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A topical microbicide gel formulation of CCR5 antagonist maraviroc prevents HIV-1 vaginal transmission in humanized RAG-hu mice.

Neff CP, Kurisu T, Ndolo T, Fox K, Akkina R - PLoS ONE (2011)

Bottom Line: Therefore, a small animal model that facilitates rapid evaluation of potential candidates for their preliminary efficacy is urgently needed in the microbicide field.Here in these proof-of-concept studies, we extended this system for topical microbicide testing using HIV-1 as the challenge virus.Maraviroc, a clinically approved CCR5 inhibitor drug for HIV treatment, was formulated as a microbicide gel at 5 mM concentration in 2.2% hydroxyl ethyl cellulose.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America.

ABSTRACT
For prevention of HIV infection many currently licensed anti-HIV drugs and new ones in the pipeline show potential as topically applied microbicides. While macaque models have been the gold standard for in vivo microbicide testing, they are expensive and sufficient numbers are not available. Therefore, a small animal model that facilitates rapid evaluation of potential candidates for their preliminary efficacy is urgently needed in the microbicide field. We previously demonstrated that RAG-hu humanized mouse model permits HIV-1 mucosal transmission via both vaginal and rectal routes and that oral pre-exposure chemo-prophylactic strategies could be tested in this system. Here in these proof-of-concept studies, we extended this system for topical microbicide testing using HIV-1 as the challenge virus. Maraviroc, a clinically approved CCR5 inhibitor drug for HIV treatment, was formulated as a microbicide gel at 5 mM concentration in 2.2% hydroxyl ethyl cellulose. Female RAG-hu mice were challenged vaginally with HIV-1 an hour after intravaginal application of the maraviroc gel. Our results showed that maraviroc gel treated mice were fully protected against vaginal HIV-1 challenge in contrast to placebo gel treated mice which all became infected. These findings highlight the utility of the humanized mouse models for microbicide testing and, together with the recent data from macaque studies, suggest that maraviroc is a promising candidate for future microbicide clinical trials in the field.

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RNA and DNA viral loads in mice administered with maraviroc.RAG-hu mice were challenged by vaginal route after an hour after vaginal application of maraviroc as described in Methods. Blood was collected weekly. Viral RNA was extracted from the plasma fraction and DNA was extracted from the cellular fraction. Viral RNA and DNA loads were determined by Q-PCR as described in methods. The dotted lines represent limits of PCR detection. A. RNA viral loads B. DNA viral loads.
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pone-0020209-g002: RNA and DNA viral loads in mice administered with maraviroc.RAG-hu mice were challenged by vaginal route after an hour after vaginal application of maraviroc as described in Methods. Blood was collected weekly. Viral RNA was extracted from the plasma fraction and DNA was extracted from the cellular fraction. Viral RNA and DNA loads were determined by Q-PCR as described in methods. The dotted lines represent limits of PCR detection. A. RNA viral loads B. DNA viral loads.

Mentions: We have previously established that RAG-hu humanize mice permit mucosal HIV-1 infection by both vaginal and rectal routes [15] and have recently shown that oral administration of anti-retrovirals, maraviroc and raltegravir protect these mice against HIIV-1 vaginal challenge [26]. Here we evaluated maraviroc as a topically applied microbicide gel to prevent HIV-1 sexual transmission. To assess efficacy, maraviroc was administered vaginally one hour prior to vaginal viral challenge to mimic a coital dependant context. Mouse plasma and blood cellular fractions were analyzed by Q-PCR weekly and bi-weekly respectively to ascertain the HIV-1 infection status. Our results showed that the placebo-gel administered and HIV-1 challenged mice started becoming virus positive by the third week with all of them infected by the 5th week post challenge (Fig. 1). Persistent viremia in plasma and proviral loads in the cellular fractions were observed throughout the evaluation period with viral loads reaching up to 106 RNA copies/ml (Fig. 2A) and proviral DNA copies at 105 DNA copies/ml (Fig. 2B). In contrast, none of the maraviroc treated mice became infected (Fig. 1). No evidence of infection was seen throughout the 16 week observation period as evaluated by either RNA or DNA PCR (Fig. 2A and B). These data taken together suggest that vaginal administration of maraviroc fully protects mice against HIV-1 vaginal challenge.


