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Introduction: Targeting antigens to dendritic cells (DCs) in vivo via a DC-restricted endocytic receptor, DEC205, has been validated to enhance immunity in several vaccine platforms. Particularly atttractive is selected delivery of proteins to DCs in vivo because it enables proteins to be more immunogenic and provides a cheaper and effective way for repeated immunizations., Methods: In this study, we tested the efficacy of a single chain antibody to DEC205 (scDEC) to deliver protein antigens selectively to DCs in vivo and to induce protective immunity., Results: In comparison to soluble Ovalbumin (OVA) antigen, when recombinant scDEC:OVA protein was injected subcutaneously (s.c.) into mice, the OVA protein was selectively presented by DCs to both TCR transgenic CD8 + and CD4 + T cells approximately 500 and 100 times more efficient than soluble OVA, respectively, and could persist for seven days following s.c. injection of the scDEC205:OVA. Similarly selective targeting of HIV Gag P24 to DCs in vivo using scDEC-Gag protein plus polyICLC vaccine resulted in strong, long lasting, polyfuntional CD4 + T cells in mice which were protective against airway challenge by a recombinant vaccinia-gag virus., Conclusion: Thus targeting protein antigens to DCs using scDEC can be used either alone or in combination with other strategies for effective immunization., (© 2017 The Authors. Immunity, Inflammation and Disease Published by John Wiley & Sons Ltd.)

Introduction: Recombinant Newcastle Disease virus (rNDV) vectored vaccines are safe mucosal applicable vaccines with intrinsic immune-modulatory properties for the induction of efficient immunity. Like all viral vectored vaccines repeated inoculation via mucosal routes invariably results to immunity against viral vaccine vectors. To obviate immunity against viral vaccine vectors and improve the ability of rNDV vectored vaccines in inducing T cell immunity in murine air way we have directed dendritic cell targeted HIV-1 gag protein (DEC-Gag) vaccine; for the induction of helper CD4 + T cells to a Recombinant Newcastle disease virus expressing codon optimized HIV-1 Gag P55 (rNDV-L-Gag) vaccine., Methods: We do so through successive administration of anti-DEC205-gagP24 protein plus polyICLC (DEC-Gag) vaccine and rNDV-L-Gag. First strong gag specific helper CD4 + T cells are induced in mice by selected targeting of anti-DEC205-gagP24 protein vaccine to dendritic cells (DC) in situ together with polyICLC as adjuvant. This targeting helped T cell immunity develop to a subsequent rNDV-L-Gag vaccine and improved both systemic and mucosal gag specific immunity., Results: This sequential DEC-Gag vaccine prime followed by an rNDV-L-gag boost results to improved viral vectored immunization in murine airway, including mobilization of protective CD8 + T cells to a pathogenic virus infection site., Conclusion: Thus, complementary prime boost vaccination, in which prime and boost favor distinct types of T cell immunity, improves viral vectored immunization, including mobilization of protective CD8 + T cells to a pathogenic virus infection site such as the murine airway., (© 2017 The Authors. Immunity, Inflammation and DiseasePublished by John Wiley & Sons Ltd.)

Regulatory T (Treg) cells play a key role in dampening excessive immune activation. However, antiretroviral therapy (ART) -naive HIV-1 infection maintains the immune system in a sustained state of activation that could alter both Treg cell surface markers and functions. As Treg cell surface markers are directly linked to their functions the overall objective of this study was to determine how ART-naive HIV infection affects the phenotypic properties of Treg cells. Our data showed that in ART-naive HIV-1 infection, Treg cells are dominated by effector (CD45RA +  CD27 -  CCR7 - CD62L - ) and effector memory (CD45RA -  CD27 -  CCR7 -  CD62L - ) cells. In contrast Treg cells from HIV-negative individuals were mainly naive (CD45RA +  CD27 +  CCR7 +  CD62L + ) and central memory (CD45RA - CD27 +  CCR7 +  CD62L + ) cells. Whereas effector and effector memory Treg cells showed enhanced expression of CD39 (P < 0·05), CD73 (P < 0·001), HLA-DR and CD38 (P < 0·001); naive and central memory Treg cells showed a significant reduction in the expression of these markers. Overall Treg cell frequencies within total CD4 + T cells correlated positively with plasmatic HIV-1 viral load. As increased viral load is associated with augmented CD4 + T-cell destruction; this could suggest a resistance of peripheral Treg cells to HIV-1 destruction. Hence the modulation of Treg cell phenotype and frequencies could be considered in designing immunotherapeutic strategies targeting immune system restoration during HIV-1 infection., (© 2017 John Wiley & Sons Ltd.)