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Visualizing Antigen Specific CD4+ T Cells using MHC Class II Tetramers
15:42

Visualizing Antigen Specific CD4+ T Cells using MHC Class II Tetramers

Published on: March 6, 2009

Molecular recognition of antigen involves lattice formation between CD4, MHC class II and TCR molecules

T Sakihama1, A Smolyar, E L Reinherz

  • 1Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.

Immunology Today
|December 1, 1995
PubMed

Insights

CD4 binding to MHC class II requires oligomerization, forming aggregates essential for T-cell activation. This molecular matrix ensures highly specific and sensitive T-cell recognition despite low-affinity interactions.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cellular Biology

Background:

  • CD4 interaction with MHC class II is crucial for T-cell activation.
  • CD4 binding to MHC class II is dependent on CD4 oligomerization.
  • T-cell receptor (TCR) engagement and lattice formation are vital for T-cell responses.

Purpose of the Study:

  • To elucidate the molecular mechanisms of CD4-MHC class II clustering.
  • To understand how low-affinity interactions form a specific and sensitive T-cell recognition matrix.

Main Methods:

  • Analysis of CD4 oligomerization and its role in MHC class II binding.
  • Investigation of the structural basis for CD4-MHC class II complex formation.
  • Examination of the T-cell receptor's role in regulating clustering and T-cell activation.

Main Results:

  • CD4 must oligomerize for stable binding to MHC class II.
  • The D1-D2 module of CD4 interacts with MHC class II, while D3-D4 mediates oligomerization.
  • CD4-MHC class II aggregates are critical for T-cell activation.
  • A molecular matrix formed by these interactions confers high specificity and sensitivity to T-cell recognition.

Conclusions:

  • CD4 oligomerization is a prerequisite for stable MHC class II engagement.
  • The formation of CD4-MHC class II aggregates is essential for initiating T-cell activation.
  • The collective effect of low-affinity interactions within a molecular matrix enhances T-cell recognition specificity and sensitivity.

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