Reduced T cell reactivity in vasectomized rhesus monkeys: association with histocompatibility type

Area of Science:

• Immunology
• Reproductive Biology

Background:

• Vasectomy is a common contraceptive procedure.
• Potential long-term effects of vasectomy on the immune system are not fully understood.

Purpose of the Study:

• To investigate the immunologic reactivity of peripheral lymphocytes in rhesus monkeys after long-term vasectomy.
• To determine if vasectomy alters T cell and B cell functions as assessed by mixed lymphocyte cultures (MLC).

Main Methods:

• Mixed lymphocyte cultures (MLC) were performed using peripheral lymphocytes from rhesus monkeys vasectomized for 7 or 11 years.
• T cell and B cell functions were assessed by measuring lymphocyte response and stimulation in MLC.
• Serum effects were ruled out by culturing cells in different plasma conditions.

Main Results:

• A significant reduction in the ability to respond in MLC (T cell function) was observed in animals vasectomized for 11 years and some for 7 years.
• An increased ability to stimulate in MLC (B cell function) was noted in the 11-year vasectomized group.
• Reduced MLC responsiveness was associated with specific RhL-A histocompatibility types (19 and 24) in 75% of affected animals.

Conclusions:

• Long-term vasectomy in rhesus monkeys may lead to altered immunologic reactivity, specifically affecting T and B cell functions.
• The observed changes in MLC reactivity appear independent of serum factors.
• Histocompatibility type may play a role in the immunologic consequences of vasectomy.