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Flt3 ligand (FL) and granulocyte-macrophage colony-stimulating factor (GM-CSF) are important growth factors for dendritic cells (DC). Substantial numbers of DC can be generated in vivo following the administration of either factor. We sought to extend our knowledge of the functional properties of these cells including their ability to prime naïve CD8(+) T cells. In addition, we compared the nature of the DC generated in vivo with the single cytokines to those generated with the combination of FL+polyethylene glycol-modified GM-CSF (pGM-CSF). Treatment with FL+pGM-CSF yielded greater numbers of both CD11b(low) and CD11b(high) DC than with either cytokine alone, and these DC were more efficient at antigen (Ag) capture. The FL+pGM-CSF-generated CD11b(low) DC lacked expression of CD8alpha. Following treatment with LPS in vivo, all DC subsets upregulated CD40, CD80, CD86, and MHC class II expression, but surprisingly Ag capture was not downregulated and some DC subsets retained expression of intracellular MHC class II vesicles. Thus, even after activation in vivo with LPS, DC retained Ag capture properties of immature DC, and Ag presentation/costimulation properties of mature DC. Though all DC subsets stimulated CD4(+) T cell proliferation equivalently, FL-generated DC were more efficient at priming Ag-specific CD8(+) cytolytic T cells than DC generated with either pGM-CSF alone or FL+pGM-CSF, and CD11b(high) DC were more efficient at priming CD8(+) T cells than CD11b(low) DC.

Reversal of the visible signs of facial aging with the use of injectable products as an alternative to surgery has become more popular, with nearly 5 million procedures performed in the United States in 2012. Volume augmentation products, such as hyaluronic acid (HA), calcium hydroxylapatite (CaHA), and poly-L-lactic acid (PLLA), are often used in combination with one another and with neurotoxins for facial rejuvenation because of the complementary modes of action. This article presents 2 case reports involving patientspecific combinations of 2 different HA products, injectable PLLA, and CaHA with incobotulinumtoxinA or abobotulinumtoxinA. The combination of HA, CaHA, PLLA, and neurotoxins has resulted in outstanding outcomes for many patients, with no clinical evidence of increased adverse events secondary to combination therapy.

Dendritic cells (DCs) represent a family of ontogenically distinct leukocytes involved in immune response regulation. The ability of DCs to stimulate T-cell immunity has led to their use as vectors for immunotherapy vaccines. However, it is unclear whether and to what degree in vitro–generated DCs are representative of DCs that develop in vivo. Treatment of mice with human Flt3 ligand (FL) dramatically increases the number of DCs. We report here that administration of FL to healthy human volunteers increased the number of circulating CD11c+ IL-3Rlow DC (mean 44-fold) and CD11c− IL-3Rhigh DC precursors (mean 12-fold). Moreover, the CD11c+ DCs were efficient stimulators of T cells in vitro. Thus, FL can expand the number of circulating, functionally competent human DCs in vivo.

Dendritic cells (DC) are potent APCs that can be characterized in the murine spleen as CD11bhighCD11chigh or CD11blowCD11chigh. Daily injection of mice of Flt3 ligand (FL) into mice transiently expands both subsets of DC in vivo, but the effect of administration of GM-CSF on the expansion of DC in vivo is not well defined. To gain further insight into the role of GM-CSF in DC development and function in vivo, we treated mice with polyethylene glycol-modified GM-CSF (pGM-CSF) which has an increased half-life in vivo. Administration of pGM-CSF to mice for 5 days led to a 5- to 10-fold expansion of CD11bhighCD11chigh but not CD11blowCD11chigh DC. DC from pGM-CSF-treated mice captured and processed Ag more efficiently than DC from FL-treated mice. Although both FL- and pGM-CSF-generated CD11bhighCD11chigh DC were CD8α−, a greater proportion of these DC from pGM-CSF-treated mice were 33D1+ than from FL-treated mice. CD11blowCD11chigh DC from FL-treated mice expressed high levels of intracellular MHC class II. DC from both pGM-CSF- and FL-treated mice expressed high levels of surface class II, low levels of the costimulatory molecules CD40, CD80, and CD86 and were equally efficient at stimulating allogeneic and Ag-specific T cell proliferation in vitro. The data demonstrate that treatment with pGM-CSF in vivo preferentially expands CD11bhighCD11chigh DC that share phenotypic and functional characteristics with FL-generated CD11bhighCD11chigh DC but can be distinguished from FL-generated DC on the basis of Ag capture and surface expression of 33D1.

