ABSTRACT
IL-2 induces growth, differentiation, and/or apoptosis of lymphoid cells. To study further the molecular basis of IL-2 function, we used a cDNA subtraction approach involving a cell line grown in IL-2 or IL-4. From the corresponding library, 66 nonredundant sequences were characterized; 16 of them encode identified proteins. The kinetics of in vitro expression of 8 selected sequences, the functions of which could be associated with IL-2-induced T cell activation/differentiation, was investigated using an IL-2-dependent T cell line. IL-2 increased the expression of cytoskeleton proteins (alpha-tubulin), oncogene-regulating proteins (CCCTC-binding factor, Jun inhibitor factor-1), and transcription factors (E2F-4, cyclic AMP-responsive element-binding protein, zhx-1). IL-2 also regulated the expression of genes coding for multifunctional proteins, e.g., beta-catenin and nucleolin. These results were verified using Con A-induced T cell blasts stimulated or not by IL-2. The in vivo expression of four of these genes was also analyzed in spleen and lymph node cells of IL-2-deficient and MRL/lpr mice, which both have high numbers of activated cells, but the latter have intact IL-2 expression. The expression of beta-catenin, CCCTC-binding factor, Jun inhibitor factor-1, and nucleolin was significantly higher in MRL/lpr animals. A similar analysis of thymocytes from IL-2-/- and IL-2+/- mice demonstrated the same expression patterns of the 4 sequences in these strains. The expression of the IL-2-induced genes described herein is similar to the regulatory pattern of IL-2R alpha. Taken together, our data provide additional evidence for the pleiotropic action of IL-2 in the periphery and IL-2 independence of molecular processes involved in thymocyte differentiation.
Subject(s)
Cytoskeleton/physiology , Gene Expression Regulation/immunology , Interleukin-2/physiology , Oncogenes/immunology , Transcription, Genetic/immunology , Animals , Base Sequence/immunology , Cell Line , Heterozygote , Homozygote , Interleukin-2/genetics , Lymph Nodes/metabolism , Lymphocyte Activation/immunology , Mice , Mice, Inbred C57BL , Mice, Inbred MRL lpr , Mice, Knockout , RNA, Messenger/metabolism , Spleen/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Thymus Gland/metabolismABSTRACT
El objetivo de este trabajo fue caracterizar la región V3 en los VIH-1 aislados de pacientes mexicanos. Se estudió la secuencia del producto obtenido por amplificación con la reacción en cadena de la polimerasa de la región variable 3 de siete aislados de VIH-1 provenientes de pacientes residentes en la República Mexicana, infectados por vía sexual o sanguínea. Con estos fragmentos amplificados se obtuvo la secuencia de nucleótidos de la región comprendida entre las dos cisteínas de la gp120 viral y se redujo la secuencia de aminoácidos de la misma (347-382 de la secuencia consenso). En promedio de homología entre las secuencias de los aislados mexicanos fue de 61.4 por ciento. Se demostraron tres grupos de subtipos virales: uno correspondiente a pacientes que adquirieron la infección por vía sexual, otro de virus de origen sanguíneo y un tercer grupo de gran similitud al virus prototipo HTLV-IIIb/LAV. El análisis de sitios antigénicos en esta región muestra por lo menos tres patrones de neutralización para estos aislados y un caso en el cual no se encuentra ningún epitipo de alto valor predictivo en esta región. Los datos muestran que en nuestro país se presenta una gran heterogeneidad en los virus circulantes, la cual es equivalente a la reportada en otras regiones del mundo
The nucleotide sequence of the human immunodeficiency virus (HIV-1) gp120 variable region (V3) was obtained by sequencing the product of the Polymerase Chain Reaction (PCR) amplification of seven HIV-1 Mexican isolates from patients who had been infected either showed a 61.4% homology between them and three viral subtypes were demonstrated. One of these corresponds to three sexually infected patients, another to two hemophiliac patients infected through blood products or transfusions and the third subtype to either sexually or blood infected patients. The latter shows a great similar ity to the HTLVIIIb/LAV prototype strain. Antigenic profiles of this region show at least three neutralization patterns for these isolates as well as one virus that does not have a high predictive value epitope in the V3 region. Our data show that Mexico has a high heterogeneity of HIV-1 circulating strains, similar to that reported in other regions of the world.
