PMC

Microscopic anatomy of lymph node tissues from SIV-infected rhesus before and after pertussis toxin injection. Inguinal lymph node biopsies were performed and samples were fixed in buffered formalin before embedding in paraffin. Similar sections were compared for the pretreatment (A) and 7 days post-pertussis injection (B) samples. The labeling in (B) shows the position of germinal centers (GC) and paracortical regions (PC).

Absolute lymphocyte counts in peripheral blood from SIV-infected animals after pertussis toxin injection. Lymphocyte counts were obtained by automated analysis of venous blood samples collected in EDTA-anticoagulant tubes; data are represented as lymphocytes per microliter of whole blood. The time scale indicates the day of toxin administration as day 0. Negative time values are samples prior to pertussis toxin treatment. Bars indicate the standard error of the mean.

In situ hybridization analysis of pertussis toxin effects on SIV RNA in lymph nodes. Sections are photographed under epifluorescent light and hybridization to viral RNA appears white on the dark background. (A) Inguinal lymph node prior to pertussis toxin administration. (B) Popliteal fossis lymph node removed 7 days after pertussis toxin injection. (C) Popliteal fossis lymph node removed 45 days after pertussis toxin injection. (D) Enlarged view of a single germinal center from the specimen shown in (B).

Infectious cell assay with PBMCs from pertussis toxin-treated, SIVmac-infected rhesus monkeys. The minimum number of PBMCs required for positive virus isolation in vitro is indicated at the left. Mitogen-stimulated PBMCs were co-cultured with CEM×174 cells for a maximum of 30 days. Infection was confirmed by the appearance of viral cytopathic effects or accumulation of reverse transcriptase activity in cell-free culture fluids. The day of pertussis toxin administration is indicated as day 0; negative time values are for samples prior to toxin administration. (A) Data for SIV-infected pertussis toxin-treated animals. (B) Similar time course for SIV-infected, untreated animals.