Alterations in RANTES Gene Expression and T-Cell Prevalence in Intestinal Mucosa during Pathogenic or Nonpathogenic Simian Immunodeficiency Virus Infection

AbstractRANTES, a β-chemokine, can suppress human immunodeficiency virus (HIV) as well as simian immunodeficiency virus (SIV) infections in T-lymphocyte cultures in vitro. However, the association of RANTES levels in peripheral blood with viral loads and disease outcome in HIV infection has been inconclusive. SIV-infected rhesus macaques were evaluated to determine whether RANTES gene expression correlated with suppression of viral infection in intestinal lymphoid tissues. Intestinal tissues were obtained from rhesus macaques infected with either pathogenic or nonpathogenic SIVmac variants at various stages of infection (primary acute, asymptomatic, and terminal). We examined the level of SIV infection (in situ hybridization), RANTES expression (quantitative competitive RT-PCR), and T-cell counts (immunohistochemistry). The most pronounced increase in RANTES gene expression in intestinal tissues was observed in primary SIV infection, which correlated with the pathogenicity of the infecting virus and not the tissue viral loads. Our results demonstrated that in contrast to the occurrence of viral suppression by RANTES in vitro, there was no direct correlation between high RANTES gene expression and suppression of viral loads in intestinal lymphoid tissues. Thus RANTES expression in the gut lymphoid tissue may not be a correlate for viral suppression. However, RANTES gene expression in primary SIV infection may be part of early host immune response to viral infection

Localization of complement factor H gene expression and protein distribution in the mouse outer retina.

To determine the localization of complement factor H (Cfh) mRNA and its protein in the mouse outer retina.Quantitative real-time PCR (qPCR) was used to determine the expression of Cfh and Cfh-related (Cfhr) transcripts in the RPE/choroid. In situ hybridization (ISH) was performed using the novel RNAscope 2.0 FFPE assay to localize the expression of Cfh mRNA in the mouse outer retina. Immunohistochemistry (IHC) was used to localize Cfh protein expression, and western blots were used to characterize CFH antibodies used for IHC.Cfh and Cfhr2 transcripts were detected in the mouse RPE/choroid using qPCR, while Cfhr1, Cfhr3, and Cfhrc (Gm4788) were not detected. ISH showed abundant Cfh mRNA in the RPE of all mouse strains (C57BL/6, BALB/c, 129/Sv) tested, with the exception of the Cfh(-/-) eye. Surprisingly, the Cfh protein was detected by immunohistochemistry in photoreceptors rather than in RPE cells. The specificity of the CFH antibodies was tested by western blotting. Our CFH antibodies recognized purified mouse Cfh protein, serum Cfh protein in wild-type C57BL/6, BALB/c, and 129/Sv, and showed an absence of the Cfh protein in the serum of Cfh(-/-) mice. Greatly reduced Cfh protein immunohistological signals in the Cfh(-/-) eyes also supported the specificity of the Cfh protein distribution results.Only Cfh and Cfhr2 genes are expressed in the mouse outer retina. Only Cfh mRNA was detected in the RPE, but no protein. We hypothesize that the steady-state concentration of Cfh protein is low in the cells due to secretion, and therefore is below the detection level for IHC

Intravitreal Administration of Human Bone Marrow CD34+ Stem Cells in a Murine Model of Retinal Degeneration.

PurposeIntravitreal murine lineage-negative bone marrow (BM) hematopoietic cells slow down retinal degeneration. Because human BM CD34+ hematopoietic cells are not precisely comparable to murine cells, this study examined the effect of intravitreal human BM CD34+ cells on the degenerating retina using a murine model.MethodsC3H/HeJrd1/rd1 mice, immunosuppressed systemically with tacrolimus and rapamycin, were injected intravitreally with PBS (n = 16) or CD34+ cells (n = 16) isolated from human BM using a magnetic cell sorter and labeled with enhanced green fluorescent protein (EGFP). After 1 and 4 weeks, the injected eyes were imaged with scanning laser ophthalmoscopy (SLO)/optical coherence tomography (OCT) and tested with electroretinography (ERG). Eyes were harvested after euthanasia for immunohistochemical and microarray analysis of the retina.ResultsIn vivo SLO fundus imaging visualized EGFP-labeled cells within the eyes following intravitreal injection. Simultaneous OCT analysis localized the EGFP-labeled cells on the retinal surface resulting in a saw-toothed appearance. Immunohistochemical analysis of the retina identified EGFP-labeled cells on the retinal surface and adjacent to ganglion cells. Electroretinography testing showed a flat signal both at 1 and 4 weeks following injection in all eyes. Microarray analysis of the retina following cell injection showed altered expression of more than 300 mouse genes, predominantly those regulating photoreceptor function and maintenance and apoptosis.ConclusionsIntravitreal human BM CD34+ cells rapidly home to the degenerating retinal surface. Although a functional benefit of this cell therapy was not seen on ERG in this rapidly progressive retinal degeneration model, molecular changes in the retina associated with CD34+ cell therapy suggest potential trophic regenerative effects that warrant further exploration