Lymphocyte ectoenzyme activity compared in healthy persons and patients seropositive to or at high risk of HIV infection

Abstract

SummaryWe measured two ectoenzymes, ecto-5'-nucleotidase (NT) and dipeptidy! peptidase IV (DP) in the peripheral blood lymphocytes of various groups of HI V-infecled patients because of the previous implied relationship of these enzymes to immune funetion.NT expressed as mean nmol/h per mg protein (±s.d.) was significantly depressed in the HlV-seropositive asymptomatic (42 ± 32; /'<OOI) and AIDS groups (14 ±7; /*<0(X)2) when compared with a healthy HIV-seronegative male population (83 ± 27). The NT activities in asymptomatic HIV-seropositive and HIV-seronegative high risk groups (53 ± 30) were nol significantly different from one another but both groups had signifieantly higher enzyme activities than the AIDS group (/' = 0 01 and <0 002. respectively). The seronegativc high risk and normal healthy group had similar NT activities. DP activities expressed as mean nmol/h per mg protein (±s.d.) in both seropositive asymptomatic (0' 188 ± 0 038) and high risk seronegative (0-180 ± 0 05) groups had higher enzyme activities than the healthy seronegative (0-11 7 ± 0 01 5; P = 0 02 and 0 05. respectively) and AIDS group (0 096 + 0 036; = 0 (X)2 and 0 02. respectively). The healthy seronegative group had DP activities not signifieantly different to the AIDS groups. Similarly the high risk seronegalive and healthy seropositive group had similar DP activities.These results taken together indicate that measurement of both DP and NT should be evaluated prospeetively as a monitor of the clinical progression of HIV infection.

CD26: A Multifunctional Integral Membrane and Secreted Protein of Activated Lymphocytes

“…The potential roles of CD26 in human immunodeficiency virus (HIV) infection relate to altering the HIV‐inhibiting capacities of the chemokines CCL5 (regulated on activation normal T cell expressed and secreted (RANTES)) and CXCL12 (stromal derived factor‐1α and ‐1β) [39], binding gp120 of HIV [40] and binding the HIV tat protein [41, 42]. These phenomena may contribute to the selective reduction in the numbers of CD4 + CD26 + cells in HIV infection [43–47]. Conflicting reports on whether intact versus DPP IV‐truncated CCL5 and CXCL12 differ in their abilities to inhibit HIV infection [35, 48–50] do not explain the loss of CD4 + CD26 + cells.…”

Celebrating 100 years of Immunology & Cell Biology – a special focus on the field of tumor immunology in Australia

“…I think that if they can do those two things, they can knock chemotherapy off the treatment list. [16][17][18][19][20][21][22][23][24][25][26] on topics including humoral and T cell responses to cervical cancer-associated human papillomaviruses, dendritic cell function and regulation of skin immunity (in particular, genetic determinants and skin engraftments; Figure 2).…”

“…His contribution, along with his late colleague, Dr Jian Zhou, led to the development of the human papillomavirus vaccine Gardasil, which is now used to prevent cervical cancer. He has contributed to 11 articles in ICB between 1990 and 2016, 16–26 on topics including humoral and T cell responses to cervical cancer‐associated human papillomaviruses, dendritic cell function and regulation of skin immunity (in particular, genetic determinants and skin engraftments; Figure 2).…”

The prooxidant state and psychologic stress.

“…That an innate or proinflammatory process persists in stressed patients is evidenced by persistent increased blood concentrations of acute phase proteins seen in these patients (9,10 We thank Chalmers et al for their interest in our paper published in EHP (1). We also thank them for sharing their earlier studies on free radical-mediated reduction of lymphocytic 5´-ectonucleotidase (NT) activity during psychologic stress (2)(3)(4) and on the reduction of this activity during HIV infection and diabetes (4,5), which were reported to be associated with a high prooxidant state. Their works have actually shown that psychologic stress results in a decreased NT activity and in a decreased tissue ascorbate that can both be normalized by antioxidant intake or when the stress resolved.…”

“…NT is significant because it has a role in lymphocyte maturation; newborns with persistently low activities have multiple infections, whereas with normalization of NT, their infections resolved (4). We previously showed that NT activities decreased, by then-unknown mechanism(s), as the course of HIV (human immunodeficiency virus) infection progressed (5). Later, we carried out this study in psychologically stressed patients to see if stress itself could lower the activity of this enzyme and thereby contribute to the immune deficiency reported for stressed/ depressed patients (6).…”