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Role of humoral versus cellular responses induced by a protective dengue vaccine candidate.

Zellweger RM, Miller R, Eddy WE, White LJ, Johnston RE, Shresta S - PLoS Pathog. (2013)

Bottom Line: Severe dengue disease is associated with sub-protective levels of antibody, which exacerbate disease upon re-infection.A dengue vaccine should generate protective immunity without increasing severity of disease.This study explores the immunological basis of protection induced by a dengue vaccine and suggests that a safe and efficient vaccine against dengue should trigger both arms of the immune system.

View Article: PubMed Central - PubMed

Affiliation: La Jolla Institute for Allergy & Immunology, La Jolla, California, United States of America.

ABSTRACT
With 2.5 billion people at risk, dengue is a major emerging disease threat and an escalating public health problem worldwide. Dengue virus causes disease ranging from a self-limiting febrile illness (dengue fever) to the potentially fatal dengue hemorrhagic fever/dengue shock syndrome. Severe dengue disease is associated with sub-protective levels of antibody, which exacerbate disease upon re-infection. A dengue vaccine should generate protective immunity without increasing severity of disease. To date, the determinants of vaccine-mediated protection against dengue remain unclear, and additional correlates of protection are urgently needed. Here, mice were immunized with viral replicon particles expressing the dengue envelope protein ectodomain to assess the relative contribution of humoral versus cellular immunity to protection. Vaccination with viral replicon particles provided robust protection against dengue challenge. Vaccine-induced humoral responses had the potential to either protect from or exacerbate dengue disease upon challenge, whereas cellular immune responses were beneficial. This study explores the immunological basis of protection induced by a dengue vaccine and suggests that a safe and efficient vaccine against dengue should trigger both arms of the immune system.

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Related in: MedlinePlus

DENV2 E85-VRP-immunization protects from DENV challenge.AG129 mice were immunized with 1×106 IU DENV2 E85-VRP either i.f. (black circles) or i.p. (black triangles) 14 and 5 days prior to challenge with 5×108 GE DENV. Two groups of mice were not immunized prior to infection with DENV, one of which was infected in the presence of anti-DENV antibody 2H2, resulting in antibody-mediated enhancement of disease (black squares, ADE group) and the other one was infected in the presence of antibody C1.18 which is an isotype control of irrelevant specificity (white squares, baseline group). Viral RNA levels were measured in the liver 3 days after challenge (A) and survival was monitored (B). One day prior to challenge, serum DENV-specific IgG were measured by ELISA on DENV-coated plates (C) and the neutralization capacity of the serum was determined by PRNT50 (D). Each symbol depicts one mouse except in B where n = 4–5, and in C where each symbol represents the mean of 4 animals, P-values from two-tailed unpaired t-test with Welch's correction, confidence interval 95% (A, C, D) or Gehan-Breslow-Wilcoxon test (B), *P≤0.05, **P≤0.01, ***P≤0.001. The dotted line represents the limit of detection of the assay. Samples with undetectable levels of DENV2 RNA are represented in gray under the detection limit. As they have no numerical value, they were not taken into account to calculate the mean.
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ppat-1003723-g001: DENV2 E85-VRP-immunization protects from DENV challenge.AG129 mice were immunized with 1×106 IU DENV2 E85-VRP either i.f. (black circles) or i.p. (black triangles) 14 and 5 days prior to challenge with 5×108 GE DENV. Two groups of mice were not immunized prior to infection with DENV, one of which was infected in the presence of anti-DENV antibody 2H2, resulting in antibody-mediated enhancement of disease (black squares, ADE group) and the other one was infected in the presence of antibody C1.18 which is an isotype control of irrelevant specificity (white squares, baseline group). Viral RNA levels were measured in the liver 3 days after challenge (A) and survival was monitored (B). One day prior to challenge, serum DENV-specific IgG were measured by ELISA on DENV-coated plates (C) and the neutralization capacity of the serum was determined by PRNT50 (D). Each symbol depicts one mouse except in B where n = 4–5, and in C where each symbol represents the mean of 4 animals, P-values from two-tailed unpaired t-test with Welch's correction, confidence interval 95% (A, C, D) or Gehan-Breslow-Wilcoxon test (B), *P≤0.05, **P≤0.01, ***P≤0.001. The dotted line represents the limit of detection of the assay. Samples with undetectable levels of DENV2 RNA are represented in gray under the detection limit. As they have no numerical value, they were not taken into account to calculate the mean.

Mentions: AG129 mice were immunized with 1×106 infectious units (IU) of DENV2 E85-VRP either intraperitoneally (i.p.) or intra footpad (i.f.) 14 and 5 days prior to challenge with 5×108 GE DENV on day 0. As non-vaccinated controls, two groups that were not immunized were challenged with 5×108 GE DENV: one group in the presence of 15 µg of exogenous monoclonal anti-DENV Ab 2H2 given i.p. to cause Ab-mediated enhancement of infection (“ADE group”) and another group in the presence of 15 µg of C1.18, an isotype control Ab of irrelevant specificity (“baseline group”). Viral RNA in the liver was quantified by qRT-PCR on day 3 (figure 1A) and survival was monitored (figure 1B). The liver was chosen because high viral RNA levels in the liver on day 3 correlate with increased severity of disease and decreased survival [9]. Immunization through either the i.p. or i.f. route dramatically reduced viral RNA levels in the liver (figure 1A) and prevented death in 80% of immunized animals (figure 1B). As expected from our previous work [9], the ADE group had approximately 10-fold more viral RNA in the liver on day 3 and its survival was decreased relative to the baseline group. These results demonstrate that DENV2 E85-VRP immunization provides protection against DENV infection and disease, as measured by liver DENV titer and survival, respectively.


