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Incorporation of a GPI-anchored engineered cytokine as a molecular adjuvant enhances the immunogenicity of HIV VLPs.

Feng H, Zhang H, Deng J, Wang L, He Y, Wang S, Seyedtabaei R, Wang Q, Liu L, Galipeau J, Compans RW, Wang BZ - Sci Rep (2015)

Bottom Line: Co-delivery of mucosal adjuvants has been shown to be essential to induce effective mucosal immunity by non-replicating vaccines.A novel cytokine, GIFT4, engineered by fusing GM-CSF and interleukin-4, was previously found to simulate B cell proliferation and effector function.Incorporation of GPI-anchored GIFT4 into VLPs as a molecular adjuvant represents a novel approach to increase their immunogenicity.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA.

ABSTRACT
HIV vaccines should elicit immune responses at both the mucosal portals of entry to block transmission and systemic compartments to clear disseminated viruses. Co-delivery of mucosal adjuvants has been shown to be essential to induce effective mucosal immunity by non-replicating vaccines. A novel cytokine, GIFT4, engineered by fusing GM-CSF and interleukin-4, was previously found to simulate B cell proliferation and effector function. Herein a membrane-anchored form of GIFT4 was constructed by fusing a glycolipid (GPI)-anchoring sequence and incorporated into Env-enriched HIV virus-like particles (VLPs) as a molecular adjuvant. Guinea pigs were immunized with the resulting HIV VLPs through an intramuscular priming-intranasal boosting immunization route. The GIFT4-containing VLPs induced higher levels of systemic antibody responses with significantly increased binding avidity and improved neutralizing breadth and potency to a panel of selected strains, as well as higher levels of IgG and IgA at several mucosal sites. Thus, the novel GPI-GIFT4-containging VLPs have the potential to be developed into a prophylactic HIV vaccine. Incorporation of GPI-anchored GIFT4 into VLPs as a molecular adjuvant represents a novel approach to increase their immunogenicity.

No MeSH data available.


Related in: MedlinePlus

Serum IgG and IgG subtype endpoint titers.Guinea pigs were immunized with Gag only VLPs, GIFT4/Gag VLPs, sVLPs, or cVLPs in the one i.m. priming-two i.n. boosting route at weeks 0, 4, 8, respectively, and immune sere were collected 2 weeks after each immunization at weeks 2, 6, 10, respectively. a, Serum IgG endpoint titers; b, IgG1 titers of immune sera from bleed 3 (week 10); c, IgG2 endpoint titers of immune sera from bleed 3. Assays were performed as described in Materials and Methods. Results are expressed as means ± standard deviations. Student t-test was used for statistical analysis. The analysis was done by using GraphPad Prism version 5.00 for Windows (San Diego, California). P values of less than 0.05 (P < 0.05) were considered to be statistically significant. *P < 0.05; **P < 0.01.
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f3: Serum IgG and IgG subtype endpoint titers.Guinea pigs were immunized with Gag only VLPs, GIFT4/Gag VLPs, sVLPs, or cVLPs in the one i.m. priming-two i.n. boosting route at weeks 0, 4, 8, respectively, and immune sere were collected 2 weeks after each immunization at weeks 2, 6, 10, respectively. a, Serum IgG endpoint titers; b, IgG1 titers of immune sera from bleed 3 (week 10); c, IgG2 endpoint titers of immune sera from bleed 3. Assays were performed as described in Materials and Methods. Results are expressed as means ± standard deviations. Student t-test was used for statistical analysis. The analysis was done by using GraphPad Prism version 5.00 for Windows (San Diego, California). P values of less than 0.05 (P < 0.05) were considered to be statistically significant. *P < 0.05; **P < 0.01.

Mentions: To investigate whether GIFT4 incorporated into HIV VLPs enhances antibody responses against the Env immunogen, groups of guinea pigs were immunized with one intramuscular (i.m.) prime followed by two intranasal (i.n.) boosts with sVLPs, cVLPs, GIFT4/Gag VLPs or Gag only VLPs, respectively. Immune serum IgG levels specific to HIV Env at 2 weeks after each immunization were assessed by ELISA. The results shown in Fig. 3a (presented as endpoint titers) demonstrate that cVLPs induced serum antibody responses with higher titers than those observed with sVLPs (P < 0.05). After three immunizations (bleed 3 at week 10, Fig. 3a), guinea pigs immunized with cVLPs exhibited 5-fold higher IgG levels than those induced by sVLPs (means of 24600 vs. 4666, P < 0.01). These results indicated that co-incorporation of the membrane-anchored GIFT4 into VLPs is highly effective in enhancing anti-Env immune responses. Although cVLPs induced elevated IgG responses, Env-specific IgA in immune sera was not detected.


