Identification and purification of a specific and immunogenic antigen of the laminated layer of the hydatid cyst and production of an antigen-specific monoclonal antibody

Cystic echinococcosis [CE] is an infection caused by the larval stage of Echinococcus granulosus. This is widely distributed through Iran, where a variety of animals act as intermediate host. The immunogenic antigens [Ag] of different compartments of the hydatid cyst have been already determined. One of these compartments is the laminated layer [LL]. We have extracted a protein with the MW of 24 kDa from a lysate prepared from the LL and produced a monoclonal antibody [mAb] against this protein. Five mAb named P[3]F[6s], P[2]Hp[4s], P[1], A[6s], P[1],C[3s], and P[1],F[7s] have been produced. The isotype analysis showed that P[3]F[6s] is IgG[1], and the rest are IgM. P[3]F[6s] was purified from the ascitic fluid of mice injected with P[3]F[6s] hybridoma intraperitoneally. Western blot and LLISA analysis showed that this mAb could recognize the purified 24 kDa prepared from lysate of LL. Since a 24 kDa protein has been shown to be an immunogenic Ag, this protein can be used as a candidate for the development of diagnostic tests and vaccine strategies. For these aims, P[3]F[6s] can be used for the purification of this 24 kDa protein

[Inhibition of immune system by an immunosuppressive factor from a human prostatic carcinoma cell line [JCA-1]]

Prostatic carcinoma is the most commonly diagnosed tumor among men over 40 which results in over 30,000 deaths each year in the United States. Previous studies indicated that tumor cell lines produce and release several growth regulatory factors into their condition media and so far a number of human tumor cell-derived suppressor factors have been isolated that affect normal immune functions. In this report, an immunosuppressive factor is identified from the supernatant of an androgen-dependent human prostatic carcinoma cell line [JCA-I]. This factor is constitutively produced by JCA-I cells and is able to suppress normal human peripheral blood lymphocyte proliferation irreversibly and in a dose-dependent manner. The immunosuppressive factor was semi-purified by a combination of ion-exchange chromatography on DEAE- Sepharose and gel filtration [Sephacryl S-200] with an apparent molecular weight of 40-55 kDa. The immunosuppressive factor was not catalytic to lymphocytes and was sensitive to 56 C, reducing agent as well as to proteinase digestion. Cell cycle analysis revealed that the immunosuppressive factor does not induce apoptosis, but is able to prevent GI lymphocytes from entering into the S phase of the cell cycle. Further biochemical purification and immunological studies are needed to determine the importance of this factor and its relationship to the immune system