Can Immune Responses to Human Immunodeficiency Virus Be Preserved, Enhanced, or Restored?

2000 ◽  
pp. 119-132
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Immunodeficiency Virus

scholarly journals Optimization of Human Immunodeficiency Virus Gag Expression by Newcastle Disease Virus Vectors for the Induction of Potent Immune Responses

2008 ◽  
Vol 83 (2) ◽  
pp. 584-597 ◽  
Author(s):  
Elena Carnero ◽  
Wenjing Li ◽  
Antonio V. Borderia ◽  
Bruno Moltedo ◽  
Thomas Moran ◽  
...  
Keyword(s):  
Immune Response ◽  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Insertion Site ◽  
Gag Protein ◽  
Immunodeficiency Virus

ABSTRACT One attractive strategy for the development of a human immunodeficiency virus (HIV) vaccine is the use of viral vectors with a proven safety profile and an absence of preexisting immunity in humans, such as Newcastle disease virus (NDV). Several NDV vaccine vectors have been generated, and their immunogenicities have been investigated with different animal models. However, a systematic study to evaluate the optimal insertion site of the foreign antigens into NDV that results in enhanced immune responses specific to the antigen has not yet been conducted. In this article, we describe the ability of NDV expressing HIV Gag to generate a Gag-specific immune response in mice. We also have determined the optimal insertion site into the NDV genome by generating recombinant NDV-HIVGag viruses in which HIV gag was located at different transcriptional positions throughout the NDV viral genome. All recombinant viruses were viable, grew to similar titers in embryonated chicken eggs, and expressed Gag in a stable manner. Our in vivo experiments revealed that higher HIV Gag protein expression positively correlates with an enhanced CD8+ T-cell-mediated immune response and protective immunity against challenge with vaccinia virus expressing HIV Gag. We also inserted a codon-optimized version of HIV gag in the described best location, between the P and M genes. Virus expressing the codon-optimized version of HIV gag induced a higher expression of the protein and an enhanced immune response against HIV Gag in mice. These results indicate that strategies directed toward increasing antigen expression by NDV result in enhanced immunogenicity and vaccine efficacy.

scholarly journals Predictive value of anti-cell and anti-human immunodeficiency virus (HIV) humoral responses in HIV-1-exposed seronegative cohorts of European and Asian origin

2005 ◽  
Vol 86 (2) ◽  
pp. 339-348 ◽  
Author(s):  
L. Lopalco ◽  
C. Barassi ◽  
C. Paolucci ◽  
D. Breda ◽  
D. Brunelli ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Serum Samples ◽  
Predictive Values ◽  
Asian Populations ◽  
Immunodeficiency Virus ◽  
Hiv Exposure ◽  
Route Of Exposure ◽  
Humoral Responses ◽  
Hiv 1

Unconventional immune responses have been demonstrated in individuals who, despite repeated exposure to human immunodeficiency virus (HIV) infection, remain seronegative. As environmental exposure to pathogens and genetic background may modulate immune responses differentially, one Italian and two Asian populations of HIV-1-exposed seronegative individuals were studied. In serum samples from each group, IgG to CCR5, IgG to CD4 and IgA to gp41 were measured, which were previously described as markers of unconventional immunity in HIV-exposed seronegative Caucasians. Given the importance of conformational epitopes in virus–cell interactions, IgG to CD4–gp120 complex was also measured. It was found that markers of HIV exposure were present in all populations studied. HIV-specific humoral responses (IgA to gp41 and IgG to CD4–gp120 complex) were extremely significant predictors of HIV exposure (P<0·0001 in both cases), whereas the predictive values of anti-cell antibodies (anti-CCR5 and anti-CD4) varied between populations. Evidence is provided for the correlation of these differences with route of exposure to HIV and level of natural antibodies to cross-reactive microbial antigens. In conclusion, exposed seronegative individuals of ethnically different origins display similar signs of HIV-dependent unconventional immunity. A specific relevance must be attributed to different innate and acquired factors.

scholarly journals Assessment of Antibody Response Elicited by a 7-valent Pneumococcal Conjugate Vaccine in Pediatric Human Immunodeficiency Virus Infection

2005 ◽  
Vol 12 (1) ◽  
pp. 165-170 ◽  
Author(s):  
David Tarragó ◽  
Julio Casal ◽  
Jesús Ruiz-Contreras ◽  
J. Tomás Ramos ◽  
Pablo Rojo ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Conjugate Vaccine ◽  
Pneumococcal Conjugate Vaccine ◽  
Correlation Coefficients ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunodeficiency Virus ◽  
Vaccine Immunogenicity ◽  
Functional Antibodies

