Immunoregulation in human malaria: the challenge of understanding asymptomatic infection

Asymptomatic Plasmodium infection carriers represent a major threat to malaria control worldwide as they are silent natural reservoirs and do not seek medical care. There are no standard criteria for asymptomaticPlasmodium infection; therefore, its diagnosis relies on the presence of the parasite during a specific period of symptomless infection. The antiparasitic immune response can result in reducedPlasmodium sp. load with control of disease manifestations, which leads to asymptomatic infection. Both the innate and adaptive immune responses seem to play major roles in asymptomatic Plasmodiuminfection; T regulatory cell activity (through the production of interleukin-10 and transforming growth factor-β) and B-cells (with a broad antibody response) both play prominent roles. Furthermore, molecules involved in the haem detoxification pathway (such as haptoglobin and haeme oxygenase-1) and iron metabolism (ferritin and activated c-Jun N-terminal kinase) have emerged in recent years as potential biomarkers and thus are helping to unravel the immune response underlying asymptomatic Plasmodium infection. The acquisition of large data sets and the use of robust statistical tools, including network analysis, associated with well-designed malaria studies will likely help elucidate the immune mechanisms responsible for asymptomatic infection.

Determinación de receptores de haptoglobina y proteína C reactiva en linfocitos de pacientes con patología autoinmune e infecciosa / Determination of haptoglobin and C reactive protein receptors in lymphocytes of patients with autoimmune and infectious diseases

En la actualidad, se desconoce el rol del aumento de proteína C recativa (PCR) y haptoglobina (Hp) en la respuesta de fase aguda. Algunos autores han postulado la posibilidad que estas proteínas intervengan en la regulación del sistema inmune. Nuestro estudio estuvo orientado a demostrar la presencia de receptores para Hp y PCR en linfocitos procedentes de niños sanos y niños con patología infecciosa y autoinmune. Para este efecto, se obtuvieron células mononucleares de 48 niños (24 sanos, 14 con infecciones demostradas y 10 con enfermedades autoinmune), se incubaron por 72 horas a 37 grados Celsius y 5 por ciento de CO2, con estímulo de fitohemaglutinina (PHA) y con diferentes concentraciones de PCR y Hp en el medio. Se separaron las subpoblaciones CD4 y CD8 mediante anticuerpos monoclonales unidos a partículas magnéticas y se analizó la presencia de receptores a distintos tiempos (0, 24, 48 y 72 horas) mediante una técnica de inmunofluorescencia indirecta