Injection Drug Use Alters Plasma Regulation of the B Cell Response

Area of Science:

• Immunology
• Public Health
• Proteomics

Background:

• Opioid epidemic affects millions of people who inject drugs (PWID).
• PWID experience increased incidence of serious infections and inflammatory conditions.
• Systemic immune alterations in PWID, particularly humoral immunity, require further investigation.

Purpose of the Study:

• To investigate systemic alterations in humoral immunity in people who inject drugs (PWID).
• To analyze the plasma proteome and its regulatory effects on B cell responsiveness in PWID.
• To understand how injection drug use impacts B cell proliferation and differentiation.

Main Methods:

• Comprehensive plasma proteomics using mass spectrometry and ELISA on HIV/HCV-negative PWID.
• In vitro assessment of B cell proliferation and transcriptional profiles using flow cytometry and RNA-Seq.
• Analysis of plasma effects from PWID and healthy controls on B cell responses.

Main Results:

• Plasma proteomes of PWID were distinct from healthy controls, with altered immune analytes (e.g., complement, immunoglobulins, inflammatory mediators).
• Plasma from PWID suppressed in vitro B cell proliferation.
• PWID plasma treatment altered B cell signaling pathways and shifted differentiation profiles.

Conclusions:

• The systemic inflammatory environment is significantly altered in people who inject drugs (PWID).
• Altered plasma proteome in PWID may negatively impact B cell immune responses.
• Findings suggest potential mechanisms for increased infection susceptibility in PWID.