Incorporation of a GPI-anchored engineered cytokine as a molecular adjuvant enhances the immunogenicity of HIV VLPs.

Feng H, Zhang H, Deng J, Wang L, He Y, Wang S, Seyedtabaei R, Wang Q, Liu L, Galipeau J, Compans RW, Wang BZ - Sci Rep (2015)

Serum IgG and IgG subtype endpoint titers.Guinea pigs were immunized with Gag only VLPs, GIFT4/Gag VLPs, sVLPs, or cVLPs in the one i.m. priming-two i.n. boosting route at weeks 0, 4, 8, respectively, and immune sere were collected 2 weeks after each immunization at weeks 2, 6, 10, respectively. a, Serum IgG endpoint titers; b, IgG1 titers of immune sera from bleed 3 (week 10); c, IgG2 endpoint titers of immune sera from bleed 3. Assays were performed as described in Materials and Methods. Results are expressed as means ± standard deviations. Student t-test was used for statistical analysis. The analysis was done by using GraphPad Prism version 5.00 for Windows (San Diego, California). P values of less than 0.05 (P < 0.05) were considered to be statistically significant. *P < 0.05; **P < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493578&req=5

f3: Serum IgG and IgG subtype endpoint titers.Guinea pigs were immunized with Gag only VLPs, GIFT4/Gag VLPs, sVLPs, or cVLPs in the one i.m. priming-two i.n. boosting route at weeks 0, 4, 8, respectively, and immune sere were collected 2 weeks after each immunization at weeks 2, 6, 10, respectively. a, Serum IgG endpoint titers; b, IgG1 titers of immune sera from bleed 3 (week 10); c, IgG2 endpoint titers of immune sera from bleed 3. Assays were performed as described in Materials and Methods. Results are expressed as means ± standard deviations. Student t-test was used for statistical analysis. The analysis was done by using GraphPad Prism version 5.00 for Windows (San Diego, California). P values of less than 0.05 (P < 0.05) were considered to be statistically significant. *P < 0.05; **P < 0.01.
Mentions: To investigate whether GIFT4 incorporated into HIV VLPs enhances antibody responses against the Env immunogen, groups of guinea pigs were immunized with one intramuscular (i.m.) prime followed by two intranasal (i.n.) boosts with sVLPs, cVLPs, GIFT4/Gag VLPs or Gag only VLPs, respectively. Immune serum IgG levels specific to HIV Env at 2 weeks after each immunization were assessed by ELISA. The results shown in Fig. 3a (presented as endpoint titers) demonstrate that cVLPs induced serum antibody responses with higher titers than those observed with sVLPs (P < 0.05). After three immunizations (bleed 3 at week 10, Fig. 3a), guinea pigs immunized with cVLPs exhibited 5-fold higher IgG levels than those induced by sVLPs (means of 24600 vs. 4666, P < 0.01). These results indicated that co-incorporation of the membrane-anchored GIFT4 into VLPs is highly effective in enhancing anti-Env immune responses. Although cVLPs induced elevated IgG responses, Env-specific IgA in immune sera was not detected.

Bottom Line: Co-delivery of mucosal adjuvants has been shown to be essential to induce effective mucosal immunity by non-replicating vaccines.A novel cytokine, GIFT4, engineered by fusing GM-CSF and interleukin-4, was previously found to simulate B cell proliferation and effector function.Incorporation of GPI-anchored GIFT4 into VLPs as a molecular adjuvant represents a novel approach to increase their immunogenicity.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA.

ABSTRACT
HIV vaccines should elicit immune responses at both the mucosal portals of entry to block transmission and systemic compartments to clear disseminated viruses. Co-delivery of mucosal adjuvants has been shown to be essential to induce effective mucosal immunity by non-replicating vaccines. A novel cytokine, GIFT4, engineered by fusing GM-CSF and interleukin-4, was previously found to simulate B cell proliferation and effector function. Herein a membrane-anchored form of GIFT4 was constructed by fusing a glycolipid (GPI)-anchoring sequence and incorporated into Env-enriched HIV virus-like particles (VLPs) as a molecular adjuvant. Guinea pigs were immunized with the resulting HIV VLPs through an intramuscular priming-intranasal boosting immunization route. The GIFT4-containing VLPs induced higher levels of systemic antibody responses with significantly increased binding avidity and improved neutralizing breadth and potency to a panel of selected strains, as well as higher levels of IgG and IgA at several mucosal sites. Thus, the novel GPI-GIFT4-containging VLPs have the potential to be developed into a prophylactic HIV vaccine. Incorporation of GPI-anchored GIFT4 into VLPs as a molecular adjuvant represents a novel approach to increase their immunogenicity.

No MeSH data available.


Related in: MedlinePlus