Visualization of HIV-1 Interactions with Penile and Foreskin Epithelia: Clues for Female-to-Male HIV Transmission
Fig 2
Tissue resident immune cells in foreskin tissues.
Tissue cryosections immunofluorescently stained with OKT6 or α-CD4 antibodies to detect Langerhans cells (LCs) or CD4+ cells, respectively. (A) Representative images of LCs (red, left panel) and CD4+ cells (green, right panel) shown. White bar = 10 μm. Cell nuclei stained with DAPI (blue). Only cells within the epithelium (above the basement membrane, denoted with white solid line and BM) were used in analysis. ES, dotted line, epithelial surface. (B) Probability density distributions using kernel density estimations of viral penetration depths from the epithelial surface after 4 hours (dotted red) and 24 hours (solid red) of exposure in inner (left) and outer (right) foreskins. Overlap of 24 hour penetrators and CD4+ cells (blue) in inner 2X greater than outer foreskin. (C) Cell count analysis shows greater numbers of CD4+ cells in inner (black squares) as compared to outer (white diamonds) foreskin (* p<0.05). (D) Analysis of cell depths show no difference between inner and outer foreskin. (E) Analysis of LCs in foreskin tissue before and after virus exposure in a subset of 4 donor samples. No difference seen in cell counts between inner and outer foreskin, but marginally more cells/image seen in inner foreskin after 24 hours of virus exposure (*p<0.05). (F) No difference in depths of cells before and after virus exposure, but this subset did have differences in LC depths between inner and outer foreskin at both time points. ***p<0.001