Enhanced T-cell rosette formation in shigellosis by the in vitro use of thymopoietin

Abstract

The results from this study suggest that the large nul cell lymphocyte population seen in patients with Shigella dysentery, does contain a sub-population of cells that will respond in vitro to thymopoietin, a bovine thymic extract, by increased E-rosette formation. It is felt that this sub-population is in fact immature T-cells. A previous study has shown that an unusual leukaemoid reaction develops in a substantial number of patients with Shigella dysentery. The leukaemoid response was primarily granulocytic in nature but there was also a substantial increase in the mean number of lymphocytes. The proportion of the various populations of lymphocytes from leukaemoid and non-leukaemoid subjects were altered, B-cells remained constant, while the T-cells were depressed with a corresponding rise in the proportion of nul cells. The cumulative results of this and other studies demonstrate that the T-cell arm of immunity is compromised in shigellosis. Indeed the degree of compromise may ultimately be the decisive factor in determining the severity of this disease.

Alterations in lymphocyte phenotype and function in children with shigellosis who develop complications

“…Lower numbers of CD3 ϩ and CD4 ϩ cells with lowering of the CD4/CD8 ratio found in the circulation of children with SCS could be due to (i) loss through the inflamed gut, (ii) maturation block in the thymus (8), and (iii) migration to local sites of inflammation. Shigellosis is a protein-losing enteropathy in which stool RBCs have been shown to correlate with stool ␣1 antitrypsin (an indicator of loss of protein from the gut) (3).…”

“…Children with leukemoid reactions in shigellosis have been shown to have more peripheral blood mononuclear cells (PBMs) that are neither E rosette positive (T cells) nor EAC rosette positive (B cells) (9). Addition of thymopoietin to these cells results in an increase in the numbers of E rosette-positive cells in some of these children, suggesting a block in maturation of T cells (8). However, the overall numbers of T and B cells are normal in those children.…”