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Lilin Lai,
Sue-Fen Kwa,
Pamela A Kozlowski,
David C Montefiori,
Tracy L Nolen,
Michael G Hudgens,
Welkin E Johnson,
Guido Ferrari,
Vanessa M Hirsch,
Barbara K Felber,
George N Pavlakis,
Patricia L Earl,
Bernard Moss,
Rama Rao Amara,
Harriet L Robinson
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ABSTRACT: Vaccine regimens using different agents for priming and boosting have become popular for enhancing T cell and Ab responses elicited by candidate HIV/AIDS vaccines. Here we use a simian model to evaluate immunogenicity and protective efficacy of a recombinant modified vaccinia Ankara (MVA) vaccine in the presence and absence of a recombinant DNA prime. The simian vaccines and regimens represent prototypes for candidate HIV vaccines currently undergoing clinical testing.
Recombinant DNA and MVA immunogens expressed simian immunodeficiency virus (SIV)mac239 Gag, PR, RT, and Env sequences. Vaccine schedules tested inoculations of MVA at months 0, 2, and 6 (MMM regimen) or priming with DNA at months 0 and 2 and boosting with MVA at months 4 and 6 (DDMM regimen). Twelve weekly rectal challenges with the heterologous SIV smE660 were initiated at 6 months following the last immunization.
Both regimens elicited similar 61-64% reductions in the per challenge risk of SIVsmE660 transmission despite raising different patterns of immune responses. The DDMM regimen elicited higher magnitudes of CD4 T cells whereas the MMM regimen elicited higher titers and greater avidity Env-specific IgG and more frequent and higher titer SIV-specific IgA in rectal secretions. Both regimens elicited similar magnitudes of CD8 T cells. Magnitudes of T cell responses, specific activities of rectal IgA Ab, and the tested specificities for neutralization and antibody-dependent cellular cytotoxicity did not correlate with risk of infection. However, the avidity of Env-specific IgG had a strong correlation with the per challenge risk of acquisition, but only for the DDMM group.
We conclude that for the tested immunogens in rhesus macaques, the simpler MMM regimen is as protective as the more complex DDMM regimen.
Vaccine 12/2011; 30(9):1737-45. · 3.77 Impact Factor
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Lilin Lai,
Suefen Kwa,
Pamela A Kozlowski,
David C Montefiori,
Guido Ferrari,
Welkin E Johnson,
Vanessa Hirsch,
Francois Villinger,
Lakshmi Chennareddi,
Patricia L Earl,
Bernard Moss,
Rama Rao Amara,
Harriet L Robinson
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ABSTRACT: A simian immunodeficiency virus (SIV) vaccine coexpressing granulocyte-macrophage colony stimulating factor (GM-CSF) prevented infection in 71% of macaques that received 12 rectal challenges. The SIVsmE660 challenge had the tropism of incident human immunodeficiency virus (HIV) infections and a similar genetic distance from the SIV239 vaccine as intraclade HIV isolates. The heterologous prime-boost vaccine regimen used recombinant DNA for priming and recombinant modified vaccinia Ankara for boosting. Co-expression of GM-CSF in the DNA prime enhanced the avidity of elicited immunoglobulin G for SIV envelope glycoproteins, the titers of neutralizing antibody for easy-to-neutralize SIV isolates, and antibody-dependent cellular cytotoxicity. Impressively, the co-expressed GM-CSF increased vaccine-induced prevention of infection from 25% in the non-GM-CSF co-expressing vaccine group to 71% in the GM-CSF co-expressing vaccine group. The prevention of infection showed a strong correlation with the avidity of the elicited Env-specific antibody for the Env of the SIVsmE660 challenge virus (r = 0.9; P < .0001).
The Journal of Infectious Diseases 07/2011; 204(1):164-73. · 6.41 Impact Factor
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Paul A Goepfert,
Marnie L Elizaga,
Alicia Sato,
Li Qin,
Massimo Cardinali,
Christine M Hay,
John Hural,
Stephen C DeRosa,
Olivier D DeFawe,
Georgia D Tomaras,
David C Montefiori,
Yongxian Xu, Lilin Lai,
Spyros A Kalams,
Lindsey R Baden,
Sharon E Frey,
William A Blattner,
Linda S Wyatt,
Bernard Moss,
Harriet L Robinson
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ABSTRACT: Recombinant DNA and modified vaccinia virus Ankara (rMVA) vaccines represent a promising approach to an HIV/AIDS vaccine. This Phase 1 clinical trial compared the safety and immunogenicity of a rMVA vaccine administered with and without DNA vaccine priming
GeoVax pGA2/JS7 DNA (D) and MVA/HIV62 (M) vaccines encode noninfectious virus-like particles. Intramuscular needle injections were used to deliver placebo, 2 doses of DNA followed by 2 doses of rMVA (DDMM), one dose of DNA followed by 2 doses of rMVA (DMM), or 3 doses of rMVA (MMM) to HIV-seronegative participants.
