Immunologic Parameters for Disease Activity in Rheumatoid Arthritis

This study aimed to determine the correlation of disease activity of rheumatoid arthritis (RA) with Th17/regulatory T cell (Treg) and Forkhead box protein 3 (Foxp3) cells ratio in patients under therapy with anti-tumor necrosis factor (TNF)-α. Totally, 84 patients with RA and 13 healthy controls were included in this case-control study. The patients were divided into four groups to receive only methotrexate (MTX) (n=25), monotherapy (anti-TNF) (n=18), and combined therapy (MTX+anti-TNF) (n=26); however, one group received no medications (n=15) and was regarded as a positive control. Other 13 healthy controls that were considered negative controls were also enrolled in this study. Patients with RA were attending Basrah General Hospital, Rheumatology Unit, Biological Therapy Center for receiving anti-TNF therapy. Flow cytometry was used for measuring Treg/Foxp3 and Th17 markers, and the DAS-28 score was utilized to measure RA disease activity. Anti-TNF inhibitors (e.g., infliximab and etanercept), as well as other inflammatory and hematological parameters (e.g., erythrocyte sedimentation rate, total white blood cells, lymphocytes, monocytes, and neutrophil counts), were also measured in this study. DAS-28 as a disease activity score was significantly correlated with Th17/Treg/Foxp3 ratio and the Th17 cells count. Statistically, Th17/Treg/Foxp3 ratio was not correlated with body mass index, morning stiffness, and duration of the disease. Th17/Treg/Foxp3 ratio correlated significantly with DAS-28 as an RA disease activity. The lower Treg/Foxp3 frequency led to the higher DAS score reflecting higher disease activity. In the combined therapy group, disease activity was found lower than that in other patient groups indicating the effect of this combination on the relationship between MTX and anti-TNF. This study demonstrated that the main advantage of this combined therapy in RA patients was the reversion of Th17 cell expansion.

Abstract B111: HDAC inhibitors modulate immune checkpoint blockade in breast cancer

Background: Breast cancer is one of the most common diseases, second only to lung cancer as the leading cause of cancer death in women. In particular hormone sensitive metastatic breast cancer (MBC) and triple-negative breast cancer (TNBC) remains a therapeutic challenge as resistance develops in almost all patients. Despite aggressive treatment strategies, survival is poor due to the development of resistance, prompting the need for novel approaches. Here, we characterize the molecular mechanisms underlying epigenetic modifiers and in particular histone deacetylase inhibitors (HDACi) as priming modulators of immunotherapy, with a specific focus on TNBC and hormone resistant breast cancers. HDACi represent a new class of anticancer agents that can reverse hormone therapy resistance, resulting in prolonged anti-tumor responses in patients. In addition to their effects on estrogen receptor (ER) signaling, HDACi can also influence immune cell function, including but not limited to modulation of Foxp3+ regulatory T-cells (Tregs), tumor-infiltrating lymphocyte (TILs) composition, as well as induction of the co-inhibitory receptors PD-L1 and PD-1. Under normal conditions the PD-1/PD-L1 pathway down-regulates cytotoxic T-cell activity to maintain immune homeostasis. Cancer cells exploit this pathway in the tumor microenvironment to suppress cytotoxic T-cell activation, significantly diminishing the anti-tumor immune response. In breast cancer, PD-L1 expression is less frequent and mainly found in TNBC, HER2+, ER- and PR- tumors. Increased PD-L1 expression correlates with increased TILs and these criteria together are indicative of improved response rates in breast cancer patients. The PD-1/PD-L1 pathway represents one of the primary immunosuppressive drivers in multiple types of cancer. Thus, inhibiting PD-1/PD-L1 interactions may prevent T-cell suppression and reactivate immunosurveillance mechanisms necessary for tumor cell eradication.

Methods and Results: Evaluation of basal PD-L1 expression in a range of human and mouse breast cancer cell lines by western blotting and real-time PCR identified TNBC and HER2+ cells as the highest expressing cells. Testing different epigenetic modifiers, we found that HDACi were able to up-regulate PD-L1 mRNA and protein in a time-dependent manner up to 72 hours. This was a direct transcriptional effect induced by HDACi and was confirmed even in tamoxifen resistant breast cancer cells, characterized by increased basal expression of PD-L1 as compared to the parental cells. To define the role of epigenetic priming in promoting immune cell activation, we co-cultured tumor cells and human peripheral blood mononuclear cell (PBMCs) and performed comprehensive immunophenotyping by flow cytometry. HDACi were able to up-regulate PD-L1 on tumor cells independent of PBMCs, while exhibiting a selective decrease in the frequency of immunosuppressive Tregs.

Conclusion: Our data demonstrate that the combination of HDACi with immune checkpoint inhibitors represents a novel therapeutic anti-tumor strategy and warrants further clinical evaluation for the treatment of TNBC and hormone resistant breast cancer.

