CD34‐derived dendritic cells transfected ex vivo with HIV‐Gag mRNA induce polyfunctional T‐cell responses in nonhuman primates

Abstract

The pivotal role of DCs in initiating the immune responses led to their use as vaccine vectors. However, the relationship between DC subsets involved in antigen presentation and the type of elicited immune responses underlined the need for the characterization of the DCs generated in vitro. The phenotypes of tissue-derived APCs from a cynomolgus macaque model for human vaccine development were compared with ex vivo-derived DCs. Monocyte/macrophages predominated in bone marrow (BM) and blood. Myeloid DCs (mDCs) were present in all tested tissues and were more highly represented than plasmacytoid DCs (pDCs). As in human skin, Langerhans cells (LCs) resided exclusively in the macaque epidermis, expressing CD11c, high levels of CD1a and Langerin (CD207). Most DC subsets were endowed with tissue-specific combinations of PRRs. DCs generated from CD34+ BM cells (CD34-DCs) were heterogeneous in phenotype. CD34-DCs shared properties (differentiation and PRR) of dermal and epidermal DCs. After injection into macaques, CD34-DCs expressing HIV-Gag induced Gag-specific CD4+ and CD8+ T cells producing IFN-γ, TNF-α, MIP-1β or IL-2. In high responding animals, the numbers of polyfunctional CD8+ T cells increased with the number of booster injections. This DC-based vaccine strategy elicited immune responses relevant to the DC subsets generated in vitro.

Whole blood stimulation with Toll-like receptor (TLR)-7/8 and TLR-9 agonists induces interleukin-12p40 expression in plasmacytoid dendritic cells in rhesus macaques but not in humans

“…Cross‐linking of DCIR was shown to result in reduced IFN‐α induction upon TLR‐9 stimulation , and similar inhibitory effects were reported following incubation with the CLR ligand mannan . Interestingly, BDCA2 [our unpublished observation and documented at the NIH non‐human primate reagent resource portal (http://nhpreagents.bidmc.harvard.edu/NHP)] and DCIR were shown to be absent on pDC in rhesus macaques. Although not investigated here, a difference in the balance between activating TLRs and inhibitory CLRs could lead to different levels of pDC activation, possibly translating into a difference in cytokine production pattern.…”

Macrophage- and Neutrophil-Derived TNF-α Instructs Skin Langerhans Cells To Prime Antiviral Immune Responses

“…NHPs are a more relevant model than mice for the testing of human vaccines. We have previously demonstrated that NHP and human DC subsets have similar tissue distributions and bear analogous differentiation and activation markers, including C-type lectin receptors (9). Diverse DC populations can be identified in the macaque skin: LCs, which express langerin (CD207), are found exclusively in the epidermis while DC expressing DC-SIGN (CD209) are localized in the dermis (Fig.…”

Immunologic Characterization of a Rhesus Macaque H1N1 Challenge Model for Candidate Influenza Virus Vaccine Assessment

“…HQ738667.1). The 12E12 antibody binds efficiently to recombinant CD40 ectodomain from rhesus macaques and to DCs from cynomolgus macaques (15). A previous study showed that the dimeric HA1 domain expressed as a C-terminal H-chain antibody fusion can fully deplete protective anti-HA1 antibodies and can generate protective immune responses in mice (16).…”

“…KM246788). The 15C4 antibody binds efficiently to recombinant rhesus macaque LOX-1 ectodomain protein (S. M. Zurawski, unpublished data) and binds to CD11c ϩ and CD14 ϩ cells in the peripheral blood mononuclear cells (PBMCs) of cynomolgus macaques (12,15). Anti-human DCIR 9E8-NP (GenBank accession no.…”

“…JX002666). The 9E8 antibody binds efficiently to recombinant rhesus macaque DCIR ectodomain protein (S. M. Zurawski, unpublished data) and binds to various antigen-presenting cell types of cynomolgus macaques (15). Anti-human CD40 12E12-HA1s (GenBank accession no.…”