Background Injectable poly-L-lactic acid (PLLA) is a synthetic polymer indicated for the correction of facial wrinkles and folds. Animal studies have shown that implantation of PLLA stimulates collagen synthesis; human studies have been limited. Objective To investigate human tissue response to injectable PLLA. Methods and materials In this exploratory single-arm, open-label study, 14 healthy subjects were administered injectable PLLA; punch biopsies at 3, 6, and 12 months were analyzed for qualitative and quantitative changes from baseline in collagen types I and III and assessed for inflammatory responses. Results Quantitative and qualitative increases were observed for collagen types I and III at 3 and 6 months and were statistically significant for collagen type I at 3 and 6 months. Post hoc analyses at 12 months showed nominal collagen increases but were hindered by technical difficulties. The degree of inflammatory response was similar to baseline at 3, 6, and 12 months; all subjects were found to have no or mild inflammation after baseline. Adverse events were mild and among those reported previously. Conclusion Results of this study in humans found statistically significant stimulation of collagen type I with no or mild inflammatory response after administration of injectable PLLA.

Background Injectable poly-L-lactic acid (PLLA) is a biodegradable synthetic polymer device that stimulates collagen production, leading to gradual volume restoration. It has been used worldwide for more than a decade to treat the lines and wrinkles of the aging face and in individuals with the human immunodeficiency virus for treatment of facial lipoatrophy. Objective To provide an overview of the experience with injectable PLLA in Europe and the United States and the practices that have improved product use. Materials and methods A review of the literature was conducted, and the authors' clinical experience was included detailing the evolution of the use of injectable PLLA for facial restoration. Results Although relatively high rates of nodule and papule formation were reported during early use of injectable PLLA, updated methods have led to better safety and efficacy, including patient selection, preparation, and instruction; product preparation; timing of injections and avoidance of overcorrection; an updated understanding of the anatomy of the aging face; and site-specific injection techniques. Conclusion Important lessons have been learned that have enhanced the safety and efficacy of injectable PLLA and have made it a desirable product for restoring facial volume.

BACKGROUND Studies of injectable poly-L-lactic acid (PLLA) in human immunodeficiency virus (HIV)-associated facial lipoatrophy have predominantly included male Caucasians. OBJECTIVE To report cumulative year 2 interim study results examining the safety and efficacy of injectable PLLA in subjects with HIV categorized according to Fitzpatrick skin type and sex. MATERIALS AND METHODS This is an ongoing open-label, multicenter, 5-year study of 290 treated subjects. After correction with injectable PLLA, subjects are being followed annually. Primary end points include incidence and severity of treatment-emergent adverse events (TEAEs). Secondary end points include mean change from baseline of James scale severity grade and treatment satisfaction. RESULTS At 2 years, TEAE incidences were: potentially related to study product (n = 53,18.3%) or injection procedure (n = 71, 24.5%), injection-site nodules (n = 24, 8.3%) and papules (n = 25, 8.6%). No hypertrophic scars, keloids, or product-related serious TEAEs were reported. Mean improvement in James scale grade for all groups was 1.4 (p < .001), and 89.4% of subjects and 95.5% of physicians rated treatment satisfaction as very good or excellent. CONCLUSION At 2 years, injectable PLLA is a safe and effective long-term treatment for HIV-associated facial lipoatrophy regardless of Fitzpatrick skin type; confirmation of these results will be needed at the completion of this 5-year study.