title: Cognate interactions: extrafollicular IL-4 drives germinal-center reactions, a new role for an old cytokine.
abstract: Over the past 25 years it has become clear that B and T lymphocytes go through a range of interactions and migratory events when B cells differentiate to become high-affinity, antibody-secreting cells. This B-cell differentiation is associated with multiple sequential cognate interactions. In this issue of the European Journal of Immunology, Turqueti-Neves et al. [Eur. J. Immunol. 2014. 44: 2130-2138] show that IL-4, a cytokine well known as a regulator of Ig class switch recombination, has another as-yet-unappreciated role. The authors show that IL-4 produced by T-helper cells outside germinal centers has a major effect on the early stages of germinal-center B-cell differentiation. This Commentary will summarize their findings and relate them to what we know on the sequence of cognate interactions and migratory events B cells undergo during T-dependent immune responses.
authors: School of Immunity and Infection, Medical School IBR, University of Birmingham, Birmingham, United Kingdom.
authors: Kai-Michael
authors: KM
authors: Toellner
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D018858:Germinal Center / Q000502:physiology*; D050800:STAT6 Transcription Factor / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D050800:STAT6 Transcription Factor; C494100:Stat6 protein, mouse
keywords: B cells; Germinal center; IL-13; IL-4; STAT6