DOCK8 is essential for LFA-1–dependent positioning of T follicular helper cells in germinal centers
Erin Janssen, Mira Tohme, Jordan Butts, Sophie Giguere, Peter T. Sage, Francisco E. Velázquez, Christy Kam, Elena Milin, Mrinmoy Das, Ali Sobh, Salem Al-Tamemi, Francis W. Luscinskas, Facundo Batista, Raif S. Geha
Erin Janssen, Mira Tohme, Jordan Butts, Sophie Giguere, Peter T. Sage, Francisco E. Velázquez, Christy Kam, Elena Milin, Mrinmoy Das, Ali Sobh, Salem Al-Tamemi, Francis W. Luscinskas, Facundo Batista, Raif S. Geha
View: Text | PDF
Research Article Immunology

DOCK8 is essential for LFA-1–dependent positioning of T follicular helper cells in germinal centers

Abstract

T follicular helper (Tfh) cell migration into germinal centers (GCs) is essential for the generation of GC B cells and antibody responses to T cell–dependent (TD) antigens. This process requires interactions between lymphocyte function–associated antigen 1 (LFA-1) on Tfh cells and ICAMs on B cells. The mechanisms underlying defective antibody responses to TD antigens in DOCK8 deficiency are incompletely understood. We show that mice selectively lacking DOCK8 in T cells had impaired IgG antibody responses to TD antigens, decreased GC size, and reduced numbers of GC B cells. However, they developed normal numbers of Tfh cells with intact capacity for driving B cell differentiation into a GC phenotype in vitro. Notably, migration of DOCK8-deficient T cells into GCs was defective. Following T cell receptor (TCR)/CD3 ligation, DOCK8-deficient T cells had impaired LFA-1 activation and reduced binding to ICAM-1. Our results therefore indicate that DOCK8 is important for LFA-1–dependent positioning of Tfh cells in GCs, and thereby the generation of GC B cells and IgG antibody responses to TD antigen.

Authors

Erin Janssen, Mira Tohme, Jordan Butts, Sophie Giguere, Peter T. Sage, Francisco E. Velázquez, Christy Kam, Elena Milin, Mrinmoy Das, Ali Sobh, Salem Al-Tamemi, Francis W. Luscinskas, Facundo Batista, Raif S. Geha

×

Figure 4

DOCK8-deficient CD4+ T cells have decreased migration into GCs and impaired activation of LFA-1.

Options: View larger image (or click on image) Download as PowerPoint
DOCK8-deficient CD4+ T cells have decreased migration into GCs and impai...
(A and B) CD4+CD45.2+ OT II WT or DOCK8-deficient T cells were adoptively transferred into CD45.1+ WT mice. Recipients were immunized with NP-OVA in the hock, and popliteal LNs were analyzed on day 9 after immunization. (A) The number of OT II CD45.2+ T cells found in the draining LNs of recipient mice was analyzed by flow cytometry. (B) Localization within the draining LNs of transferred CD4+CD45.2+ OT II WT or DOCK8-deficient T cells was examined by immunofluorescence microscopy. Representative photomicrographs at ×20 magnification: B cell follicles (IgD+) are in green, GCs (GL7+) in red, CD45.2+ T cells in white, and T cell zones (CD3+) in blue. Percentage of CD45.2+ in GCs relative to total CD45.2+ cells in GC plus the surrounding follicle normalized to the GC and follicle area. n = 5 mice/group. (C) MFI of total surface LFA-1 expression on CD4+ T cells from Dock8–/– mice and WT controls. (D) Number of adherent CD4+ T cells, stimulated with anti-CD3 or PMA from Dock8–/– mice and controls, to ICAM-1 10 minutes after application to a flow chamber with a flow rate of 0.75 dynes/cm2. Five fields were examined per slide. (E) Representative histograms and MFI of LFA-1 surface expression by unstimulated and anti-CD3–stimulated CD4+ T cells from DOCK8-deficient patients (DEF Pt) and healthy shipped controls (n = 3/group). MFI values were normalized to the mean value of shipped controls. (F) Representative histograms and MFI of activated LFA-1 expression by unstimulated and anti-CD3–stimulated CD4+ T cells from DOCK8-deficient patients and healthy shipped controls (n = 3/group). MFI values were normalized to the mean value of unstimulated shipped controls. Results in C and D are from 3 independent experiments, each with 3 mice/group. Data in A–F are presented as mean ± SEM. In A–C, Student’s t test; *P < 0.05. In D–F, 1-way ANOVA with Tukey’s multiple comparisons; *P < 0.05, **P < 0.01, ***P < 0.001.