October 2011 | Volume 208, No. 11
- Assembling defenses against therapy-resistant leukemic stem cells: Bcl6 joins the ranks
Bcl6 is added to a growing list of signaling pathways and molecules that influence resistance of leukemic stem cells to targeted therapy.
- Unraveling the basic biology and clinical significance of the chlamydial plasmid
New evidence indicates that the conserved plasmid shared among Chlamydial species may be key for understanding and vaccinating against these pathogenic bacteria.
Brief Definitive Reports
- Osteoclasts are dispensable for hematopoietic stem cell maintenance and mobilization
The mobilization of hematopoietic stem cells does not require osteoclasts, which may even have an inhibitory effect.
- The p.Arg63Trp polymorphism controls Vav1 functions and Foxp3 regulatory T cell development
A single nucleotide polymorphism causing constitutive activation of Vav1 results in increased natural Treg generation and is responsible for the imbalance between Vav1 GEF and adaptor functions.
- Tolerogenic function of Blimp-1 in dendritic cells
Diminished expression of Blimp-1 in DCs results in the development of lupus-like autoantibodies in female mice, but not male mice, as a result of increased IL-6 driving enhanced germinal center responses.
- The requirements for natural Th17 cell development are distinct from those of conventional Th17 cells
A distinct population of Th17 cells develops in the thymus with innate immune cell characteristics, different selection requirements, and skewed TCR gene usage compared with peripheral Th17 cells.
- XRCC1 suppresses somatic hypermutation and promotes alternative nonhomologous end joining in Igh genes
As revealed using mice heterozygous for the base excision repair (BER) protein XRCC1, BER and mutagenic repair pathways can simultaneously compete for access to single-strand breaks induced by activation-induced deaminase.
- A live-attenuated chlamydial vaccine protects against trachoma in nonhuman primates
In cynomolgus macaques, ocular infection with a live trachoma strain lacking the conserved 7.5-kb plasmid induced no ocular pathology but facilitated solid or partial protection from subsequent infection with a virulent strain of trachoma.
- Critical role of the neutrophil-associated high-affinity receptor for IgE in the pathogenesis of experimental cerebral malaria
FcεR1-expressing neutrophils accumulate in the brain of mice infected with Plasmodium berghei (PbANKA) and promote the development of experimental cerebral malaria.
- Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated
Many HIV-1 envelope-reactive antibodies shortly after HIV-1 transmission may arise from crow-reactive memory B cells previously stimulated by non-HIV-1 host or microbial antigens
- Regulation of neutrophils by interferon-γ limits lung inflammation during tuberculosis infection
IFN-γ functions to suppress neutrophil accumulation in the lungs of mice infected with M. tuberculosis, in part by suppressing IL-17 production from CD4+ T cells.
- Transcytosis of Listeria monocytogenes across the intestinal barrier upon specific targeting of goblet cell accessible E-cadherin
Listeria monocytogenes targets accessible E-cadherin expressed on mucus-producing goblet cells to invade the intestinal tissue.
- Involvement of interleukin-21 in the regulation of colitis-associated colon cancer
IL-21 expression is increased in the gut of patients with colitis-associated colon cancer, and genetic ablation or antibody neutralization of IL-21 reduces tumor size and inflammation in mice treated with dextran sulfate sodium and azoxymethane.
- Fumarates improve psoriasis and multiple sclerosis by inducing type II dendritic cells
Fumarates suppress Th1 responses by blocking IL-12 and IL-23 production by dendritic cells via distinct pathways.
- DOCK8 deficiency impairs CD8 T cell survival and function in humans and mice
As shown by analysis of mice and humans bearing DOCK8-inactivating mutations, DOCK8 plays a cell-autonomous role in survival of naive CD8 T cells, LFA-1 polarization toward the immune synapse, and CD8 T cell memory and recall responses following viral infection.