RESUMO
ABSTRACT Parvovirus B19 (B19V) can be transmitted by the respiratory route, vertically - from the mother to the fetus - and via blood transfusion or organ transplantation. Infection by transfusion of blood or blood products occurs due to the resistance of B19V to viral inactivation methods. Our study evaluated the presence of B19V deoxyribonucleic acid (DNA) and the prevalence of anti-B19V class G immunoglobulin (IgG) in women of childbearing age blood donors of the Federal District, Brazil. Our results demonstrated the absence of B19V DNA in these blood donors. However, the seroprevalence for anti-B19V IgG was observed in 60.7% of this population. This study provides important data of B19V circulation in the Center-West of Brazil.
RESUMO O parvovírus B19 (B19V) pode ser transmitido por via respiratória, verticalmente - da mãe para o feto - e via transfusão de sangue e transplante de órgãos. A infecção por transfusão de sangue ou hemoderivados ocorre devido à resistência do B19V aos métodos de inativação viral. Nosso estudo avaliou a presença do ácido desoxirribonucleico (DNA) B19V e a prevalência de imunoglobulina da classe G (IgG) anti-B19V em mulheres em idade fértil, doadoras de sangue do Distrito Federal, Brasil. Nossos resultados demonstraram a ausência de DNA de B19V nesses doadores. No entanto, foi observada a soroprevalência de IgG anti-B19V em 60,7% dessa população. Este estudo fornece dados importantes da circulação do B19V no Centro-Oeste do Brasil.
RESUMO
Strategies to minimize the immunogenicity and toxicity of murine anti-CD3 antibodies (e.g. OKT3) are of special interest for organ transplantation and for the treatment of autoimmune diseases. In the present work, we have developed two humanized anti-CD3 antibodies. These molecules were shown to bind to human CD3, though less efficiently, and display less mitogenic activity than OKT3. These results prompted us to investigate whether this reduced mitogenic potential was associated with the development of anti-inflammatory properties. Indeed, in peripheral blood mononuclear cells (PBMCs), the humanized antibody versions induced a predominantly anti-inflammatory cytokine profile, in contrast with the pro-inflammatory profile induced by OKT3. Neither OKT3 nor the humanized versions induced the expression of IL-4, IL-2 or TGF-beta. Both humanized antibodies induced significantly lower production of IFN-gamma and IL-5 and slightly higher production of IL-10 than OKT3. This immunomodulatory profile was most evident by the 80-fold higher ratio of IL-10/IFN-gamma production in PBMCs cultured in the presence of the humanized antibodies, compared to those stimulated with OKT3. Furthermore, these humanized anti-CD3 antibodies induced a late FOXP3 gene expression while OKT3 led to a more transient expression of FOXP3. Taken our results, we suggest that these humanized anti-CD3 antibodies may promote the development of T cells with immunoregulatory activity.