1. Preimplantation factor inhibits circulating natural killer cell cytotoxicity and reduces CD69 expression: implications for recurrent pregnancy loss therapy 
Roumen G. Roussev, Boris V. Dons’koi, Christopher Stamatkin, Sivakumar Ramu, Viktor P. Chernyshov, Carolyn B. Coulam, Eytan R. Barnea 
Reproductive BioMedicine Online 
Volume 26, Issue 1, Pages (January 2013)
DOI: /j.rbmo
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions

2. Figure 1
Low doses of synthetic preimplantation factor (sPIF) inhibit NK cell cytotoxicity. The effect of sPIF at two different concentrations (2.5 and 25ng/ml) was tested with a NK cell cytotoxicity assay using blood samples from an unselected group of nonpregnant recurrent pregnancy loss patients (n=21). sPIF at a physiological range was effective in both doses tested, as compared with scrambled PIF control (PIFscr) tested at 25 and 50μg/ml (neither with significant effect) in 16 of the same patients (P<0.001).
Reproductive BioMedicine Online  , 79-87DOI: ( /j.rbmo )
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions

3. Figure 2
Synthetic preimplantation factor (sPIF) inhibits NK cell cytotoxicity in recurrent pregnancy loss patients with elevated (⩾10%) NKCD56+ cells. The effect of low-dose sPIF 25ng/ml was compared with intravenous gamma Ig (12.5mg/ml) and Intralipid (18mg/ml; n=25). sPIF efficacy was similar to the two other agents (all P<0.001) when compared with the scrambled PIF control (PIFscr) data obtained in a different group of patients (same as in Figure 1).
Reproductive BioMedicine Online  , 79-87DOI: ( /j.rbmo )
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions

4. Figure 3
Synthetic preimplantation factor (sPIF) inhibits NK cell cytotoxicity in recurrent pregnancy loss patients with normal (<10%) NKCD56+ cells. The effect of low-dose sPIF (25ng/ml) was compared with intravenous gamma Ig (12.5mg/ml) and Intralipid (18mg/ml; n=61). sPIF efficacy was similar to the two other agents (all P<0.001) when compared with the scrambled PIF control (PIFscr) data obtained in a different group of patients (same as in Figure 1).
Reproductive BioMedicine Online  , 79-87DOI: ( /j.rbmo )
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions

5. Figure 4
CD69+ expression on NK cells following 24h pre-incubation with synthetic preimplantation factor (sPIF) or scrambled PIF (PIFscr) with and without stimulation by K562 cells. Pre-incubation with sPIF 100ng/ml significantly inhibited CD69stim compared with PIFscr 100ng/ml. Data are mean±standard error for each treatment for blood samples from 26 infertile patients undergoing IVF. CD69sp=CD69 spontaneous expression after incubation without K562; CD69exp=CD69 expression after incubation with K562; CDstim=[(CD69exp−CD69sp)/CD69sp]×100.
Reproductive BioMedicine Online  , 79-87DOI: ( /j.rbmo )
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions

6. Figure 5
Synthetic preimplantation factor (sPIF) inhibits NK cell activity by lowering CD69+ expression. The effect of pre-incubation with sPIF 100ng/ml for 6h (n=10), 12h (n=20) and 24h (n=26) in blood samples from infertile patients undergoing IVF treatment compared with PIFscr 100ng/ml as a control. P-values were calculated for mean activation of CD69stim incubated with sPIF versus CD69stim incubated with PIFscr. A time-dependent sPIF-induced inhibition was significant following 24h pre-incubation (P<0.05). Data are results from different patient blood samples.
Reproductive BioMedicine Online  , 79-87DOI: ( /j.rbmo )
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions