ABSTRACT
Malaria is one of the major causes of health and disability globally, even after tremendous efforts to eradicate it. Till date no highly effective vaccine is available for its control. The primary reason for the low efficacy of vaccines is extensive polymorphism in potential vaccine candidate antigen genes and HLA polymorphisms in the human population. This problem can be resolved by developing a vaccine using promiscuous peptides to combine the number of HLA alleles. This study predicted T and B cell epitopes (promiscuous peptides) by targeting PPPK-DHPS and DHFR-TS proteins of Plasmodium vivax, using different in silico tools. Selected peptides were characterized as promiscuous peptides on the basis of their immunogenicity, antigenicity and hydrophobicity. Furthermore, to confirm their immunogenicity, these peptides were utilized for molecular modelling and docking analysis. For determining the requisite affinity with distinct HLA Class-I, and HLA Class-II alleles, only five peptides for DHFR-TS and 3 peptides for PPPK-DHPS were chosen as promiscuous peptides. The D1 peptide has the maximum binding energy with HLA alleles, according to HLA-peptide complex modelling and binding interaction analyses. These findings could lead to the development of epitope-based vaccinations with improved safety and efficacy. These epitopes could be major vaccine targets in P. vivax as they possess a higher number of promiscuous peptides. Also, the B cell epitopes possess maximum affinity towards different alleles as analyzed by docking scores. However, further investigation is warranted in vitro and in vivo.
ABSTRACT
Objectives: This study aimed to throw some light on knowledge, attitude and the histological changes in human placenta exposed to passive smoking. Methods: Hospital-based studies were conducted to assess the knowledge and attitude of passive smoking in pregnant women and non-smoker controls (n=50) were selected. A structured questionnaire was used for data collection. Differences between the 2 groups were determined by the Chi-square test and the significance level was set at p<0.05. Total 50 placentas were collected immediately from interviewed pregnant women after delivery (38-40 weeks of gestation) from the Department of Obstetrics and Gynecology. According to the result yielded from the questionnaire 20 out of 50 placentas, showed no history of exposure to tobacco smoke, or consumption of tobacco in any form, and were labeled as controls. About 30 placentas were collected from passive smokers mostly exposed to smoke. The pregnant mother exposed to tobacco used by a chain-smoking husband or very close relative in a nuclear family was designated as a passive smoker. Results: The study indicated that there are significant statistical differences found among the pregnant women’s on their knowledge, attitude in term of pregnancy outcome and adverse effect on labor. The placenta exposed to passive smoking showed an increase in the connective tissue stroma in chorionic villi (intravillous fibroid) and some of them lost their trophoblastic covering. Also, the lumen of blood capillaries appeared obliterated and irregular. Conclusion: Our findings suggested that quantitative parameters of the placenta significantly showed changes in placenta from the passive smoker group compared to the controls. These changes can probably be associated with pregnancy complications in smoking mothers and may affect the development and survival of the fetus and even it’s future.