Citation Format: Manuela Terranova Barberio, Scott Thomas, Niwa H. Ali, Jeenah Park, Michael D. Rosenblum, Alfredo Budillon, Pamela N. Munster. HDAC inhibitors modulate immune checkpoint blockade in breast cancer [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B111.

Cutting Edge: Regulatory T Cells Facilitate Cutaneous Wound Healing

Foxp3-expressing regulatory T cells (Tregs) reside in tissues where they control inflammation and mediate tissue-specific functions. The skin of mice and humans contain a large number of Tregs; however, the mechanisms of how these cells function in skin remain largely unknown. In this article, we show that Tregs facilitate cutaneous wound healing. Highly activated Tregs accumulated in skin early after wounding, and specific ablation of these cells resulted in delayed wound re-epithelialization and kinetics of wound closure. Tregs in wounded skin attenuated IFN-γ production and proinflammatory macrophage accumulation. Upon wounding, Tregs induce expression of the epidermal growth factor receptor (EGFR). Lineage-specific deletion of EGFR in Tregs resulted in reduced Treg accumulation and activation in wounded skin, delayed wound closure, and increased proinflammatory macrophage accumulation. Taken together, our results reveal a novel role for Tregs in facilitating skin wound repair and suggest that they use the EGFR pathway to mediate these effects.

Cryptosporidiosis among animal handlers and their livestock in Basrah, Iraq

OBJECTIVE

To investigate the prevalence of cryptosporidiosis among groups at risk (animal handlers) and among domestic animals.

DESIGN

Comparative study with zoonotic aspect.

METHOD

Stool samples were collected from 60 animal handlers, 175 non-animal handlers and 198 domestic animals (60 cows, 45 sheep, 45 goats, 25 horses and 23 camels). Direct smear method and then formalin-ether sedimentation method were carried out for stool samples to detect intestinal parasites. Faecal smears were prepared from the sediment and stained by the modified Ziehl-Neelsen method for the recovery of red-pink oocysts of Cryptosporidium.

RESULTS

Out of the 60 animal handlers, 30 (50%) were found to be positive for intestinal parasites compared to 26 (14.8%) of non-animal handlers (P < 0.01). Cryptosporidium oocysts were found to be excreted by three (5%) animal handlers and two (1.14%) of the non-animal handlers (P > 0.05). Cryptosporidiosis was also diagnosed in 20%, 13.3%, 17.7% and 12% of cattle, sheep, goats and horses respectively. No single positive case was detected among the examined camels.

CONCLUSION

Veterinarians, butchers and breeders should be aware of the disease among farm animals in order to avoid great losses and to prevent its transmission to humans.

Intestinal parasites, including Cryptosporidium species, in Iraqi patients with sickle-cell anaemia

Stool samples were obtained from individuals admitted to three hospitals in Basra during November 1997-May 1998. Of 40 patients with sickle-cell anaemia, 25 (62.5%) had parasitic infections. In the apparently healthy comparison group, 26 of 175 individuals (14.8%) had intestinal parasitic infections, a statistically significant difference. The most common intestinal parasites isolated in the sickle-cell patients were Blastocystis hominis (36%) and Giardia lamblia (28%). The isolation rate of Cryptosporidium species in sickle-cell patients (5%) was not significantly different from that in apparently healthy individuals (1.14%). We report for the first time the isolation of Isospora belli from a sickle-cell patient in Iraq and the Mediterranean region.

Optimization of alpha-galactosidase production in Streptomyces erythrus

Physiological studies on Streptomyces erythrus NRRL ISP 5517 grown on fourteen different media have revealed that the enzyme was formed and released in the medium with different levels depending upon the type of the medium and the carbon source used. The results indicate that S. erythrus produced the highest level of extracellular and endocellular enzyme when grown in modified Czapek-Dox's medium (containing 2% D-galactose as the only carbon source). The highest levels of enzyme formation was obtained upon using D-galactose (9.94 Units/ml and 2.92 Units/ml), raffinose (8.87 Units/ml and 2.69 Units/ml) or melibiose (8.14 Units/ml and 2.52 Units/ml) at a final concentration of 2% as inducers for extra- and endocellular enzyme, respectively. With respect to nitrogen sources tested, sodium nitrate produced the highest level of alpha-galactosidase in both fractions optimally at 2.0 g/l. Studies revealed that the extracellular enzyme levels were produced optimally at initial pH in culture of 7.0 and air:medium ratio in flasks corresponding to 1:5 and after 5 days of incubation at 30 degrees C. On testing the effect of the addition of eight leguminous seeds powders (at a final concentration of 2%), it was found that soybean powder gave the highest induction effect. The addition of sodium nitrate at a concentration of 2 g/l to Dox's soybean medium, the adjustment of initial pH value of the medium to 7.0 and the air:medium ratio in flasks to 1:5 for an incubation period of 4 days produced the highest level of extracellular alpha-galactosidase.