ABSTRACT
Objective: To observe the expression characteristics and co-localization of exogenous TRIM22 and HIV capsid protein p24 in glioma cells. Methods: The vectors of pEGFP-N3-TRIM22 or pDsRed1-p24 were transfected into U-251 glioma cells respectively to examine the expression of TRIM22-EGFP or p24-DsRed1 by confocal microscopy. Moreover, we used a confocal z-stacking program to achieve series of optical sections and to rebuild 3-D images by ImageJ 1.50i software to detect the expression characteristics of p24-DsRed1 in U-251 cells. In the end, the vectors of pEGFP-N3-TRIM22 and pDsRed1-p24 were co-transfected into U-251 cells to detect the co-localization between TRIM22 and p24 by confocal microscopy. Results: Confocal microscopy results showed that TRIM22-EGFP or p24-Dsred1 was localized to the cell body as well as to protuberance in U-251 cells, and 3D structural reconstruction showed that p24-Dsred1 could be transferred to foot processes of U-251 cells. Simultaneously, confocal microscopy results also showed that TRIM22 and p24 could be co-localized and their combination could be released by budding in U-251 cells co-transfected with pEGFP-N3-TRIM22 and pDsRed1-p24. Conclusion: TRIM22 co-localized to HIV capsid protein p24 and their combination can be released by budding in glioma cells.
ABSTRACT
The gag gene of HIV-1 encodes a single open reading frame of 55 kDa that contains three subdomains: the matrix domain (p17), the capsid domain (p24) and the nucleocapsid domain (p15). The p24 and p17 proteins have a predominant a-helical structure and perform important functions throughout thevirallife-cycle. The determination of gag-specific antibodies is important because declining titers of these antibodies herald clinical deterioration.In this work we present the results obtained on immunoreactiviy of synthetic peptides that mimic immunogenic a-helical regions of p24 and p17. The influence on the immunoreactivity of structural modifications in native sequences, including the addition of non immunogenic side chains: AAAC- and -CAAA on both side of minimal epitopes was evaluated in indirect and competitive enzymeimmunoassays. The conformational characteristcs to the peptides were analysed by circular dichroism and these results were correlated with that obtained in the immunoassays. It was shown that the reactivity of peptides mimicking short a-helical regions of p24 and p17 is improved by adding short non immunogenic chains on both N- and C- terminus. These modifications enhanced the immobilization of the peptides onto the solid support and allowed more accesibility to the minimal epitopes byspecific antibodies, in solution.
El gen gag del VIH-1 codifica una región de 55kDA que contiene tres subdominios: matriz (p17), cápside (p24) y nucleocápside (p15). Las proteínas p24 y p17 tienen una estructura predominante helicoidal y cumplen un rol importante en el ciclo de vida del virus. En este trabajo presentamos los resultados de inmunorreactividad de péptidos sintéticos que imitan regiones helicoidales de p24 y p17. Utilizando enzimoinmunoensayos se evaluó la influencia de modificaciones en las secuencias nativas sobre la capacidad de reconocimiento de anticuerpos específicos en solución y en fase sólida, incluyendo el agregado de cadenas no inmunogénicas en ambos extremos de los epitopes mínimos. La conformación de los péptidos se determinó por dicroísmo circular y los resultados se correlacionaron con los de inmunorreactividad. Se observó que la capacidad de reconocimiento de anticuerpos por péptidos pequeños que imitan estructuras helicoidales de p24 y p17 mejoró con el agregado de cadenas no inmunogénicas en ambos extremos de los epitopes. Estas modificaciones mejoran la inmovilización sobre las superficies sólidas y permiten una mayor accesibilidad de los anticuerpos a los epitopes mínimos en solución.