Role of humoral versus cellular responses induced by a protective dengue vaccine candidate.

Zellweger RM, Miller R, Eddy WE, White LJ, Johnston RE, Shresta S - PLoS Pathog. (2013)

DENV2 E85-VRP-immunization protects from DENV challenge.AG129 mice were immunized with 1×106 IU DENV2 E85-VRP either i.f. (black circles) or i.p. (black triangles) 14 and 5 days prior to challenge with 5×108 GE DENV. Two groups of mice were not immunized prior to infection with DENV, one of which was infected in the presence of anti-DENV antibody 2H2, resulting in antibody-mediated enhancement of disease (black squares, ADE group) and the other one was infected in the presence of antibody C1.18 which is an isotype control of irrelevant specificity (white squares, baseline group). Viral RNA levels were measured in the liver 3 days after challenge (A) and survival was monitored (B). One day prior to challenge, serum DENV-specific IgG were measured by ELISA on DENV-coated plates (C) and the neutralization capacity of the serum was determined by PRNT50 (D). Each symbol depicts one mouse except in B where n = 4–5, and in C where each symbol represents the mean of 4 animals, P-values from two-tailed unpaired t-test with Welch's correction, confidence interval 95% (A, C, D) or Gehan-Breslow-Wilcoxon test (B), *P≤0.05, **P≤0.01, ***P≤0.001. The dotted line represents the limit of detection of the assay. Samples with undetectable levels of DENV2 RNA are represented in gray under the detection limit. As they have no numerical value, they were not taken into account to calculate the mean.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3814346&req=5

ppat-1003723-g001: DENV2 E85-VRP-immunization protects from DENV challenge.AG129 mice were immunized with 1×106 IU DENV2 E85-VRP either i.f. (black circles) or i.p. (black triangles) 14 and 5 days prior to challenge with 5×108 GE DENV. Two groups of mice were not immunized prior to infection with DENV, one of which was infected in the presence of anti-DENV antibody 2H2, resulting in antibody-mediated enhancement of disease (black squares, ADE group) and the other one was infected in the presence of antibody C1.18 which is an isotype control of irrelevant specificity (white squares, baseline group). Viral RNA levels were measured in the liver 3 days after challenge (A) and survival was monitored (B). One day prior to challenge, serum DENV-specific IgG were measured by ELISA on DENV-coated plates (C) and the neutralization capacity of the serum was determined by PRNT50 (D). Each symbol depicts one mouse except in B where n = 4–5, and in C where each symbol represents the mean of 4 animals, P-values from two-tailed unpaired t-test with Welch's correction, confidence interval 95% (A, C, D) or Gehan-Breslow-Wilcoxon test (B), *P≤0.05, **P≤0.01, ***P≤0.001. The dotted line represents the limit of detection of the assay. Samples with undetectable levels of DENV2 RNA are represented in gray under the detection limit. As they have no numerical value, they were not taken into account to calculate the mean.
Mentions: AG129 mice were immunized with 1×106 infectious units (IU) of DENV2 E85-VRP either intraperitoneally (i.p.) or intra footpad (i.f.) 14 and 5 days prior to challenge with 5×108 GE DENV on day 0. As non-vaccinated controls, two groups that were not immunized were challenged with 5×108 GE DENV: one group in the presence of 15 µg of exogenous monoclonal anti-DENV Ab 2H2 given i.p. to cause Ab-mediated enhancement of infection (“ADE group”) and another group in the presence of 15 µg of C1.18, an isotype control Ab of irrelevant specificity (“baseline group”). Viral RNA in the liver was quantified by qRT-PCR on day 3 (figure 1A) and survival was monitored (figure 1B). The liver was chosen because high viral RNA levels in the liver on day 3 correlate with increased severity of disease and decreased survival [9]. Immunization through either the i.p. or i.f. route dramatically reduced viral RNA levels in the liver (figure 1A) and prevented death in 80% of immunized animals (figure 1B). As expected from our previous work [9], the ADE group had approximately 10-fold more viral RNA in the liver on day 3 and its survival was decreased relative to the baseline group. These results demonstrate that DENV2 E85-VRP immunization provides protection against DENV infection and disease, as measured by liver DENV titer and survival, respectively.

Bottom Line: Severe dengue disease is associated with sub-protective levels of antibody, which exacerbate disease upon re-infection.A dengue vaccine should generate protective immunity without increasing severity of disease.This study explores the immunological basis of protection induced by a dengue vaccine and suggests that a safe and efficient vaccine against dengue should trigger both arms of the immune system.

View Article: PubMed Central - PubMed

Affiliation: La Jolla Institute for Allergy & Immunology, La Jolla, California, United States of America.

ABSTRACT
With 2.5 billion people at risk, dengue is a major emerging disease threat and an escalating public health problem worldwide. Dengue virus causes disease ranging from a self-limiting febrile illness (dengue fever) to the potentially fatal dengue hemorrhagic fever/dengue shock syndrome. Severe dengue disease is associated with sub-protective levels of antibody, which exacerbate disease upon re-infection. A dengue vaccine should generate protective immunity without increasing severity of disease. To date, the determinants of vaccine-mediated protection against dengue remain unclear, and additional correlates of protection are urgently needed. Here, mice were immunized with viral replicon particles expressing the dengue envelope protein ectodomain to assess the relative contribution of humoral versus cellular immunity to protection. Vaccination with viral replicon particles provided robust protection against dengue challenge. Vaccine-induced humoral responses had the potential to either protect from or exacerbate dengue disease upon challenge, whereas cellular immune responses were beneficial. This study explores the immunological basis of protection induced by a dengue vaccine and suggests that a safe and efficient vaccine against dengue should trigger both arms of the immune system.

Show MeSH
Related in: MedlinePlus