Isolation and cryopreservation of functionally competent equine leucocytes

What Is the Evolutionary Fingerprint in Neutrophil Granulocytes?

Over the years of evolution, thousands of different animal species have evolved. All these species require an immune system to defend themselves against invading pathogens. Nevertheless, the immune systems of different species are obviously counteracting against the same pathogen with different efficiency. Therefore, the question arises if the process that was leading to the clades of vertebrates in the animal kingdom-namely mammals, birds, amphibians, reptiles, and fish-was also leading to different functions of immune cells. One cell type of the innate immune system that is transmigrating as first line of defense in infected tissue and counteracts against pathogens is the neutrophil granulocyte. During the host-pathogen interaction they can undergo phagocytosis, apoptosis, degranulation, and form neutrophil extracellular traps (NETs). In this review, we summarize a wide spectrum of information about neutrophils in humans and animals, with a focus on vertebrates. Special attention is kept on the development, morphology, composition, and functions of these cells, but also on dysfunctions and options for cell culture or storage.

Successful isolation of equine mesenchymal stromal cells from cryopreserved umbilical cord blood-derived mononuclear cell fractions

REASONS FOR PERFORMING STUDY

The therapeutic potential of mesenchymal stromal cells for cellular therapy has generated increasing interest in human as well as veterinary medicine. Considerable research has been performed on the cryopreservation of expanded mesenchymal stromal cells, but little information is available on the cryopreservation of the original mononuclear cell fraction.

OBJECTIVES

The present study describes a protocol to expand equine mesenchymal stromal cells after cryopreserving the mononuclear cells of umbilical cord blood.

METHODS

To this end, mononuclear cells were isolated from 7 umbilical cord blood samples and cryopreserved at a concentration of 1-2 × 10(9) cells/l cold freezing solution. Cells were cryopreserved and kept frozen for at least 6 months before thawing. Frozen cryotubes were thawed in a 37°C water bath. Putative equine mesenchymal stromal cells were immunophenotyped using multicolour flow cytometry based on a selected 9 marker panel.

RESULTS

Average cell viability upon thawing was 98.7 ± 0.6%. In 6 out of 7 samples, adherent spindle-shaped cell colonies were observed within 9.0 ± 2.6 days and attained 80% confluency at 12.3 ± 3.9 days. After 3 passages, putative equine mesenchymal stromal cells were successfully immunophenotyped as CD29, CD44 and CD90 positive, and CD45, CD73, CD79α, CD105, MHC II and monocyte-marker negative.

CONCLUSIONS AND POTENTIAL RELEVANCE

Equine mesenchymal stromal cells can be cultured after cryopreservation of the isolated mononuclear cells, a time- as well as cost-efficient approach in equine regenerative medicine.

Synthetic porphyrins in experimental photodynamic therapy induce a different antitumoral effect

The aim of the study was to investigate the influence of discrete structural differences in synthetic porphyrins on the antineoplastic effect induced in myelocitic cell line K562 after experimental photodynamic therapy procedure. For this study, we used 5,10,15,20-tetra(1-naphthyl)porphyrin, 5,10,15,20-tetra(4-sulfonatophenyl)porphyrin and their Zn complexes. For all these compounds, the following photodynamic therapy parameters were optimized: cell concentration, dye loading concentration, loading time and irradiation procedure. The non-toxic doses of porphyrins were different according to their structure: for 5,10,15,20-tetra(1-naphthyl)porphyrin compounds, the dose was of 10 μg.mL-1, and for 5,10,15,20-tetra(4-sulfonatophenyl)porphyrin compounds, the dose was 20 μg.mL-1. Cell functionality was assessed as membrane integrity, viability, and number of metabolically active cells. Photodynamic cell degradation kinetics showed that during irradiation tumor cells are actively destroyed, in contrast to unloaded cells. K562 cells loaded with the above-mentioned compounds and subjected to irradiation, displayed lower proliferative capacity compared to the control, for a period of 72 h after irradiation. The proliferative capacity of K562 cell line was more strongly inhibited by the 5,10,15,20-tetra(1-naphthyl)porphyrin family of compounds than by the 5,10,15,20-tetra(4-sulfonatophenyl)porphyrin family. The tested synthetic porphyrins showed effective antineoplastic activity against K562 leukemia cells in our in vitro photodynamic therapy experimental model.

Cryopreservation: an optimizing factor for therapeutic potential of fetoplacental complex products

The therapeutic potential of cryopreserved fetoplacental complex cells (FPCP) has been explored for the treatment of autoimmune diseases, including autoimmune hemolytical anemia (AIHA). In this study, a murine AIHA model was utilized to investigate the application of cryopreserved fetal liver cells (cFLC), from varying gestation intervals (14 and 19 postcoital days) to correct the functional state of the lymphohemopoietic complex (LHPC). The results demonstrate that cryopreservation had little negative effect on FLC-14 corrective ability from that of nonfrozen FLC-14. Cryopreservation of FLC-19 (later gestation period) resulted in an increase in functional corrective potential over that of matched controls. Further, the increase in corrective effect of the cFLC-19 was found to be similar to that of both FLC-14 populations. In summary, these results demonstrate the potential for the use of cryopreserved FLCs as a therapeutic option for the treatment of AIHA.

The diagnosis and treatment of endometritis in the mare: yesterday and today

Diagnosis and treatment of endometritis in the mare has been controversial and mostly empirical. The lack or inability of researchers to establish or develop a model that can serve as a standard or control makes this area of equine reproduction difficult to address scientifically. However, major advances have been made, particularly with the demonstration of the importance of uterine contractility in the elimination of bacteria, fluid, and inflammatory products from the uterus after breeding. This review provides a historical perspective of what has been done, and where we are now, in the approach to the diagnosis and therapy of endometritis in the mare.

Use of leukocytes as treatment for endometritis in mares experimentally infected with Streptococcus equi subsp. zooepidemicus

This study compared four treatments for bacterial endometritis in mares experimentally infected with Streptococcus zooepidemicus. Twenty-five mares were used, 20 resistant and five susceptible to endometritis. Mares would be in estrus when infected. Twenty-four hours after inoculation, clinical, bacteriological and cytological examinations were performed and repeated until the first occurrence: negative cytology and no Streptococcus growth or the seventh day post-infection. All mares showed clinical signs of endometritis and were assigned to one of the following treatments: (1) intrauterine infusion of fresh leukocytes; (2) intrauterine infusion of frozen-thawed leukocytes; (3) intrauterine infusion of lysed leukocytes; (4) intrauterine infusion of recombinant human interleukin-8 (rhIL-8); (5) control. Mares were submitted to all treatments, with at least a 14-day interval between treatments in a Latin square design. Treatment did not affect (P=0.121) time needed for resistant mares to eliminate bacteria. Time needed for elimination of bacteria was similar in susceptible mares treated with fresh and frozen leukocytes (P=0.333). Susceptible mares treated with frozen leukocytes also did not differ from those treated with lysed leukocytes (P=0.227) for time to eliminate bacteria, but were significantly different (P>0.02) from those treated with rhIL-8 and control. In resistant mares, physical clearance ability was probably the responsible for bacterial elimination. Intrauterine infusions in susceptible mares with viable or lysed leukocytes associated or not to opsonizing factors, reduced the time to elimination of bacteria. Infusions with bactericidal effect (functional neutrophils and granules) was likely effective and responsible for the more rapid elimination of bacteria in susceptible mares.