Genetic Variation at Exon 2 of the MHC Class II DQB Locus in Blue Whale (Balaenoptera musculus) from the Gulf of California

An unusually high prevalence of metastatic urogenital carcinoma has been observed in free-ranging California sea lions stranded off the coast of California in the past two decades. No cases have been reported for sea lions in the relatively unpolluted Gulf of California. We investigated occurrence of genital epithelial transformation in 60 sea lions ( n =57 pups and 3 adult females) from the Gulf of California and examined whether infection by a viral pathogen previously found to be associated with urogenital carcinoma accounted for such alterations. We also explored the contribution of MHC class II gene expression on transformation. Cellular alterations, such as squamous cell atypia (ASC), atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesions were observed in 42% of the pups and in 67% of the adult females. Normal genital epithelium was more common in male than female pups. ASC was five times more likely to occur in older pups. Epithelial alterations were unrelated to infection by the potentially oncogenic otarine type I gammaherpesvirus (OtHV-1), but ASCUS was more common in pups with marked and severe inflammation. Expression of MHC class II DRB loci ( Zaca DRB-D ) by peripheral antigen-presenting leucocytes showed a slightly ‘protective’ effect for ASC. We propose that transformation of the California sea lion genital epithelium is relatively common in young animals, increases with age and is probably the result of infection by an unidentified pathogen. Expression of a specific MHC class II gene, suggestive of presentation of specific antigenic peptides to immune effectors, appears to lower the risk of transformation. Our study provides the first evidence that epithelial transformation of the California sea lion genital tract is relatively common, even from an early age, and raises questions regarding differences in sea lion cancer-detection and -repair success between geographical regions.

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Turkey humoral and cell-mediated immune responses to a Newcastle viscerotropic vaccine and its association with major histocompatibility complex.

BULGARIAN JOURNAL OF VETERINARY MEDICINE ◽

10.15547/bjvm.2031 ◽

2019 ◽

Vol 22 (1) ◽

pp. 26-40

Author(s):

H. Al-Karagoly ◽

G. Nikbakht ◽

M. Hassanzadeh ◽

T. Tolouei

Keyword(s):

Major Histocompatibility Complex ◽

Immune Responses ◽

Mhc Class Ii ◽

Cellular Response ◽

Class Ii ◽

Secretory Iga ◽

Enzyme Linked Immunosorbent Assay ◽

Major Histocompatibility ◽

Exon 2 ◽

Histocompatibility Complex

Immune responses to vaccines are mainly influenced by the nature of vaccines and host variation in response to vaccination. In this study we aimed to investigate turkey humoral and cell-mediated immune responses to a Newcastle viscerotropic vaccine and its association with major histocompatibility complex (MHC). Turkeys were vaccinated with Villegas–Glisson/University of Georgia (VG/GA) attenuated vaccine against Newcastle disease. The stimulation index of lymphocyte proliferation and antigen-specific local secretory IgA responses in bile, duodenum, ileum, as well as serum IgY and IgA responses were analysed by enzyme-linked immunosorbent assay. The turkey MHC class II B locus was selected as candidate gene for detection of associations with cellular and humoral immune responses. Significant differences were observed between both cellular and humoral responses of vaccinated and unvaccinated groups. A significant positive correlation was also found between ND specific IgY and ND specific IgA titres in serum, intestine (duodenum and ileum) and trachea. Moreover, the correlation between specific IgA titres in ileum and specific bile, duodenum and trachea was positively significant. High resolution melting analysis (HRM) was used to genotype MHC class II B exon 2. Eight melting profiles (A-G) were identified, among which, profile G showed a significant association with cellular response. The profile B revealed significant association with total IgA titres in serum and ileum. These findings help our understanding of the association of turkey MHC types with immune responses. Further correlation analysis between serum and mucosal antibody titres demonstrated that the levels of IgY and IgA in serum can give an impression about the levels of secretory IgA and situation of mucosal immunity. Based on the significant effects, ND specific IgY in serum appears to be a promising indirect marker for specific IgA in serum and trachea.

