It has been much debated how the Drosophila immune system can recognize bacterial peptidoglycan that is often hidden. We show that bacteria separated from Drosophila S2 cells by a semipermeable membrane can upregulate the Imd pathway. Supernatants from exponentially growing but not from stationary-phase bacterial cultures induce antimicrobial peptides. It is also made likely that the shed elici...

The duration of immunity to heartwater normally varies from 6 months to 4 years. In Angora goats it may be difficult to produce a specific immune response with vaccination. Humoral immunity does not appear to play a role in the development of immunity. It has been suggested that cellular immunity may play a role, but the actual mechanism involved remains obscure. The specific immune response de...

The ligand for CD40 (CD40L) is expressed on the surface of activated CD4+ T cells and its role in T-B cell collaborations and thymus-dependent humoral immunity is well established. Recently, by generating CD40L-knockout mice, we have confirmed its previously described role in humoral immunity and defined another important function of this molecule in the in vivo clonal expansion of antigen-spec...

Dengue viruses (DENV) are the most important mosquito transmitted viral pathogens infecting humans. DENV infection produces a spectrum of disease, most commonly causing a self-limiting flu-like illness known as dengue fever; yet with increased frequency, manifesting as life-threatening dengue hemorrhagic fever (DHF). Waning cross-protective immunity from any of the four dengue serotypes may enh...