scholarly journals Attenuated Modified Vaccinia Virus Ankara Can Be Used as an Immunizing Agent under Conditions of Preexisting Immunity to the Vector

2000 ◽  
Vol 74 (16) ◽  
pp. 7651-7655 ◽  
Author(s):  
Juan C. Ramírez ◽  
M. Magdalena Gherardi ◽  
Dolores Rodríguez ◽  
Mariano Esteban
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Human Immunodeficiency Virus Type ◽  
Human Population ◽  
Cellular Immune Responses ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus ◽  
Cellular Immune

ABSTRACT A problem associated with the use of vaccinia virus recombinants as vaccines is the existence of a large human population with preexisting immunity to the vector. Here we showed that after a booster with attenuated recombinant modified vaccinia virus Ankara (rMVA), higher humoral and cellular immune responses to foreign antigens (human immunodeficiency virus type 1 Env and β-galactosidase) were found in mice preimmunized with rMVA than in mice primed with the virulent Western Reserve strain and boosted with rMVA. This enhancement correlated with higher levels of expression of foreign antigens after the booster.

scholarly journals Cellular Immune Responses of Schistosomiasis Patients Are Altered by Human Immunodeficiency Virus Type 1 Coinfection

2001 ◽  
Vol 184 (4) ◽  
pp. 488-496 ◽  
Author(s):  
Pauline N. M. Mwinzi ◽  
Diana M. S. Karanja ◽  
Daniel G. Colley ◽  
Alloys S. S. Orago ◽  
W. Evan Secor
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune

scholarly journals DNA and Modified Vaccinia Virus Ankara Vaccines Encoding Multiple Cytotoxic and Helper T-Lymphocyte Epitopes of Human Immunodeficiency Virus Type 1 (HIV-1) Are Safe but Weakly Immunogenic in HIV-1-Uninfected, Vaccinia Virus-Naive Adults

2012 ◽  
Vol 19 (5) ◽  
pp. 649-658 ◽  
Author(s):  
Geoffrey J. Gorse ◽  
Mark J. Newman ◽  
Allan deCamp ◽  
Christine Mhorag Hay ◽  
Stephen C. De Rosa ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
T Lymphocyte ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACTWe evaluated a DNA plasmid-vectored vaccine and a recombinant modified vaccinia virus Ankara vaccine (MVA-mBN32), each encoding cytotoxic and helper T-lymphocyte epitopes of human immunodeficiency virus type 1 (HIV-1) in a randomized, double-blinded, placebo-controlled trial in 36 HIV-1-uninfected adults using a heterologous prime-boost schedule. HIV-1-specific cellular immune responses, measured as interleukin-2 and/or gamma interferon production, were induced in 1 (4%) of 28 subjects after the first MVA-mBN32 immunization and in 3 (12%) of 25 subjects after the second MVA-mBN32 immunization. Among these responders, polyfunctional T-cell responses, including the production of tumor necrosis factor alpha and perforin, were detected. Vaccinia virus-specific antibodies were induced to the MVA vector in 27 (93%) of 29 and 26 (93%) of 28 subjects after the first and second immunizations with MVA-mBN32. These peptide-based vaccines were safe but were ineffective at inducing HIV-1-specific immune responses and induced much weaker responses than MVA vaccines expressing the entire open reading frames of HIV-1 proteins.

scholarly journals Enhancement of Primary and Secondary Cellular Immune Responses against Human Immunodeficiency Virus Type 1 Gag by Using DNA Expression Vectors That Target Gag Antigen to the Secretory Pathway

2000 ◽  
Vol 74 (13) ◽  
pp. 5997-6005 ◽  
Author(s):  
Jian-Tai Qiu ◽  
Bindong Liu ◽  
Chunjuan Tian ◽  
George N. Pavlakis ◽  
Xiao-Fang Yu
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Human Immunodeficiency Virus Type ◽  
Expression Vectors ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Dna Vector ◽  
Cellular Immune ◽  
Hiv 1

ABSTRACT In this study, we have investigated the influence of antigen targeting after DNA vaccination upon the induction of cellular immune responses against human immunodeficiency virus type 1 (HIV-1) Gag. In addition to the standard version of HIV-1 Gag, we constructed Gag expression vectors that encode a secreted (Sc-Gag) and a cytoplasmic (Cy-Gag) Gag molecule. Although all three HIV-1 Gag expression vectors induced detectable humoral and cellular immune responses, after intramuscular injection the DNA vector encoding the Sc-Gag generated the highest primary cytotoxic T-lymphocyte (CTL) and T-helper responses. Mice immunized with one of the HIV-1 Gag DNA vectors (but not with the control vector pcDNA3.1) developed a protective immune response against infection with recombinant vaccinia virus expressing HIV-1 Gag, and this response persisted for 125 days. The magnitude of the protection correlated with the levels of Gag-specific ex vivo CTL activity and the number of CD8+ T cells producing gamma interferon. The DNA vector encoding the Sc-Gag induced higher levels of protection and greater secondary CTL responses than did the DNA vector encoding Cy-Gag.

scholarly journals Human Immunodeficiency Virus Type 1-Hepatitis C Virus Coinfection: Intraindividual Comparison of Cellular Immune Responses against Two Persistent Viruses

