Identification of Autophagy as a Functional Target Suitable for the Pharmacological Treatment of Mitochondrial Membrane Protein-Associated Neurodegeneration (MPAN) In Vitro

Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a relentlessly progressive neurodegenerative disorder caused by mutations in the C19orf12 gene. C19orf12 has been implicated in playing a role in lipid metabolism, mitochondrial function, and autophagy, however, the precise functions remain unknown. To identify new robust cellular targets for small compound treatments, we evaluated reported mitochondrial function alterations, cellular signaling, and autophagy in a large cohort of MPAN patients and control fibroblasts. We found no consistent alteration of mitochondrial functions or cellular signaling messengers in MPAN fibroblasts. In contrast, we found that autophagy initiation is consistently impaired in MPAN fibroblasts and show that C19orf12 expression correlates with the amount of LC3 puncta, an autophagy marker. Finally, we screened 14 different autophagy modulators to test which can restore this autophagy defect. Amongst these compounds, carbamazepine, ABT-737, LY294002, oridonin, and paroxetine could restore LC3 puncta in the MPAN fibroblasts, identifying them as novel potential therapeutic compounds to treat MPAN. In summary, our study confirms a role for C19orf12 in autophagy, proposes LC3 puncta as a functionally robust and consistent readout for testing compounds, and pinpoints potential therapeutic compounds for MPAN.

Mucosal antibodies to human cytomegalovirus glycoprotein B occur following both natural infection and immunization with human cytomegalovirus vaccines

Because antibodies against human cytomegalovirus (HCMV) glycoprotein B (gB) neutralize, levels of IgG, secretory IgA (sIgA), and mucosal IgA1 antibodies to HCMV were measured in saliva and nasal washes. Ten seronegative adults lacked these antibodies, but of 10 naturally seropositive adults, 10 had IgG to gB, 5 had sIgA, and 0 had mucosal IgA. Among 12 recipients of a live HCMV vaccine, 8 had IgG to gB, 4 had sIgA, and 2 had mucosal IgA in samples collected 10-20 months after immunization; of 10 recipients of a gB vaccine, 8 had IgG to gB, 7 had sIgA, and 7 had mucosal IgA in samples collected just before or 1 month after a booster. IgG to gB and neutralizing titers in serum correlated with IgG to gB in mucosal samples. IgG to gB was in the saliva of 25 of 26 subjects with serum neutralizing titers > 1:64. Serum neutralizing titers > 1:64, whether induced by vaccine or wild type virus, are associated with mucosal IgG to HCMV.

Antibodies induced by a primary cytomegalovirus infection react with human herpesvirus 6 proteins

After a primary human cytomegalovirus (HCMV) infection, antibody titer to human herpes-virus 6 (HHV-6) rises. To determine if this occurs because of simultaneous infection with both viruses, serologic responses to these viruses were investigated among healthy women who received a live HCMV vaccine or acquired HCMV from an infected child. Both vaccination and natural infection caused four-fold or greater titer rises to HHV-6. Analysis of sera from 5 children with primary HHV-6 showed no serologic response to HCMV. Absorption of 7 sera with HCMV antigens reduced titers to HHV-6 by two- to fourfold. Immunoblot analysis of sera obtained from 10 persons before and after a primary HCMV infection revealed that after HCMV infection, 2 persons developed IgG reactivity to the 116-kDa protein (gp116) of HHV-6 and to two cleavage products of this protein. Reactivity to HHV-6 gp116 appeared after HCMV sero-conversion and was removed by absorption of sera with HCMV glycoprotein gB (gB), indicating that antibodies to HCMV gB cross-react with HHV-6 gp116, the likely gB homologue of HHV-6. The serologic diagnosis of HHV-6 infection requires excluding a primary HCMV infection.

Tourette syndrome and HLA

Five kindreds with multiple individuals manifesting Tourette syndrome (TS) or related abnormal movements were evaluated for linkage between TS and HLA-A, B, C and DR antigens. Families were selected to have a constellation of affected individuals which gave the appearance of transmission of a major susceptibility gene. All kindreds had at least two clearly affected first or second degree relatives. Although developmental neurobehavioral disorders are candidates for showing a relationship to specific tissue antigens, we found no evidence for a close linkage between a gene locus determining susceptibility to TS and the HLA loci.