A topical microbicide gel formulation of CCR5 antagonist maraviroc prevents HIV-1 vaginal transmission in humanized RAG-hu mice.

Neff CP, Kurisu T, Ndolo T, Fox K, Akkina R - PLoS ONE (2011)

RNA and DNA viral loads in mice administered with maraviroc.RAG-hu mice were challenged by vaginal route after an hour after vaginal application of maraviroc as described in Methods. Blood was collected weekly. Viral RNA was extracted from the plasma fraction and DNA was extracted from the cellular fraction. Viral RNA and DNA loads were determined by Q-PCR as described in methods. The dotted lines represent limits of PCR detection. A. RNA viral loads B. DNA viral loads.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3105981&req=5

pone-0020209-g002: RNA and DNA viral loads in mice administered with maraviroc.RAG-hu mice were challenged by vaginal route after an hour after vaginal application of maraviroc as described in Methods. Blood was collected weekly. Viral RNA was extracted from the plasma fraction and DNA was extracted from the cellular fraction. Viral RNA and DNA loads were determined by Q-PCR as described in methods. The dotted lines represent limits of PCR detection. A. RNA viral loads B. DNA viral loads.
Mentions: We have previously established that RAG-hu humanize mice permit mucosal HIV-1 infection by both vaginal and rectal routes [15] and have recently shown that oral administration of anti-retrovirals, maraviroc and raltegravir protect these mice against HIIV-1 vaginal challenge [26]. Here we evaluated maraviroc as a topically applied microbicide gel to prevent HIV-1 sexual transmission. To assess efficacy, maraviroc was administered vaginally one hour prior to vaginal viral challenge to mimic a coital dependant context. Mouse plasma and blood cellular fractions were analyzed by Q-PCR weekly and bi-weekly respectively to ascertain the HIV-1 infection status. Our results showed that the placebo-gel administered and HIV-1 challenged mice started becoming virus positive by the third week with all of them infected by the 5th week post challenge (Fig. 1). Persistent viremia in plasma and proviral loads in the cellular fractions were observed throughout the evaluation period with viral loads reaching up to 106 RNA copies/ml (Fig. 2A) and proviral DNA copies at 105 DNA copies/ml (Fig. 2B). In contrast, none of the maraviroc treated mice became infected (Fig. 1). No evidence of infection was seen throughout the 16 week observation period as evaluated by either RNA or DNA PCR (Fig. 2A and B). These data taken together suggest that vaginal administration of maraviroc fully protects mice against HIV-1 vaginal challenge.

Bottom Line: Therefore, a small animal model that facilitates rapid evaluation of potential candidates for their preliminary efficacy is urgently needed in the microbicide field.Here in these proof-of-concept studies, we extended this system for topical microbicide testing using HIV-1 as the challenge virus.Maraviroc, a clinically approved CCR5 inhibitor drug for HIV treatment, was formulated as a microbicide gel at 5 mM concentration in 2.2% hydroxyl ethyl cellulose.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America.

ABSTRACT
For prevention of HIV infection many currently licensed anti-HIV drugs and new ones in the pipeline show potential as topically applied microbicides. While macaque models have been the gold standard for in vivo microbicide testing, they are expensive and sufficient numbers are not available. Therefore, a small animal model that facilitates rapid evaluation of potential candidates for their preliminary efficacy is urgently needed in the microbicide field. We previously demonstrated that RAG-hu humanized mouse model permits HIV-1 mucosal transmission via both vaginal and rectal routes and that oral pre-exposure chemo-prophylactic strategies could be tested in this system. Here in these proof-of-concept studies, we extended this system for topical microbicide testing using HIV-1 as the challenge virus. Maraviroc, a clinically approved CCR5 inhibitor drug for HIV treatment, was formulated as a microbicide gel at 5 mM concentration in 2.2% hydroxyl ethyl cellulose. Female RAG-hu mice were challenged vaginally with HIV-1 an hour after intravaginal application of the maraviroc gel. Our results showed that maraviroc gel treated mice were fully protected against vaginal HIV-1 challenge in contrast to placebo gel treated mice which all became infected. These findings highlight the utility of the humanized mouse models for microbicide testing and, together with the recent data from macaque studies, suggest that maraviroc is a promising candidate for future microbicide clinical trials in the field.

Show MeSH
Related in: MedlinePlus