Human proximal tubular cells modulate allogen responses of leukocytes in vitro
H Blaehr1, C B Andersen, J Ladefoged
1Medical Department P, Copenhagen, Denmark.
Insights
Proximal tubular cells interact with leukocytes, reducing immune responses. A soluble factor, possibly prostaglandin, mediates this suppression, impacting kidney health research.
Area of Science:
- Immunology
- Nephrology
- Cell Biology
Background:
- Understanding the interplay between renal tubular cells and immune cells is crucial for kidney disease research.
- Leukocyte interactions with proximal tubular cells can lead to tissue damage and influence immune responses.
Purpose of the Study:
- To investigate the interaction dynamics between proximal tubular cells and allogeneic leukocytes.
- To determine the effect of proximal tubular cells on leukocyte immune function and identify mediating factors.
Main Methods:
- Co-culture of proximal tubular cells with allogeneic leukocytes.
- Assessment of tubular cell viability, MHC antigen and ICAM-1 expression.
- Measurement of leukocyte proliferation and cytokine production, including interleukin-1 and interferon-gamma.
- Analysis of supernatant effects and the impact of indomethacin.
Main Results:
- Tubular cells expressed MHC antigens and ICAM-1, with limited leukocyte adhesion and cytotoxic damage (65% tubular cell viability).
- Leukocyte alloreactive capacity was low, independent of interleukin-1 or interferon-gamma.
- Tubular cells significantly modulated leukocyte immune responses, reducing mitogen, allogen, and interleukin-2 effects.
- A soluble factor in co-culture supernatants suppressed mitogen responses, potentially prostaglandin, as indomethacin reversed this suppression.
Conclusions:
- Proximal tubular cells can suppress leukocyte immune responses through a soluble mediator, likely prostaglandin.
- This interaction suggests a mechanism by which renal tubular cells may modulate local immune activity in the kidney.
- Findings have implications for understanding immune privilege and inflammatory processes in renal environments.
Abstract:
The interaction between proximal tubular cells and leukocytes was examined. In co-cultures of tubular cells and allogenic leukocytes, tubular cells expressed MHC antigens and ICAM-1. A small number of leukocytes adhered to tubular cells and induced cytotoxic damage. Thus, 65% of the tubular cells were viable after co-culturing with allogenic leukocytes. These cells had low alloreactive capacity, which was not due to lack of interleukin-1 or interferon-gamma. The presence of tubular cells modulated the immune response of leukocytes by reducing the effect of mitogen by 80%, allogens by 65% and interleukin-2 by 40%. A soluble factor released in the co-cultures was a likely mediator, since addition of supernatants from co-cultures suppressed mitogen responses by 27% compared to leukocytes cultured alone. This mediator might be prostaglandin, because addition of indomethacin to co-cultures increased the growth response of leukocytes.
