Report from the second cytomegalovirus and immunosenescence workshop

The Second International Workshop on CMV & Immunosenescence was held in Cambridge, UK, 2-4th December, 2010. The presentations covered four separate sessions: cytomegalovirus and T cell phenotypes; T cell memory frequency, inflation and immunosenescence; cytomegalovirus in aging, mortality and disease states; and the immunobiology of cytomegalovirus-specific T cells and effects of the virus on vaccination. This commentary summarizes the major findings of these presentations and references subsequently published work from the presenter laboratory where appropriate and draws together major themes that were subsequently discussed along with new areas of interest that were highlighted by this discussion.     

Comparative and evolutionary analysis of plasmid pREN isolated from Lactobacillus rennini, a novel member of the theta-replicating pUCL287 family

Here, we describe plasmid pREN of Lactobacillus rennini ACA-DC 1534, isolated from traditional Kopanisti cheese. pREN is a circular molecule of 4371 bp. Orf calling revealed a novel repA-orf2 operon with the deduced product of orf2 showing no similarity to other known proteins. Downstream of this operon, a gene cluster encoding different mobilization proteins, namely mobC, mobA1, mobA2 and mobB, was detected. Based on the sequence of the origin of replication (ori) and the similarity pattern of RepA, pREN was placed in the pUCL287 family of theta-replicating plasmids. Multiple sequence alignment demonstrated for the first time the degree of conservation in the pUCL287 oris. Our analysis supported that the identified conserved repeats could drive similar secondary structures in the oris of all plasmids. Furthermore, comparative mapping of pREN with its related plasmids (i.e. pLB925A03 and pLJ42) showed that they retain a unique combination in the architecture of their replication and mobilization elements within the pUCL287 family. Phylogenetic analysis also established that these plasmids have undergone a modular evolutionary process in order to acquire their mob genes. Research on plasmids from uncommon lactic acid bacteria will expand our appreciation for their divergence and will aid their rational selection for biotechnological applications.     

Differential white blood cell count and type 2 diabetes: systematic review and meta-analysis of cross-sectional and prospective studies

Objective

Biological evidence suggests that inflammation might induce type 2 diabetes (T2D), and epidemiological studies have shown an association between higher white blood cell count (WBC) and T2D. However, the association has not been systematically investigated.

Research Design and Methods

Studies were identified through computer-based and manual searches. Previously unreported studies were sought through correspondence. 20 studies were identified (8,647 T2D cases and 85,040 non-cases). Estimates of the association of WBC with T2D were combined using random effects meta-analysis; sources of heterogeneity as well as presence of publication bias were explored.

Results

The combined relative risk (RR) comparing the top to bottom tertile of the WBC count was 1.61 (95% CI: 1.45; 1.79, p = 1.5*10⁻¹⁸). Substantial heterogeneity was present (I² = 83%). For granulocytes the RR was 1.38 (95% CI: 1.17; 1.64, p = 1.5*10⁻⁴), for lymphocytes 1.26 (95% CI: 1.02; 1.56, p = 0.029), and for monocytes 0.93 (95% CI: 0.68; 1.28, p = 0.67) comparing top to bottom tertile. In cross-sectional studies, RR was 1.74 (95% CI: 1.49; 2.02, p = 7.7*10⁻¹³), while in cohort studies it was 1.48 (95% CI: 1.22; 1.79, p = 7.7*10⁻⁵). We assessed the impact of confounding in EPIC-Norfolk study and found that the age and sex adjusted HR of 2.19 (95% CI: 1.74; 2.75) was attenuated to 1.82 (95% CI: 1.45; 2.29) after further accounting for smoking, T2D family history, physical activity, education, BMI and waist circumference.

Conclusions

A raised WBC is associated with higher risk of T2D. The presence of publication bias and failure to control for all potential confounders in all studies means the observed association is likely an overestimate.     

In silico evidence for the horizontal transfer of gsiB, a σ(B)-regulated gene in gram-positive bacteria, to lactic acid bacteria

gsiB, coding for glucose starvation-inducible protein B, is a characteristic member of the σ(Β) stress regulon of Bacillus subtilis and several other Gram-positive bacteria. Here we provide in silico evidence for the horizontal transfer of gsiB in lactic acid bacteria that are devoid of the σ(Β) factor.