The death receptor (DR) ligand TRAIL is being evaluated in clinical trials as an anti-cancer agent; however, many studies have found that TRAIL also enhances tumor progression by activating the NF-κB pathway in apoptosis-resistant cells. Although RIP1, cFLIP and caspase-8 have been implicated in TRAIL-induced JNK and NF-κB activation, underlying mechanisms are unclear. By examining the kinetics of pathway activation in TRAIL-sensitive lymphoma cells wild-type or deficient for RIP1, TRAF2, cIAP1/2 or HOIP, we report here that TRAIL induces two phases of JNK and NF-κB activation. The early phase is activated by TRAF2- and cIAP1-mediated ubiquitination of RIP1, whereas the delayed phase is induced by caspase-dependent activation of MEKK1 independent of RIP1 and TRAF2 expression. cFLIP overexpression promotes the early phase but completely suppresses the delayed phase of pathway activation in lymphoma cells, whereas Bcl-2 overexpression promotes both the early and delayed phases of the pathways. In addition, stable overexpression of cFLIP in RIP1- or TRAF2-deficient cells confers resistance to apoptosis, but fails to mediate NF-κB activation. HOIP is not essential for, but contributes to, TRAIL-induced NF-κB activation in cFLIP-overexpressing cells. These findings not only elucidate details of the mechanisms underlying TRAIL-induced JNK and NF-κB activation, but also clarify conflicting reports in the field.

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Lyme disease classically evolves through clinical manifestations according to the stage of illness. Because many of the systemic symptoms are non-specific, and because serology may yield false negative results, cutaneous findings merit even greater importance to diagnosis. The prototypical skin lesion, erythema migrans (EM), occurs early and is the only independent diagnostic clinical feature according to the guidelines of the Infectious Diseases Society of America. EM itself has protean guises, being, at times, vesicular, indurated, necrotic, purpuric, solid, or targetoid, but it is not the sole Borrelia-associated skin lesion. Acrodermatitis chronica atrophicans and borrelial lymphocytoma cutis are other well-known skin manifestations. A rare cutaneous manifestation that is increasingly reported in Lyme patients is panniculitis, which develops after dissemination of the spirochete. We present such a case in a patient who was initially treated for cellulitis as well as neck and radicular leg pain, thereby expanding the cutaneous spectrum of Lyme disease.

Amyloid elastosis is an exceedingly rare form of amyloidosis characterized by amyloid material deposited on dermal elastic fibers. Most reported cases have been associated with systemic amyloid light-chain amyloidosis. A single previously reported case of amyloid elastosis showed evidence that the amyloid material was derived from light-chain proteins and was associated with a monoclonal plasma cell infiltrate but failed to demonstrate systemic involvement. As a result, the case was felt to represent localized cutaneous amyloid elastosis. We present a case of localized cutaneous amyloid elastosis that is not associated with a definitive monotypic plasma cell population or with systemic amyloidosis. We also review the clinical and histopathologic features of reported cases of amyloid elastosis and discuss possible etiologic considerations. Because amyloid elastosis can be either localized to the skin or associated with systemic involvement, additional workup to exclude an underlying plasma cell dyscrasia or hematologic malignancy is warranted.