title: Chemokine CXCL8 promotes HIV-1 replication in human monocyte-derived macrophages and primary microglia via nuclear factor-κB pathway.
abstract: BACKGROUND
  Chemokine CXCL8 is an important neutrophil chemoattractant implicated in various neurodegenerative disorders. Cytokine/chemokine imbalance, with an increase in proinflammatory cytokines like interleukin-1β and tumor necrosis factor-α within the central nervous system, is a hallmark of human immunodeficiency virus (HIV)-1 infection. We previously reported that HIV-1 infection is linked to upregulation of CXCL8 in brain tissues and human astrocytes. Chemokines play crucial roles in trafficking of leukocytes and trafficking of HIV-1-infected across the blood-brain barrier play an important role in HIV-1 central nervous system disease. In the post-antiretroviral therapy era, low level of productive replication of HIV-1 in brain is a critical component of neuropathogenesis regulation. The present study investigated the effect of CXCL8 on productive infection of HIV-1 in human monocytes-derived macrophages (MDM) and primary human microglia.
  
  
  RESULTS
  Human MDM and microglia were infected with the blood or brain derived HIV-1 isolates, HIV-1ADA or HIV-1JRFL. Treatment with CXCL8 significantly upregulated HIV-1p24 levels in supernatants of both HIV-1-infected MDM as well as microglia. In addition, the formation of 2-long terminal repeat (LTR) circles, a measure of viral genome integration, was significantly higher in CXCL8-treated, HIV-1-infected MDM and microglia. Transient transfection of U937 cells with HIV-1 LTR luciferase reporter construct resulted in increased promoter activity when treated with CXCL8. Moreover, increased nuclear translocation of nuclear factor-κB was seen in HIV-1-infected MDM following CXCL8 treatment. Blocking CXCL8 receptors CXCR1 and CXCR2 abrogated the CXCL8-mediated enhanced HIV-1 replication.
  
  
  CONCLUSIONS
  Our results show that CXCL8 mediates productive infection of HIV-1 in MDM and microglia via receptors CXCR1 and CXCR2. These results demonstrate that CXCL8 exerts its downstream effects by increasing translocation of nuclear factor-κB into the nucleus, thereby promoting HIV-1 LTR activity.
authors.affiliation: Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, Texas, United States of America.
authors.forename: Manmeet K
authors.initials: MK
authors.lastname: Mamik
authors.affiliation: Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, Texas, United States of America.
authors.forename: Anuja
authors.initials: A
authors.lastname: Ghorpade
mesh_terms: D001921:Brain / Q000166:cytology / Q000821:virology; D002460:Cell Line; D005260:Female; D016655:HIV Core Protein p24 / Q000378:metabolism; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D016209:Interleukin-8 / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000821:virology*; D017628:Microglia / Q000166:cytology / Q000187:drug effects / Q000821:virology*; D009000:Monocytes / Q000166:cytology*; D016328:NF-kappa B / Q000378:metabolism*; D011247:Pregnancy; D011401:Promoter Regions, Genetic / Q000235:genetics; D023062:Receptors, Interleukin-8A / Q000378:metabolism; D023063:Receptors, Interleukin-8B / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D020079:Terminal Repeat Sequences / Q000235:genetics; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D016655:HIV Core Protein p24; D016209:Interleukin-8; D016328:NF-kappa B; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B