2002 ◽  
Vol 76 (6) ◽  
pp. 2817-2826 ◽  
Author(s):  
Georg M. Lauer ◽  
Tam N. Nguyen ◽  
Cheryl L. Day ◽  
Gregory K. Robbins ◽  
Theresa Flynn ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
T Lymphocyte ◽  
Viral Loads ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune ◽  
Lymphocyte Responses ◽  
Hiv 1

ABSTRACT Both human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) lead to chronic infection in a high percentage of persons, and an expanding epidemic of HIV-1-HCV coinfection has recently been identified. These individuals provide an opportunity for simultaneous assessment of immune responses to two viral infections associated with chronic plasma viremia. In this study we analyzed the breadth and magnitude of the CD8+- and CD4+-T-lymphocyte responses in 22 individuals infected with both HIV-1 and HCV. A CD8+-T-lymphocyte response against HIV-1 was readily detected in all subjects over a broad range of viral loads. In marked contrast, HCV-specific CD8+-T-lymphocyte responses were rarely detected, despite viral loads in plasma that were on average 1,000-fold higher. The few HCV-specific responses that were observed were relatively weak and limited in breadth. CD4-proliferative responses against HIV-1 were detected in about half of the coinfected subjects tested, but no proliferative response against any HCV protein was found in these coinfected persons. These data demonstrate a major discordance in immune responses to two persistent RNA viruses. In addition, they show a consistent and profound impairment in cellular immune responses to HCV compared to HIV-1 in HIV-1-HCV-coinfected persons.

scholarly journals Induction of Neutralizing Antibodies and Gag-Specific Cellular Immune Responses to an R5 Primary Isolate of Human Immunodeficiency Virus Type 1 in Rhesus Macaques

2001 ◽  
Vol 75 (13) ◽  
pp. 5879-5890 ◽  
Author(s):  
David C. Montefiori ◽  
Jeffrey T. Safrit ◽  
Shari L. Lydy ◽  
Ashley P. Barry ◽  
Miroslawa Bilska ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Cellular Immune ◽  
Hiv 1

ABSTRACT The ability to generate antibodies that cross-neutralize diverse primary isolates is an important goal for human immunodeficiency virus type 1 (HIV-1) vaccine development. Most of the candidate HIV-1 vaccines tested in humans and nonhuman primates have failed in this regard. Past efforts have focused almost entirely on the envelope glycoproteins of a small number of T-cell line-adapted strains of the virus as immunogens. Here we assessed the immunogenicity of noninfectious virus-like particles (VLP) consisting of Gag, Pro (protease), and Env from R5 primary isolate HIV-1Bx08. Immunogens were delivered to rhesus macaques in the form of either purified VLP, recombinant DNA and canarypox (ALVAC) vectors engineered to express VLP, or a combination of these products. Seroconversion to Gag and Pro was detected in all of the immunized animals. Antibodies that could neutralize HIV-1Bx08 were detected in animals that received (i) coinoculations with DNABx08 and VLPBx08, (ii) DNABx08 followed by ALVACBx08 boosting, and (iii) VLPBx08 alone. The neutralizing antibodies were highly strain specific despite the fact that they did not appear to be directed to linear epitopes in the V3 loop. Virus-specific cellular immune responses also were generated, as judged by the presence of Gag-specific gamma interferon (IFN-γ)-producing cells. These cellular immune responses required the inclusion of DNABx08 in the immunization modality, since few or no IFN-γ-producing cells were detected in animals that received either VLPBx08 or ALVACBx08 alone. The results demonstrate the feasibility of generating neutralizing antibodies and cellular immune responses that target an R5 primary HIV-1 isolate by vaccination in primates.

scholarly journals Heterologous Prime/Boost Immunization of Rhesus Monkeys by Using Diverse Poxvirus Vectors

2007 ◽  
Vol 81 (16) ◽  
pp. 8563-8570 ◽  
Author(s):  
Sampa Santra ◽  
Yue Sun ◽  
Jenny G. Parvani ◽  
Valerie Philippon ◽  
Michael S. Wyand ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccinia Virus ◽  
Rhesus Monkeys ◽  
Recombinant Vaccinia Virus ◽  
Boost Regimen ◽  
Cellular Immune Responses ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus ◽  
Boost Immunization ◽  
Cellular Immune

ABSTRACT As the diversity of potential immunogens increases within certain classes of vectors, the possibility has arisen of employing heterologous prime/boost immunizations using diverse members of the same family of vectors. The present study was initiated to explore the use of divergent pox vectors in a prime/boost regimen to elicit high-frequency cellular immune responses to human immunodeficiency virus type 1 envelope and simian immunodeficiency virus gag in rhesus monkeys. We demonstrated that monkeys vaccinated with a recombinant modified vaccinia virus Ankara (rMVA) prime/recombinant fowlpox virus (rFPV) boost regimen and monkeys vaccinated with a recombinant vaccinia virus prime/rFPV boost regimen developed comparable cellular immune responses that were greater in magnitude than those elicited by a homologous prime/boost with rMVA. Nevertheless, comparable magnitude recall cellular immune responses were observed in monkeys vaccinated with heterologous and homologous recombinant poxvirus following challenge with the CXCR4-tropic SHIV-89.6P. Consistent with this finding, comparable levels of containment of viral replication and CD4+ T-lymphocyte preservation were seen in these groups of recombinant poxvirus-vaccinated monkeys. This study supports further exploration of combining recombinant vectors of the same family in prime/boost immunization strategies to optimize vaccine-elicited cellular immune responses.

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