Higher proportion of CD8+ T cells in the blood in healthy adults from Ethiopia and Bangladesh compared with Sweden

Abstract

he phenotypic composition of peripheral blood lymphocytes in 45 healthy adults (15 each from Bangladesh, Ethiopia and Sweden) was analysed as an indicator of the influence of environment and/or ethnic background on the human immune response. The possible interference of technical factors was minimized by highly standardized handling of samples and by use of a similar simultaneous 3-colour flow cytometry analysis technique for all samples. The percentage of CD4+ cells was lower, and the percentage of CD8+ cells was higher, in Bangladeshi and Ethiopian subjects than in those from Sweden. A higher percentage of CD57+/CD8+ T cells was also found in these 2 groups than in Swedish subjects. The percentage of gamma delta T cells was higher in Bangladeshi subjects and a difference in T cell receptor V beta expression was also noted between Bangladeshi and Swedish subjects. The data suggest that environmental or genetic factors are important bias factors to be considered in immunophenotyping studies. Possibly differences in the pattern or level of microbial challenge, as well as nutritional factors, may lead to different adaptive changes in the immune response. The potential influence of such immune adaptation on the response to vaccination or pharmaceutical therapy may be important in the development of new strategies of medical intervention in different geographical regions or ethnic groups.

PIP: The phenotypic composition of peripheral blood lymphocytes in 45 healthy adult blood donors (15 each from Bangladesh, Ethiopia, and Sweden) was examined as an indicator of the influence of environment and/or ethnic background on the human immune response. A highly standardized 3-color flow cytometry analysis was performed on all samples. The percentage of CD4+ cells was lower and the percentage of CD8+ cells was higher in Bangladeshi and Ethiopian subjects than in those from Sweden. A higher percentage of CD57+/CD8+ T cells was likewise found in these 2 groups compared to Swedish subjects. The percentage of gammadelta T cells was higher in Bangladeshi subjects and a difference in T cell receptor Vbeta expression was also noted between Bangladeshi and Swedish subjects. The findings suggest that environmental or genetic factors are important bias factors to be taken into account in phenotyping studies. Possible variations in the patterns or level of microbial challenge, as well as nutritional factors, may lead to different adaptive changes in the immune response. The potential influence of such immune adaptation on the response to vaccination or pharmaceutical therapy may be essential in the development of new medical intervention approaches in different geographical regions or ethnic groups.