Estatus inmunológico de las madres infectadas por T. cruzi / Immunological status of mothers infected with Trypanosoma cruzi

The mechanisms of congenital transmission of Chagas disease remain largely unknown. To better understand the role of maternal immunology during pregnancy in congenital Chagas transmission, we studied the cytokine production and the parasitic load in three groups of mothers: infected mothers who transmitted the disease to their babies (M+B+-), infected mothers who did not transmit the disease to their babies (M+B-) and not infected mothers as a control group (M-B-). M+B+ mothers produced less IFNgamma and more IL-10 than the M+B- mothers, and they are not able to produce IL-2. M+B+ mothers showed a higher parasitic load. These results, indicated that the congenital Chagas transmission is associated with an immunological imbalance and a high parasitic load in the M+B+ mothers.

Relationship of interferon synthesis and the resistance of mice infected with street rabies virus

Genetically homogeneous and heterogeneous mouse populations were tested for resistance to experimental street rabies virus infection and their ability to synthesize interferon (IFN) during the infection. The genetically heterogenous HI mouse population was highly resistant (12 per cent mortality), and the genetically homogeneous BALB/c and C3H mice as well as the genetically heterogeneous Sw and LI mouse populations were susceptible (60 to 71 per cent mortality). The genetically homogeneous A/J mice were highly susceptible (85 per cent mortality) to experimental street rabies infection. The ability of these mice to synthesize IFN as measured in serum 4 days after the infection was directly related to the degree of resistance, with the highly resistant HI mice showing large amounts of IFN (850 U/ml), and the susceptible mice showing low amounts of IFN (50 to 280 U/ml). IFN induced within the central nervous system and measured in brain homogenates during infection was not correlated with resistance. The present data suggest that high levels of IFN occurring in serum early during infection with street rabies virus contribute to the resistance of these mice

Some biological properties of the human amniotic membrane interferon

Human amniotic interferon was investigated to define the species specificity of its antiviral action and compare its anti-cellular and NK cell stimulating activities with those of other human interferons. The antiviral effect was titrated in bovine (RV-IAL) and monkey (VERO) cells. Amniotic interferon exhibited, in bovine cells, 5% of the activity seen in monkey cells, while alpha interferon displayed 200%. No effect was detected with either beta or gamma interferon in bovine cells. Daudi cells were exposed to different concentrations of various interferons and the cell numbers were determined. The anticellular effect of the amniotic interferon reached its peak on the third day of incubation. Results suggested a higher activity for alpha and gamma interferons and a lower activity for beta when compared to amniotic interferon. Using total mononuclear cells as effector cells and K 562 as target cell in a 51Cr release assay, it was demonstrated that low concentrations of amniotic interferon consistently stimulated NK cell activity in cells derived from several donors, the results indicating a higher level of activity with this interferon than with alpha and beta interferons

Produçäo de interferon humano de membranas amnióticas em microtécnica / Production of human amniotic interferon by microtechnique

Foi desenvolvido um sistema de produçäo de interferon humano de membranas amnióticas (IFN-MA) em microtécnica. Fragmentos de âmnio de 1,4 ou 2,2cm de diâmetro, em placas de microtécnica (24 câmaras), foram infectados por vírus Sendai e o IFN-MA resultante foi titulado. Maiores títulos (12.800 e 13.000 unidades por ml) foram obtidos quando utilizadas quantidades de meio de 0,5ml e 1,0ml); 6,4 unidades hemaglutinantes do vírus Sendai e um fragmento por câmara. Níveis de IFN-MA mais consistentes e altos foram alcançados na regiäo coriônica do âmnio (6.000 a 9.600 unidades/ml) quando comparados com aqueles da regiäo umbilical (860 a 2.500 unidades/ml) e reflexa (200 a 6.500 unidades/ml). O sistema com fragmentos de 2,2cm de diâmetro produziu, em média, quantidades de interferon/ml superiores (9.300 unidades/ml) quando comparado ao da produçäo do âmnio total (2.200 unidades/ml). Apesar da variabilidade nos títulos produzidos individualmente pelos fragmentos de 2,2cm de diâmetro, devido a econômia de tempo e de materiais e aos altos níveis de IFN resultantes, a microtécnica poderá se empregada quando um grande número de variáveis for investigada

Produçäo de interferon por placenta humana / Production of interferon by human placenta

No presente trabalho, foi investigada a produçäo de interferon nos tecidos da placenta humana induzidos por diferentes vírus. A membrana amniótica mostrou ser mais eficiente produtora de interferon quando infectada pelo vírus da doença de Newcastle (NDV) que a membrana ou as vilosidades coriônicas. A irradiaçäo do NDV com a luz ultravioleta (UV) diminuiu sua capacidade indutora nos três tecidos placentários. Os níveis de interferon encontrados em culturas da membrana amniótica ou coriônica, induzidos por vírus para-influenza I (Sendai), foram muito diferentes, dependendo da placenta utilizada, tanto com o vírus vivo como o tratado com a UV. Quando vilosidades coriônicas foram infectadas com este vírus, näo foi encontrada atividade de IFN. Testes comparativos mostraram que o NDV é melhor indutor de interferon do que o vírus Sendai em membrana amniótica. Os vírus Sindbis e Oriboca (vivos ou inativados pela UV) näo induziram títulos mensuráveis de interferon em qualquer dos tecidos mencionados. Concluiu-se que o sistema NDV - membrana amniótica é o mais eficiente na induçäo de IFN e merece investigaçöes mais abrangentes

Lack of interferon induction in man by two rabies tissue culture vaccines.

Both neutralising antibody and interferon play a part in protection of animals against death from rabies virus infection. Interferon induction was therefore sought in 53 volunteers within 24 hours of receiving human diploid cell strain vaccine or fetal bovine kidney cell vaccine given either intramuscularly or intradermally. Repeat observations were made in 18 subjects following a second dose of vaccine seven days later. No interferon was detected in any sample tested although no subject had any detectable rabies neutralising antibody on day 0. The sensitivity of the interferon assay, and comparison with other studies are discussed. An interferon inducer suitable for human use should be sought as an alternative to, or a replacement for, passive rabies immunization.

Clonación de un cDNA de interferon leucocitario humano y su estrategia de producción en E. coli / Molecular cloning of a human leukocyte interferon cDNA and its production strategy in E. coli

En el presente trabajo se describe la clonación del cDNA correspondiente al interferón leucocitario humano tipo A, preparado a partir de el RNAm purificado de un mieloblastoma. Asimismo, se detalla la estrategia seguida para la producción de esta proteína en E. coli. Para estos efectos se fusionó un adaptador de DNA sintético al cDNA de interferón, uniéndole luego el promotor y sitio de unión a ribosomas del operón de triptofano. Se determinó utilizando un sistema de minicélulas, la expresión de interferón