China
Africa
Explore chapters and articles related to this topic
The Immunological System and Neoplasia
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
All chickens are susceptible to infection resulting in latent infections, but not all chickens develop tumors (Figure 12.5). The development of tumors depends on the combination of oncogenicity of the infecting virus strain, the genetic background of the chicken, vaccine status, and environmental factors such as age of infection with MDV, stress, and infection with other pathogens (Figure 12.6). A major part of the genetic resistance is linked to the expression of certain MHC Class i antigens. The basis for the MHC-based resistance is still unknown but it is probably related to T-cell-mediated immune responses (see below). Although birds of all ages are susceptible to tumor development, young chicks are in general more susceptible because they are still immunologically immature and therefore less able to control virus replication. Maternal antibodies, which are IgG or IgY in chickens, derived from the yolk provide limited protection during the first three weeks.
Macrophages As Effectors Of Cell-Mediated Immunity
Published in Hans H. Gadebusch, Phagocytes and Cellular Immunity, 2020
The suppression of parental strain bone marrow grafts by irradiated Ft mice is an apparent exception to the genetic “laws” of transplantation in inbred animals. Termed genetic resistance, this phenomenon is attributed to the operation of hemopoietic-histocompatibility (Hh) genes that are distinct from other components of the major histocompatibility complex. Heterozygous F! hybrid mice, in which parental strain Hh antigens are not expressed, are resistant to hemopoietic cell grafts, provided they also have the appropriate immune-response (I) genes.201,202 As genetic resistance is inhibited by treatment of recipient mice with silica or carrageenan, it seems likely that macrophages are involved in its expression.203a Similar observations in other species203b suggest that macrophages may play a more general role in resistance to bone marrow grafts.
The Impact of Hospital Epidemiology on the Management and Control of Antimicrobial Resistance: Issues and Controversies
Published in Robert C. Owens, Lautenbach Ebbing, Antimicrobial Resistance, 2007
Supporters of the SHEA guideline find the correlation of these measures with control of MRSA and VRE in so many studies compelling enough to urge broad adoption of ASC/CP. The potential for transfer of genetic resistance factors from VRE to staphylococci—which has been demonstrated to occur in vitro—and the possibility of creating a highly resistant staphylococcus, lends urgency to the argument for aggressive control of these organisms (161). So what, then, are the barriers to recommending greater utilization of ASC/CP, and why the debate?
Significance of the coexistence of non-codon 315 katG, inhA, and oxyR-ahpC intergenic gene mutations among isoniazid-resistant and multidrug-resistant isolates of Mycobacterium tuberculosis: a report of novel mutations
Published in Pathogens and Global Health, 2022
Fatemeh Norouzi, Sharareh Moghim, ShimaSadat Farzaneh, Hossein Fazeli, Mahshid Salehi, Bahram Nasr Esfahani
Tuberculosis (TB) is an acute or chronic infectious disease, with an estimated mortality of 1.4 million deaths and ten million new cases annually [1]. Approximately 465,000 new drug-resistant TB cases were reported in 2019, and The prevalence of multidrug-resistant tuberculosis (MDR-TB), which is resistant to both isoniazid (INH) and rifampin (RIF), was estimated at 9.5%. Consequently, due to the emergence and spread of drug-resistant TB, this condition has become a global health challenge [2]. Extensively drug-resistant TB (XDR-TB) is defined as MDR-TB in addition to resistance to any of the fluoroquinolones (such as levofloxacin or moxifloxacin) and to at least one of the three injectable second-line drugs (amikacin, capreomycin or kanamycin). MDR-TB and XDR-TB have become major public health concerns in TB management programs [3]. Point mutations in chromosome-specific genes are the cause of genetic resistance [4]. Overall, accurate diagnosis of drug resistance, disease prevention, and treatment without delay are important to control TB and develop an End-TB Strategy [5].
Genetic variations in the human immune system influence susceptibility to tegumentary leishmaniasis: a systematic review and meta-analysis
Published in Expert Review of Clinical Immunology, 2021
Daniele Stéfanie Sara Lopes Lera-Nonose, Larissa Ferreira De Oliveira, Aline Brustolin, Thais Silva Santos, Jully Oyama, Áquila Carolina Fernandes Herculano Ramos-Milaré, Mariana De Souza Terron-Monich, Izabel Galhardo Demarchi, Quirino Alves De Lima Neto, Jorge Juarez Vieira Teixeira, Maria Valdrinez Campana Lonardoni
Previous studies have highlighted the importance of host genetic factors in modulating the immune system and predisposition, susceptibility and resistance to TL development. The identification of several gene variants has allowed the association of specific alleles or genotypes to leishmaniasis outcomes [7], called genetic predisposition. This term implies that having a particular genetic background can increase (genetic susceptibility) or decrease (genetic resistance) the likelihood of developing a particular disease but not directly cause it. Single nucleotide polymorphisms (SNPs) are one of the most important sources of genetic variability [8]. This systematic review provides an overview of studies on polymorphisms in immune system genes and their association with TL. We also systematically summarize the quality and meta-analysis results of these studies.
Chicken toll-like receptors and their significance in immune response and disease resistance
Published in International Reviews of Immunology, 2019
Aamir Nawab, Lilong An, Jiang Wu, Guanghui Li, Wenchao Liu, Yi Zhao, Qimin Wu, Mei Xiao
Interleukins and chemokines play a significant role in Salmonella infections [54]. A comparative study has observed the interleukin mRNA expression in the heterophils of resistant and susceptible chickens [103]. The above study concluded that the mRNA level of transforming growth factor (TGFβ4) was decreased and various interleukins such as IL-6, IL-8 and IL-18 mRNA levels were increased significantly in resistant chicken when compared with the susceptible chicken [103, 149]. In addition, the mRNA levels of interferon gamma (IFN γ) were lowered in susceptible chicken as compared to resistant chicken [105]. Different genes for example chTLR4, chTLR15, chTLR21, chMD-2, ILs, IFNγ and iNOS have been classified as potent candidates for disease resistance against bacterial infection [15, 107]. In addition, resistant chicken lines had higher expression of the interleukins such as IL-2, IL-6, IL-8 and IFNγ in the small intestines when compared with susceptible chicken lines [108]. Hence, the candidate gene approach is a useful method to investigate genes that are involved in genetic resistance.