title: Cell reservoirs in lymph nodes infected with HIV-1 subtype E differ from subtype B: identification by combined in situ polymerase chain reaction and immunohistochemistry.
abstract: In Thailand, the predominant HIV subtype is E, rather than subtype B as in North America and Europe. Subtype E has the ability to replicate in vitro in Langerhans cells. We hypothesized that this cell type might constitute a reservoir for the HIV virus in infected lymph nodes. We examined lymph nodes from 25 HIV-1 subtype E-infected patients to determine the immunophenotype of HIV-1-infected cells, their numbers and their distribution. The presence of HIV was detected either by in situ reverse transcriptase-polymerase chain reaction or immunoperoxidase. Cell identity was determined by double labelling using alkaline phosphatase-based immunohistochemistry. The majority of HIV-infected cells in the lymph nodes were Langerhans cells (CD1a+S100+) and Langerhans-related dendritic cells (p55+S100+). These cells were located in the paracortical areas of lymph nodes, with a few cells scattered at the edges of germinal centers, but were absent from germinal centers themselves, in contrast to the reported distribution of subtype B virus. In addition, multinucleated giant cells were significantly more common in HIV-infected nodes (64%) compared to controls (4%) (P=0.00002). In conclusion, Langerhans histiocytes and related cells are reservoirs for HIV subtype E in lymph nodes. Disrupting the pathway of infection of Langerhans cells and related cells may be a viable strategy to interfere with transmission of HIV subtype E.
authors.affiliation: Department of Pathology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. lbhoopat@mail.med.cmu.ac.th
authors.forename: Lertlakana
authors.initials: L
authors.lastname: Bhoopat
authors.forename: Tat S
authors.initials: TS
authors.lastname: Rithaporn
authors.forename: Surapan
authors.initials: S
authors.lastname: Khunamornpong
authors.forename: Tanin
authors.initials: T
authors.lastname: Bhoopat
authors.forename: Clive R
authors.initials: CR
authors.lastname: Taylor
authors.forename: Paul S
authors.initials: PS
authors.lastname: Thorner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018949:Antigens, CD1 / Q000032:analysis; D005260:Female; D016655:HIV Core Protein p24 / Q000032:analysis; D015658:HIV Infections / Q000378:metabolism / Q000473:pathology* / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D006644:Histiocytes / Q000737:chemistry / Q000473:pathology / Q000821:virology; D006801:Humans; D007150:Immunohistochemistry; D007801:Langerhans Cells / Q000737:chemistry / Q000473:pathology / Q000821:virology; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008198:Lymph Nodes / Q000737:chemistry / Q000473:pathology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D018949:Antigens, CD1; C419393:CD1a antigen; D016655:HIV Core Protein p24; D018950:Lipopolysaccharide Receptors; D012367:RNA, Viral