Local and systemic symptoms were mild or moderate. Immune response rates for CD4 + and CD8 + T cells were highest in the DDMM group and lowest in the MMM group (77% vs 43% CD4 + and 42% vs 17% CD8 +). In contrast, response rates for Env binding and neutralizing Ab were highest in the MMM group. The DMM group had intermediate response rates. A 1/10th-dose DDMM regimen induced similar T cell but reduced Ab response rates compared with the full-dose DDMM.
MVA62 was well tolerated and elicited different patterns of T cell and Ab responses when administered alone or in combination with the JS7 DNA vaccine.
The Journal of Infectious Diseases 03/2011; 203(5):610-9. · 6.41 Impact Factor
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Sunil Kannanganat,
Pragati Nigam,
Vijayakumar Velu,
Patricia L Earl, Lilin Lai,
Lakshmi Chennareddi,
Benton Lawson,
Robert L Wilson,
David C Montefiori,
Pamela A Kozlowski,
Bernard Moss,
Harriet L Robinson,
Rama Rao Amara
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ABSTRACT: The influence of preexisting immunity to viral vectors is a major issue for the development of viral-vectored vaccines. In this study, we investigate the effect of preexisting vaccinia virus immunity on the immunogenicity and efficacy of a DNA/modified vaccinia Ankara (MVA) SIV vaccine in rhesus macaques using a pathogenic intrarectal SIV251 challenge. Preexisting immunity decreased SIV-specific CD8 and CD4 T cell responses but preserved the SIV-specific humoral immunity. In addition, preexisting immunity did not diminish the control of an SIV challenge mediated by the DNA/MVA vaccine. The peak and set point viremia was 150- and 17-fold lower, respectively, in preimmune animals compared with those of control animals. The peak and set point viremia correlated directly with colorectal virus at 2 wk postchallenge suggesting that early control of virus replication at the site of viral challenge was critical for viral control. Factors that correlated with early colorectal viral control included 1) the presence of anti-SIV IgA in rectal secretions, 2) high-avidity binding Ab for the native form of Env, and 3) low magnitude of vaccine-elicited SIV-specific CD4 T cells displaying the CCR5 viral coreceptor. The frequency of SIV-specific CD8 T cells in blood and colorectal tissue at 2 wk postchallenge did not correlate with early colorectal viral control. These results suggest that preexisting vaccinia virus immunity may not limit the potential of recombinant MVA vaccines to elicit humoral immunity and highlight the importance of immunodeficiency virus vaccines achieving early control at the mucosal sites of challenge.
The Journal of Immunology 11/2010; 185(12):7262-73. · 5.79 Impact Factor
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ABSTRACT: A major challenge for human immunodeficiency virus (HIV)/AIDS vaccines is the elicitation of anti-Env antibodies (Ab) capable of neutralizing the diversity of isolates in the pandemic. Here, we show that high-avidity, but nonneutralizing, Abs can have an inverse correlation with peak postchallenge viremia for a heterologous challenge. Vaccine studies were conducted in rhesus macaques using DNA priming followed by modified vaccinia Ankara boosting with HIV type 1 (HIV-1) immunogens that express virus-like particles displaying CCR5-tropic clade B (strain ADA) or clade C (IN98012) Envs. Rhesus granulocyte-macrophage colony-stimulating factor was used as an adjuvant for enhancing the avidity of anti-Env Ab responses. Challenge was with simian/human immunodeficiency virus (SHIV)-162P3, a CCR5-tropic clade B chimera of SIV and HIV-1. Within the groups receiving the clade B vaccine, a strong inverse correlation was found between the avidity of anti-Env Abs and peak postchallenge viremia. This correlation required the use of native but not gp120 or gp140 forms of Env for avidity assays. The high-avidity Ab elicited by the ADA Env had excellent breadth for the Envs of incident clade B but not clade C isolates, whereas the high-avidity Ab elicited by the IN98012 Env had excellent breadth for incident clade C but not clade B isolates. High-avidity Ab elicited by a SHIV vaccine with a dual-tropic clade B Env (89.6) had limited breadth for incident isolates. Our results suggest that certain Envs can elicit nonneutralizing but high-avidity Ab with broad potential for blunting incident infections of the same clade.