ABSTRACT We investigated antibody responses against pneumococci of serotypes 6B, 14, and 23F in 56 children and adolescents with perinatal human immunodeficiency virus (HIV) infection who were vaccinated with 7-valent pneumococcal conjugate vaccine. Overall immune responses differed greatly between serotypes. Correlation coefficients between immunoglobulin G (IgG) measured by enzyme-linked immunosorbent assay (ELISA) and functional antibodies measured by a flow cytometry opsonophagocytosis assay (OPA) varied with serotype and time points studied. After 3 months of administering a second PCV7 dose we got the highest correlation (with significant r values of 0.754, 0.414, and 0.593 for serotypes 6B, 14, and 23F, respectively) but no significant increase in IgG concentration and OPA titers compared to the first dose. We defined a responder to a serotype included in the vaccine with two criteria: frequency of at least twofold OPA and ELISA increases for each serotype and frequency of conversion from negative to positive OPA levels. Responders varied from 43.9% to 46.3%, 28.5% to 50.0%, and 38.0% to 50.0% for serotypes 6B, 14, and 23F, respectively, depending on the response criterion. The present research highlights the importance of demonstrating vaccine immunogenicity with suitable immunological endpoints in immunocompromised patients and also the need to define how much antibody is required for protection from different serotypes, since immunogenicity differed significantly between serotypes.

scholarly journals DNA Vaccination with the Human Immunodeficiency Virus Type 1 SF162ΔV2 Envelope Elicits Immune Responses That Offer Partial Protection from Simian/Human Immunodeficiency Virus Infection to CD8+ T-Cell-Depleted Rhesus Macaques

2001 ◽  
Vol 75 (3) ◽  
pp. 1547-1550 ◽  
Author(s):  
S. Cherpelis ◽  
I. Shrivastava ◽  
A. Gettie ◽  
X. Jin ◽  
D. D. Ho ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Cd8 T Cell ◽  
Dna Immunization ◽  
Plasma Virus ◽  
Partial Protection ◽  
Immunodeficiency Virus

ABSTRACT DNA immunization of macaques with the SF162ΔV2 envelope elicited lymphoproliferative responses and potent neutralizing antibodies. The animals were depleted of their CD8+ T lymphocytes and then challenged intravenously with SHIV162P4. Compared to unvaccinated animals, the vaccinated macaques had lower peak viremia levels, rapidly cleared plasma virus, and showed delayed seroconversion.

scholarly journals Induction of Humoral Immune Responses following Vaccination with Envelope-Containing, Formaldehyde-Treated, Thermally Inactivated Human Immunodeficiency Virus Type 1

2005 ◽  
Vol 79 (8) ◽  
pp. 4927-4935 ◽  
Author(s):  
B. Poon ◽  
J. T. Safrit ◽  
H. McClure ◽  
C. Kitchen ◽  
J. F. Hsu ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Thermal Treatment ◽  
Immune Responses ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The lack of success of subunit human immunodeficiency virus type 1 (HIV-1) vaccines to date suggests that multiple components or a complex virion structure may be required. We previously demonstrated retention of the major conformational epitopes of HIV-1 envelope following thermal treatment of virions. Moreover, antibody binding to some of these epitopes was significantly enhanced following thermal treatment. These included the neutralizing epitopes identified by monoclonal antibodies 1b12, 2G12, and 17b, some of which have been postulated to be partially occluded or cryptic in native virions. Based upon this finding, we hypothesized that a killed HIV vaccine could be derived to elicit protective humoral immune responses. Shedding of HIV-1 envelope has been described for some strains of HIV-1 and has been cited as one of the major impediments to developing an inactivated HIV-1 vaccine. In the present study, we demonstrate that treatment of virions with low-dose formaldehyde prior to thermal inactivation retains the association of viral envelope with virions. Moreover, mice and nonhuman primates vaccinated with formaldehyde-treated, thermally inactivated virions produce antibodies capable of neutralizing heterologous strains of HIV in peripheral blood mononuclear cell-, MAGI cell-, and U87-based infectivity assays. These data indicate that it is possible to create an immunogen by using formaldehyde-treated, thermally inactivated HIV-1 virions to induce neutralizing antibodies. These findings have broad implications for vaccine development.

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