Hisashi Akiyama

Research Assistant Professor, Virology, Immunology & Microbiology

Hisashi Akiyama


My research goal is to understand pathogenesis of HIV. In particular, I am interested in the role of myeloid cells in establishment and dissemination of HIV infection and mechanisms of virus evasion from innate and adaptive host immune responses.

Cells of myeloid lineage such as monocytes, dendritic cells (DCs) and macrophages in addition to CD4+ T cells, are susceptible to HIV infection. Myeloid cells have been shown to play a critical role in HIV acquisition at mucosal surfaces and replication in tissues such as central nervous system. Moreover, tissue-resident macrophages can be a major source of HIV production at the late stages of viral infection. To fully understand HIV pathogenesis, it is crucial to elucidate the roles of myeloid cells in HIV infection.

HIV-1 has exploited DCs as a vehicle to infect T cells via a unique mechanism called trans-infection. Our previous work has identified CD169/Siglec1 as the receptor on DCs that binds to virion-incorporated lipids to initiate trans-infection. CD169 not only enhances HIV-1 replication by trans-infecting T cells, but also contributes to immune evasion. Upon binding to HIV-1 particles, CD169 traffics HIV-1 virions into a sac-like plasma membrane-associated structure, which serves as a sanctuary for HIV-1 against neutralizing antibodies. Ongoing projects are focused on a role of CD169–HIV-1 interaction in attenuating host countermeasures against HIV-1 infection including humoral immunity and type I interferon responses.

Myeloid cells are sentinel cells and elicit robust immune responses upon sensing of invading pathogens. Since antigen persists chronically in HIV-1 infection, continuous activation of/by myeloid cells may play a key role in chronic immune activation, a hallmark of HIV-1 infection. In fact, it has been shown that infection of macrophages with HIV-1 induces production of pro-inflammatory cytokines and interferon stimulated genes (ISGs) expression. However, the molecular mechanisms underlying the HIV-1-induced activation of macrophages still remain unclear. Current studies are focused on understanding the viral and host factors involved in macrophage activation and its consequences in HIV-1 pathogenesis.


  • Kyoto University, PhD
  • Kyoto University, BE/BEng


  • Published on 3/11/2024

    Akiyama H, Okubo R, Toyomaki A, Miyazaki A, Hattori S, Nohara M, Sasaki Y, Kubota R, Okano H, Takahashi K, Hasegawa Y, Wada I, Uchino T, Takeda K, Ikezawa S, Nemoto T, Ito YM, Hashimoto N. The evaluation study for social cognition measures in Japan: Psychometric properties, relationships with social function, and recommendations. Asian J Psychiatr. 2024 Mar 11; 95:104003. PMID: 38518537.

    Read at: PubMed
  • Published on 11/1/2023

    Komori M, Morey AL, Quiñones-Molina AA, Fofana J, Romero L, Peters E, Matsuda K, Gummuluru S, Smith JF, Akahata W, Akiyama H. Incorporation of 5 methylcytidine alleviates innate immune response to self-amplifying RNA vaccine. bioRxiv. 2023 Nov 01. PMID: 37961509.

    Read at: PubMed
  • Published on 10/24/2022

    Jalloh S, Olejnik J, Berrigan J, Nisa A, Suder EL, Akiyama H, Lei M, Ramaswamy S, Tyagi S, Bushkin Y, Mühlberger E, Gummuluru S. CD169-mediated restrictive SARS-CoV-2 infection of macrophages induces pro-inflammatory responses. PLoS Pathog. 2022 Oct; 18(10):e1010479. PMID: 36279285.

    Read at: PubMed
  • Published on 3/30/2022

    Jalloh S, Olejnik J, Berrigan J, Nisa A, Suder EL, Akiyama H, Lei M, Tyagi S, Bushkin Y, Mühlberger E, Gummuluru S. CD169-mediated restrictive SARS-CoV-2 infection of macrophages induces pro-inflammatory responses. bioRxiv. 2022 Mar 30. PMID: 35378756.

    Read at: PubMed
  • Published on 12/9/2020

    Akiyama H, Jalloh S, Park S, Lei M, Mostoslavsky G, Gummuluru S. Expression of HIV-1 Intron-Containing RNA in Microglia Induces Inflammatory Responses. J Virol. 2021 Mar 01; 95(5). PMID: 33298546.

    Read at: PubMed
  • Published on 7/29/2020

    Eshaghi B, Alsharif N, An X, Akiyama H, Brown KA, Gummuluru S, Reinhard BM. Stiffness of HIV-1 Mimicking Polymer Nanoparticles Modulates Ganglioside-Mediated Cellular Uptake and Trafficking. Adv Sci (Weinh). 2020 Sep; 7(18):2000649. PMID: 32999830.

    Read at: PubMed
  • Published on 6/30/2020

    Akiyama H, Gummuluru S. HIV-1 Persistence and Chronic Induction of Innate Immune Responses in Macrophages. Viruses. 2020 06 30; 12(7). PMID: 32630058.

    Read at: PubMed
  • Published on 3/31/2020

    Wooten AK, Shenoy AT, Arafa EI, Akiyama H, Martin IMC, Jones MR, Quinton LJ, Gummuluru S, Bai G, Mizgerd JP. Unique Roles for Streptococcus pneumoniae Phosphodiesterase 2 in Cyclic di-AMP Catabolism and Macrophage Responses. Front Immunol. 2020; 11:554. PMID: 32300347.

    Read at: PubMed
  • Published on 9/6/2018

    Xu F, Bandara A, Akiyama H, Eshaghi B, Stelter D, Keyes T, Straub JE, Gummuluru S, Reinhard BM. Membrane-wrapped nanoparticles probe divergent roles of GM3 and phosphatidylserine in lipid-mediated viral entry pathways. Proc Natl Acad Sci U S A. 2018 09 25; 115(39):E9041-E9050. PMID: 30190430.

    Read at: PubMed
  • Published on 8/27/2018

    Akiyama H, Miller CM, Ettinger CR, Belkina AC, Snyder-Cappione JE, Gummuluru S. HIV-1 intron-containing RNA expression induces innate immune activation and T cell dysfunction. Nat Commun. 2018 08 27; 9(1):3450. PMID: 30150664.

    Read at: PubMed

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