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Eugene Appenteng Osae,1,2 Reynolds Kwame Ablordeppey,1 Jens Horstmann,2 David Ben Kumah,1 Philipp Steven2,3 1Department of Optometry and Visual Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; 2Department of Ophthalmology, Division for Dry-Eye and Ocular GvHD, Medical Faculty, University of Cologne, Cologne, Germany; 3Cluster of Excellence: Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, GermanyCorrespondence: Eugene Appenteng OsaeDepartment of Optometry and Visual Science, Kwame Nkrumah University of Science and Technology, Private Mail Bag, Kumasi, GhanaTel +233 200 466 637Email osaeappen@gmail.comAim: To compare differences in clinical dry eye features and meibomian gland health status between dry eye patients from rural and urban populations in Ghana.Methods: We examined 211 (rural=109, urban=102) participants with subjective dry eye symptoms. Tear film break -up time (TBUT), Schirmer’s test and ocular surface staining (OSS) were assessed. Symptoms were evaluated using the SPEED II questionnaire. Meibomian glands (MG) in the right eye upper (UL) and lower lids (LL) were imaged using a custom meibographer. MG area was determined by intensity threshold segmentation using Image J software. MG loss (MGL) was also graded based on Pult’s grading scheme. Mann–Whitney, Spearman correlation, chi-square and odds analyses were performed; p< 0.05 was considered significant.Results: Rural participants showed greater SPEED scores, reduced TBUT, and lower Schirmer scores, p < 0.05. The proportion of rural participants with MGL were significantly more (82.3%) than urban participants (63.3%), p < 0.05. They also showed greater MGL than urban participants, p < 0.05. Chi-square test revealed significantly different meiboscale distributions (UL: χ2=13.58, LL: χ2=15.29) between the groups, p < 0.05. Overall significant relationships were observed between MGL and age [rs= 0.61], OSS [rs= 0.35], TBUT [rs= − 0.52], and Schirmer scores [rs= − 0.40], p < 0.05.Conclusion: The data suggest that the participants from the rural population have worse dry eye and meibomian gland health status than those from the urban population. The significant relationships between the various clinical variables suggest important links between MGD and DED. Subtle differences in the everyday working and living environment could likely account for the differences in the severity of DED and MGD between the two groups. And considering the increased pattern of urbanization, industrialization and modernization and the related environmental effects in Africa, future longitudinal studies on specific environmental risk factors or mediators of DED and MGD are necessary to ascertain the MGD and DED situation in Ghana and Africa at large.Keywords: dry eye, meibomian gland dysfunction, ocular surface, dysfunctional tear syndrome

CD4+T (helper) cells migrate in huge numbers through lymphoid organs. However, little is known about traffic routes and kinetics of CD4+T-cell subsets within different organ compartments. Such information is important because there are indications that CD4+T cells may influence the function of microenvironments depending on their developmental stage. Therefore, we investigated the migration of resting (naïve), activated, and recently activated (memory) CD4+T cells through the different compartments of the spleen. Resting and recently activated CD4+T cells were separated from thoracic duct lymph and activated CD4+T cells were generated in vitro by cross-linking the T-cell receptor and CD28. The present study shows that all three CD4+T-cell subsets selectively accumulate in the T-cell zone of the spleen. However, only activated T cells induce the formation of germinal centers (GCs) and autoantibodies in rats and mice. Our results suggest that in a two-step process they first activate B cells independent of the T-cell receptor repertoire and CD40 ligand (CD154) expression. The activated B cells then form GCs whereby CD154-dependend T-cell help is needed. Thus, activated T cells may contribute to the development of autoimmune diseases by activating autoreactive B cells in an Ag-independent manner. European Journal of Immunology published by Wiley-VCH Verlag GmbH & Co. KGaA Weinheim.

CD4+T (helper) cells migrate in huge numbers through lymphoid organs. However, little is known about traffic routes and kinetics of CD4+T-cell subsets within different organ compartments. Such information is important because there are indications that CD4+T cells may influence the function of microenvironments depending on their developmental stage. Therefore, we investigated the migration of resting (naïve), activated, and recently activated (memory) CD4+T cells through the different compartments of the spleen. Resting and recently activated CD4+T cells were separated from thoracic duct lymph and activated CD4+T cells were generated in vitro by cross-linking the T-cell receptor and CD28. The present study shows that all three CD4+T-cell subsets selectively accumulate in the T-cell zone of the spleen. However, only activated T cells induce the formation of germinal centers (GCs) and autoantibodies in rats and mice. Our results suggest that in a two-step process they first activate B cells independent of the T-cell receptor repertoire and CD40 ligand (CD154) expression. The activated B cells then form GCs whereby CD154-dependend T-cell help is needed. Thus, activated T cells may contribute to the development of autoimmune diseases by activating autoreactive B cells in an Ag-independent manner. European Journal of Immunology published by Wiley-VCH Verlag GmbH & Co. KGaA Weinheim.