Immunosuppression in experimental cryptococcosis in rats: modification of macrophage functions by T suppressor cells. Macrophages functions in cryptococcosis
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Published on: July 10, 2014
H R Rubinstein1, C E Sotomayor, L A Cervi
1Departamento de Bioquimica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Insights
Cryptococcus neoformans infection in rats impairs macrophage function. Suppressor T cells induced by the infection reduce phagocytosis and microbicidal activity, impacting immune responses.
Area of Science:
- Immunology
- Microbiology
- Cell Biology
Background:
- Cryptococcus neoformans infection alters host immune states.
- Lymphocytes play a role in modulating macrophage functions.
Purpose of the Study:
- To investigate the influence of lymphocytes on macrophage function during Cryptococcus neoformans infection.
- To determine how T suppressor cells affect phagocytic and microbicidal activities of peritoneal cells.
Main Methods:
- Induction of T suppressor cells in rats via Cryptococcus neoformans infection.
- Transfer of T suppressor cells into recipient rats.
- Assessment of in vitro phagocytic and microbicidal activity of peritoneal cells.
- Evaluation of delayed-type hypersensitivity (DTH) response to human serum albumin (HSA).
Main Results:
- T suppressor cells significantly decreased phagocytic activity against C. neoformans and Candida tropicalis.
- Microbicidal function of peritoneal cells was reduced when challenged with C. tropicalis.
- Phagocytosis of HSA-human red cells was altered in rats receiving T suppressor cells.
- DTH response to HSA was negative in rats treated with suppressor T cells.
Conclusions:
- Cryptococcus neoformans infection induces T suppressor cells that impair macrophage phagocytosis and microbicidal functions.
- These alterations affect immune responses beyond the primary pathogen, including responses to unrelated antigens.
- The study highlights the significant role of T suppressor cells in modulating accessory cell behavior during infection.
Abstract:
The influence of lymphocytes on the modulation of macrophage functions in altered immune states induced by Cryptococcus neoformans infection in rats has been investigated. In this report we observed a decrease of 'in vitro' phagocytic activity by peritoneal cells (PC) from rats that received T suppressor cells induced by cryptococcal infection, against both the same microorganism that stimulated this suppressor population (p less than 0.05) and another non-pathogenic primary yeast (Candida tropicalis), (p less than 0.02). The microbicide function of the PC from these animals present a significant decrease in challenge by C. tropicalis (p less than 0.002) when compared with PC from animals transferred with T normal cells. The transference of T suppressor cells induced by cryptococcal infection in animals immunized with human serum albumin-complete Freund's adjuvant (HSA-CFA) produces a significant alteration of the phagocytosis to HSA-human red cells (HSA-HRC) when compared with the phagocytosis observed in animals that received T normal cells or the phagocytosis of normal animals (p less than 0.001). We could also observe that the DTH to HSA studied during 30 days was negative in rats transferred with PC sensitizated with HSA and treated with suppressor T cells, when compared with the DTH response of animals transferred with PC-HSA cocultured with normal cells (p less than 0.05 21st day). The data presented in this paper illustrated that following infection of rats with C. neoformans there is a change in some population of accessory cells behavior reflected by the modification of several functions, such as phagocytosis, lytic activity and antigen presentation.