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Hae III locus at Major Histocompatibility Complex (MHC) class II region hints duplicated DQA genes in Indian mithun (Bos frontalis)

Indian Journal of Animal Research ◽

10.18805/ijar.v0i0f.3795 ◽

2016 ◽

Author(s):

S K Niranjan ◽

D. S. Gonge ◽

S. K. Mishra ◽

R. K . Singh ◽

S Kumar ◽

...

Keyword(s):

Major Histocompatibility Complex ◽

Gene Duplication ◽

Mhc Class Ii ◽

Class Ii ◽

Major Histocompatibility ◽

Exon 2 ◽

Heterozygous Condition ◽

Colony Pcr ◽

Histocompatibility Complex ◽

Pcr Rflp

In bovines, duplication of major histocompatibility complex (MHC) class II DQ genes increase the advantage of high genetic polymorphism in the region multifold to produce better immune response and population fitness. In this study, the DQA gene duplication was explored at MHC class II locus in mithun (Bos frontalis, Bofr), a unique bovine of North-East region of India. A 776 nucleotide long genomic region encompassing hyper-variable exon 2 of Bofr-DQA was amplified in 79 mithuns and digested with Hae III restriction enzyme for PCR-RFLP analysis. The analysis revealed some of the restriction patterns, which were carrying the total fragment size of the alleles aggregating more than a heterozygous condition. Colony PCR-RFLP of clones of mithun DQA by Hinf I enzyme revealed a total of three DQA alleles in single PCR product. The RFLP of direct PCR and clone (colony) PCR products indicated the amplification of three DQA alleles at a time, suggesting duplication of the DQA locus in mithun. Further, the RFLP based typing of mithun DQA locus revealed the presence of five different DQA1 and DQA2 alleles in different combinations during duplication in mithun population. The duplication of DQA, carrying both DQA1 and DQA2 alleles gene was found to be present in nearly half of the mithun population. In mithun, similar to other bovines, DQA gene duplication may have much importance in creating more and diversified MHC class II molecules, thus conferring an advantage to bind with a more number of pathogenic antigens.

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Low MHC class II variability in a marsupial

Reproduction Fertility and Development ◽

10.1071/rd9940721 ◽

1994 ◽

Vol 6 (6) ◽

pp. 721 ◽

Cited By ~ 10

Author(s):

LM McKenzie ◽

DW Cooper

Keyword(s):

Genetic Variation ◽

Mhc Class Ii ◽

Fragment Length Polymorphism ◽

Tammar Wallaby ◽

Class Ii ◽

Mixed Lymphocyte Culture ◽

Lymphocyte Culture ◽

Macropus Eugenii ◽

Histocompatibility Complex ◽

Marsupial Species

The major histocompatibility complex (MHC) loci have been shown to be highly polymorphic in most eutherian ('placental') species studied. Several hypotheses have been advanced for the maintenance of this exceptional level of genetic variation, one of which suggests that it is necessary for successful eutherian reproduction. Marsupials (metatherians) and eutherians are the only two groups of viviparous mammals, but their modes of reproduction are quite distinct. Although marsupials have placentae, they are generally shorter lived and less invasive than in eutherians. Other investigations have shown that genetic variation at marsupial MHC class I loci is probably high. Weak or non-existent mixed lymphocyte culture responses previously reported in several marsupial species have suggested a lack of class II variation. Data have therefore been collected on the level of restriction fragment length polymorphism at MHC class II beta-chain encoding loci of a marsupial, Macropus eugenii (the tammar wallaby). This level is shown to be low, between the level of MHC variation found in cheetahs and a population of lions with a restricted genetic base. Attention is drawn to the need to collect more data on the level of class II variability in both eutherians and marsupials, and to the potential of marsupials for understanding the relation, if any, between mode of reproduction and MHC variability.

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