Splenocyte transfer exacerbates salt-sensitive hypertension in rats

Area of Science:

• Immunology
• Nephrology
• Cardiovascular Science

Background:

• Immune cell infiltration into the kidney contributes to hypertensive pathology.
• Current methods for assessing immune cell function in hypertension are limited, especially in rat models of salt-sensitive hypertension.
• Adoptive transfer of immune cells is a valuable tool for studying specific immune cell subsets.

Purpose of the Study:

• To test the hypothesis that splenocyte transfer into T-cell-deficient rats exacerbates salt-sensitive hypertension.
• To investigate the role of specific immune cell populations, particularly T-cells, in salt-sensitive hypertension.
• To establish a functional adoptive transfer model in T-cell-deficient Dahl salt-sensitive rats.

Main Methods:

• Splenocytes from wild-type Dahl salt-sensitive (SS) rats, maintained on low- or high-salt diets, were transferred into T-cell-deficient SS rats (SS^CD247-/-).
• Recipients were challenged with a high-salt diet.
• Blood pressure, renal damage, and immune cell infiltration into the kidney (including T-cells, macrophages, and B-cells) were assessed.

Main Results:

• Splenocyte transfer elevated blood pressure in rats on both low- and high-salt diets, exacerbating the salt-sensitive increase.
• Transfer of splenocytes led to increased renal damage.
• Immune cell infiltration into the kidney, including T-cells, macrophages, and B-cells, was elevated in recipients.
• Enrichment in the CD4+ T-cell compartment was identified as a key driver of the observed hypertension.

Conclusions:

• Splenocyte transfer into T-cell-deficient rats is sufficient to exacerbate salt-sensitive hypertension and renal injury.
• CD4+ T-cells play a critical role in mediating this exacerbated hypertension.
• This study provides a robust model for dissecting the contribution of specific immune cell subsets to salt-sensitive hypertension.