Immunosuppression in deer mice with experimentally induced trypanosomiasis.

Area of Science:

• Immunology
• Parasitology
• Veterinary Pathology

Background:

• Trypanosoma equiperdum is a parasite that causes significant health issues.
• Chronic infections can lead to complex immunological changes.
• Deer mice (Peromyscus maniculatus) are a model organism for studying host-parasite interactions.

Purpose of the Study:

• To investigate the immunological effects of chronic Trypanosoma equiperdum infection in deer mice.
• To examine the impact of virulent and radioattenuated trypanosomes on host immune responses.

Main Methods:

• Light and electron microscopy were used to examine spleen and lymph nodes.
• In vitro lymphocyte stimulation assays (PHA, ConA, LPS, PWM) were performed.
• Immunological response to sheep red blood cells was assessed in infected and control mice.

Main Results:

• Infection led to germinal center lymphocyte hyperplasia and plasma cell infiltration in lymphoid organs.
• Plasma cell proliferation disrupted normal B- and T-lymphocyte areas.
• T- and B-lymphocyte responses to mitogens were significantly depressed in infected mice.
• Virulent trypanosome infection decreased immune response to sheep red blood cells, while radioattenuated trypanosomes resulted in normal to enhanced responses.

Conclusions:

• Chronic Trypanosoma equiperdum infection severely impairs cellular immunity in deer mice.
• The virulence of the trypanosome strain significantly influences the host's immune response.
• Radioattenuated trypanosomes may offer a potential strategy for maintaining or boosting immune function during infection.