Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

2.3K
T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
2.3K
Diversity of Antigen Receptors01:28

Diversity of Antigen Receptors

720
Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
720
Cross-reactivity00:42

Cross-reactivity

31.4K
Overview
31.4K
Viral Mutations00:36

Viral Mutations

32.7K
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
32.7K
Antigens Involved in Adaptive Immunity01:26

Antigens Involved in Adaptive Immunity

611
An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and...
611

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

In silico functional analysis of the human, chimpanzee, and gorilla MHC-A repertoires.

Immunogenetics·2025
Same author

Role of T cells in severe COVID-19 disease, protection, and long term immunity.

Immunogenetics·2023
See all related articles

Related Experiment Video

Updated: Aug 12, 2025

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay
07:10

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay

Published on: September 14, 2014

14.4K

Evolution of SARS-CoV-2-specific CD4+ T cell epitopes.

Marina Brand1, Can Keşmir2

  • 1Theoretical Biology & Bioinformatics, Utrecht University, Utrecht, Netherlands.

Immunogenetics
|January 31, 2023
PubMed
Summary

COVID-19 vaccines reduce mortality but drive immune escape variants. This study found that T helper cell responses to variants remain largely intact, suggesting other factors cause waning immunity.

Keywords:
BioinformaticsCD4 T cell epitopesConservationSARS-CoV-2VOCsVaccination

More Related Videos

Engineering Antiviral Agents via Surface Plasmon Resonance
13:00

Engineering Antiviral Agents via Surface Plasmon Resonance

Published on: June 14, 2022

2.4K
Author Spotlight: Advancing Antiviral Strategies Through Novel Immunocapture and Mass Spectrometry Techniques
08:07

Author Spotlight: Advancing Antiviral Strategies Through Novel Immunocapture and Mass Spectrometry Techniques

Published on: January 12, 2024

804

Related Experiment Videos

Last Updated: Aug 12, 2025

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay
07:10

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay

Published on: September 14, 2014

14.4K
Engineering Antiviral Agents via Surface Plasmon Resonance
13:00

Engineering Antiviral Agents via Surface Plasmon Resonance

Published on: June 14, 2022

2.4K
Author Spotlight: Advancing Antiviral Strategies Through Novel Immunocapture and Mass Spectrometry Techniques
08:07

Author Spotlight: Advancing Antiviral Strategies Through Novel Immunocapture and Mass Spectrometry Techniques

Published on: January 12, 2024

804

Area of Science:

  • Immunology
  • Virology
  • Computational Biology

Background:

  • Vaccination against COVID-19 reduces mortality but can promote immune escape variants.
  • Omicron variant caused widespread breakthrough infections despite high vaccination rates, indicating efficient antibody evasion.
  • T helper cell responses are crucial for durable antibody immunity.

Purpose of the Study:

  • To investigate the impact of COVID-19 variants of concern (VOCs) on T helper cell responses.
  • To predict T helper cell epitopes on the spike protein across common human leukocyte antigen-II (HLA-II) alleles.
  • To assess population-level T helper cell immunity and the effect of VOC mutations.

Main Methods:

  • In silico prediction of T helper cell epitopes on the SARS-CoV-2 spike protein.
  • Analysis of epitopes for common HLA-DRB1 alleles worldwide.
  • Population simulations using realistic HLA-II frequencies to model T helper cell immunity.

Main Results:

  • Most common HLA-DRB1 alleles possess predicted T helper cell epitopes, but some, like HLA-DRB1 13:01 and 11:01, show limited predicted responses.
  • Population simulations revealed that while a small fraction has minimal CD4 T cell epitopes, the majority retain sufficient epitopes for B cell responses.
  • Mutations in VOC spike proteins minimally affect T helper epitopes, primarily occurring elsewhere on the protein.

Conclusions:

  • T helper cell epitopes are largely preserved across major COVID-19 variants of concern.
  • The predicted T helper cell response suggests that waning antibody immunity is unlikely due to the loss of these critical epitopes in new VOCs.
  • Further research is needed to understand the mechanisms behind decreased long-lasting antibody responses despite preserved T helper cell epitopes.