# Preparation and application of fluorescent monoclonal antibodies recognizing goat CD4+CD25+ regulatory T cells

## TL;DR

Researchers created fluorescent antibodies to detect goat regulatory T cells and found their frequency correlates with viral load during orf virus infection.

## Contribution

Development of species-specific fluorescent monoclonal antibodies for goat Tregs and their application in disease monitoring.

## Key findings

- The combination of C11 and D12 mAbs effectively detects goat Tregs in flow cytometry and immunofluorescence.
- Treg frequency positively correlates with orf virus viral load in goats.
- C11 mAb demonstrates excellent species specificity for goat Tregs.

## Abstract

Regulatory T cells (Tregs) are a subset of T cells participating in a variety of diseases including mycoplasmal pneumonia, contagious ecthyma, and so on. The role of Tregs in goat contagious ecthyma is not completely understood due to the lack of species-specific antibodies. Here, we developed a combination of CD4 and CD25 fluorescence monoclonal antibodies (mAb) to recognize goat Tregs and assessed its utility in flow cytometry, immunofluorescence staining. Using immunofluorescence staining, we found that the frequency of Treg cells was positively correlated with the viral load during orf virus infection. These antibodies could serve as important tools to monitor Tregs during orf virus infection in goats.

• A combination of fluorescent mAbs (C11 and D12) was prepared for the detection of goat Tregs.

• C11 and D12 are effective in flow cytometry, immunofluorescence staining, and C11 has excellent species specificity.

• The frequency of Treg cells was positively correlated with the viral load during orf virus infection.

The online version contains supplementary material available at 10.1007/s00253-024-13115-4.