Suppression of T-Helper Cell Function by a Soluble Immunosuppressive Factor From Plasmodium Berghei Infected Rat Erythrocytes

A soluble factor derived from Plasmodium berghei infected rat or mouse erythrocytes, but not control erythrocytes, exhibited immunosuppressive properties when tested in vivo. Mice treated with the immunosuppressive factor (ISF) and then immunized with sheep red blood cells (SRBC) had a reduced number of plaque forming cells (PFC) as compared to mice injected with control preparations. The delayed type hypersensitivity reaction elicited by SRBC was also suppressed in mice treated with the ISF. Purification by affinity chromatography and analysis by SDS-PAGE revealed that the ISF had a molecular weight of approximately 30 KD. Neither nylon wool enriched nor unfractionated spleen cells of mice treated with the ISF contained cells capable of suppression the in vitro response to SRBC. Macrophages from treated mice restored the PFC response of macrophage-depleted spleen cells as efficiently as those from control mice. B-cells from treated and untreated mice responded similarly when supplemented with the appropriate T-helper cells. T-helper cells from ISF treated mice failed to supplement naive B cells in a primary in vitro anti-SRBC response as successfully as cells from untreated mice. Interleukin 2 production was not affected by the ISF. Treatment of infected mice with the ISF resulted in higher parasitemia levels and earlier mortality. On the contrary, mice immunized with the ISF then infected with P. berghei had lower levels of parasitemia and lived longer than control mice.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Veterinary Medical Science

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Srour, Edward Fayik

• Health Sciences, Immunology

Identifier

(UMI)AAI8610982

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71332