alpha-Defensins 1, 2, and 3 are expressed by granulocytes in lymphoid tissues of HIV-1-seropositive and -seronegative individuals.
alpha-Defensins 1, 2, and 3 exert antiretroviral activity in vitro, but their role in controlling HIV-1 replication in vivo and the cells that produce them are controversial. This study sought to determine whether alpha-defensins are present in HIV-1-infected individuals' lymphoid tissues, the major site of HIV-1 replication, and to identify the cells that express them. alpha-Defensin expression was evaluated by immunostaining inguinal lymph node sections from 19 untreated HIV-1-infected individuals and 8 individuals at low risk or seronegative for HIV-1 infection. Percentages of tissue sections that stained positively for alpha-defensins were not significantly different between HIV-seropositive (median, 7.6%) and -seronegative (median, 5.5%) individuals. Conditions that could have produced lymph node inflammation were present in most seronegative subjects, and their lymph node weights correlated with alpha-defensin expression (Spearman rho = 0.833; P = 0.010). A median of 100% (range, 95%-100%) of alpha-defensin-expressing lymph node cells from 8 subjects coexpressed the granulocyte marker, CD15. CD15 and alpha-defensin staining correlated (Spearman rho = 0.622; P < 0.001). These data suggest that alpha-defensins within lymphoid tissue are expressed by granulocytes and are prevalent in HIV-1-seronegative individuals with inflammatory processes as well as HIV-1-infected individuals. The role of alpha-defensins in controlling HIV-1 replication merits further investigation.
Folkvord
Joy M
JM
Department of Medicine, Division of Infectious Diseases, University of Colorado Health Sciences Center, Denver, 80262, USA.
McCarter
Martin D
MD
Ryder
John
J
Meditz
Amie L
AL
Forster
Jeri E
JE
Connick
Elizabeth
E
D005260:Female; D006098:Granulocytes / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology; D016256:Lewis X Antigen / Q000032:analysis; D008198:Lymph Nodes / Q000276:immunology / Q000473:pathology; D008221:Lymphoid Tissue / Q000737:chemistry / Q000276:immunology*; D008297:Male; D008856:Microscopy, Fluorescence; D023084:alpha-Defensins / Q000096:biosynthesis*
D016256:Lewis X Antigen; D023084:alpha-Defensins; C406413:human neutrophil peptide 1; C406416:human neutrophil peptide 2; C406427:human neutrophil peptide 3