Relativity Research Between Alzheimer's Disease-like Pathological In Brain And Immunological Risk Phenotypes Of Aged Mouse With HCMV Innate Latent Infection

Objective Establishing the model of Innate latent human cytomegalovirus infection in old mice.To research and discuss the relativity between immunological risk phenotypes of mouse with HCMV innate latent infection and Alzheimer's Disease -like Pathological Change in Brain of mouse.Methods Three groups mouse including HCMV innate latent infection (A group), HCMV reactivation infection (B group) and HF cell control (C group) were selected randomly, every group included 6 mouse aged 24~26 months. After mouse were killed by bleeding from mouse eyepit, peripheral blood and brain assembling spleen of mouse were tested by following methods: (1) How HCMV infection state of these mouse was validated by virus separation in base of cell co-cultivation of HF and mouse brain cells; indirect immunofluorescent assay; gene testing through PCR and RT-PCR assembled hybridization in situ. (2) Testing immune state of mouse: HCMV IgG,IgM of mouse serum were tested by indirect enzyme linked immunosorbent assay; T lymphocyte subgroups including CD3+/CD4+/CD8+ molecule in peripheral blood and spleen cells were tested by flow cell meter. (3) Testing pathological changes about Alzheimer's disease included followings:Hematoxylin-eosin (H.E.) stain tested construction, pathological change of mouse brain tissue; Congo red stain tested amyloid-like plaque correlated AD; Silver stain tested neural fibre tangle related with AD; indirect immunofluorescence tested P-Tau. Results (1) Infection state of HCMV in mouse brain was identified. We observed the CPE of HF in the co-cultivation experiment in A and B groups; We detected HCMV pp65 antigen in cell slide by indirect immunofluorescent assay; We could detect HCMV UL83 gene of mouses brain in A and B groups by PCR;The results of in situ hybridization was also positive, but we could detect HCMV UL83 mRNA only in group B by RT- PCR. The results demonstrated group A was Latent Infection , group B was reactivation of latent Infection but group C wasn't infected.(2) Value of HCMV IgG in group A/B/C mouse was 0.50±0.08 ,0.76±0.05 and 0.10±0.05,the differences between every group were significant (p<0.01);value of HCMV IgM was 0.14±0.03 ,0.58±0.06 and 0.08±0.03,the differences between group A ,C and group B were significant (p<0.01), but there was no significant differences between group A and group C (p>0.05). The quantity of CD3+ T limphocyte was 29.14%,6.87%and 44.03%, CD8+T limphocyte was 34.25%,39.61%and 28.73%,while CD4+T limphocyte was 47.03%,38.50% and 58.82% respectively in peripheral blood in A/B/C group, the differences between every group were significant (p<0.01). Quantity of CD4+CD8+ double positive T limphocyte was 10.00%,15.26%and 9.00% in peripheral blood in A/B/C group,the differences between group A /C and group B were significant (p<0.01),but there was no significant differences (p>0.05) between group A and group C;ratio of CD4+/CD8+ T limphocyte was less than one in group B. Results of T limphocyte subgroups in spleen cells were the same as in peripheral blood. (3) In infected mouse,a lot of neuron in the cerebral cortex and hippocampi were stained slightly by HE stain, neuron lost could be observed and quantity was decreased,the amyloid plaque existed in the cerebral cortex in infected mouse by Congo red stain,the amyloid plaque and abundant neurofibrillary tangles (NFTs) were found by silver stain in the cerebral cortex.The apple green signal (P-Tau) could be tested in group A and B by indirect immunofluorescence. Conclusion (1) On the basis of Aged Mouse with HCMV Innate Latent Infection ,We found changes of immunological risk phenotypes.Therefore, The results showed that HCMV infection could induce immunodeficiency and then induce central nervous system disease further in mouse(2) We found AD-like pathologic changes in mouses with HCMV congenital Latent Infection. The results showed that HCMV infection could induce AD, and immunodeficiency could be one of the mechanisms.(3) Establishment on animal model of AD with viral infection could provide a new idea and a technic platform to study pathogeny and the pathogenic mechanism of neuro degenerative disease .