The accumulated circulating Tfh-like cells in lupus patients share phenotypic and functional properties with GC-Tfh cells. Tfh-like cells may serve as perpetuators in the pathogenesis of SLE by enhancing the self-reactive B cell clones to further differentiate into auto antibody-producing plasmablasts, and ultimately cause autoimmunity.

The objective of this study was to determine the tissue density, in vitro expansion and differentiation of canine adipose tissue-derived (ASC) and bone marrow-derived (BMSC) stromal cells. Primary (P0) and cell passages 1–6 (P1–6) cell doubling numbers (CD) and doubling times (DT) were determined in fresh cells. The P0, P3, and P6 adipogenic (CFU-Ad), osteogenic (CFU-Ob), and fibroblastic (CFU-F) colony forming unit frequencies, lineage specific mRNA levels in differentiated P3 cells and composition of P3 and P6 chondrogenic pellets were assessed in cryogenically preserved cells. Cell yields from bone marrow were significantly higher than adipose tissue. Overall ASC and BMSC CDs and DTs and P3 and P6 CFU-F, CFU-Ad, and CFU-Ob were comparable. The P0 BMSC CFU-Ob was significantly higher than ASC. Lineage specific mRNA levels were higher in differentiated versus control cells, but similar between cell types. Protein was significantly greater in P3 versus P6 ASC chondrogenic pellets. Based on these findings, fresh and revitalized canine ASCs are viable alternatives to BMSCs for stromal cell applications.

Posterolateral spinal fusion is the standard treatment for lumbar compression fractures. Adult adipose tissue-derived stem cells (ASCs) promote osteogenesis in vivo and in vitro. The hypothesis tested in this study was that syngeneic and allogeneic ASCs on a biomaterial scaffold composed of tricalcium phosphate and collagen I will accelerate spinal fusion in a rat model. ASCs from male Fischer or ACI rats were loaded onto scaffolds (53,571 cells/mm 3 ) and cultured in stromal media for 48 h. Male Fisher rats were assigned to 4 cohorts (n ¼ 14/cohort) after bilateral decortication of the L4 and L5 transverse processes: (1) No treatment; (2) scaffold only; (3) scaffold þ syngeneic ASCs; or (4) scaffold þ allogeneic ASCs. Half of each cohort was harvested 4 or 8 weeks after surgery. Spinal fusion was evaluated with radiographs, microcomputed tomography, and light microscopy. Callus did not form in spines without scaffolds. There were no significant differences in callus formation among scaffold cohorts 4 weeks after surgery. Callus formation was more mature in both ASC cohorts versus scaffold alone 8 weeks after surgery based on microstructure as well as radiographic and microcomputed tomographic evidence of active bone formation. Inflammatory cell infiltrate was significantly lower in both ASC cohorts (syngeneic ¼ 18.3 AE 0.85%; allogeneic ¼ 23.5 AE 2.33%) versus scaffold alone (46.8 AE 11.8%) 4 weeks after surgery. Results of this study support syngeneic and allogeneic ASC acceleration of posterior lumbar spinal fusion in a rat model. ß

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of cancer-related deaths in America. Nearly two thirds of newly diagnosed CRC cases include lymph node (LN) involvement, and LN metastasis is one of the strongest negative prognostic factors for CRC. It is thought that CRC tumors contain a small population of drug-resistant CRC tumor-initiating cells (Co-TICs) that may be responsible for cancer recurrence. To evaluate the effects of the LN stromal cells on Co-TICs, we established a unique xenoplant model using CRC cells isolated by enzymatic digestion from consented patient specimens, HT-29 cells, HCA-7 cells, and LN stromal cell line HK cells. We found that HK cells and HK cell-conditioned media enhanced CRC tumor formation and tumor angiogenesis. Cells expressing CD133(+) and the stromal cell-derived factor 1α (SDF-1α) receptor CXCR4 were enriched in chemotherapeutic-resistant CRC cells. CD133(+)CXCR4(+) Co-TICs isolated from patient specimens are more tumorigenic than unsorted tumor cells. Furthermore, the inhibitors specific to HK cell-derived SDF-1α reduced tumor formation and tumor angiogenesis. Our results have demonstrated a role for Co-TICs in tumor growth and defined the influence of LN stromal cells on Co-TICs. We have identified a major Co-TIC/LN microenvironment-specific mechanism for CRC resistance to chemotherapeutic agents and established experimental platforms for both in vitro and in vivo testing, indicating that SDF-1α and its receptor, CXCR4, may be targets for clinical therapy.

Adipose-derived stem cells (ASCs) express a nonimmunogenic profile as shown by in vitro studies that demonstrate a lack of T cell proliferation to allogeneic ASCs as well as ASC-mediated suppression of mixed lymphocyte reactions. To determine whether these observations would translate in vivo, immune monitoring studies were carried out in conjunction with a rat spinal fusion study. ASCs derived from Fischer or ACI strain rats were loaded onto scaffolds and implanted in Fischer recipients that had undergone the following treatments: (1) No treatment; (2) Scaffold only; (3) Syngeneic ASCs+Scaffold; or (4) Allogeneic ASCs+Scaffold. Half of each group was sacrificed at 4 weeks postimplantation, and the remaining animals were sacrificed at 8 weeks. As determined in a separate study, allogeneic and syngeneic ASCs were equally efficacious in accelerating spinal fusion compared to No treatment and Scaffold only control groups. To determine whether donor ASCs induced an immune response in recipient rats, lymph nodes were harvested for T cell proliferation studies and serum was collected to assess antibody responses. Although T cell priming was not detected to donor alloantigens in recipients at either time point, significant antibody responses were detected to ACI ASCs in animals implanted with syngeneic or allogeneic ASCs. Antibodies were of the IgG isotype, noncytotoxic in the presence of complement, and reactive to fetal bovine serum. These results support the use of allogeneic ASCs for spinal fusion.