Cytokines made by T lymphocytes — breadth of secreted mediators T cells are a source of which of the following immune mediators?

Introduction / Context:
T lymphocytes orchestrate immune responses not only through cytotoxicity or help but also via cytokine secretion. Recognizing the variety of mediators produced by T cells clarifies their roles in inflammation, antiviral defense, and B-cell help.

Given Data / Assumptions:

• Activated T cells include Th1, Th2, Th17, Tfh, and cytotoxic subsets.
• Cytokine profiles are subset-dependent but overlap exists.
• Lymphotoxin (TNF-beta) is historically linked to activated lymphocytes.

Concept / Approach:
Helper T cells secrete interleukins such as IL-2, IL-4, IL-17, and others that modulate adaptive responses. T cells (especially Th1 and activated CD8) can produce interferon-gamma, a critical antiviral and macrophage-activating cytokine. Lymphotoxin (TNF-beta) is a T cell–derived member of the TNF family, contributing to lymphoid organogenesis and inflammation. Therefore, T cells are indeed a source of interleukins, interferons (notably IFN-gamma), and lymphotoxin.

Step-by-Step Solution:

Verification / Alternative check:
Standard immunology references detail T cell cytokine profiles; Th1 cells produce IFN-gamma and lymphotoxin; Th2 produce IL-4, IL-5, IL-13; Th17 produce IL-17 family; Tfh produce IL-21.

Why Other Options Are Wrong:

• Single selections (interleukin/interferon/lymphotoxin) are incomplete as T cells can secrete all.
• Only chemokines: T cells do produce chemokines, but the option excludes the listed cytokines; thus incorrect.

Common Pitfalls:
Assuming interferons come only from innate cells; IFN-gamma is strongly T cell–derived (and NK-derived).

Final Answer:
All of these