Remote effects of inflammation on non-specific immunity

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• Inflammation can non-specifically enhance host resistance against various challenges.
• This phenomenon occurs even in immune-compromised animal models.
• The underlying molecular mechanisms require further elucidation.

Purpose of the Study:

• To investigate the molecular basis of inflammation-induced host resistance.
• To identify proteins responsible for enhanced immune cell activity.
• To explore the potential of these proteins in immunotherapy.

Main Methods:

• Induction of inflammation in mice using inert substances.
• Analysis of immune cell responses, including leukopoiesis and macrophage activation.
• Protein isolation and characterization (MW, pI) from inflammatory sites and serum.
• In vitro and in vivo assays to assess protein function and efficacy against pathogens and tumor cells.

Main Results:

• Inflammation led to increased leukopoiesis via a 40 kDa protein inducing polymorph differentiation.
• Giant cells in granulomas released an immunostimulatory protein activating macrophages.
• A distinct 56 kDa heat-labile protein activated liver and spleen macrophages, conferring protection against Listeria monocytogenes and activating macrophages against tumor cells.
• This 56 kDa protein is distinct from TNF and GM-CSF and shows cross-species activity.

Conclusions:

• Inflammation triggers complex molecular events enhancing host defense mechanisms.
• Specific proteins isolated from inflammatory sites and serum play crucial roles in immune activation.
• These identified proteins represent promising candidates for novel immunotherapeutic strategies against infections and cancer.