Journal of Virology 03/2009; 83(9):4102-11. · 5.40 Impact Factor
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Vijayakumar Velu,
Kehmia Titanji,
Baogong Zhu,
Sajid Husain,
Annette Pladevega, Lilin Lai,
Thomas H Vanderford,
Lakshmi Chennareddi,
Guido Silvestri,
Gordon J Freeman,
Rafi Ahmed,
Rama Rao Amara
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ABSTRACT: Chronic immunodeficiency virus infections are characterized by dysfunctional cellular and humoral antiviral immune responses. As such, immune modulatory therapies that enhance and/or restore the function of virus-specific immunity may protect from disease progression. Here we investigate the safety and immune restoration potential of blockade of the co-inhibitory receptor programmed death 1 (PD-1) during chronic simian immunodeficiency virus (SIV) infection in macaques. We demonstrate that PD-1 blockade using an antibody to PD-1 is well tolerated and results in rapid expansion of virus-specific CD8 T cells with improved functional quality. This enhanced T-cell immunity was seen in the blood and also in the gut, a major reservoir of SIV infection. PD-1 blockade also resulted in proliferation of memory B cells and increases in SIV envelope-specific antibody. These improved immune responses were associated with significant reductions in plasma viral load and also prolonged the survival of SIV-infected macaques. Blockade was effective during the early (week 10) as well as late ( approximately week 90) phases of chronic infection even under conditions of severe lymphopenia. These results demonstrate enhancement of both cellular and humoral immune responses during a pathogenic immunodeficiency virus infection by blocking a single inhibitory pathway and identify a novel therapeutic approach for control of human immunodeficiency virus infections.
Nature 01/2009; 458(7235):206-10. · 36.28 Impact Factor
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Harriet L Robinson,
Sunita Sharma,
Jun Zhao,
Sunil Kannanganat, Lilin Lai,
Lakshmi Chennareddi,
Tianwei Yu,
David C Montefiori,
Rama Rao Amara,
Linda S Wyatt,
Bernard Moss
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ABSTRACT: The clinical product for a clade B HIV DNA/MVA vaccine expressing Gag, Pol, and Env has been tested for immunogenicity in macaques. Responding T cells were at the threshold for detection following DNA priming at weeks 0 and 8 but underwent sharp expansions and contractions following MVA boosting at weeks 16 and 24. Both CD4 and CD8 T cell responses had high frequencies of cytokine coproducing cells with >50% of the memory cells coproducing multiple cytokines including IL-2. The highest responses were elicited to Gag, followed by Env and then Pol. In two of six macaques, the vaccine also elicited low levels of neutralizing Ab for easy to neutralize clade B isolates.
AIDS Research and Human Retroviruses 01/2008; 23(12):1555-62. · 2.25 Impact Factor
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Lilin Lai,
Dalma Vödrös,
Pamela A Kozlowski,
David C Montefiori,
Robert L Wilson,
Vicki L Akerstrom,
Lakshmi Chennareddi,
Tianwei Yu,
Sunil Kannanganat,
Lazarus Ofielu,
Francois Villinger,
Linda S Wyatt,
Bernard Moss,
Rama Rao Amara,
Harriet L Robinson
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ABSTRACT: Single intradermal or intramuscular inoculations of GM-CSF DNA with the DNA prime for a simian-human immunodeficiency virus (SHIV)-89.6 vaccine, which consists of DNA priming followed by modified vaccinia Ankara (MVA) boosting, increased protection of both the blood and intestines against the acute phase of an intrarectal SHIV-89.6P challenge. GM-CSF appeared to contribute to protection by enhancing two antibody responses: the avidity maturation of anti-Env IgG in blood (p=or<0.01) and the presence of long lasting anti-viral IgA in rectal secretions (p<0.01). The avidity of anti-Env IgG showed strong correlations with protection both pre and post challenge. Animals with the highest avidity anti-Env Ab had 1000-fold reductions in peak viremia over those with the lowest avidity anti-Env Ab. The enhanced IgA response was associated with the best protection, but did not achieve significance.
