Fundamental role of dendritic cells in inducing Th2 responses

A mysterious puzzle in immunology is how the immune system decides what types of immune response to initiate against various stimuli. Although much is known about control of T helper 1 (Th1) and Th17 responses, the mechanisms that initiate Th2 responses remain obscure. Antigen-presenting cells, particularly dendritic cells (DCs), are mandatory for the induction of a Th cell response. Numerous studies have documented the organizing role of DCs in this process. The present review summarizes the fundamental roles of DCs in inducing Th2 responses.

Eosinophils Regulate Type 2 Immune Responses Following Infection with the Nematode Trichinella spiralis

Eosinophils are multifunctional leukocytes implicated in protection against helminth infections. Although eosinophils comprise between 1~5% of peripheral blood leukocytes, they primarily reside in the gastrointestinal tract under homeostatic conditions, and rapidly proliferate upon parasitic infection. Intestinal infection with Trichinella spiralis (T. spiralis) induces eosinophilia when the parasite enters the larval stages and larvae finally migrate to the skeletal muscle. Eosinophils are known to mediate parasite death through antibody-dependent cellular cytotoxicity. In this study, we aimed to address the functional significance of eosinophils in the intestinal phase of T. spiralis infection by analysis of immune responses in the Peyer's patch (PP) of infected BALB/c and eosinophil-ablated ΔdblGATA mice. Trafficking of eosinophils to the PP was significantly increased, with upregulation of interleukin-5 at 14 days post infection. Eosinophil deficiency led to a significant augmentation of serum immunoglobulin (Ig) M and IgG1 antibody levels. In accordance with this, IgG1+ B cells in the PP were substantially increased in ΔdblGATA mice compared to that in BALB/c mice. Transforming growth factor-β expression in the PP of infected ΔdblGATA mice was significantly decreased compared to that in BALB/c mice, whereas the number of T. spiralis larvae in the diaphragm was increased. Taken together, these findings indicate that eosinophils contribute to the regulation of Th2 immune responses, and protect the host from T. spiralis attempting to establish larvae in the skeletal muscle.

Helmintos parásitos de importancia veterinaria: regulación de la respuesta inmunitaria del portador y su uso potencial para el tratamiento de enfermedades inflamatorias / Parasitic helminths of veterinary concern: host immune response regulation and potential use for the treatment of inflammatory diseases

In recent years, a new alternative for the treatment of human inflammatory diseases, such as Crohn's disease, by oral administration of eggs from the swine parasitic nematode Trichuris suis has attracted attention, based on the capacity of helminths to polarize T helper cells (Th) to Th2 type which inhibits inflammation. In the present review the mechanisms used by parasitic helminths to modify the host immune response are analyzed and their potential use for the treatment of a variety of inflammatory diseases is discussed.

En años recientes ha llamado la atención una nueva alternativa para el tratamiento de enfermedades inflamatorias de humanos, como la enfermedad de Crohn, por medio de la administración oral de huevos del nematodo parásito de cerdos Trichuris suis, con base en la capacidad que tienen los helmintos de polarizar la respuesta de las células T cooperadoras (Th) a una de tipo Th2 que inhibe la inflamación. En la presente revisión se analizan los mecanismos que utilizan los helmintos parásitos para modificar la respuesta inmunitaria del portador y se discute su uso potencial para el tratamiento de una variedad de enfermedades inflamatorias.