Rhadinovirus Host Entry by Co-operative Infection
Fig 9
An antibody-mediated block to heparan binding inhibits MuHV-4 interaction with alveolar epithelial cells but not macrophages.
MuHV-4 virions were incubated with mAb 8F10 (100μg / 105 p.f.u.) or not (control) (2h, 26°C), then given i.n. to C57BL/6 mice (104 p.f.u.). 5h later lung sections were stained for CD68 (red, alveolar macrophages), PDP (green, type 1 AECs) and virion antigens (cyan). Open arrows show cells accumulating virion antigens. All these were CD68+, regardless of antibody treatment (>50 cells counted from at least 3 sections of 2 mice). Antigen accumulation was highly variable between sections, so while higher with 8F10 the difference was not statistically significant. Filled arrows show isolated virions. Without antibody there were 70.0 ± 4.7 isolated virions per section (mean ± SEM, 6 sections), of which 96% were associated with PDP+ cells. With antibody there were 6.7 ± 1.4 per section, of which 67.5% were associated with PDP+ cells. Therefore antibody significantly reduced virion binding to epithelial cells (p<10-6 by Student's 2-tailed, unpaired t test) without affecting their accumulation by macrophages.