Modification of Lymphocyte and Monocyte Functional Activity by Polymorphonuclear Neutrophils in HIV Infection

Abstract

The aim of this study was to determine whether polymorphonuclear neutrophils (PMN) can modify the immune response in HIV cases. Supernatants of PMN (PMNS) from 33 HIV-infected patients (16 with lymphoadenopathy syndrome, 17 with AIDS-related complex) were tested for their influence on the functional activity of lymphocytes and monocytes from 6 healthy donors. PMNS from another 6 healthy donors comprised a control group. It was found that PMNS from HIV-infected patients, but not from healthy donors, induced suppression of lymphocyte proliferative response and down-regulation of CD8 receptor expression on lymphocytes. Decrease of NK-cell cytotoxicity in the presence of PMNS from HIV-infected patients was the same as that from healthy donors. PMNS did not influence the production of anti-HIV antibody by lymphocytes from HIV-infected patients, as well as non-specific IgG by lymphocytes from healthy donors. PMNS effect on functional activity of lymphocytes was blocked completely after treatment of PMN by catalase and superoxide dismutase. At the same time PMNS from HIV-infected patients but not from healthy donors induced increased production of TNF-alpha by monocytes and up-regulation of monocyte phagocytosis. These effects were independent of catalase and superoxide dismutase and were not abrogated by antibody against IL-1, IL-8, TNF-alpha, IFN-gamma or IFN-alpha.

Increased Level of Arginase Activity Correlates with Disease Severity in HIV‐Seropositive Patients

“…We cannot exclude the possibility that a switch in the ratio of T cells to neutrophils, rather then an absolute increase in the number of neutrophils, could be responsible for the increase in the level of arginase activity; however, when we exclude the number of cells as a factor in the calculation of the levels of arginase activity, our results clearly show that the levels of arginase activity are statistically significantly higher in HIV-seropositive patients with low CD4 + T cell counts, compared with HIV-seropositive patients with high CD4 + T cell counts. An impairment of T cell functions by neutrophils has already been demonstrated in HIV-seropositive patients [34].…”

Neutrophils: Neglected Players in Viral Diseases

“…Neutrophils also regulate NK cell functions (Seaman et al, 1982;Dallegri et al, 1985;Shau and Kim, 1988;Shau and Golub, 1989;Gabrilovich et al, 1993;Sporri et al, 2008), maturation ( Jaeger et al, 2012), and homeostasis ( Jaeger et al, 2012). Recent evidences revealed that NK cells were less responsive, more proliferative, and less mature in patients suffering from SCN ( Jaeger et al, 2012).…”

The defensive alliance between neutrophils and NK cells as a novel arm of innate immunity

“…In both studies, the neutrophil-mediated, suppressive action was reversed by catalase (a H 2 O 2 -detoxifying enzyme) but not SOD (which instead, converts O 2 to H 2 O 2 ) [39,40], indicating that it was dependent specifically on H 2 O 2 . Since then, it has been confirmed consistently, using PBMCs/PBLs or purified NK cells, that granulocyte-derived ROS have inhibitory effects on several NK cell effector functions, ranging from NK-dependent cytotoxic activities to NK survival or the expression of NCRs [35][36][37][38][41][42][43][44]. Interestingly, 3 studies [37,38,44] have identified NK subset-specific differences further in terms of sensitivity to neutrophil-derived ROS.…”