Koka Prasad S, Ramdass Bharathi
Biomedical Research Institute of Southern California, Oceanside, CA, United States.
Front Cell Dev Biol. 2024 Apr 24;12:1382789. doi: 10.3389/fcell.2024.1382789. eCollection 2024.
Cytopenias are a common occurrence due to abnormal hematopoiesis persistent in patients suffering from and advancing with HIV/AIDS. In order to develop efficacious therapies against cytopenias, it is necessary to understand the mechanisms by which HIV infection affects the differentiation of hematopoietic stem-progenitor cells (HSPCs), causing hematopoietic inhibition, that leads to hematological disorders. Currently, only the antiretrovirals that are being used to treat HIV infection and indirectly lower the levels of virus replication also co-attenuate cytopenias. The evidence available suggests that this indirect efficacy may not prevail for the lifetime of the infected patients, and the acquired immunodeficiency can overtake the beneficial consequences of decreased virus replication. As cited in this article, we and our colleagues are the first to make a foray into the involvement of microRNAs and their use as potential interventional treatments for the cytopenias that occur with HIV/AIDS. Herein, we progressed further in the direction of the mechanisms of the involvement of homeobox gene regulation to cause cytopenias. We had previously shown that HIV-1 inhibits multi-lineage hematopoiesis of the CD34 cells using SCID-hu Thy/Liv animals . Furthermore, we demonstrated that the virus-induced hematopoietic inhibition occurred despite the CD34 cells being resistant to HIV-1 infection. We set out to search for the specific host factors secreted by CD4 T-cells that likely participate in the inhibition of hematopoiesis of the HIV infection-resistant CD34 cells. More recently, we reported the identification of virus-infected CD4 thymocyte-secreted miRNA-15a and miRNA-24 and that their differential expression following HIV infection causes the indirect inhibition of hematopoiesis. We then hypothesized that the observed miRNA differential expression in the virus-infected T-cells causes the abnormal regulation of homeobox (HOX) gene-encoded transcriptomes in the CD34 cells, affecting specific MAPK signaling and CD34 cell fate, thereby disrupting normal hematopoiesis. We present that in HIV infection, miRNA-mediated post-transcriptional dysregulation of HOXB3 mRNA inhibits multi-lineage hematopoiesis, which translates into hematological disorders in virus-infected patients with HIV/AIDS. These observations portend specific microRNA candidates for potential efficacy against the virus-induced cytopenias that are otherwise not treatable by the existing HAART/ART regimens, which are primarily designed and applicable for the attenuation of virus replication.
血细胞减少在感染艾滋病毒/艾滋病并病情进展的患者中很常见,这是由于异常造血持续存在所致。为了开发针对血细胞减少的有效疗法,有必要了解艾滋病毒感染影响造血干祖细胞(HSPCs)分化的机制,这种影响会导致造血抑制,进而引发血液系统疾病。目前,仅用于治疗艾滋病毒感染并间接降低病毒复制水平的抗逆转录病毒药物也会同时减轻血细胞减少。现有证据表明,这种间接疗效在受感染患者的一生中可能无法持续,获得性免疫缺陷可能会抵消病毒复制减少带来的有益后果。如本文所述,我们和同事率先探讨了微小RNA的作用及其作为艾滋病毒/艾滋病相关血细胞减少潜在干预治疗手段的应用。在此,我们朝着同源框基因调控导致血细胞减少的机制方向取得了进一步进展。我们之前利用SCID-hu Thy/Liv动物模型表明,HIV-1抑制CD34细胞的多谱系造血。此外,我们证明,尽管CD34细胞对HIV-1感染具有抗性,但病毒仍会诱导造血抑制。我们着手寻找CD4 T细胞分泌的可能参与抑制抗HIV感染的CD34细胞造血的特定宿主因子。最近,我们报告了鉴定出病毒感染的CD4胸腺细胞分泌的miRNA-15a和miRNA-24,并且它们在HIV感染后的差异表达会间接抑制造血。然后我们推测,在病毒感染的T细胞中观察到的miRNA差异表达会导致CD34细胞中同源框(HOX)基因编码转录组的异常调控,影响特定的MAPK信号传导和CD34细胞命运,从而扰乱正常造血。我们提出,在HIV感染中,miRNA介导的HOXB3 mRNA转录后失调会抑制多谱系造血,这在感染HIV的艾滋病毒/艾滋病患者中会转化为血液系统疾病。这些观察结果预示着特定的微小RNA候选物可能对病毒诱导的血细胞减少具有潜在疗效,而现有的高效抗逆转录病毒治疗/抗逆转录病毒治疗方案主要是为了减轻病毒复制而设计和应用的,无法治疗这些血细胞减少。