Day 5 · Type-I IFNs, DCs and Antigen Processing

Session 1: Dr. Elina Zuniga

Introduction:

Dr. Elina Zuniga, a prominent Argentinian immunologist and Molecular Biology Professor at the University of California, San Diego, focuses on understanding viral chronic infections and immune evasion mechanisms. Her contributions include:

Host-Virus Interactions: Uncovering how viruses manipulate the immune system.
Chronic Viral Infections: Studying the persistence mechanisms of viruses like HIV and hepatitis C.
Immune Exhaustion: Investigating immune dysfunction during chronic infections hindering virus control.

Question-Answer Session:

i) Division of Labor between Type I and Type II Interferons:

VSV susceptibility to type I interferons is not fully understood. Differential interferon responses are due to the varied impact of interferon-stimulated genes on the virus lifecycle.

ii) Downstream Signaling Differences between Type I and Type II Interferons:

The distinct receptor components for type I and type II interferons lead to different signaling pathways, affecting gene expression and cellular functions.

iii) Differential Antiviral Responses in Different Tissues:

Attributes include tissue-specific viral receptors, varying immune cell populations, tissue-specific infection consequences, and viral countermeasures.

iv) Epigenetic Memory Mechanisms and Cells Involved:

Memory involves long-lived progenitors in the bone marrow, impacting gene responsiveness. Brain regions and various cell populations are involved in memory and turbulence dynamics.

v) Longevity of Memory B and T Cells:

While memory cells aren’t immortal, their lifespan varies depending on the pathogen encountered. Boosters or re-exposure help maintain immunological memory.

vi) Variability in Memory Generation for Different Infections and Vaccines:

Factors include the mutation rate of the pathogen, vaccine type, and individual differences affecting the immune response.

vii) Role of Bats as Viral Reservoirs:

Bat biology, immune tolerance, diverse viral exposure, flight mobility, social behavior, and habitat overlap contribute to their role in carrying and transmitting viruses.

Session 2: Prof Deeptiman, IISc

Major Histocompatibility Complex (MHC):

Two main classes: Class I and Class II molecules.
MHC plays a crucial role in T cell activation and thymic T cell secretion.

Structure of MHC:

MHC has implications beyond T cell activation, including roles in thymic T cell secretion and primary immunodeficiency (bare lymphocyte syndrome).

Important MHC Concepts:

Graft rejections in the 1940s, specific immunity involving humoral (B cells) vs. cellular (T cells), and the vast MHC gene size.

Brief History of MHC:

Influential figures like Peter Medawar, Ray Owen, Abbie Lathrop, and William Castle pioneered MHC research, observing immune specificity and lymphocyte behaviors.
The Jackson Lab in Maine played a significant role in advancing mouse genetics for research purposes.

Advantages of Mice for Research:

Mice, especially inbred strains like C57BL/6 and BALB/c, offer standardized genetic backgrounds for controlled experiments.
They are ideal for studying genetics, immunology, and disease progression due to their similarity to human genes and immune responses.
The Jackson Laboratory in Maine, known for its vast collection of mouse mutants, has greatly contributed to genetic research.

What are Congenic Mice?

Congenic mice are strains that are genetically identical to another except for a specific genomic segment derived from a different strain.
They aid in identifying the genetic basis of particular traits or diseases by isolating the effects of specific genes or regions.

Why Study MHC?

Understanding the MHC is crucial for transplantation, vaccine development, and comprehending autoimmune diseases.
MHC molecules play a significant role in immune recognition and response to infections.

Dr. Elina Zuniga’s insights into viral interactions and immune evasion highlight the complex dynamics between viruses and the immune system. Meanwhile, the historical and foundational work in MHC research paves the way for understanding immune responses and genetic influences in immunology.