This post is a melding of two related papers A 1994 Japanese paper shows activation of T cells by what they call crysotile. Cystotile is the silicate we commonly call asbestos,  A 2004 Croatian paper describes a clinical trial of clinoptilolite, a mineral that contains silica and alumina, on immune cells in immunocompromised participants. 
In the 1994 study peripheral blood mononuclear cells (PBMC) were separated from the heparinized blood of healthy volunteers and cultured with chrysotile (international standard reference sample) in a common culture medium supplemented with 20% fetal calf serum (FCS) containing growth factors, and antibiotics for 6 days. The cells were incubated with fluorescein diacetate (FDA. FDA is a cell permeable fluorescent probe that is hydrolyzed and retained in the intracellular compartment of viable cells and then analyzed for cell viability. The total number of cells, live or dead, were assessed with a nuclear stain. 
An interesting nuance of these cells is that cells had to be detached from the asbestos with phosphate buffered saline spiked with the divalent cation chelating agent EDTA. The cells were double stained with FITC-CD3 and PE-CDl9 (B) or FITC-CD4 and PE-CD8 (C) mAb for 1 hr at room temperature, and analyzed for cell-surface markers flow cytometrically. Calculation of the index was based on the control cells incubated without chrysotile/asbestos. 
Polyclonal human T-cell activation by silicate in vitro
BPMC were loaded with fluo-3, an intracellular calcium indicator whose fluorescence increases when intracellular calcium increases. Note that the intracellular calcium has a monomodal peak count the center of the scale after 5 min (panel B) There is only a hint of a bimodal distribution in terms of the concentration per cell. Note the Y-axis is the number of cells. Prolonged incubation with 50 µM crysotile increases the concentration of intracellular calcium as well as the cell count of that calcium in this heterogeneous population of BPMC. 
Table 1 concerned the β variable regions, as opposed to the α variable regions, of the T cell receptor that is pre-programmed to recognize foreign antigens. Ueki and coauthors cited references suggesting that these regions of the T cell receptor may also recognized self antigens in autoimmune diseases. 
PBMC were incubated with or without chrysotile for 48 hr. The release of IL-2 was higher in PBMC incubated with chrysotile than in control cells (P < 0 05, Table 2). The culture supernatant was used for the subsequent assay to examine the role of the MHC/HLA complex. Monoclonal anti-HLA DP and DR antibodies were used to bind cells expressing MHC/HLA surface receptors. Complement was added to bind to the antibody and destroy the cells to which the antibody was attached. . The authors found that the number of IL-2 receptor positive cells also increased with chrysotile treatment (p<0.005, not shown in the publication). Some of this study is based on the concept of a super antigen that increases intracellular Ca2+ and IL-2 release.
A clinical trial in immuno compromised humans 
Ten years later, a Croatian and German group investigated a treatment for immunoc ompromised patients as a result of their treatment. Nine primary care physicians in the greater Neubrandenburg area in Germany recruited patients frequenting their private practice for the treatment of known immunodeficiency.  During a 6- to 8-week period, participants received trice daily:
- Mild to moderate immunodeficient patients received 4 Megamin capsules
- Patients with severe immunodeficiency were given Lycopenomin, since this product was anticipated to be the more powerful antioxidant.
All other medical therapies intended to treat the immunodeficiency disorder were continued. 
were to be continued unchanged throughout the study
The primary ingredient in both products is TMAZ®, a tribomechanically activated version of
the natural zeolite clinoptilolite that contains other compounds: SiO2, 65.0–71.3%; Al2O3, 11.5–13.1%; CaO 2.7-5.2%; K2O, 2.2–3.4%; Fe2O3, 0.7–1.9%; MgO, 0.6–1.2%; Na2O, 0.2–1.3%; TiO2, 0.1–0.3%; Si/Al ratio, 4.8–5.4.
- Each 300-mg Megamin capsule also contains 87 mg of dolomite (CaMg(CO3)2)
- 200-mg Lycopenomin capsule contains several antioxidants, including 75 mg of vitamin C, 50 mg of natural tomato-derived lycopene, 50 mg of tomato powder, 25 mg of grape seed extract, and 2 mg of plant derived magnesium stearate.
The ratio of CD4+ to CD8+ cells did not change.  This table was modified from the publication to illustrate global changes.
What exactly do these immune cell markers mean?
- CD3, or cluster of differentiation 3, is a co receptor in CD4+ and CD8+ T cells. The clays increase the count of cells positive for this antigen. The increase in crude counts with a p=0.06 backs up the other data.
- CD19 is a surface receptor that plays a role in B cell survival.
- CD4, or cluster of differentiation 4, is a marker for T helper cells. CD4 binds to the HLA/MHC receptor that presents antigen to the T cell receptor. T helper cells also secrete cytokines to bring in other immune cells.
- CD8, or cluster of differentiation 8, is also a coreceptor for the MHC I complex of tumor and virus infected cells. T cells expressing CD8 are also called cytotoxic T cells. Natural killer cells also express CD8. CD8 is also associated with autoimmunity.
- HLA-DR is found in professional antigen presenting cells like dendritic cells and macrophage whose role is to present antigen to T cells. Clinoptilolite also increases this marker.
- CD56 is more commonly expressed in non-lymphoid cells. It may also be found in CD8+ T cells (no change in this study) and γδ T cells whose role in autoimmunity will not be addressed in this post. γδ T cells seem to reside in the mucosa.
The authors cited previous studies from the Croat’s laboratory showing that the traces of silicon were not detected in the serum but that were found in the first and second layers of the duodenal cells. This observation is what explains the usefulness of activation: breaking the clay up into pieces small enough to penetrate into the superficial cells of the mucosa to activate the immune system there without actually becoming systemic.
- Ueki A, Yamaguchi M, Ueki H, Watanabe Y, Ohsawa G, Kinugawa K, Kawakami Y, Hyodoh F. Polyclonal human T-cell activation by silicate in vitro. Immunology. 1994 Jun;82(2):332-5. PMC free paper
- Ivkovic S, Deutsch U, Silberbach A, Walraph E, Mannel M. Dietary supplementation with the tribomechanically activated zeolite clinoptilolite in immunodeficiency: effects on the immune system. Adv Ther. 2004 Mar-Apr;21(2):135-47. doi: 10.1007/BF02850340.