Immunological Consequences of Intestinal Helminth Infections: Antigen Presentation and Immunosuppression by Peritoneal Cells

Abstract

Summary The functional characteristics of peritoneal cells (PC's) acquired in response to infection with Nematospiroides dubius were studied to identify changes which could be associated with the high level, long‐term survival of this parasite or explain its transient immunosuppressive properties. The number of cells in the peritoneal cavity increased steadily during the infection, and the population displayed a transient hyperreponsiveness to inflammatory stimulation. N. dubius did not affect the ability of antigen‐pulsed PC's to induce humoral responses or delayed‐type hypersensitivity (DTH) in primed recipients, but lymphoproliferative responses induced in vitro were depressed by PC's from infected donors. In addition, unpulsed PC's from N. dubius‐infected mice depressed proliferative responses to parasite antigens by autologous mesenteric lymph node cells. These effects are attributable to increased lymphocytostatic activity in the PC's, which peaked one week after infection and correlated with the expansion of a population of large plastic‐adherent vacuolated cells with elevated acid phosphatase activity (activated macrophages). Comparable inhibitory cells did not develop in the same period of time during a short‐lived infection with Nippostrongylus brasitiensis.

Heligmosomoides polygyrusPromotes Regulatory T-Cell Cytokine Production in the Murine Normal Distal Intestine

“…Mice colonized with H. polygyrus have a blunted delayed-type hypersensitivity response to ovalbumin (25). Colonization with H. polygyrus induces lamina propria (LP) macrophages that have an alternatively activated phenotype (3,24).…”

Genetically Determined Resistance to Murine Cytomegalovirus: A Role for Lymphocytostatic Macrophages

“…OA-driven proliferation was measured over 96 h and mitogen-driven responses over 48 or 72 h, with [3H]thymidine added 18 h before harvest. These techniques, and the use of indomethacin (Sigma) to evaluate the contribution of prostaglandins to lymphocytostasis, are described in an earlier publication (Price & Holt, 1986).…”

“…PCs were collected aseptically from groups of six to 12 mice and resuspended in HEPES-buffered RPMI 1640 containing 40 ~tM-2-mercaptoethanol and 0.5 ~ normal mouse serum (Price & Holt, 1986). This medium was used for all prolonged incubations as viability was retained without background macrophage activation or lymphoproliferation observed after culture with FCS.…”

“…Acid phosphatase levels and nitro blue tetrazolium (NBT) reductase activity were determined colorimetrically as indices of macrophage activation (Price & Holt, 1986;Rook et al, 1985).…”

“…These dishes had been coated with FCS overnight and washed with phosphate-buffered saline (PBS) immediately before use. Non-adherent cells were removed by gentle washing with pre-warmed RPMI with FCS, then 0.02~ EDTA buffer (Wood et al, 1979) was added for 30 min and the adherent cells were dislodged by vigorous pipetting (Price & Holt, 1986).…”