scholarly journals Evaluation of Human Immunodeficiency Virus (HIV) Type 1 Load, CD4 T Cell Level, and Clinical Class as Time‐Fixed and Time‐Varying Markers of Disease Progression in HIV‐1–Infected Children

1999 ◽  
Vol 180 (5) ◽  
pp. 1514-1520 ◽  
Author(s):  
Leslie A. Kalish ◽  
Kenneth McIntosh ◽  
Jennifer S. Read ◽  
Clemente Diaz ◽  
Sheldon H. Landesman ◽  
...  
1997 ◽  
Vol 185 (4) ◽  
pp. 621-628 ◽  
Author(s):  
Ruth I. Connor ◽  
Kristine E. Sheridan ◽  
Daniel Ceradini ◽  
Sunny Choe ◽  
Nathaniel R. Landau

Recent studies have identified several coreceptors that are required for fusion and entry of Human Immunodeficiency Virus type 1 (HIV-1) into CD4+ cells. One of these receptors, CCR5, serves as a coreceptor for nonsyncytium inducing (NSI), macrophage-tropic strains of HIV-1, while another, fusin or CXCR-4, functions as a coreceptor for T cell line–adapted, syncytiuminducing (SI) strains. Using sequential primary isolates of HIV-1, we examined whether viruses using these coreceptors emerge in vivo and whether changes in coreceptor use are associated with disease progression. We found that isolates of HIV-1 from early in the course of infection predominantly used CCR5 for infection. However, in patients with disease progression, the virus expanded its coreceptor use to include CCR5, CCR3, CCR2b, and CXCR-4. Use of CXCR-4 as a coreceptor was only seen with primary viruses having an SI phenotype and was restricted by the env gene of the virus. The emergence of variants using this coreceptor was associated with a switch from NSI to SI phenotype, loss of sensitivity to chemokines, and decreasing CD4+ T cell counts. These results suggest that HIV-1 evolves during the course of infection to use an expanded range of coreceptors for infection, and that this adaptation is associated with progression to AIDS.


2002 ◽  
Vol 76 (5) ◽  
pp. 2298-2305 ◽  
Author(s):  
Bradley H. Edwards ◽  
Anju Bansal ◽  
Steffanie Sabbaj ◽  
Janna Bakari ◽  
Mark J. Mulligan ◽  
...  

ABSTRACT The importance of CD8+ T-cell responses in the control of human immunodeficiency virus type 1 (HIV-1) infection has been demonstrated, yet few studies have been able to correlate these responses with markers of HIV-1 disease progression. This study measured cell-mediated immune responses using peripheral blood mononuclear cells (PBMC) obtained from 27 patients with chronic HIV-1 infection, the majority of whom were off antiretroviral therapy. The ELISPOT assay was used to detect gamma interferon-secreting PBMC after stimulation with overlapping HIV-1 peptides spanning the Gag, Pol, Env, and Nef proteins in addition to the baculovirus-derived p24 and gp160 proteins. All volunteers had responses to at least one HIV-1-specific peptide. All but one of the subjects (96%) responded to the Gag peptide pool, and 86% responded to the Pol and/or Nef peptide pools. The magnitude and the breadth of T-cell responses directed to either the Gag or p24 peptide pools correlated inversely with viral load in plasma (r = −0.60, P < 0.001 and r = −0.52, P < 0.005, respectively) and directly with absolute CD4+ T-cell counts (r = 0.54, P < 0.01 and r = 0.39, P < 0.05, respectively) using the Spearman rank correlation test. Responses to the Pol and integrase peptide pools also correlated with absolute CD4+ T-cell counts (r = 0.45, P < 0.05 and r = 0.49, P < 0.01, respectively). No correlation with markers of disease progression was seen with specific T-cell responses directed toward the Env or Nef peptides. These data serve as strong evidence that major histocompatibility complex class I presentation of Gag peptides is an essential feature for any HIV-1 vaccine designed to elicit optimal CD8+ T-cell responses.


2004 ◽  
Vol 78 (19) ◽  
pp. 10747-10754 ◽  
Author(s):  
Angela Ciuffi ◽  
Gabriela Bleiber ◽  
Miguel Muñoz ◽  
Raquel Martinez ◽  
Corinne Loeuillet ◽  
...  

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.


2009 ◽  
Vol 83 (22) ◽  
pp. 11715-11725 ◽  
Author(s):  
Vijay Sivaraman ◽  
Liguo Zhang ◽  
Eric G. Meissner ◽  
Jerry L. Jeffrey ◽  
Lishan Su

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.


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