Specific short peptides derived from motifs found in full-length proteins, in our case HIV-1 Nef, not only retain their biological function, but can also competitively inhibit the function of the full-length protein. A set of 20 Nef scanning peptides, 20 amino acids in length with each overlapping 10 amino acids of its neighbor, were used to identify motifs in Nef responsible for its induction of apoptosis. Peptides containing these apoptotic motifs induced apoptosis at levels comparable to the full-length Nef protein. A second peptide, derived from the Secretion Modification Region (SMR) of Nef, retained the ability to interact with cellular proteins involved in Nef's secretion in exosomes (exNef). This SMRwt peptide was used as the "bait" protein in co-immunoprecipitation experiments to isolate cellular proteins that bind specifically to Nef's SMR motif. Protein transfection and antibody inhibition was used to physically disrupt the interaction between Nef and mortalin, one of the isolated SMR-binding proteins, and the effect was measured with a fluorescent-based exNef secretion assay. The SMRwt peptide's ability to outcompete full-length Nef for cellular proteins that bind the SMR motif, make it the first inhibitor of exNef secretion. Thus, by employing the techniques described here, which utilize the unique properties of specific short peptides derived from motifs found in full-length proteins, one may accelerate the identification of functional motifs in proteins and the development of peptide-based inhibitors of pathogenic functions. Video LinkThe video component of this article can be found at

placed): 0.929(0.712); (undisplaced/displaced): 0.847(0.249); Comorbidities (no/yes): 0.963(0.836); Surgical types (arthroplasty/osteosynthesis): 1.405(0.026); Antiosteoporotic treatment (Ͻ2years/none): 0.512(0.006); (2years/none): 0.529 (0.004). CONCLUSIONS: The risk of second hip fracture in elderly 8 year follow up period was the highest in female, in older age-group, in patient after arthroplasty and in patient without pharmacologic treatment for osteoporosis. The effect of single risk factors on the risk of subsequent hip fractures should be investigated in the future. OBJECTIVES:To perform a systematic review of prospective observational studies in patients with RA to examine the safety of TNF-I in daily practice, with particular focus on malignancy, and serious and opportunistic infections. METHODS: Comprehensive searches of Medline, Embase, the Cochrane Database of Systematic Reviews, and ACR, EULAR and BSR conference abstracts were performed according to a pre-specified protocol that excluded randomised controlled trials. Type and site of malignancies, as well as serious and opportunistic infections, such as tuberculosis, were extracted. Publications that reported incidence rates, standardised incidence ratios or measures of relative risk, such as incidence rate ratios, odds ratios or hazard ratios, were selected for random effects meta-analyses. RESULTS: A total of 2039 papers and 1979 abstracts were identified, of which 48 and 21 respectively met the pre-specified inclusion criteria. The pooled estimate for the relative risk (RR) of overall malignancy from seven studies was 0.94 (95% CI 0.84, 1.05; I2 ϭ 0.0%). In contrast, the meta-analysis of serious infections had much higher heterogeneity, I2 ϭ 40.9%, RR ϭ 1.34 (95% CI 1.06, 1.62). CONCLUSIONS: This review included data from European, US and Japanese studies with Ͼ130,000 patient years of exposure. Data from such a large number of patients, often with extended follow-up, overcomes the weaknesses of clinical trial data, specifically fewer patient numbers and usually shorter exposure times. Observational data has known weaknesses related to non-randomisation such that statistical techniques have to be used to overcome differences between the exposed and reference cohorts. Despite such confounding factors, consideration of the available evidence leads to the conclusion that there is an increased risk of serious and opportunistic infections with TNF-I, although no evidence of increased the risk of malignancy. Meta-analyses of randomised controlled trials have come to different conclusions regarding both the risk of infections and of malignancy.

Purpose: Our group and others have demonstrated a potential role for exosomes in HIV pathogenesis. Exosomes secreted from HIV-infected cells were shown to contain coreceptors for HIV. We have shown HIV Nef-containing exosomes from HIV-infected cells induced apoptosis in bystander CD4+ T cells. This suggests that exosomes from HIV-infected cells could drive CD4 depletion and immune activation contributing to HIV pathogenesis. Thus, exosomes from HIV-1+ viremic individuals were investigated for protein content. Methods: Exosomes were isolated from plasma of ARV naïve, HIV+ and negative control individuals by differential centrifugation followed by iodixanol density gradient ultracentrifugation. Biochemical characterization included AChE activity, flotation in iodixanol gradients, and Western analysis for exosomal markers. Plasma and purified exosomes were also tested for levels of 30 cytokines and chemokines by multiplex assay. Results: The concentrations of 10 innate cytokines (IL-15, IP-10, FasL, CD40L, IFNα, IFNβ, MIP-1α, MIP-1β, TNFα, and ICAM-1) were found to be associated with and significantly elevated in exosomes from HIV+ individuals relative to negative controls, suggesting a contributing role in generalized chronic immune inflammation. Conclusion: This is the first demonstration of innate cytokines in exosomes of HIV+ individuals. It suggests a potential mechanism for HIV-1 driven immune modulation and propagation of HIV via activation of bystander target cells.

Specific short peptides derived from motifs found in full-length proteins, in our case HIV-1 Nef, not only retain their biological function, but can also competitively inhibit the function of the full-length protein. A set of 20 Nef scanning peptides, 20 amino acids in length with each overlapping 10 amino acids of its neighbor, were used to identify motifs in Nef responsible for its induction of apoptosis. Peptides containing these apoptotic motifs induced apoptosis at levels comparable to the full-length Nef protein. A second peptide, derived from the Secretion Modification Region (SMR) of Nef, retained the ability to interact with cellular proteins involved in Nef's secretion in exosomes (exNef). This SMRwt peptide was used as the "bait" protein in co-immunoprecipitation experiments to isolate cellular proteins that bind specifically to Nef's SMR motif. Protein transfection and antibody inhibition was used to physically disrupt the interaction between Nef and mortalin, one of the isolated SMR-binding proteins, and the effect was measured with a fluorescent-based exNef secretion assay. The SMRwt peptide's ability to outcompete full-length Nef for cellular proteins that bind the SMR motif, make it the first inhibitor of exNef secretion. Thus, by employing the techniques described here, which utilize the unique properties of specific short peptides derived from motifs found in full-length proteins, one may accelerate the identification of functional motifs in proteins and the development of peptide-based inhibitors of pathogenic functions.