# A hemoperfusion column selectively adsorbs LAP+ lymphocytes to improve anti-tumor immunity and survival of tumor-bearing rats

## TL;DR

A new hemoperfusion column removes LAP+ immune cells, boosting anti-tumor immunity and survival in rats with cancer.

## Contribution

A novel hemoperfusion column that selectively adsorbs LAP+ lymphocytes to enhance anti-tumor immunity in tumor-bearing rats.

## Key findings

- DHP significantly reduced LAP+ Tregs in peripheral blood and tumor tissues.
- Cytotoxic T-lymphocytes increased in tumor-bearing rats after DHP treatment.
- Detached cells from the adsorbent negated the anti-tumor effect, highlighting their inhibitory role.

## Abstract

Reducing the number of immunosuppressive cells in blood is a potential strategy for activating anti-tumor immunity, which provides a promising approach to cancer treatment. In this study, we developed an adsorbent designed to selectively target and adsorb lymphocytes expressing latency-associated peptide (LAP), which is abundantly expressed on the surface of CD4+ regulatory T cells (Tregs) and CD14+ monocytes. We investigated whether diethylenetriamine-conjugated polysulfone adsorbent-based direct hemoperfusion (DHP) enhances anti-tumor immunity in a rat cancer model with KDH-V liver cells. Our findings revealed that DHP significantly reduced LAP+ Tregs in both peripheral blood and tumor tissues in treated mice. Consequently, cytotoxic T-lymphocytes increased in tumor-bearing rats. The anti-tumor effect was negated by the addition of cells detached from the absorbent, indicating that these cells play a crucial role in inhibiting the observed therapeutic effect. The results suggest that depleting LAP+ immunosuppressive cells in blood can enhance anti-tumor immunity and improve survival of patients.