Assessment of CD40 and CD40L expression in rheumatoid arthritis patients, association with clinical features and DAS28
CLINICAL AND EXPERIMENTAL MEDICINE
Authors: Valeria Roman-Fernandez, Ilce; Garcia-Chagollan, Mariel; Cerpa-Cruz, Sergio; Felipe Jave-Suarez, Luis; Azucena Palafox-Sanchez, Claudia; Garcia-Arellano, Samuel; Athziri Sanchez-Zuno, Gabriela; Francisco Munoz-Valle, Jose
Abstract
The predominance of the effector mechanisms by CD4 + T cells is a characteristic of inflammatory autoimmune diseases such as rheumatoid arthritis (RA). The CD40/CD40L costimulatory pathway contributes to these pathogenic mechanisms by promoting autoantibody production and inflammation. Aberrant expression of CD40 and CD40L in RA patients has been shown, the latter prevailing in females. However, contrasting results have emerged regarding the clinical associations of these findings. We determined the association of CD40 and CD40L expression with the clinical activity evaluated through DAS28 in RA patients. A total of 38 female RA patients and 10 age- and sex-matched control subjects were included. CD40 and CD40L mRNA expression was quantified by real-time qPCR, cell surface proteins were determined by flow cytometry, and protein soluble forms were determined by ELISA. The expansion of a CD4 + T cell subpopulation expressing CD40 was identified in the RA group. In addition, high frequencies of CD4 + CD40L + T cells expressing high levels of CD40L, increased levels of sCD40L and overexpression of CD40L mRNA were observed in these patients. Moreover, there was a gradual increase in CD40L when data were stratified according to DAS28, except for very active patients. No correlation was observed between the levels of mRNA, cell surface protein and soluble protein of CD40 and CD40L with the clinical features of RA patients. There is an altered expression of CD40L in female RA patients in association with clinical activity assessed by DAS28, these findings support the evidence that suggests CD40L as a marker of clinical activity.
Early T Cell Differentiation with Well-Maintained Function across the Adult Life Course in Sub-Saharan Africa
JOURNAL OF IMMUNOLOGY
Authors: Miles, David J. C.; Shumba, Florence; Pachnio, Annette; Begum, Jusnara; Corbett, Elizabeth L.; Heyderman, Robert S.; Moss, Paul
Abstract
Immune senescence is a significant contributor to health problems in the developed world and may be accelerated by chronic viral infections. To date, there have been few studies of immune function in healthy older people in sub-Saharan Africa. We assessed T cell and B cell phenotypes and immune responses to CMV, EBV, and influenza virus in Malawians aged 20-69 y. Notably, the proportion of naive (CCR7(+)CD45RA(+)) CD4 and CD8 T cells was only 14% of the lymphoid repertoire even in donors aged under 30 y but did not decrease further with age. A small increase in the late differentiated (CD27(-)CD28 (-)) CD8 T cell subpopulation was observed in older donors but the CD4/CD8 T cell ratio remained stable in all age groups. Interestingly, the regulatory (CD25(hi)FOXP3(hi)) T cell subpopulation was small in all age groups, and we observed no age-associated accumulation of cells expressing the senescence- and exhaustion-associated markers CD57 and PD-1. We assessed functional T cell responses to mitogenic and viral antigenic stimulation by the expression of CD154, IFN-gamma, TNF-alpha, IL-2, and IL-17 and proliferation. All responses were robust across the life course, although we observed an age-associated shift from IFN-gamma to TNF-alpha in the response to EBV. In summary, we found the naive T cell subpopulation of young adult Malawians was smaller than in their contemporaries in high-income settings but remains stable thereafter and that lymphocyte function is retained across the life course. These observations indicate that studies of the genetic and environmental factors influencing immune function in different environments may provide insights into minimizing immune ageing.