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I Vouldoukis

Publications and source records attributed to I Vouldoukis.

47 records · Page 3Linked to original sources

Inhibition in vivo of both infective Leishmania major and L. mexicana amazonensis mediated by a single monoclonal antibody.

Monoclonal antibodies raised against a strain of Leishmania infantum isolated in Greece were produced and tested for their protective effect in an in vivo system (in BALB/C mice). A single monoclonal antibody, IgG2b isotype, can prevent the development of two Leishmania strains in vivo: one of L. major and one of L. mexicana amazonensis. This antibody-mediated protection may be dependent on complement.

Animals↗

[Culture systems for production of promastigote and amastigote forms of Leishmania. Application to serological diagnosis and therapeutic trials].

Several species of leishmania and three methods of cultivation: monophasic, biphasic and co-cultivation were used in a compared study bearing on the intensive production of leishmania. In addition by applying, a new in vivo model, comprising an injection of sarcomatous cells and promastigotes into BALB/c mice and also an extraction on a discontinuous gradient (Radioselectan 60%), it was possible to obtain highly purified isolates of amastigote forms. The use of two antigens: promastigotes and amastigotes, is to be recommended for the serological diagnosis, by indirect immunofluorescence, of kala-azar. The new in vivo model merits further consideration for research concerning new molecules active against leishmania.

Animals↗

[Monoclonal antibodies against defined Leishmania antigens protect mice against infection by different species of Leishmania].

Mice monoclonal antibodies (IgG) have been raised against Leishmania infantum promastigotes by fusing SP 2/0 myeloma cells and immunized mice splenic cells. The monoclonal antibodies have been detected by indirect immunofluorescence. In vivo tests showed that some of them could inhibit the life cycle of several Leishmania species from the Old and the New World. Studies of these protective monoclonals by the western blot technique showed the presence of three constant antigens (40 kD, 70 kD and 113 kD) amongst the Leishmania species studied.

Animals↗

[Efficacy of the vaccination of C57BL/6 mice against infection with different species of Leishmania].

Antigens were isolated from lysates of promastigotes of Leishmania infantum by electro-elution from polyacrylamide gels. Antigens with respective molecular weights for F2 = 94-67 kd; F5 = 30-20 kd and F6 below 20 kd, were injected intravenously in C 57 BL/6 mice. The immune sera were studied by indirect immunofluorescence; an in vivo test showed their inhibitory effect on the life cycle of several Leishmania species from the Old and the New world. Furthermore, mice immunized with F2, F5 or F6 were protected against an infection by Leishmania major. These results demonstrate that vaccination is efficient in mice differing genetically for either susceptibility (BALB/c) or partial resistance (C 57 BL/6) to Leishmania infections. Recently, we reported that a single monoclonal antibody raised against Leishmania infantum can prevent the development of Leishmania major and Leishmania mexicana amazonensis. Indeed, BALB/c mice injected subcutaneously with promastigotes pre-treated with this monoclonal antibody, did not present any cutaneous lesions over a period of 3 months. Using a mouse in vivo model--intraperitoneal injection of TG 180 mouse sarcoma cells along with monoclonal antibody pre-treated promastigotes--such an antibody-mediated inhibition was also observed against Old and New World Leishmania species. Protective monoclonal antibodies recognized by immunoblotting technique three antigenic fractions (40, 70 and 113 kd) common to several Leishmania species. Antigenic preparations from Leishmania infantum extracts were isolated by electro-elution from polyacrylamide gels.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Exploitation of parasite derived antigen in therapeutic success of human cutaneous leishmaniasis in Brazil.

In a complete study in 25 patients with American cutaneous leishmaniasis, caused by Leishmania braziliensis complex, immunotherapeutic efficacy of parasite derived antigen (94-67 KD) has been compared to antimonial therapy. Additionally, to delineate the mechanism of therapeutic success, microscopical features of immune response in active lesions and healed or non-healed lesions following therapy were analyzed. The results showed that cure rates in immunotherapy and chemotherapy were equal (> 83%). The immunohistochemical changes in two therapeutic groups were also largely similar. The analysis of humoral and cellular immune response suggest that appropriate stimulation of T helper cells in the lesion site, in association with one or more cytokines, play a key role in the healing process.

Adolescent↗

Partial protection of mice against Trypanosoma cruzi after immunizing with the TcY 72 antigenic preparation.

A 72 kDa Trypanosoma cruzi glycoprotein recognized by the 164C11 monoclonal antibody (IgM isotype) was purified by preparative electrophoresis. The antigenic preparation obtained, named TcY 72, was used to immunize C57Bl/10 mice. The following results were observed after immunization: (1) induction of higher titres of IgG than IgM antibodies, as evaluated by indirect immunofluorescence; (2) significant DTH after injection of epimastigotes in mice footpads; (3) peak parasitemia in immunized mice was significantly reduced and animals were negative by 13 days post-infection, although the mice still succumb to infection; (4) the phenotypic analysis of spleen cell populations showed a decrease in the CD4/CD8 ratio in immunized mice. Taken as a whole, these findings indicate that TcY 72 is immunogenic and potentially important for protective immunity.

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