Cytomegalovirus and Proliferative Signals in the Vascular Wall of CABG Patients

OBJECTIVE

To further elucidate the mechanism by which cytomegalovirus (CMV) may promote atherosclerosis, we studied the expression pattern of cellular inflammatory and proliferative signals in the aortic wall of CMV(+) and CMV(-) patients undergoing coronary artery bypass grafting (CABG).

METHODS

Aortic biopsies and blood samples of 68 CABG patients were investigated for CMV-DNA by PCR and IN SITU hybridisation. Expression of pp65 antigen, adhesion molecules (ICAM-1, VCAM-1, E-selectin), growth factors (PDGF-AA, TGF-beta), and the cellular proliferation factor Ki-67 was studied by immunohistochemistry. Logistic regression was used to test the correlation between the presence of CMV, vascular inflammation, and traditional noninflammatory risk factors for atherosclerosis.

RESULTS

CMV-DNA was detected in the aortic tissue of 52 (76%) patients, and was localised predominantly in vascular smooth muscle cells. In CMV(+) patients, the expression of adhesion molecules and growth factors in the aortic endothelium was increased compared with CMV(-) patients. A positive correlation of elevated CRP, the induction of adhesion molecules and growth factors and CMV(+) was found. Female gender, smoking, and hyperlipidaemia were identified as risk factors for CMV(+).

CONCLUSIONS

CMV-DNA in smooth muscle cells induces local growth factor expression as well as endothelial activation, both of which can promote the progression of atherosclerosis. Since traditional atherogenic risk factors increase the likelihood of aortic CMV manifestation, we suggest that CMV plays a crucial role in mediating the progression of atherosclerosis.

Primer design for a prokaryotic differential display RT-PCR

We have developed a primer set for a prokaryotic differential display of mRNA in the Enterobacteriaceae group. Each combination of ten 10mer and ten 11mer primers generates up to 85 bands from total Escherichia coli RNA, thus covering expressed sequences of a complete bacterial genome. Due to the lack of polyadenylation in prokaryotic RNA the type T11VN anchored oligonucleotides for the reverse transcriptase reaction had to be replaced with respect to the original method described by Liang and Pardee [ Science , 257, 967-971 (1992)]. Therefore, the sequences of both the 10mer and the new 11mer oligonucleotides were determined by a statistical evaluation of species-specific coding regions extracted from the EMBL database. The 11mer primers used for reverse transcription were selected for localization in the 3'-region of the bacterial RNA. The 10mer primers preferentially bind to the 5'-end of the RNA. None of the primers show homology to rRNA or other abundant small RNA species. Randomly sampled cDNA bands were checked for their bacterial origin either by re-amplification, cloning and sequencing or by re-amplification and direct sequencing with 10mer and 11mer primers after asymmetric PCR.

[EBV-specific antibodies in patients with nasopharyngeal cancer and tonsillar cancer. Follow-up of over 4 years]

26 NPC patients and 47 TC patients were investigated clinically, and in the sera of these patients EBV-specific antibodies were determined. No relapse occurred in 11 patients with NPC and in 17 patients with TC during the period of 4 years. In addition to the determination of antibodies we looked for EBNA in 3 undifferentiated NPC and 4 undifferentiated TC, and for EBV-DNA in 2 of these NPC and one of these TC. The 3 NPC and 4 TC tested for EBNA showed this antigen in the cells. 2 NPC and 1 TC showed EBV-DNA with in situ hybridization technique. In the blot hybridization according to Southern the Eco R 1 fragment of both NPC was identical with the Eco R 1 fragment of the positive control of P 3 HR 1 cells. The 15 NPC-patients with tumour (4 with primary NPC, 11 with relapse) in the observation period showed higher IgA-VCA titres than the NPC patients free of relapse during this time. Subsequent to therapy, IgG-VCA titres decreased. Most of the NPC-patients with tumour during the time of testing mentioned before had IgA-VCA once or several times. Most of half of these patients had IgA-EA, but there was no patient without relapse. IgA-VCA increase and the presence of IgA-EA may be the first sign of a relapse. Thus, intensive research into this phenomenon will be required. No remarkable difference could be found in EBV-specific antibody patterns between TC patients without relapse and TC patients with tumour progression or relapse.

[Herpes simplex virus infections]

There are two serological types of herpes simplex virus, HSV-1 and HSV-2. The types can be differentiated by different methods. After a primary infection HSV reaches the sensory ganglions by the way of peripheral nervous tracts. The virus remains for life in the ganglion as virus genome. After activation and return movement a new infection can appear. A lot of various diseases are caused by primary infection, reactivation or reinfection. The diagnosis in herpes virus diseases includes the detection of virus or viral antigens and the demonstration of specific antibodies against HSV. Effective antiviral drugs are available for chemotherapy of HSV-infection. Acyclovir is a beneficial drug without toxic secondary effects. The prevalence of HSV-antibodies in the population is very high.

Antibodies to Epstein-Barr virus in nasopharyngeal carcinoma, tonsillar carcinoma and control groups

In the sera of 17 patients with nasopharyngeal carcinoma (NPC) and of 19 patients with tonsillar carcinoma (TC) the titres of IgA, IgG and IgM antibodies to EBV VCA (viral capsid antigen) and of IgG antibodies to EBV EA (early antigen) were determined by the indirect immunofluorescence (IF) method. Significant difference was observed in the frequency of IgA antibodies to EBV VCA and IgG antibodies to EBV EA between NPC patients and controls. There was also a significant difference between the frequency of IgM antibody to EBV VCA and EBV EA antibody titres in TC patients and controls. The geometric mean titre (GMT) of IgG antibodies to EBV VCA was significantly higher in the NPC and TC patients as compared to controls.

Persistence of IgM antibodies to cytomegalovirus-induced late antigen in pregnancy and postpartum

21 women with IgM antibodies to cytomegalovirus-induced late antigen (CMV LA) as determined in the first, second or third trimester were tested for the persistence of these antibodies during pregnancy and postpartum. Out of 21 women 16 still showed IgM antibodies against CMV LA by 6-9 months after delivery. No striking differences could be found between women with primary or recurrent CMV infections as well as those who had intrauterine infection.

Epstein-Barr virus infections in childhood

IgM and IgG antibodies against Epstein-Barr virus (EBV) capsid antigen and antibodies against EBV nuclear antigen and heterophil antibodies were investigated in 115 paired sera of children with acute infections and in 100 sera of healthy controls of the same age and sex. EBV-specific IgM antibodies could be recognized in 13.7% of the patients and in 7% of the controls. Antibodies against EBV nuclear antigen were not detected in the IgM-positive sera.