Proliferative Response Of Peripheral Lymphocytes Research Articles

Immune response to human embryonic stem cell‐derived cardiac progenitors and adipose‐derived stromal cells

Transplantation of allogeneic human embryonic stem cell-derived cardiac progenitors triggers an immune response. We assessed whether this response could be modulated by the concomitant use of adipose-derived stromal cells (ADSC). Peripheral blood mononuclear cells were collected from 40 patients with coronary artery disease (CAD) and nine healthy controls. Cardiac progenitors (CD15+ Mesp1+) were generated as already reported from the I6 cell line treated with bone morphogenetic protein (BMP)-2. Adipose-derived stromal cells were obtained from abdominal dermolipectomies. We assessed the proliferative response of peripheral lymphocytes from patients and controls to cardiac progenitors cultured on a monolayer of ADSC, to allogeneic lymphocytes in mixed lymphocyte culture and to the T cell mitogen phytohemaglutin A in presence or absence of ADSC. Cardiac progenitors cultured on a monolayer of ADSC triggered a proliferation of lymphocytes from both patients and controls albeit lower than that induced by allogeneic lymphocytes. When cultured alone, ADSC did not induce any proliferation of allogeneic lymphocytes. When added to cultures of lymphocytes, ADSC significantly inhibited the alloantigen or mitogen-induced proliferative response. Compared to healthy controls, lymphocytes from patients presenting CAD expressed a decreased proliferative capacity, in particular to mitogen-induced stimulation. Adipose-derived stromal cells express an immunomodulatory effect that limits both alloantigen and mitogen-induced lymphocyte responses. Furthermore, lymphocytes from patients with CAD are low responders to conventional stimuli, possibly because of their age and disease-associated treatment regimens. We propose that, in combination, these factors may limit the in vivo immunogenicity of cardiac progenitors co-implanted with ADSC in patients with CAD.

Alterations in the proliferative response of peripheral lymphocytes in tick-borne encephalitis.

Alterations in the proliferative response of peripheral lymphocytes in tick-borne encephalitis.

Proliferative response of peripheral blood lymphocytes and lymphocyte subpopulations in n-Hexane, toluen, and methyl ethyl ketone co-exposed workers

To estimate the quantitative relation between chronic co-exposure to airborne n-hexane, toluen, methyl ethyl ketone (MEK) and various markers of immune function such as proliferative response of peripheral blood lymphocytes and lymphocyte subpopulations, a group of workers employed in a shoe factory were examined and compared with the unexposed controls. A significant increase was observed in the proliferative response of the peripheral lymphocytes to 2.5 and 5 μg PHA in the exposed group compared with that of the control group. There was no significant change in the percentage of circulating CD3 +, CD4 +, CD8 +, CD19 +, CD16 + lymphocytes even in those workers with 3.3-fold higher mean levels of urine 2,5-hexanedione (2,5-Hxdn) and approximately twofold higher mean levels of urine hippuric acid (HA) as compared to controls. No difference was also observed between the mean granulocyte, monocyte, lymphocyte percentages of the groups, but a significant increase was observed in mean serum C3 level of the workers. Our results suggest that while lymphocyte subpopulations and leucocyte percentages are not affected, the proliferative response of the peripheral lymphocytes is stimulated after chronic co-exposure to n-hexane, toluen and MEK at the defined levels.

Peripheral lymphocyte subsets and their responsiveness in human strongyloidiasis

Surface phenotypes and proliferative responses of peripheral lymphocytes were investigated in a total of 64 patients with strongyloidiasis. A significant increase of CD4 + and OKIa1 + cells and a relative decrease of CD8 + cells were observed among the patients. A considerable rise of spontaneous mitogenesis and an enhanced ability to produce interleukin 2 of peripheral lymphocytes were also found in many patients. On the other hand, lymphoproliferative responses to mitogens were found to be significantly lower in the strongyloidiasis patients than in the controls. The possible relationships among these observations were discussed.

Studies of marginal zinc deprivation in rhesus monkeys. VIII Effects in early adolescence

Arrested adolescent growth and sexual maturation are striking symptoms of severe dietary zinc deprivation. More general implications of mild or marginal Zn deficiency during adolescence are not known. Five marginally Zn-deprived (ZD) male monkeys (4 mg Zn/kg diet) were compared with five controls pair fed a diet containing 100 mg Zn/kg during early adolescence. Mean plasma Zn levels were 38% lower in ZD group than in controls when evaluations began. During rapid growth plasma Zn decreased in controls but not ZD animals. ZD animals had delayed onset of accelerated weight gain and linear growth; loss of subcutaneous fat typical of early adolescence did not occur. ZD monkeys required two to three times more trials for both learning and reversal a visual discrimination task. Immune function was depressed 20-30% as reflected in early reduced proliferative response of peripheral lymphocytes and later lower immunoglobulin levels. Marginal dietary Zn deprivation affects growth and function in adolescence without producing frank developmental retardation.

Cytokinetic analysis of the impaired proliferative response of peripheral lymphocytes from aged humans to phytohemagglutinin.

The effect of donor age on the rate of cell entry into the proliferating pool and subsequent cell cycle duration for peripheral lymphocytes stimulated by phytohemagglutinin (PHA) were examined by using the bromodeoxyuridine incorporation-differential staining technique. Distribution curves for the appearance of metaphase cells in successive generations as a function of culture time were obtained and analyzed both graphically and by a computer simulation model. Peripheral lymphocytes from aged individuals (approximately 75 yr) were stimulated by PHA at approximately one-half of the rate of peripheral lymphocytes from young individuals (approximately 21 yr). Subsequent cell-cycle durations were estimated to range from 10.0 to 25.0 h for aged individual lymphocyte cultures and 10.6-15.6 h for young individual lymphocyte cultures. The possible significance of these findings to aging in general is discussed.

Pathogenesis of rinderpest virus infection in rabbits. II. Effect of rinderpest virus on the immune functions of rabbits.

Rinderpest virus infection was shown to induce marked suppression of both humoral antibody response and cell-mediated immunity in rabbits. The virus exhibited a suppressive effect on primary antibody response as indicated by a decrease in numbers of plaque-forming cells (immunoglobulin [Ig]M) and hemagglutinating antibody titers of both IgM and IgG types to sheep red blood cells, whereas there was no detectable effect of the virus on the production of memory cells. Virus-induced suppression of cell-mediated immunity was demonstrated by a decreased rate of proliferative response of peripheral lymphocytes to phytohemagglutinin stimulus and by a depression of delayed-type skin reactions to purified protein derivative. Such suppressive effects were indicated to persist for 14 days or longer. Alteration in phagocytic activity of the reticuloendothelial system was not observed. The relevance of the virus-induced histological lesions in the lymphoid tissues to the virus-induced immunosuppression was discussed.