Virology 12/2007; 369(1):153-67. · 3.35 Impact Factor
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Brian A Van Tine,
John C Kappes,
N Sanjib Banerjee,
Judith Knops, Lilin Lai,
Renske D M Steenbergen,
Chris L J M Meijer,
Peter J F Snijders,
Pamela Chatis,
Thomas R Broker,
Phillip T Moen,
Louise T Chow
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ABSTRACT: Primary keratinocytes immortalized by human papillomaviruses (HPVs), along with HPV-induced cervical carcinoma cell lines, are excellent models for investigating neoplastic progression to cancer. By simultaneously visualizing viral DNA and nascent viral transcripts in interphase nuclei, we demonstrated for the first time a selection for a single dominant papillomavirus transcription center or domain (PVTD) independent of integrated viral DNA copy numbers or loci. The PVTD did not associate with several known subnuclear addresses but was almost always perinucleolar. Silent copies of the viral genome were activated by growth in the DNA methylation inhibitor 5-azacytidine. HPV-immortalized keratinocytes supertransduced with HPV oncogenes and selected for marker gene coexpression underwent crisis, and the surviving cells transcribed only the newly introduced genes. Thus, transcriptional selection in response to environmental changes is a dynamic process to achieve optimal gene expression for cell survival. This phenomenon may be critical in clonal selection during carcinogenesis. Examination of HPV-associated cancers supports this hypothesis.
Journal of Virology 11/2004; 78(20):11172-86. · 5.40 Impact Factor
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ABSTRACT: The human immunodeficiency virus type 1 (HIV-1) integrase (IN) protein augments the initiation of reverse transcription. Chimeric HIV-1 containing HIV-2 IN (SG3(IN2)) is severely impaired in virus infectivity and DNA synthesis. To analyze the nature of this defect, we infected T cells with the chimeric SG3(IN2) virus and by continuous passage in cell culture selected for virus with improved replication properties. Viruses from two different time points were chosen for further analysis, an early culture-adapted virus (CF-65) that exhibited an intermediate level of infectivity, and a later-passaged virus (CF-131) that was significantly more infectious. Sequence analysis of multiple clones derived from the CF-65 virus culture demonstrated a diversity of mutations in the reverse transcriptase (RT) and a common V204I IN mutation. Analysis of clones derived from the CF-131 virus indicated the selection of two additional IN mutations, Q96H and K127E, and a fixed V179I RT mutation. By cloning RT and/or IN sequences back into the original SG3(IN2) chimeric virus, we demonstrated that mutations in both RT and IN contributed to the improvement in viral fitness. The effect of the HIV-2IN(IN(2)) mutations on virus DNA synthesis was analyzed by packaging IN(2) mutants into HIV-1 as Vpr-IN(2) fusion proteins. This analysis revealed that the Q96H, K127E and V204I mutations increased the infectivity of the chimeric virus by augmenting the initiation of viral cDNA synthesis in infected cells. The Q96H and K127E mutations are present in adjacent helical structures on the surface of the IN protein and together account for most of the increase observed in DNA synthesis. Our findings provide evidence that the IN protein augments the initiation of reverse transcription through specific interactions with other viral components comprising the initiation complex. Moreover, they implicate specific regions on the surface of IN that may help to elucidate mechanisms by which the HIV-1 IN protein augments the initiation of HIV-1 reverse transcription in vivo.
Journal of Virology 11/2003; 77(20):11050-9. · 5.40 Impact Factor
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ABSTRACT: The assembly of human cytomegalovirus (HCMV) with recombinant systems has not been accomplished. An understanding of specific interactions between individual capsid proteins could point to unique characteristics of the assembly process of HCMV capsids. Similar to its herpes simplex virus counterpart, VP26 (UL35), the HCMV smallest capsid protein (SCP; UL48/49) decorates hexons in the mature capsid. In contrast to VP26, the HCMV SCP is essential for virus assembly. In this study we have shown that the major capsid protein (MCP) and the SCP interact in the cytoplasm of transfected cells and can be coprecipitated from insect cells expressing the MCP and the SCP. Using a two-hybrid reporter assay, we demonstrated that two linear sequences within the SCP are sufficient for SCP and MCP interactions.
Journal of Virology 03/2003; 77(4):2730-5. · 5.40 Impact Factor
