CD3 expression distinguishes two gdT cell receptor subsets with different phenotype and effector function in tuberculous pleurisy

• Published in: Clinical and experimental immunology 2009-09, Vol.157 (3), p.385-394
• Main Authors: Yokobori, N, Schierloh, P, Geffner, L, Balboa, L, Romero, M, Musella, R, Castagnino, J, De Stefano, G, Aleman, M, de la Barrera, S, Abbate, E, Sasiain, M C
• Format: Article
• Language: English
• Subjects: CD3 antigen; Cell migration; Chemokine receptors; Effector cells; g-Interferon; Infection; Lymphocytes T; Mycobacterium tuberculosis; Natural killer cells; Peripheral blood; Pleural effusion; Pleurisy; Receptor mechanisms; T-cell receptor; Tuberculosis
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2009.03974.x

SummaryTuberculous pleurisy is a naturally occurring site of Mycobacterium tuberculosis (Mtb) infection. Herein, we describe the expression of activation, natural killer (NK) and cell migration markers, as well as effector functions from gdT cells in peripheral blood (PB) and pleural effusion (PE) from tuberculosis patients (TB). We observed a decreased percentage of circulating gdT from TB patients and differential expression of NK as well as of chemokine receptors on PB and PE. Two subsets of gdT cells were differentiated by the CD3/gdT cell receptor (gdTCR) complex. The gdTCRlow subset had a higher CD3 to TCR ratio and was enriched in Vd2+ cells, whereas most Vd1+ cells belonged to the gdTCRhigh subset. In PB from TB, most gdTCRhigh were CD45RA+CCR7- and gdTCRlow were CD45RA+/-CCR7+CXCR3+. In the pleural space the proportion of CD45RA-CCR7+CXCR3+ cells was higher. Neither spontaneous nor Mtb-induced interferon (IFN)-g production was observed in PB-gdT cells from TB; however, PE-gdT cells showed a strong response. Both PB- and PE-gd T cells expressed surface CD107a upon stimulation with Mtb. Notably, PE-gdTCRlow cells were the most potent effector cells. Thus, gdT cells from PB would acquire a further activated phenotype within the site of Mtb infection and exert full effector functions. As gdT cells produce IFN-g within the pleural space, they would be expected to play a beneficial role in tuberculous pleurisy by helping to maintain a T helper type 1 profile.