scholarly journals Cytotoxicological Analysis of a gp120 Binding Aptamer with Cross-Clade Human Immunodeficiency Virus Type 1 Entry Inhibition Properties: Comparison to Conventional Antiretrovirals

2009 ◽  
Vol 53 (7) ◽  
pp. 3056-3064 ◽  
Author(s):  
Walter Rangel Lopes de Campos ◽  
Dayaneethie Coopusamy ◽  
Lynn Morris ◽  
Bongani M. Mayosi ◽  
Makobetsa Khati
Keyword(s):  
Human Immunodeficiency Virus ◽  
Mitochondrial Dna ◽  
Reverse Transcriptase ◽  
Mononuclear Cells ◽  
Nuclear Dna ◽  
Cell Types ◽  
Reverse Transcriptase Inhibitors ◽  
Human Cardiomyocytes ◽  
Immunodeficiency Virus

ABSTRACT The long-term cumulative cytotoxicity of antiretrovirals (ARVs) is among the major causes of treatment failure in patients infected with human immunodeficiency virus (HIV) and patients with AIDS. This calls for the development of novel ARVs with less or no cytotoxicity. In the present study, we compared the cytotoxic effects of a cross-clade HIV type 1-neutralizing aptamer called B40 with those of a panel of nonnucleoside reverse transcriptase inhibitors (NNRTIs), nucleoside reverse transcriptase inhibitors (NRTIs), protease inhibitors (PIs), and the entry inhibitor (EI) T20 in human cardiomyocytes and peripheral blood mononuclear cells. An initial screen in which cell death was used as the end-point measurement revealed that the B40 aptamer and T20 were the only test molecules that had insignificant (0.61 < P < 0.92) effects on the viability of both cell types at the maximum concentration used. PIs were the most toxic class (0.001 < P < 0.00001), followed by NNRTIs and NRTIs (0.1 < P < 0.00001). Further studies revealed that B40 and T20 did not interfere with the cellular activity of the cytochrome P450 3A4 enzyme (0.78 < P < 0.24) or monoamine oxidases A and B (0.83 < P < 0.56) when the activities of the enzymes were compared to those in untreated controls of both cell types. Mitochondrion-initiated cellular toxicity is closely associated with the use of ARVs. Therefore, we used real-time PCR to quantify the relative ratio of mitochondrial DNA to nuclear DNA as a marker of toxicity. The levels of mitochondrial DNA remained unchanged in cells exposed to the B40 aptamer compared to the levels in untreated control cells (0.5 > P > 0.06). These data support the development of B40 and related EI aptamers as new ARVs with no cytotoxicity at the estimated potential therapeutic dose.

scholarly journals CD4-Negative Cells Bind Human Immunodeficiency Virus Type 1 and Efficiently Transfer Virus to T Cells

2000 ◽  
Vol 74 (18) ◽  
pp. 8550-8557 ◽  
Author(s):  
Gene G. Olinger ◽  
Mohammed Saifuddin ◽  
Gregory T. Spear
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Mononuclear Cells ◽  
Cell Types ◽  
Virus Binding ◽  
Peripheral Blood Mononuclear ◽  
Human Immunodeficiency Virus Strain ◽  
Immunodeficiency Virus

ABSTRACT The ability of human immunodeficiency virus strain MN (HIVMN), a T-cell line-adapted strain of HIV, and X4 and R5 primary isolates to bind to various cell types was investigated. In general, HIVMN bound to cells at higher levels than did the primary isolates. Virus bound to both CD4-positive (CD4+) and CD4-negative (CD4−) cells, including neutrophils, Raji cells, tonsil mononuclear cells, erythrocytes, platelets, and peripheral blood mononuclear cells (PBMC), although virus bound at significantly higher levels to PBMC. However, there was no difference in the amount of HIV that bound to CD4-enriched or CD4-depleted PBMC. Virus bound to CD4− cells was up to 17 times more infectious for T cells in cocultures than was the same amount of cell-free virus. Virus bound to nucleated cells was significantly more infectious than virus bound to erythrocytes or platelets. The enhanced infection of T cells by virus bound to CD4− cells was not due to stimulatory signals provided by CD4− cells or infection of CD4− cells. However, anti-CD18 antibody substantially reduced the enhanced virus replication in T cells, suggesting that virus that bound to the surface of CD4−cells is efficiently passed to CD4+ T cells during cell-cell adhesion. These studies show that HIV binds at relatively high levels to CD4− cells and, once bound, is highly infectious for T cells. This suggests that virus binding to the surface of CD4− cells is an important route for infection of T cells in vivo.

scholarly journals Characterization and Structural Analysis of Novel Mutations in Human Immunodeficiency Virus Type 1 Reverse Transcriptase Involved in the Regulation of Resistance to Nonnucleoside Inhibitors

2007 ◽  
Vol 81 (20) ◽  
pp. 11507-11519 ◽  
Author(s):  
Francesca Ceccherini-Silberstein ◽  
Valentina Svicher ◽  
Tobias Sing ◽  
Anna Artese ◽  
Maria Mercedes Santoro ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Reverse Transcriptase Inhibitors ◽  
Data Set ◽  
Nnrti Resistance ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Resistance to antivirals is a complex and dynamic phenomenon that involves more mutations than are currently known. Here, we characterize 10 additional mutations (L74V, K101Q, I135M/T, V179I, H221Y, K223E/Q, and L228H/R) in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase which are involved in the regulation of resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs). These mutations are strongly associated with NNRTI failure and strongly correlate with the classical NNRTI resistance mutations in a data set of 1,904 HIV-1 B-subtype pol sequences from 758 drug-naïve patients, 592 nucleoside reverse transcriptase inhibitor (NRTI)-treated but NNRTI-naïve patients, and 554 patients treated with both NRTIs and NNRTIs. In particular, L74V and H221Y, positively correlated with Y181C, were associated with an increase in Y181C-mediated resistance to nevirapine, while I135M/T mutations, positively correlated with K103N, were associated with an increase in K103N-mediated resistance to efavirenz. In addition, the presence of the I135T polymorphism in NNRTI-naïve patients significantly correlated with the appearance of K103N in cases of NNRTI failure, suggesting that I135T may represent a crucial determinant of NNRTI resistance evolution. Molecular dynamics simulations show that I135T can contribute to the stabilization of the K103N-induced closure of the NNRTI binding pocket by reducing the distance and increasing the number of hydrogen bonds between 103N and 188Y. H221Y also showed negative correlations with type 2 thymidine analogue mutations (TAM2s); its copresence with the TAM2s was associated with a higher level of zidovudine susceptibility. Our study reinforces the complexity of NNRTI resistance and the significant interplay between NRTI- and NNRTI-selected mutations. Mutations beyond those currently known to confer resistance should be considered for a better prediction of clinical response to reverse transcriptase inhibitors and for the development of more efficient new-generation NNRTIs.

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