Recovery of T-lymphocytes for adoptive immunotherapy by lymphapheresis of HIV-infected patients without alterations of virological, immunological or clinical parameters

Changes in immunological and virological parameters in HIV-1 infected subjects following leukapheresis

In order to assess immune responses during HIV-1 therapeutic immunization, a large number of blood mononuclear cells (PBMC) are needed. Clinical tolerance and safety, as well as changes in immunological and virological parameters, were assessed, following leukapheresis in HIV-1 infected subjects with CD4(+) cell count >200 x 10(6)/l. PBMC were collected using a Fenwal CS3000 cell separator in 29 subjects with mean CD4(+) cell counts of 503 x 10(6)/l (range 172-1,119) and viral load of 2.5 log(10) copies/ml (range <1.7-5.4). Twenty-four (83%) subjects were on antiretroviral therapy while 5 (17%) were untreated. The blood volume processed was 7 L over a period of 3 hours. A mean value (+/- standard error) of 82 +/- 26 x 10(9)/l lymphocytes was collected by a single apheresis in a mean volume of 200 +/- 1.8 ml, containing 9.0 +/- 1.3 x 10(9)/l CD4(+) and 10.2 +/- 1.3 x 10(9)/l CD8(+) cells. The leukapheresis procedures were well tolerated and no immediate or delayed side effects were observed within 90 days of follow-up. No changes from blood pre-leukapheresis values were detected for white blood cells, lymphocytes, monocytes, CD8(+), CD34(+), naive and memory CD4(+) cell counts immediately after, 1 h, 7 days, or within 90 days after leukapheresis. However, absolute CD4(+) cell counts and percentage significantly increased from pre-leukapheresis values after 1 h (530 +/- 43 vs. 700 +/- 75 cell x 10(6)/l; 32.6 +/- 1.6 vs. 36.9 +/- 1.9%; P < 0.001 for both paired t-tests) before returning to pre-leukapheresis levels on day 7. No significant changes in viral load from pre-leukapheresis levels in treated or untreated subjects were detected at any time points. We conclude that leukapheresis in HIV-1 infected subjects with CD4(+) cell counts >200 x 10(6)/l is safe and induces a transient increase in the absolute and percentage of CD4(+) cell count without enhancing viral replication.

The beneficial effects of lymphocytapheresis for treatment of nephrotic syndrome

A considerable permeability factor (or factors) derived from circulating T cells has a crucial role in proteinuria of nephrotic syndrome (NS). We attempted to remove pathogenic T cells through lymphocytapheresis (LCAP) in 6 patients with primary NS, 2 patients with minimal change nephrotic syndrome (MCNS), 2 patients with focal segmental glomerulosclerosis (FSGS), 1 patient with membranous nephropathy (MN), and 1 patient with MN and FSGS using Cellsorba (Asahi Medical Co., Osaka, Japan). LCAP was performed 2 times in 2 consecutive weeks and was followed with corticosteroid therapy with or without cyclosporine A in 5 patients. Two patients with MCNS, 1 with FSGS, and 1 with MN and FSGS showed a dramatic decrease of proteinuria (-30% and -94%) in their urine protein/creatinine ratio. Three out of 4 patients had a complete or partial remission (proteinuria <1g/day) within 8 weeks following immunosuppressive therapy. During the LCAP, T cells, especially activated T cells, decreased significantly in the response group. The other 2 patients, 1 with FSGS and 1 with MN, however, had no response to LCAP and following immunosuppressive therapy or low-density lipoprotein apheresis and suffered from end-stage renal failure or death by pneumonia. These results suggested that LCAP might have a beneficial effect on the treatment of NS, especially MCNS and in some patients with FSGS, despite varying responses to LCAP and concomitant immunosuppressive therapy.

Investigations on autologous T-cells for adoptive immunotherapy of AIDS

We report on the preclinical results of an immunotherapeutic approach of AIDS mediated by ex vivo propagated CD4+ and CD8+ T-cells. A mean yield of 6.23 x 10(9) lymphocytes, containing 1.82 x 10(9) CD4+, 3.23 x 10(9) CD8+ T-lymphocytes and 8.39 x 10(6) CD34+ peripheral blood progenitor cells (PBPC) were be obtained by continuous flow cytapheresis (CFC) in 15 asymptomatic HIV infected patients (CD4-count > 350/mm3). The CD4/CD8 ratio (mean: 0.53, SD: +/- 0.15) in the cell concentrates reflected the distribution of the circulating lymphocyte subsets in vivo. Absolute lymphocyte counts decreased at a mean of 404/microliter (25%) immediately after CFC but were replaced from the extravascular pool within one hour. Neither the CD4/CD8 ratio nor p24-antigen and neopterin levels did change significantly after cell separation. No alteration of the number of proviral DNA copies (1/10(3)-1/10(6)) could be detected in peripheral T-helper cells by semiquantitative PCR after lymphapheresis. Cells were cryopreserved in liquid nitrogen without substantial loss of viability or function. Ex vivo propagation of T-cells in a strictly autologous manner in the presence of PHA + IL-2 for 14d resulted in a 50-fold expansion rate (140-fold in healthy controls, p < 0.001). Viral replication could be controlled but not completely eliminated by cocultivation with autologous CD8+ T-lymphocytes as measured by limiting dilution nested PCR (NPCR). The expanded cells showed the typical phenotype of highly activated memory type T-lymphocytes (CD3+ CD45RO+ CD25+ HLA-DR+). The distribution of CD4+ and CD8+ T-cells did not reveal significant changes before and after culture indicating that both subsets were equally expanded. Functionally important membrane or intracellular epitopes which were found to be decreased in HIV infected subjects (CD7, CD55, CD59) before culture were reconstituted after ex vivo propagation of T-cells. The functional importance of the up-regulation of complement regulating epitopes (CD55, CD59) after culture could be proven by a significant inhibition of cytolysis of T-cells in the presence of autologous complement. The majority (75%) of expanded CD8+ T-cells stained positive with mAb TIA-1 which is directed to intracellular granules within cytotoxic T-cells. Furthermore, programmed cell death of expanded T-cells could be prevented by cocultivation with fibroblasts which are believed to secrete a cytokine pattern preventing activated T-cells from apoptosis after withdrawal of IL-2 and other stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)