1. A vesicle called "texosome" freed from its natural environment, characterized in that said vesicle derived from tumor cells and that comprises lipidic bilayer surrounding cytosolic fraction, comprising tumor antigen molecules and/or immuno modulators and/or chemo-attractants and/or hormones and/or nucleic acids and that molecules of I class and/or II class are present on the surface of major complex of histocompatibility (CMH), and that comprises "Heat shock" protein HSP70, and that has the diameter from about 60 to 100 nm. 2. The vesicle according to claim 1, having the molecules of I class and/or II class on the surface of major complex of histocompatibility (CMH). 3. The vesicle according to any one of claims 1 or 2, characterized in that having, besides, adhesion molecules and/or molecules of lymphocytic co-stimulation on the surface. 4. The vesicle according to any one of claims 1 to 3, characterized in that having antigen peptides on the surface. 5. The vesicle according to claim 4, characterized in that said antigen peptides are associated with the molecules of I class and/or II class of major complex of histocompatibility. 6. The vesicle according to any one of claims 1 to 5, characterized in that being secreted with vesicular compartments of tumor cells, said vesicular compartments having the diameter from 200 to 300 nm. 7. A vesicle, called "texosome", freed from its natural environment, characterized in that said vesicle (i) derived from tumor cells and that comprises (ii) lipidic bilayer surrounding cytosolic fraction, comprising (iii) molecules of I class and/or II class major complex of histocompatibility (CMH), comprising (iv) antigen peptides derived from tumor cells, comprising (v) CD40 or CD80 molecules, comprising (vi) "Heat shock" protein HSP70, comprising (vii) phosphatidylserine and having (viii) the diameter from about 60 to 100 nm. 8. The vesicle according to any one of claims 1 to 7, characterized in that not having gp96 protein. 9. A process for preparing vesicles, called texosome, according to any one of claims 1 to 7, characterized in that comprising the following steps: - obtaining a biological sample, comprising tumor cells, said sample is selected from a sample of blood, plasma, tumor cells culture, tumor biopsy or a preparation derivative thereof comprising tumor cells, and - isolating vesicles from said sample by the method comprising at least one step of centrifugation, electrophoresis, chromatography and/or nanofiltration. 10. The process according to claim 9, characterized in that the biological sample is a membrane fraction, culture supernatants or tumor cells lysates, or newly-prepared tumor cells suspensions. 11. The process according to claim 9 or 10, characterized in that the biological sample is subjected to one or a plurality of stimulating treatments, selected from the treatments using steroid agents, pharmacological agents, agents capable to increase a number of multivesicular endosomes, or by irradiation. 12. Use of texosomes according to any one of claims 1 to 8 for sensitization of antigen presenting cells. 13. A process for the sensitization of antigen presenting cells, comprising incubation of the antigen presenting cells in the presence of one or a plurality of texosomes according to any one of claims 1 to 8 under condition permitting to sensibilize the antigen presenting cells, and selection of the obtained sensibilised antigen presenting cells. 14. The process according to claim 13, characterized in that comprise the step of vesicles selection secreted by the antigen presenting cells. 15. Use of texosomes according to any one of claims 1 to 8 for stimulation and, if necessary, amplification in vitro of antigen specific T-lymphocytes, comprised in said texosomes, or B-lymphocytes, and, in particular, for stimulation and amplification in vitro T-lymphocytes. 16. Use of the antigen presenting cells obtained according to claim 13 and 14 for stimulation and, if necessary, amplification in vitro of antigen specific T-lymphocytes, comprised in said antigen presenting cells, or B-lymphocytes, and, in particular, for stimulation and amplification in vitro T-lymphocytes. 17. A medicament, comprising as an active substance one or a plurality of texosomes according to any one of claims 1 to 8 in combination with pharmaceutically acceptable vehicle. 18. The medicament, comprising as an active substance one or a plurality of antigen presenting cells obtained according to claim 13 or 14 in combination with pharmaceutically acceptable vehicle. 19. The medicament according to claim 17 or 18 for treating cancers, infectious and parasitic diseases. 20. The medicament according to claim 17 or 18 further comprising a stabilizer. 21. A composition, comprising texosomes according to any one of claims 1 to 8 and immune-stabilizing adjuvant for simultaneous, separated or spaced in time utilisation.