Research Letters

The influence of HLA/HIV genetics on the occurrence of elite controllers and a need for therapeutics geotargeting view

The interaction of HIV-1, human leukocyte antigen (HLA), and elite controllers (EC) compose a still intricate triad. Elite controllers maintain a very low viral load and a normal CD4 count, even without antiretrovirals. There is a lot of diversity in HIV subtypes and HLA alleles. The most common subtype in each country varies depending on its localization and epidemiological history. As we know EC appears to maintain an effective CD8 response against HIV. In this phenomenon, some alleles of HLAs are associated with a slow progression of HIV infection, others with a rapid progression. This relationship also depends on the virus subtype. Epitopes of Gag protein-restricted by HLA-B*57 generated a considerable immune response in EC. However, some mutations allow HIV to escape the CD8 response, while others do not. HLA protective alleles, like HLA-B*27, HLA-B*57 and HLA-B*58:01, that are common in Caucasians infected with HIV-1 Clade B, do not show the same protection in sub-Saharan Africans infected by HIV-1 Clade C. Endogenous pathway of antigen processing and presentation is used to present intracellular synthesized cellular peptides as well as viral protein fragments via the MHC class I molecule to the cytotoxic T-lymphocytes (CTLs). Some epitopes are immunodominant, which means that they drive the immune reaction to some virus. Mutation on an anchor residue of epitope necessary for binding on MHC class I is used by HIV to escape the immune system. Mutations inside or flanking an epitope may lead to T cell lack of recognition and CTL escape. Studying how immunodominance at epitopes drives the EC in a geographically dependent way with genetics and immunological elements orchestrating it may help future research on vaccines or immunotherapy for HIV.

Etiology, seasonality, and clinical characteristics of respiratory viruses in children with respiratory tract infections in Eastern India (Bhubaneswar, Odisha)

Acute respiratory tract infections (ARTIs) are a leading cause of morbidity and mortality in young children in low and middle income countries. To analyse the overall burden of respiratory viruses responsible for ARTIs in paediatrics population in eastern India, this study was performed. Clinical information, demographic information and nasal/oral swabs were collected from 332 paediatric patients (aged from 1 month to 12 years old) with the symptoms of ARTI, enrolled from the outpatient department from Nov 2012 to Oct 2014. Multiplex PCR was performed to detect eight respiratory viral pathogens. Seasonal, as well as age-wise prevalence of respiratory viruses was analysed. Of these 332 cases, 32.53% (108/332) were positive for at least one pathogen. Human rhinovirus (HRV) was the most frequently detected pathogen (24.7%, 82/332) followed by respiratory syncytial virus (RSV) (4.22%, 14/332), PIV (2.11%, 7/332), and hMPV (2.11%, 7/332). Single infection was detected in 92.6% (100/108) of positive cases. Respiratory virus infections showed seasonal variation, with peaks during the rainy season followed by winter season, and were most common in patients under 1 year of age. Phylogenetic analysis of HMPV positive samples confirmed the circulation of A2 subgroup in the study area. The present study is first of its kind and adds to our knowledge of the epidemiological characteristics of these common respiratory viruses among patients with ARTIs in the study area. J. Med. Virol. 89:553-558, 2017. © 2016 Wiley Periodicals, Inc.