard ◽  
Edwin DeJesus ◽  
Anthony Rodgers ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Cell Count ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cd4 T Cell ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Cd4 T Cell Count

AbstractBackgroundDoravirine (DOR) demonstrated noninferior efficacy to darunavir plus ritonavir (DRV+r) and efavirenz (EFV) in 2 ongoing phase 3 trials: DRIVE-FORWARD (NCT02275780) and DRIVE-AHEAD (NCT02403674).MethodsThis prespecified analysis pooled efficacy data through the first 48 weeks of DRIVE-FORWARD and DRIVE-AHEAD from the DOR groups (DOR/lamivudine [3TC]/tenofovir disoproxil fumarate [TDF] or DOR [100 mg daily] with emtricitabine [FTC]/TDF or abacavir [ABC]/3TC [n = 747]) compared with DRV+r (800/100 mg daily) with FTC/TDF or ABC/3TC (n = 383) or EFV/FTC/TDF (600/200/300 mg daily; n = 364). Efficacy assessments included the proportion of participants with human immunodeficiency virus type 1 (HIV-1) RNA &lt;50 copies/mL and change in CD4+ T-cell count.ResultsAt week 48, DOR demonstrated noninferior efficacy to DRV+r and EFV, with 84.1% of DOR-treated participants achieving HIV-1 RNA &lt;50 copies/mL compared with 79.9% of the DRV+r and 80.8% of the EFV groups. Results were similar across demographic/prognostic subpopulations, including baseline plasma HIV-1 RNA, gender, race, and HIV-1 subtype. Mean increases from baseline in CD4+ T-cell count through 48 weeks were 195.5 cells/mm3 for DOR, 185.6 cells/mm3 for DRV+r, and 188.4 cells/mm3 for EFV/FTC/TDF.ConclusionsDOR, as a single entity (in combination with other antiretroviral agents) and as a fixed-dose combination (DOR/3TC/TDF), demonstrated noninferior efficacy to DRV+r and EFV as assessed by the proportion of HIV-1-infected, treatment-naive adults with HIV-1 RNA &lt;50 copies/mL.Clinical Trials RegistrationNCT02275780 and NCT02403674.

scholarly journals Mutually Exclusive T-Cell Receptor Induction and Differential Susceptibility to Human Immunodeficiency Virus Type 1 Mutational Escape Associated with a Two-Amino-Acid Difference between HLA Class I Subtypes

2006 ◽  
Vol 81 (4) ◽  
pp. 1619-1631 ◽  
Author(s):  
Xu G. Yu ◽  
Mathias Lichterfeld ◽  
Senica Chetty ◽  
Katie L. Williams ◽  
Stanley K. Mui ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Hla Class I ◽  
Viral Escape ◽  
Class I ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The relative contributions of HLA alleles and T-cell receptors (TCRs) to the prevention of mutational viral escape are unclear. Here, we examined human immunodeficiency virus type 1 (HIV-1)-specific CD8+ T-cell responses restricted by two closely related HLA class I alleles, B*5701 and B*5703, that differ by two amino acids but are both associated with a dominant response to the same HIV-1 Gag epitope KF11 (KAFSPEVIPMF). When this epitope is presented by HLA-B*5701, it induces a TCR repertoire that is highly conserved among individuals, cross-recognizes viral epitope variants, and is rarely associated with mutational escape. In contrast, KF11 presented by HLA-B*5703 induces an entirely different, more heterogeneous TCR β-chain repertoire that fails to recognize specific KF11 escape variants which frequently arise in clade C-infected HLA-B*5703+ individuals. These data show the influence of HLA allele subtypes on TCR selection and indicate that extensive TCR diversity is not a prerequisite to prevention of allowable viral mutations.

scholarly journals Enhanced immunogenicity using an alphavirus replicon DNA vaccine against human immunodeficiency virus type 1

2005 ◽  
Vol 86 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Eva K. L. Nordström ◽  
Mattias N. E. Forsell ◽  
Christina Barnfield ◽  
Eivor Bonin ◽  
Tomas Hanke ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Dna Vaccine ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Semliki Forest Virus ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Hiv 1

With the human immunodeficiency virus type 1 (HIV-1) epidemic expanding at increasing speed, development of a safe and effective vaccine remains a high priority. One of the most central vaccine platforms considered is plasmid DNA. However, high doses of DNA and several immunizations are typically needed to achieve detectable T-cell responses. In this study, a Semliki Forest virus replicon DNA vaccine designed for human clinical trials, DREP.HIVA, encoding an antigen that is currently being used in human trials in the context of a conventional DNA plasmid, pTHr.HIVA, was generated. It was shown that a single immunization of DREP.HIVA stimulated HIV-1-specific T-cell responses in mice, suggesting that the poor immunogenicity of conventional DNA vaccines may be enhanced by using viral replicon-based plasmid systems. The results presented here support the evaluation of Semliki Forest virus replicon DNA vaccines in non-human primates and in clinical studies.

scholarly journals Ontogeny and Specificities of Mucosal and Blood Human Immunodeficiency Virus Type 1-Specific CD8+ Cytotoxic T Lymphocytes

2003 ◽  
Vol 77 (1) ◽  
pp. 291-300 ◽  
Author(s):  
L. Musey ◽  
Y. Ding ◽  
J. Cao ◽  
J. Lee ◽  
C. Galloway ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cytotoxic T Lymphocyte ◽  
Infected Individual ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Induction of adaptive immunity to human immunodeficiency virus type 1 (HIV-1) at the mucosal site of transmission is poorly understood but crucial in devising strategies to control and prevent infection. To gain further understanding of HIV-1-specific T-cell mucosal immunity, we established HIV-1-specific CD8+ cytotoxic T-lymphocyte (CTL) cell lines and clones from the blood, cervix, rectum, and semen of 12 HIV-1-infected individuals and compared their specificities, cytolytic function, and T-cell receptor (TCR) clonotypes. Blood and mucosal CD8+ CTL had common HIV-1 epitope specificities and major histocompatibility complex restriction patterns. Moreover, both systemic and mucosal CTL lysed targets with similar efficiency, primarily through the perforin-dependent pathway in in vitro studies. Sequence analysis of the TCRβ VDJ region revealed in some cases identical HIV-1-specific CTL clones in different compartments in the same HIV-1-infected individual. These results clearly establish that a subset of blood and mucosal HIV-1-specific CTL can have a common origin and can traffic between anatomically distinct compartments. Thus, these effectors can provide immune surveillance at the mucosa, where rapid responses are needed to contain HIV-1 infection.

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