Cell interaction in B/W mice: a reversible defect at the T-cell level

Area of Science:

• Immunology
• Aging Research
• T cell immunology

Background:

• The antibody-producing cell response to sheep red blood cells (SRBC) declines with age in B/W mice.
• Aging is associated with various immune system dysfunctions, including reduced T cell function.

Purpose of the Study:

• To investigate the mechanisms underlying the diminished anti-SRBC plaque-forming cell (PFC) response in aged B/W mice.
• To determine if the defect lies in T cell activation or in the intrinsic function of lymphoid cells.

Main Methods:

• In vitro restoration of the anti-SRBC PFC response using activated T cells or primed spleen cells.
• In vivo restoration using lipopolysaccharide (LPS) and SRBC.
• Adoptive transfer of bone marrow and thymocytes to assess cooperation between lymphoid cells.

Main Results:

• The anti-SRBC PFC response in old B/W mice was restored by adding activated T cells or primed spleen cells in vitro.
• In vivo administration of LPS and SRBC also restored the response.
• Bone marrow and thymocytes from aged mice cooperated normally in adoptive transfer experiments, indicating no intrinsic defects in these cells.

Conclusions:

• The lack of response to SRBC in intact aged B/W mice is attributed to a block in T cell activation, not intrinsic lymphoid cell defects.
• This T cell activation block may be mediated by suppressor cells present in the spleens of aged B/W mice.
• The presence of suppressor cells could potentially contribute to a loss of self-tolerance in aging.