A non-hepatotropic parasite infection increases mortality in the acetaminophen-induced acute liver failure murine model: possible roles for IL-5 and IL-6

We evaluated the effects of a non-hepatotropic parasite infection (Taenia crassiceps) on the outcome of acetaminophen-induced acute liver failure in mice. Uninfected and T. crassiceps infected mice orally received either 300 mg/kg acetaminophen or water as vehicle (n = 5 per group). Survival analysis, hepatocyte necrosis, alanine aminotransferase (ALT) levels, CYP2E1 protein, interleukin (IL-) 5, and IL-6 were assessed for all groups. All infected mice died within 16 h after exposure to acetaminophen (Tc+APAP group), whereas only one-third of uninfected animals exposed to acetaminophen (APAP group) died. Uninfected (Control group) and infected (Tc group) mice that received the vehicle showed no liver damage. Tc+APAP mice exhibited massive liver necrosis characterised by marked balloning degeneration of hepatocytes and higher serum ALT compared to Control, Tc, and APAP animals. Liver tissue from Tc+APAP mice also displayed increased expression of CYP2E1 protein and higher mRNA and protein levels of IL-5 and IL-6 compared to the other groups. These findings suggest that non-hepatotropic parasite infections may increase mortality following acute liver failure by promoting hepatocyte necrosis via IL-5 and IL-6-dependent CYP2E1 overproduction. This study identifies new potential risk factors associated with severe acute liver failure in patients.

Dimorfismo sexual inmunitario: ¿pueden los esteroides sexuales polarizar el perfil de citocinas Th1/Th2? / Immune sexual dimorphism: Can sex steroids affect the Thl/Th2 cytokine profile?

Cytokine secretion is a crucial aspect in immune system modulation. The secretion pattern of these molecules determines the immune response type that will confront a particular antigen, and this pattern can be at least of two types. A Thl pattern, effective to eliminate mainly intracellular pathogens and a Th2 pattern, crucial to eradicate extra cellular pathogens. There are many immunological factors that affect expression of these proteins and auto regulate the Th1/Th2 balance, but there are few evidences about effect of other protagonists of mammals physiology. This review focuses on the regulation of the Th1/Th2 cytokine secretion pattern of immune cells by sexual steroids. The evidences indicate that cytokines and steroids form a common chemical language effective to keep the balance between immune and endocrine systems. Alterations of this delicate network can explain different pathologies where gender-associated differences exist and where sexual steroids are crucial factors.

La secreción de citocinas es uno de los aspectos más importantes en la modulación de la respuesta inmune. El patrón de secreción de estas moléculas determina el tipo de respuesta inmune que confrontará a un antígeno particular. Ésta puede ser al menos de dos tipos: la respuesta Th1 (encargada principalmente de controlar patógenos intracelulares) y la respuesta Th2 (involucrada en el control de patógenos extracelulares). Existe una autorregulación del balance del tipo de respuesta Th1/Th2 por mecanismos inmunológicos que pueden afectar la expresión de estas proteínas, pero poco se sabe con respecto al papel de otros protagonistas de la fisiología de los mamíferos. En esta revisión se discuten los trabajos referentes al efecto de los esteroides sexuales en la regulación de la secreción de citocinas Th1/Th2 por parte de células del sistema inmune. Las evidencias indican que las citocinas y los esteroides constituyen un lenguaje químico común para el funcionamiento balanceado de los sistemas inmune y endocrino. La alteración de la delicada comunicación entre estos sistemas puede explicar diversas patologías en que existe susceptibilidad asociada al sexo, y en las que los esteroides sexuales son factores clave.