Total numbers of lymphocyte subsets in different lymph node regions of uninfected and SIV‐infected macaques

Abstract

Human immunodeficiency virus (HIV) infection leads to a decline of CD4+ T-cells in blood. Because blood represents only a small proportion of the total lymphocyte pool, it is important to investigate other lymphoid organs. So far, only relative proportions of lymphocyte subsets in single peripheral lymph node (LN) regions of HIV-infected patients and simian immunodeficiency virus (SIV)-infected macaques have been documented. We have therefore quantified the absolute numbers of lymphocyte subsets in blood and six different LN regions of 10 uninfected and 26 SIV-infected macaques. In addition, we have determined the expression of markers of activation and differentiation. Already, in uninfected monkeys, there were significant differences in the cellular composition of different LN regions. Infection with SIV resulted in drastic changes in the proportion as well as absolute numbers of different lymphocyte subsets. Moreover, the relative contribution of the single LN regions to the total lymphocyte pool was also altered.

The Fate of Effector T Cells In Vivo Is Determined During Activation and Differs for CD4+ and CD8+ Cells

“…Similar observations were made in HIV-infected primates in which activated CD4 ϩ T cells seem to be more sessile, whereas activated CD8 ϩ T cells are able to leave into the blood and migrate through the body (Ref. 25 and S. Sopper, personal communication). However, the different migratory properties of CD4 ϩ and CD8 ϩ effector mLN T cells have to be confirmed by injecting them i.v.…”

Impact of simian immunodeficiency virus (SIV) infection on lymphocyte numbers and T-cell turnover in different organs of rhesus monkeys

“…27 After carefully removing adhering connective and fat tissue, lymph nodes (LNs) as well as spleen, thymus, liver, lung, bone marrow (BM), brain, intestine, and other organs were weighed. A representative part of these organs was weighed again, and cells were isolated from this piece of tissue as described.…”

“…Cell-associated viral loads in blood were determined by limiting dilution coculture of monkey peripheral blood mononuclear cells (PBMCs) and the permanent T cells C81-66 as indicator cells as described. 27 From the Institut für Virologie und Immunbiologie, Julius-Maximilians-Universität, Würzburg, Germany; Deutsches Primatenzentrum, Göttingen, Germany; Innere Medizin II, Universität des Saarlandes, Homburg/Saar, Germany; and Institut für Pathologie, Julius-Maximilians-Universität, Würzburg, Germany. Reprints: S. Sopper, Institut fü r Virologie und Immunbiologie, JuliusMaximilians-Universitä t, Versbacherstr 7, D-97078 Wü rzburg, Germany; e-mail: sopper@vim.uni-wuerzburg.de.…”

“…A representative part of these organs was weighed again, and cells were isolated from this piece of tissue as described. 3,27,28 Briefly, total numbers of lymphocytes (N) per organ were calculated as follows: n ϭ nW/w, where n is the number of lymphocytes isolated, W the total weight of the organ or LN region, and w the weight of the tissue sample used to isolate the lymphocytes. For the organs, where we did not determine the actual total weight, the following values were estimated: bone marrow, 50 g; gut, 200 g; and blood, 300 mL.…”

CD4+ effector T cell distribution in vivo: TGF‐β1/TGF‐β receptor II interaction during activation mediates accumulation in the target tissue by preferential proliferation

“…In functional terms this means that CD4 + effector T cells generated in mLN are distributed to mLN and its drainage area -although a direct connection is missing during the effector phase of an immune response. There are indications that the distribution of CD8 + effector T cells [24] and activated B cells follows similar rules [4] in principle, although differences may exist [17,25].…”