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Taking into account the effects of the immune response and delay, and complexity on HIV-1 transmission, a multiscale AIDS/HIV-1 model is formulated in this paper. The multiscale model is described by a within-host fast time model with intracellular delay and immune delay, and a between-host slow time model with latency delay. The dynamics of the fast time model is analyzed, and includes the stability of equilibria and properties of Hopf bifurcation. Further, for the coupled slow time model without an immune response, the basic reproduction number R 0 h is defined, which determines whether the model may have zero, one, or two positive equilibria under different conditions. This implies that the slow time model demonstrates more complex dynamic behaviors, including saddle-node bifurcation, backward bifurcation, and Hopf bifurcation. For the other case, that is, the coupled slow time model with an immune response, the threshold dynamics, based on the basic reproduction number R ˜ 0 h , is rigorously investigated. More specifically, if R ˜ 0 h < 1 , the disease-free equilibrium is globally asymptotically stable; if R ˜ 0 h > 1 , the model exhibits a unique endemic equilibrium that is globally asymptotically stable. With regard to the coupled slow time model with an immune response and stable periodic solution, the basic reproduction number R 0 is derived, which serves as a threshold value determining whether the disease will die out or lead to periodic oscillations in its prevalence. The research results suggest that the disease is more easily controlled when hosts have an extensive immune response and the time required for new immune particles to emerge in response to antigenic stimulation is within a certain range. Finally, numerical simulations are presented to validate the main results and provide some recommendations for controlling the spread of HIV-1. [ABSTRACT FROM AUTHOR]

Immunomodulatory biomaterials are increasingly used in regenerative medicine. Biomimetic glycopeptide hydrogel is found to accelerate cutaneous wound healing by inducing macrophage M2‐type polarization, however, it is unclear whether this will possibly orchestrate a pro‐regenerative T cell immunity. Here the aim of this study is to elucidate the reparative T‐cell immune response in tissue regeneration by augmenting macrophage‐T cell crosstalk with a novel immunomodulatory glycopeptide hydrogel (termed as GRKgel) self‐assembled by mannose receptor‐binding glucomannan (GM) chemically grafted with RADA16‐conjugated T‐cell epitope. The glycopeptide can be phagocytized and processed by macrophages, which then presents peptides to naïve T cells and polarizes them into T helper 2 (TH2) cells through IL‐4‐dependent STAT6/GATA3 or c‐Maf pathways. Strikingly, full‐thickness skin wound repair in mice indicates a superior efficacy of GRKgel on restoring the pathological structure and hair follicle by provoking TH2 immune response, increasing the residence of M2 macrophages, as well as promoting angiogenesis at the local tissue environment. Furthermore, genomics results illustrates the role of GRKgel serving as an immunomodulatory niche, orchestrating immune cell crosstalk and promoting extracellular matrix (ECM) reconstruction. Collectively, this study highlights the significance of crosstalk between immune cells in evoking pro‐healing T‐cell immunity, providing a promising drug‐/cytokine‐free strategy for endogenous tissue regeneration. [ABSTRACT FROM AUTHOR]

Rab GTPases not only play a crucial role in the exocytosis and membrane transport of all eukaryotic cells, but are also gradually being found to be involved in innate immunity in mammals. However, the immunological function of Rab3a in fish remains unclear. In this study, two members of Rab3a, CiRab3aa and CiRab3ab, were cloned from grass carp (Ctenopharyngodon idella) for the first time. It was observed that CiRab3aa exhibited a prompt response to grass carp reovirus (GCRV) infection, and suppressing the expression of the CiRab3aa effectively inhibited GCRV replication, whereas the expression level of the CiRab3ab gene did not affect GCRV replication. Furthermore, overexpression of CiRab3aa significantly suppressed the mRNA levels of TLR9 , TNF-α , IL-1β , IL-6 , IL-10 , ERK , and IFN-I following stimulation with CpG ODN 1670 A, suggesting that CiRab3aa is a negative regulator of TLR9 signaling pathway. In conclusion, this study not only revealed functional differences between CiRab3aa and CiRab3ab in grass carp immunity, providing new sights into understanding their function in teleost fish, but also provided a new target for the treatment strategy of grass carp hemorrhagic disease. These results will help address the harm and economic losses caused by GCRV infection in grass carp breeding industry. • CiRab3aa and CiRab3ab genes were cloned and characterized in grass carp. • There are 7 amino acid differences in the Rab domain of Rab3aa and Rab3aa protein. • Knockdown of CiRab3aa significantly inhibited the replication of GCRV. • CiRab3aa was a negative regulator of the TLR9 signaling pathway. [ABSTRACT FROM AUTHOR]