ProImmune launches MHC Class II Ultimers™ for consistent and reliable detection of antigen-specific CD4⁺ T cells, improving analysis of the immune response

ProImmune has launched MHC Class II Ultimers™, an advanced, affordable tool for evaluating and characterizing CD4⁺ single antigen-specific T cells, enabling in-depth evaluation of the T cell immune response in a wide range of disease areas including, autoimmune disease, cancer and infectious diseases.

Class II Ultimers™, the result of several years of intensive research at ProImmune, are the next generation of MHC Class II multimers, with a superior peptide-linked planar design to improve the interaction between the MHC-peptide complexes and the T cell receptors, for consistent, reliable detection of CD4⁺ single antigen-specific T cells.

Traditional functional assays, such as proliferation or cytokine secretion, for studying antigen-specific CD4⁺ T cells are not truly antigen-specific. The MHC tetramer, a more recently available tool, has been difficult to reproduce with a high level of consistency, which has meant that these reagents have not been widely accessible. The detection of CD4⁺ T cells using MHC tetramers has also been difficult due to the low frequency of these T cells (down to 1 in 100,000 white blood cells) and the low avidity of binding between the MHC-peptide binding complex and the T cell receptor. The peptide-linked planar design of Class II Ultimers™ addresses these issues by improving reproducibility and sensitivity of CD4⁺ T cell detection. The Class II Ultimer™ fluorescent detection label has been optimized to maximize the signal to noise ratio of this assay.

ProImmune provides Class II Ultimers™ with responsive, expert technical support and customer service. Contrary to ordering Class II tetramers from in-house or non-commercial facilities, customers do not need to apply and wait for reagents or supply any peptide. Class II Ultimers™ are delivered quickly with stringent quality control and low batch-to-batch variability. The newly launched Class II Ultimers™ complement ProImmune’s existing Pro5® Class I Pentamer technology, which was introduced in 2003, for detecting antigen-specific CD8⁺ T cells.

Commenting on the launch of Class II Ultimers™, Dr. Nikolai Schwabe, CEO of ProImmune said: "The launch of our new Class II Ultimers™ underlines our strategy to provide innovative, affordable solutions to improve analysis of the T cell immune response. The combined use of Class II Ultimers™ with our Pro5® Class I Pentamer technology will enable investigators to gain a more complete understanding of the specificity of immune responses, and aid the development of novel immunotherapies to combat many life threatening diseases."