Cell biology: Taking dendritic cells into medicine

The medical importance of a key component of the immune system is reviewed in this week’s Nature. Dendritic cells (DCs) — named for their tree-like or dendritic shapes — have a pivotal role in antigen recognition and the generation of an immune response, and have the capacity to either prevent or encourage disease.

In the review, Ralph Steinman and Jacques Banchereau present some of the medical implications of DC biology that account for illness and suggest opportunities for prevention and therapy. They outline recent advances in DC biology, which concern the location, maturation and specialization of these cells, and discuss the relevance of DCs to a number of medical situations. In the settings of infection and cancer, microbes and tumours can exploit DCs to evade an immune response, but DC’s can also induce resistance to infection, which can be readily enhanced with DC-targeted vaccines. During allergy, autoimmunity and transplant rejection, DCs instigate unwanted responses that cause disease, but again can be harnessed to silence these conditions with novel therapies.

The authors suggest that further research should be aimed at these key players in disease development, which represent an unavoidable target in the design of future treatments.

Quantum information: Processing with superconducting circuits

Two research groups have successfully used a superconducting communication line to store and transfer information between distant quantum bits, or qubits, on a chip. The development reported in Nature this week is an important step towards developing quantum computers.

Previously scientists had only transferred information directly qubit to qubit in a superconducting system. Now groups led by Raymond Simmonds and Johannes Majer demonstrate that quantum coherence of the signal can be maintained over longer distances using photons. Information about the quantum state of one qubit is passed into an optical resonant cavity several millimetres long. A second qubit at the other end of the cavity retrieves the information at a later time. The technique could be scaled up, allowing a large number of qubits to communicate across an electronic chip.

Molecular biology: Effective gene silencing

Despite recent concerns, new research shows that small interfering RNAs (siRNAs) can be effective and safe tools for silencing genes in vivo. The work, published online this week in Nature, demonstrates the use of siRNAs in mouse and hamster, without any demonstrable effect on microRNAs.

The in vivo application of RNA interference for basic research as well as development of therapeutics is rapidly expanding. However, recent work has identified potential for toxic effects in the mouse liver caused by saturation of the microRNA biosynthetic pathway.

David Bumcrot and colleagues show near-complete silencing of two mouse and hamster liver genes by intravenous administration of siRNAs. This silencing is specific to the targeted gene and is not associated with any overt toxicity. They argue that their findings support continued siRNA research and their further development as a new class of therapeutics.