Volume 12 Issue 2, February 2011

The migration of T_H2 cells into allergy-affected tissue is key to maintaining the inflammatory response. CCR8-CCL8, a newly identified chemokine receptor–ligand pair, mediates the skin accumulation of T_H2 cells with the specific potential to drive chronic eosinophilic inflammation.

Maintenance of hematopoietic stem cells depends on a fine-tuned transcriptional network. A detailed study of the nuclear adaptor Ldb1 provides additional clues as to how hematopoietic stem cell homeostasis is controlled.

Recent work highlights the requirement for 2′-O-methylation of capped mRNA to prevent recognition by the antiviral host response.

Long-lived plasma cells require a specialized bone marrow microenvironment in order to survive and produce antibody. Eosinophils make an important contribution to maintaining this survival niche.

Ldb1 functions as a core component of various multiprotein transcription complexes. Love and co-workers show a continuous requirement for Ldb1 in the maintenance of both fetal and adult HSC.

The biological role of 2′-O-methylation of host and viral mRNA has remained elusive. Thiel and co-workers show that this modification modulates the induction of type I interferon and sensitivity to interferon.

Pathways dependent on the transcription factor NF-κB provide innate immunity against microbes. Karin and colleagues show that mice lacking the kinase IKKβ have IL-1-dependent neutrophilia. Loss of IL-1 signaling restores blood cellularity but severely compromises antimicrobial defense.

The cellular components of the plasma cell niche in the bone marrow have remained elusive. Berek and co-workers show that eosinophils are key providers of plasma cell survival factors in the bone marrow.

The cytidine deaminase AID is essential for the immunoglobulin-diversification processes. Chaudhuri and colleagues identify the splicing factor PTBP2, which promotes the binding of AID to switch-region DNA.

The function of the chemokine CCL8 has remained unknown. Luster and colleagues show that CCL8 has high expression in allergic skin, where it recruits CCR8⁺ T_H2 cells with abundant IL-5 expression.

T_H2 cells are important for allergic and antiparasitic responses. Sun and colleagues demonstrate highly selective expression of the ECM1 protein in T_H2 cells and a key role for it in regulating migration.