RESUMEN
Various T-cell co-receptor molecules and calcium channel CRAC play a pivotal role in the maintenance of cell’s functional responses by regulating the production of effector molecules (mostly cytokines) that aids in immune clearance and also maintaining the cell in a functionally active state. Any defect in these co-receptor signalling pathways may lead to an altered expression pattern of the effector molecules. To study the propagation of such defects with time and their effect on the intracellular protein expression patterns, a comprehensive and largest pathway map of T-cell activation network is reconstructed manually. The entire pathway reactions are then translated using logical equations and simulated using the published time series microarray expression data as inputs. After validating the model, the effect of in silico knock down of co-receptor molecules on the expression patterns of their downstream proteins is studied and simultaneously the changes in the phenotypic behaviours of the T-cell population are predicted, which shows significant variations among the proteins expression and the signalling routes through which the response is propagated in the cytoplasm. This integrative computational approach serves as a valuable technique to study the changes in protein expression patterns and helps to predict variations in the cellular behaviour.
RESUMEN
Mediante ensayos biológicos clásicos se ha podido determinar el uso del correceptor por las cepas de VIH-1, las cuales se han clasificado en R5, X4 o R5/X4, características que guardan relación con el fenotipo NIS o IS y con la evolución clínica. Por métodos bioinformáticos se han relacionado cambios aminoacídicos en la región del lazo V3 del env con el uso del correceptor. En este trabajo se presentan los resultados del estudio de caracterización de once cepas provenientes de individuos infectados con VIH-1, cinco de ellos seropositivos asintomáticos y seis progresores rápidos al SIDA. Se compararon los resultados del estudio fenotípico realizado por dos ensayos biológicos clásicos, uso de correceptores y capacidad de inducir sincicios en MT2 y tres métodos bioinformáticos, regla 11/25, matrices de puntos en posiciones específicas (PSSM) y el programa geno2pheno. Las cinco cepas de seropositivos asintomáticos coincidieron por todos los métodos como R5/NIS. Cinco de las seis cepas de progresores rápidos se clasificaron R5/X4 e IS por los ensayos biológicos; mientras dos clasificaron R5/X4 por Geno 2 Pheno, una por PSSM y todas fueron X4 puras por la regla 11/25. Los ensayos utilizados en el estudio permitieron caracterizar las cepas aisladas y relacionar el fenotipo con la evolución de la infección, por lo que valoramos que por ensayos biológicos o métodos bioinformáticas se pueden hacer estudios de caracterización, su utilidad está en dependencia del objetivo que se persiga
By the classic biological assays it has been possible to determine the use of HIV-1 strains co-receptor, which have been classified in R5, X4 or R5/X4, characteristic related to the NIS or IS phenotype and to the clinical course. By bio-information methods the amino acid changes in the region of V3 loop of the env using the co-receptor. In present paper are showed the results of a characterization study of eleven strains from HIV-1 infected subjects, five seropositive and six with a fast progression to AIDS. Authors compared the results of phenotype study conducted by two classic assays, use of co-receptors and ability to induce syncytia in MT2 and three bio-information methods, rule 11/25, point matrices in specific locations (PSSM) and the geno2pheno program. The five strains from asymptomatic seropositive patients coincided according all methods used as R5/NIS. Five of the six strains from fast progression patients were classified as R5/X4 and IS by biological assays; whereas two were classified as R5/X4 by Geno 2 Pheno, one by PSSM and all were pure X4 by the rule 11/25. The assays used in the study allowed us to characterize the isolated strains and to relate the phenotype to the infection course, thus, we considered that using biological assays or bio-information methods it is possible to conduct characterization studies, its usefulness depends on the pursued objectives