ABSTRACT
Prohibitin (PHB), an evolutionarily conserved mitochondrial inner membrane protein, is highly expressed in cells that require strong mitochondrial function. Recently, we demonstrated that the deletion of Phb in spermatocytes results in impaired mitochondrial function. In addition, PHB expression in the mitochondrial sheath of human sperm has a significantly negative correlation with mitochondrial reactive oxygen species levels, but a positive one with mitochondrial membrane potential and sperm motility. These results suggest that mitochondrial PHB expression plays a role in sperm motility. However, the mechanism of PHB-mediated regulation of sperm motility remains unknown. Here, we demonstrate for the first time that PHB interacts with protein kinase B (AKT) and exists in a complex with phospho-PHB (pT258) and phospho-AKT in the mitochondrial sheath of murine sperm, as determined using colocalization and coimmunoprecipitation assays. After blocking AKT activity using wortmannin (a phosphatidylinositol 3-kinase [PI3K] inhibitor), murine sperm have significantly ( P < 0.05) decreased levels of phospho-PHB (pT258) and the total and progressive motility. Furthermore, significantly ( P < 0.05) lower levels of phospho-PI3K P85 subunit α+γ (pY199 and pY467) and phospho-AKT (pS473; pT308) are found in sperm from infertile asthenospermic and oligoasthenospermic men compared with normospermic subjects, which suggest a reduced activity of the PI3K/AKT pathway in these infertile subjects. Importantly, these sperm from infertile subjects also have a significantly ( P < 0.05) lower level of phospho-PHB (pT258). Collectively, our findings suggest that the interaction of PHB with AKT in the mitochondrial sheath is critical for sperm motility, where PHB phosphorylation (pT258) level and PI3K/AKT activity are key regulatory factors.
ABSTRACT
<p><b>OBJECTIVE</b>To compare the foreign gene-specific and vector-specific immune responses in BALB/c mice immunized with rAd5 or rAAV2/1 expressing the same gene.</p><p><b>METHODS</b>BALB/c mice were immunized with rAd5-gag or rAAV2/1-gag once, HIV-1 Gag-specific and vector-specific cellular immune responses were analyzed by Elispot assay, HIV-1 P24-specific IgG and vector-specific IgG were tested by ELISA assay.</p><p><b>RESULTS</b>Mice immunized with rAd5-gag induced potent Gag-specific cellular immune responses and that were significantly higher than Ad5-specfic cellular responses, while rAAV2/1-gag elicited weak Gag-specific and AAV2/1-specific cellular responses. Both P24-specific and Ad5-specific IgG titers induced by rAd5-gag were high and in similar level. Higher level of P24-specific IgG was found in mice inoculated with rAAV2/1-gag than rAd5-gag. And the P24-specific IgG titers were higher than the vector-specific IgG titers in mice immunized with rAAV2/1.</p><p><b>CONCLUSION</b>rAd5 could elicit strong foreign gene-specific cellular and humoral immune responses, weak vector-specific cellular responses and strong vector-specific antibodies, rAAV2/1 could induce potent foreign gene-specific antibodies that were much higher than vector-specific IgG, while both foreign gene-specific and vector-specific cellular responses were very low.</p>
Subject(s)
Animals , Female , Mice , AIDS Vaccines , Allergy and Immunology , Adenoviridae , Allergy and Immunology , Antibodies, Viral , Blood , Dependovirus , Allergy and Immunology , Genetic Vectors , Allergy and Immunology , HIV Core Protein p24 , Allergy and Immunology , Immunoglobulin G , Blood , Mice, Inbred BALB C , Vaccines, Synthetic , Allergy and ImmunologyABSTRACT
<p><b>OBJECTIVE</b>To construct DNA and recombinant adenovirus vector vaccines containing an env gene from the prevalent subtype B strain in China and try to use them for therapeutic and prophylactic vaccines.</p><p><b>METHODS</b>The candidate plasmid DNA vaccine pVR-gp160 and recombinant adenovirus vaccine rAdV-gp160 were constructed separately. BALB/c mice were immunized with these two vaccines in different administration schemes. HIV-1 Gp120-specific cellular responses and antibody levels were detected by ELISPOT and ELISA respectively.</p><p><b>RESULTS</b>DNA vaccine alone and combined vaccines in a DNA prime/rAdV-gp160 boost vaccination regimen induced high level of Gp120-specific cellular responses. While low level of Gp120-specific antibodies were elicited in all groups.</p><p><b>CONCLUSION</b>DNA and rAdV vaccines could efficiently express Gp160 protein and activate specific cellular responses.</p>