Pertussis specific IgG levels decrease with time.

<p>Box plots of specific IgG concentrations of Ptx (left), FHA (middle) and Prn (right) in symptomatic cases in <i>acute</i> (≤1.5 months), <i>intermediate</i> (1.6–8.9 months) and <i>maintenance phase</i> (≥9 months) after the last known immunizing event. Box plots show first and third quartiles and medians and whiskers represent 5–95% CI. Below the x-axis geometric mean values are given for each group. ∧ =  p<0.1; * = p<0.05; ** =  p< 0.01; *** =  p<0.001, **** =  p<0.0001</p

Extended O‑GlcNAc on HLA Class-I-Bound Peptides

We report unexpected mass spectrometric observations of glycosylated human leukocyte antigen (HLA) class I-bound peptides. Complemented by molecular modeling, <i>in vitro</i> enzymatic assays, and oxonium ion patterns, we propose that the observed O-linked glycans carrying up to five monosaccharides are extended O-GlcNAc’s rather than GalNAc-initiated O-glycans. A cytosolic O-GlcNAc modification is normally terminal and does not extend to produce a polysaccharide, but O-GlcNAc on an HLA peptide presents a special case because the loaded HLA class I complex traffics through the endoplasmic reticulum and Golgi apparatus on its way to the cell membrane and is hence exposed to glycosyltransferases. We also report for the first time natural HLA class I presentation of O- and N-linked glycopeptides derived from membrane proteins. HLA class I peptides with centrally located oligosaccharides have been shown to be immunogenic and may thus be important targets for immune surveillance

Spearman correlations between pertussis specific B_mem and corresponding IgG levels.

<p>Dots represent paired antigen specific B_mem cell frequencies and plasma IgG levels for Ptx (A), FHA (B) and Prn (C) for each participant.</p

Age-related differences in pertussis specific B_mem cell levels in <i>acute phase</i>.

<p>Box plots representing age stratified levels of Ptx-, (A) FHA- (B) and Prn- (C) specific B_mem frequencies in <i>acute</i> (≤1.5 months), <i>intermediate</i> (1.6-8.9 months) and <i>maintenance phase</i> (≥9 months) after last known immunizing event. Age groups are designated as follows; u4s (under-fours), sch (schoolchildren), ado (adolescents), adu (adults) and eld ((pre-) elderly). Below the x-axis geometric mean values are given for each group. ∧ =  p<0.1; * = p<0.05; ** =  p< 0.01; *** =  p<0.001, #  = significantly lower than same age group in <i>acute phase</i></p

Description of subjects sampled for longitudinal data.

<p>Description of subjects sampled for longitudinal data.</p

Reverse cumulative distribution curves of IgG-Ptx levels (IU/ml) measured in SKI and Pienter-2 cohorts.

<p>Shown are SKI <i>acute cases</i>, (dotted red line), SKI <i>retrospective cases</i> (blue line) and the population sample PIENTER-2 (green line). The vertical line indicates the pre-defined cut-off level of 62.5 IU/ml. The horizontal coloured lines indicate the percentages of the respective cohorts above the cut-off.</p

Time shift analysis of the negative IgG-Ptx component of SKI <i>retrospective cases</i> and overlay with PIENTER-2 data.

<p>Left panels: Density distribution of IgG-Ptx (IU/ml) in samples obtained from <i>retrospective cases</i> (bars) having τ >24 months (A), τ >42 months (B), or τ >60 months (C), respectively. Lines indicate the fitted negative (blue line) and positive (red line). Right panels: Density distribution of IgG-Ptx (IU/ml) in samples obtained from the PIENTER-2 study (bars + dotted line), the blue line indicates the time shifted overlay of the <i>retrospective cases</i> indicated in the left panel.</p

Longitudinal analysis of levels of specific IgG and B_mem cells in nine pertussis patients.

<p>Antigen specific IgG levels at two time points per patient for Ptx (A), FHA (B) and Prn (C) and corresponding B_mem frequencies for Ptx (D), FHA (E) and Prn (F) are depicted.</p

Flow cytometry analysis of B cell populations before and after culture.

<p>Shown are bar charts of B cell frequencies of our five age groups with geometric means and 95% CI. Graphs show relative frequencies of total B cells (A) as well as memory B cells (C) and plasma cells (D) as percentage of all lymphocytes and memory B cells as percentage of all CD19⁺ B cells (B) per age group. The factor of enrichment of memory B cells due to in vitro stimulation is likewise shown per age-group (E) and exemplified by one donor in two flow cytometry dot plots (F). Age groups are designated as follows; u4s (under-fours), sch (schoolchildren), ado (adolescents), adu (adults) and eld ((pre-) elderly).</p

Cohort description.

<p>¹ aP and wP; acellular or whole cell pertussis vaccine; ² ‘time since exposure’ is either time between blood sampling and episode of symptomatic pertussis infection or time between blood sampling and last (aP or wP) vaccination, following an earlier episode of symptomatic pertussis; ³ all had wP(1–4) as primary series except two participants who had aP(1–4) and 1 participant who had wP(1–3), aP(4);⁴ all had wP (1–4) as primary series except three participants who had aP(1–4) and 1 participant who had wP(1–3), aP(4); ⁵ all had wP (1–4) as primary series except two participants who had aP(1–4) and 1 participant who had wP(1–3), aP(4).</p