Reviews & Analysis

Is apoptotic cell death due to the action of caspases? Caspase inhibition can actually encourage death in tumor necrosis factor–induced shock, indicating that caspase activation is not synonymous with apoptotic demise.

Tissue-specific antigens are expressed in the thymic medulla under the influence of the AIRE gene, suggesting that unresponsiveness to these peripheral antigens is a result of central tolerance. New data on T cell tolerance in AIRE^−/− mice strongly support this hypothsis.

How autoreactive thymocytes die remains a question that has not been fully answered. New results supporting a role for the death ligand TRAIL may take us a step closer to unraveling this mystery.

Angiogenin was discovered as an inducer of blood vessel formation. However, a new study implicates it in antimicrobial host defense.

In a sea of potential suitors, it is important for T cells to discriminate between self and nonself ligands. New data provide a molecular understanding of how this may be achieved.

The idea that genes are transcriptionally activated by rapid CpG demethylation has been controversial. New data provides the most compelling evidence yet, implicating a mysterious enzyme activity that can actively demethylate DNA.

The lineage relationships of T_EM and T_CM and their ability to confer protective immunity are not well understood. New data suggest T_EM are poorer mediators of protective immunity and convert to T_CM over time.

Cellular parasites have evolved clever anti-apoptosis strategies to avoid being killed by CTLs. However, CTL release of granzyme A inactivates a key repair enzyme, Ape1, ensuring death of infected cells.

The histone methyltransferases E(Z) and Ezh2 may control developmental fate by regulating homeobox gene expression. Emerging evidence suggests Ezh2 also plays a role in B cell development by controlling V(D)J recombination.

Graft-versus-host disease results when donor T cells attack immunocompromised hosts. New data show the distinct environment of Peyer's patches triggers the activation of these aggressive anti-host responses.

The identification of a third TIR domain adaptor molecule involved in TLR3-mediated interferon-β induction helps explain TLR signaling specificity.

Common lymphoid progenitor cells are the earliest lymphoid progenitor cells assumed to give rise to B and T lineages. The identification of a novel early T lineage progenitor now challenges this model.

Although elimination may be key to a healthy response to some microbes, a recent paper in Nature reports that regulatory T cells actually aid the survival of some intracellular parasites, which ensures a memory response.

Type I IFNs are important in antiviral immunity. Two studies report the identification of another family of molecules that have similar properties to the type I IFNs but are otherwise structurally and genetically distinct.

A study in a recent issue of Nature showing the lack of cross-protective immunity in an infected patient to a closely related strain of HIV-1 suggests that vaccine strategy may need to be re-examined.

Serum IgE concentrations are kept low to avoid potential allergic complications. New data show how Id2 suppresses class switching to the ε isotype and reduces IgE expression.

Signals through the pre-BCR play key roles in B cell development. New data reveal how two downstream components, SLP-65 and the tyrosine kinase Abl, regulate pre-BCR surface expression and immunoglobulin light chain expression.